MEpedia - User contributions [en]

Craniocervical instability

2020-07-10T00:48:34Z

Rheadw:Changed some wording for accuracy and concision. Removed some statements that weren’t factual and didn’t have citations. Moved text that was more related to surgical outcomes into that section.

{{Cleanup|reason=Image copyright issues|date =5 August, 2018}}
[[File:Craniocervical instability MRI.jpg|thumb|A cervical MRI is assessed for possible craniocervical instability.]]
'''Craniocervical instability''' (CCI) is a pathological condition of increased mobility at the craniocervical junction, the area where the skull meets the spine. In CCI the ligamentous connections of the craniocervical junction can be stretched, weakened or ruptured.<ref name=":2">{{Cite journal|last=Henderson|first=Fraser C.|last2=Austin|first2=Claudiu|last3=Benzel|first3=Edward|last4=Bolognese|first4=Paolo|last5=Ellenbogen|first5=Richard|last6=Francomano|first6=Clair A.|last7=Ireton|first7=Candace|last8=Klinge|first8=Petra|last9=Koby|first9=Myles|date=2017|title=Neurological and spinal manifestations of the Ehlers–Danlos syndromes|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/ajmg.c.31549|journal=American Journal of Medical Genetics Part C: Seminars in Medical Genetics|language=en|volume=175|issue=1|pages=195–211|doi=10.1002/ajmg.c.31549|issn=1552-4876}}</ref> This can lead to stretching and/or compression of the [[Brainstem compression|brainstem]], upper [[spinal cord]], or [[cerebellum]] and result in myelopathy, neck pain and a range of other symptoms.<ref name=":11">{{Cite journal|last=Choi|first=Sung Ho|last2=Lee|first2=Sang Gu|last3=Park|first3=Chan Woo|last4=Kim|first4=Woo Kyung|last5=Yoo|first5=Chan Jong|last6=Son|first6=Seong|date=Apr 2013|title=Surgical Outcomes and Complications after Occipito-Cervical Fusion Using the Screw-Rod System in Craniocervical Instability|url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3698232/|journal=Journal of Korean Neurosurgical Society|volume=53|issue=4|pages=223–227|doi=10.3340/jkns.2013.53.4.223|issn=2005-3711|pmc=3698232|pmid=23826478}}</ref>

CCI usually develops as a result of physical trauma such as a car accident, an inflammatory disease such as rheumatoid arthritis or a congenital disorder such as Down's syndrome.<ref name=":10">{{Cite journal|last=Ashafai|first=Nabeel S.|last2=Visocchi|first2=Massimiliano|last3=Wąsik|first3=Norbert|date=2019|title=Occipitocervical Fusion: An Updated Review|url=https://www.ncbi.nlm.nih.gov/pubmed/30610329|journal=Acta Neurochirurgica. Supplement|volume=125|pages=247–252|doi=10.1007/978-3-319-62515-7_35|issn=0065-1419|pmid=30610329}}</ref> More recently, physicians have reported an increased prevalence of CCI in patients with hereditary disorders of connective tissue such as Ehlers Danlos Syndromes (EDS).<ref name=":9">{{Cite journal|last=Henderson|first=Fraser C.|date=2016|title=Cranio-cervical Instability in Patients with Hypermobility Connective Disorders|url=https://www.omicsonline.org/open-access/craniocervical-instability-in-patients-with-hypermobility-connective-disorders-2165-7939-1000299.php?aid=71754|journal=Journal of Spine|language=En|volume=05|issue=02|doi=10.4172/2165-7939.1000299|issn=2165-7939}}</ref> There have also been anecdotal reports of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) who were later diagnosed with CCI,<ref>{{Cite web|url=https://forums.phoenixrising.me/index.php?threads/have-you-ruled-out-chiari-as-a-cause-of-your-cfs.56908/|title=Have you ruled out Chiari as a cause of your CFS|last=|first=|date=|website=Phoenix Rising|archive-url=|archive-date=|dead-url=|access-date=}}</ref><ref>{{Cite web|url=https://medium.com/@jenbrea/cci-tethered-cord-series-e1e098b5edf|title=CCI + Tethered cord series|last=Brea|first=Jennifer|date=2019-06-06|website=Medium|language=en|access-date=2019-06-06}}</ref><ref>{{Cite web|url=https://www.mechanicalbasis.org/interviews.html|title=Craniocervical instability, Atlantoaxial Instability, Myalgic Encephalomyelitis, ME, CFS|website=MEchanical Basis|language=en|access-date=2019-06-06}}</ref> although no scientific publication on this subject exists. It frequently co-occurs with [[atlantoaxial instability]] (AAI).{{Citation needed|reason=|date=10 December 2019}}
== Symptoms ==
Symptoms of craniocervical instability include [[occipital headache]], [[neck pain]] and [[Nervous system|neurological]] abnormalities such as [[numbness]], [[motor weakness]], [[dizziness]], and [[gait instability]].<ref>{{Cite journal|last=Bobinski|first=Lukas|last2=Levivier|first2=Marc|last3=Duff|first3=John M.|date=Feb 2015|title=Occipitoaxial spinal interarticular stabilization with vertebral artery preservation for atlantal lateral mass failure|url=https://www.ncbi.nlm.nih.gov/pubmed/25415481|journal=Journal of Neurosurgery. Spine|volume=22|issue=2|pages=134–138|doi=10.3171/2014.10.SPINE14131|issn=1547-5646|pmid=25415481}}</ref><ref>{{Cite journal|last=O'Brien|first=Michael F.|last2=Casey|first2=Adrian T. H.|last3=Crockard|first3=Alan|last4=Pringle|first4=Jean|last5=Stevens|first5=John M.|date=2002-10-15|title=Histology of the craniocervical junction in chronic rheumatoid arthritis: a clinicopathologic analysis of 33 operative cases|url=https://www.ncbi.nlm.nih.gov/pubmed/12394902|journal=Spine|volume=27|issue=20|pages=2245–2254|doi=10.1097/01.BRS.0000029252.98053.43|issn=1528-1159|pmid=12394902}}</ref><ref>{{Cite journal|last=Young|first=Richard M.|last2=Sherman|first2=Jonathan H.|last3=Wind|first3=Joshua J.|last4=Litvack|first4=Zachary|last5=O'Brien|first5=Joseph|date=Aug 2014|title=Treatment of craniocervical instability using a posterior-only approach: report of 3 cases|url=https://www.ncbi.nlm.nih.gov/pubmed/24785968|journal=Journal of Neurosurgery. Spine|volume=21|issue=2|pages=239–248|doi=10.3171/2014.3.SPINE13684|issn=1547-5646|pmid=24785968}}</ref><ref>{{Cite journal|last=Botelho|first=Ricardo V.|last2=Neto|first2=Eliseu B.|last3=Patriota|first3=Gustavo C.|last4=Daniel|first4=Jefferson W.|last5=Dumont|first5=Paulo A. S.|last6=Rotta|first6=José M.|date=Oct 2007|title=Basilar invagination: craniocervical instability treated with cervical traction and occipitocervical fixation. Case report|url=https://www.ncbi.nlm.nih.gov/pubmed/17933321|journal=Journal of Neurosurgery. Spine|volume=7|issue=4|pages=444–449|doi=10.3171/SPI-07/10/444|issn=1547-5654|pmid=17933321}}</ref><ref>{{Cite journal|last=Henderson|first=Fraser C.|last2=Henderson|first2=Fraser C.|last3=Wilson|first3=William A.|last4=Mark|first4=Alexander S.|last5=Koby|first5=Myles|date=Jan 2018|title=Utility of the clivo-axial angle in assessing brainstem deformity: pilot study and literature review|url=https://www.ncbi.nlm.nih.gov/pubmed/28258417|journal=Neurosurgical Review|volume=41|issue=1|pages=149–163|doi=10.1007/s10143-017-0830-3|issn=1437-2320|pmc=5748419|pmid=28258417|quote=|author-link=|author-link2=|author-link3=|author-link4=|author-link5=|author-link6=|via=}}</ref> Patients sometimes describe the feeling that their head is too heavy for their neck to support (“bobble-head”).<ref name=":9" /> No particular symptom is mandatory for a diagnosis of CCI and each symptom listed might have a cause other than CCI.

Other symptoms reported in patients with CCI include:
* [[Muscle weakness|Muscle weakness,]]<ref name=":0">{{Cite journal|last=Henderson|first=Fraser C.|last2=Francomano|first2=C. A.|last3=Koby|first3=M.|last4=Tuchman|first4=K.|last5=Adcock|first5=J.|last6=Patel|first6=S.|date=2019-01-09|title=Cervical medullary syndrome secondary to craniocervical instability and ventral brainstem compression in hereditary hypermobility connective tissue disorders: 5-year follow-up after craniocervical reduction, fusion, and stabilization|url=https://doi.org/10.1007/s10143-018-01070-4|journal=Neurosurgical Review|language=en|doi=10.1007/s10143-018-01070-4|issn=1437-2320}}</ref> [[numbness|numbness,]]<ref name=":1">{{Cite journal|last=Francomano|first=Clair A.|last2=McDonnell|first2=Nazli B.|last3=Nishikawa|first3=Misao|last4=Bolognese|first4=Paolo A.|last5=Milhorat|first5=Thomas H.|date=2007-12-01|title=Syndrome of occipitoatlantoaxial hypermobility, cranial settling, and Chiari malformation Type I in patients with hereditary disorders of connective tissue|url=https://thejns.org/view/journals/j-neurosurg-spine/7/6/article-p601.xml|journal=Journal of Neurosurgery: Spine|language=en-US|volume=7|issue=6|pages=601–609|doi=10.3171/SPI-07/12/601}}</ref><ref name=":2" /> [[paralysis]], [[parasthesias]]<ref name=":0" /><ref name=":4">{{Cite web|url=https://search.proquest.com/openview/34b3b18a8854c04ffa0fc50273d68313/1?pq-origsite=gscholar&cbl=47886|title=MRI video diagnosis and surgical therapy of soft tissue trauma to the craniocervical junction - ProQuest|website=search.proquest.com|language=en|access-date=2019-06-01}}</ref><ref name=":5">{{Cite journal|last=Rebbeck|first=Trudy|last2=Liebert|first2=Ann|date=2014-12-01|title=Clinical management of cranio-vertebral instability after whiplash, when guidelines should be adapted: A case report|url=http://www.sciencedirect.com/science/article/pii/S1356689X14000101|journal=Manual Therapy|volume=19|issue=6|pages=618–621|doi=10.1016/j.math.2014.01.009|issn=1356-689X}}</ref><ref name=":6">{{Cite journal|last=Mathers|first=K. Sean|last2=Schneider|first2=Michael|last3=Timko|first3=Michael|date=Jun 2011|title=Occult Hypermobility of the Craniocervical Junction: A Case Report and Review|url=https://www.jospt.org/doi/full/10.2519/jospt.2011.3305|journal=Journal of Orthopaedic & Sports Physical Therapy|language=en|volume=41|issue=6|pages=444–457|doi=10.2519/jospt.2011.3305|issn=0190-6011}}</ref>
* Poor [[proprioception]],<ref name=":7">{{Cite journal|last=Bergholm|first=Ulla|last2=Johansson|first2=Bengt H.|last3=Johansson|first3=Hakan|date=2004-01-01|title=New Diagnostic Tools Can Contribute to Better Treatment of Patients with Chronic Whiplash Disorders|url=https://doi.org/10.3109/J180v03n02_02|journal=Journal of Whiplash & Related Disorders|volume=3|issue=2|pages=5–19|doi=10.3109/J180v03n02_02|issn=1533-2888}}</ref> impaired [[coordination]], [[gait]] changes<ref name=":0" /><ref name=":7" />
* [[Dizziness|Dizzinesss]], [[vertigo|vertigo,]]<ref name=":0" /><ref name=":2" /><ref name=":7" /><ref name=":4" /><ref name=":6" /><ref name=":5" /> syncope,<ref name=":0" /><ref name=":1" /><ref name=":2" /><ref name=":7" /> nausea<ref name=":1" /><ref name=":2" />
* [[Tension headache|Headache behind the eyes]],<ref name=":6" /> [[neck stiffness]], [[torticollis]],<ref name=":7" /><ref>{{Cite journal|last=Ghanem|first=Ismat|last2=El Hage|first2=Samer|last3=Rachkidi|first3=Rami|last4=Kharrat|first4=Khalil|last5=Dagher|first5=Fernand|last6=Kreichati|first6=Gabi|date=2008-03-01|title=Pediatric cervical spine instability|url=https://online.boneandjoint.org.uk/doi/full/10.1007/s11832-008-0092-2|journal=Journal of Children's Orthopaedics|volume=2|issue=2|pages=71–84|doi=10.1007/s11832-008-0092-2|issn=1863-2521|pmc=2656787|pmid=19308585}}</ref> [[Scalp Dysesthesia|posterior scalp irritation]],<ref name=":7" /> [[facial pain]]
* [[Apnea]],<ref>{{Cite journal|last=Janjua|first=M. Burhan|last2=Hwang|first2=Steven W.|last3=Samdani|first3=Amer F.|last4=Pahys|first4=Joshua M.|last5=Baaj|first5=Ali A.|last6=Härtl|first6=Roger|last7=Greenfield|first7=Jeffrey P.|date=2019-01-01|title=Instrumented arthrodesis for non-traumatic craniocervical instability in very young children|url=https://doi.org/10.1007/s00381-018-3876-9|journal=Child's Nervous System|language=en|volume=35|issue=1|pages=97–106|doi=10.1007/s00381-018-3876-9|issn=1433-0350}}</ref><ref name=":1" /><ref name=":3">{{Cite journal|last=Henderson|first=Fraser C.|last2=Austin|first2=Claudiu|last3=Benzel|first3=Edward|last4=Bolognese|first4=Paolo|last5=Ellenbogen|first5=Richard|last6=Francomano|first6=Clair A.|last7=Ireton|first7=Candace|last8=Klinge|first8=Petra|last9=Koby|first9=Myles|date=2017|title=Neurological and spinal manifestations of the Ehlers–Danlos syndromes|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/ajmg.c.31549|journal=American Journal of Medical Genetics Part C: Seminars in Medical Genetics|language=en|volume=175|issue=1|pages=195–211|doi=10.1002/ajmg.c.31549|issn=1552-4876}}</ref> [[dyspnea]] (shortness of breath),<ref name=":0" /><ref name=":1" /> and [[dysphagia]] (difficulty swallowing)<ref name=":1" /><ref name=":2" />
* [[Visual disturbance|Visual disturbances]]<ref name=":4" /> downward [[nystagmus]] (irregular eye movements),<ref name=":1" /><ref name=":7" /> [[tinnitus]]<ref>{{Cite journal|last=Montazem|first=Abbas|author-link=|author-link2=|author-link3=|author-link4=|author-link5=|date=2000|title=Secondary tinnitus as a symptom of instability in the upper cervical spine: Operative management|url=https://pdfs.semanticscholar.org/21c4/85984a6ebe07efed38cf82a2f7a49b2a644e.pdf|journal=International Tinnitus Journal|volume=|issue=|pages=|quote=|via=}}</ref><ref name=":4" />
* [[Fatigue]],<ref name=":0" /><ref name=":14">{{Cite journal|last=Henderson|first=Fraser C.|last2=Henderson|first2=Fraser C.|last3=Wilson|first3=William A.|last4=Mark|first4=Alexander S.|last5=Koby|first5=Myles|date=2018-01-01|title=Utility of the clivo-axial angle in assessing brainstem deformity: pilot study and literature review|url=https://doi.org/10.1007/s10143-017-0830-3|journal=Neurosurgical Review|language=en|volume=41|issue=1|pages=149–163|doi=10.1007/s10143-017-0830-3|issn=1437-2320|pmc=5748419|pmid=28258417}}</ref><ref>{{Cite journal|last=Henderson|first=Fraser C.|last2=Wilson|first2=William A.|last3=Mott|first3=Stephen|last4=Mark|first4=Alexander|last5=Schmidt|first5=Kristi|last6=Berry|first6=Joel K.|last7=Vaccaro|first7=Alexander|last8=Benzel|first8=Edward|date=2010-07-16|title=Deformative stress associated with an abnormal clivo-axial angle: A finite element analysis|url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2940090/|journal=Surgical Neurology International|volume=1|doi=10.4103/2152-7806.66461|issn=2152-7806|pmc=2940090|pmid=20847911}}</ref> [[Sleep dysfunction|sleep disturbance]],<ref name=":0" /><ref name=":4" /> [[Cognitive dysfunction|cognitive impairment]],<ref name=":4" /> and [[memory loss]].

== Risk factors and comorbidities ==
Established risk factors for CCI include physical [[trauma]], [[inflammatory disease]], [[Neoplasm|neoplasms]] and [[congenital]] disorders.<ref name=":10" /><ref name=":12">{{Cite journal|last=Sapkas|first=George|last2=Papadakis|first2=Stamatios A|last3=Segkos|first3=Dimitrios|last4=Kateros|first4=Konstantinos|last5=Tsakotos|first5=George|last6=Katonis|first6=Pavlos|date=2011-06-02|title=Posterior Instrumentation for Occipitocervical Fusion|url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3139273/|journal=The Open Orthopaedics Journal|volume=5|pages=209–218|doi=10.2174/1874325001105010209|issn=1874-3250|pmc=3139273|pmid=21772931}}</ref>

More recently, physicians have reported an increased prevalence of CCI in patients with hereditary [[Connective tissue disorder|connective tissue disorders]].<ref name=":9" /> According to Brodbelt & Flint, however, an "increased range of joint movement, caused by [[ligamentous laxity]], is not the same as [[spinal instability]] resulting from trauma or major inflammatory arthropathies such as (historically) [[rheumatoid arthritis]]."<ref name=":19">{{Cite journal|last=Brodbelt|first=Andrew R.|last2=Flint|first2=Graham|date=Aug 2017|title=Ehlers Danlos, complex Chiari and cranio-cervical fixation: how best should we treat patients with hypermobility?|url=https://www.ncbi.nlm.nih.gov/pubmed/28961036|journal=British Journal of Neurosurgery|volume=31|issue=4|pages=397–398|doi=10.1080/02688697.2017.1386282|issn=1360-046X|pmid=28961036|pmc=|quote=|last3=|first3=|last4=|first4=|last5=|first5=|last6=|first6=|last7=|first7=|last8=|first8=|author-link=|author-link2=|access-date=|author-link3=|author-link4=|author-link5=|author-link6=|via=}}</ref> Others have argued that "pathological instability at the cranio-cervical junction has not been clearly established in the literature for the [[Joint hypermobility|hypermobility]] population."<ref name=":9" />

{| class="wikitable"
|'''Cause of instability'''
|'''Example'''
|-
|Physical trauma<ref>{{Cite journal|last=Ghatan|first=Saadi|last2=Newell|first2=David W.|last3=Grady|first3=M. Sean|last4=Mirza|first4=Sohail K.|last5=Chapman|first5=Jens R.|last6=Mann|first6=Frederick A.|last7=Ellenbogen|first7=Richard G.|date=Aug 2004|title=Severe posttraumatic craniocervical instability in the very young patient. Report of three cases|url=https://www.ncbi.nlm.nih.gov/pubmed/16206980|journal=Journal of Neurosurgery|volume=101|issue=1 Suppl|pages=102–107|doi=10.3171/ped.2004.101.2.0102|issn=0022-3085|pmid=16206980}}</ref>
|Car accident<ref>{{Cite journal|last=Uribe|first=Juan S.|last2=Ramos|first2=Edwin|last3=Baaj|first3=Ali|last4=Youssef|first4=A. Samy|last5=Vale|first5=Fernando L.|date=Dec 2009|title=Occipital cervical stabilization using occipital condyles for cranial fixation: technical case report|url=https://www.ncbi.nlm.nih.gov/pubmed/19934947|journal=Neurosurgery|volume=65|issue=6|pages=E1216–1217; discussion E1217|doi=10.1227/01.NEU.0000349207.98394.FA|issn=1524-4040|pmid=19934947}}</ref><ref>{{Cite journal|last=Volle|first=E.|last2=Montazem|first2=A.|date=Jan 2001|title=MRI video diagnosis and surgical therapy of soft tissue trauma to the craniocervical junction|url=https://www.ncbi.nlm.nih.gov/pubmed/11209518|journal=Ear, Nose, & Throat Journal|volume=80|issue=1|pages=41–44, 46–48|issn=0145-5613|pmid=11209518}}</ref>, blow to the head.<ref>{{Cite journal|last=Mathers|first=K. Sean|last2=Schneider|first2=Michael|last3=Timko|first3=Michael|date=Jun 2011|title=Occult hypermobility of the craniocervical junction: a case report and review|url=https://www.ncbi.nlm.nih.gov/pubmed/21628827|journal=The Journal of Orthopaedic and Sports Physical Therapy|volume=41|issue=6|pages=444–457|doi=10.2519/jospt.2011.3305|issn=1938-1344|pmid=21628827}}</ref>
|-
|Infection & inflammatory disease
|Rheumatoid arthritis<ref>{{Cite journal|last=O'Brien|first=Michael F.|last2=Casey|first2=Adrian T. H.|last3=Crockard|first3=Alan|last4=Pringle|first4=Jean|last5=Stevens|first5=John M.|date=2002-10-15|title=Histology of the craniocervical junction in chronic rheumatoid arthritis: a clinicopathologic analysis of 33 operative cases|url=https://www.ncbi.nlm.nih.gov/pubmed/12394902|journal=Spine|volume=27|issue=20|pages=2245–2254|doi=10.1097/01.BRS.0000029252.98053.43|issn=1528-1159|pmid=12394902}}</ref>, tuberculosis<ref>{{Cite journal|last=Chaudhary|first=Kshitij|last2=Potdar|first2=Prabodhan|last3=Bapat|first3=Mihir|last4=Rathod|first4=Ashok|last5=Laheri|first5=Vinod|date=2012-06-15|title=Structural odontoid lesions in craniovertebral tuberculosis: a review of 15 cases|url=https://www.ncbi.nlm.nih.gov/pubmed/22261632|journal=Spine|volume=37|issue=14|pages=E836–843|doi=10.1097/BRS.0b013e31824a4c8f|issn=1528-1159|pmid=22261632}}</ref>
|-
|Neoplasms
|Tumors<ref name=":12" /> such as haemangioma, aneurysmal bone cyst
|-
|Congenital
|Down’s syndrome<ref>{{Cite journal|last=Hankinson|first=Todd C.|last2=Anderson|first2=Richard C. E.|date=Mar 2010|title=Craniovertebral junction abnormalities in Down syndrome|url=https://www.ncbi.nlm.nih.gov/pubmed/20173525|journal=Neurosurgery|volume=66|issue=3 Suppl|pages=32–38|doi=10.1227/01.NEU.0000365803.22786.F0|issn=1524-4040|pmid=20173525}}</ref>, os odontoideum<ref>{{Cite journal|last=Zhao|first=Deng|last2=Wang|first2=Shenglin|last3=Passias|first3=Peter G.|last4=Wang|first4=Chao|date=May 2015|title=Craniocervical instability in the setting of os odontoideum: assessment of cause, presentation, and surgical outcomes in a series of 279 cases|url=https://www.ncbi.nlm.nih.gov/pubmed/25635883|journal=Neurosurgery|volume=76|issue=5|pages=514–521|doi=10.1227/NEU.0000000000000668|issn=1524-4040|pmid=25635883}}</ref>, dwarfism
|-
|Hereditary connective tissue disorder
|Ehlers Danlos Syndromes<ref name=":0" /><ref name=":1" />
|}
It is not unusual for CCI to co-occur with other structural neurological abnormalities such as [[atlantoaxial instability]] (AAI) and [[chiari malformation]] (CM).<ref>{{Cite journal|last=Camino Willhuber|first=Gaston O.|last2=Bosio|first2=Santiago T.|last3=Puigdevall|first3=Miguel H.|last4=Halliburton|first4=Carolina|last5=Sola|first5=Carlos A.|last6=Maenza|first6=Ruben A.|date=Jan 2017|title=Craniocervical spinal instability after type 1 Arnold Chiari decompression: a case report|url=https://www.ncbi.nlm.nih.gov/pubmed/27258364|journal=Journal of Pediatric Orthopedics. Part B|volume=26|issue=1|pages=80–85|doi=10.1097/BPB.0000000000000346|issn=1473-5865|pmid=27258364}}</ref><ref name=":0" />

== Diagnosis ==
{{Video|id=https://youtu.be/MsYDA3SXTkg|service=youtube|dimensions=550|description=Dr. Paolo Bolognese discusses methods of imaging and measurement for diagnosis.|alignment=right|urlargs=}}
The diagnosis of CCI is based on symptom presentation, a supportive history, demonstrable neurological findings and abnormal imaging.

=== Imaging ===
CCI is typically diagnosed via a [[cervical]] [[Magnetic resonance imaging|MRI]], whether supine or upright. If supine, a [[3 Tesla MRI]] is preferred over a [[1.5 Tesla]]. Most neurosurgeons prefer upright MRI with [[flexion]] and [[extension]].<ref>{{Cite web|url=https://www.mechanicalbasis.org/diagnosis.html|title=Craniocervical instability, Atlantoaxial Instability, Myalgic Encephalomyelitis, ME, CFS|website=MEchanical Basis|language=en|access-date=2019-06-02}}</ref> According to Henderson FC, “ventral [[brainstem]] compression may exist in flexion of the cervical spine, but appear normal on routine imaging.”<ref name=":9" />

{| class="wikitable"
!Imaging
!Sensitive for
|-
|Upright MRI with flexion/extension
|Horizontal instability
|-
|CT scan with rotation
|Rotational instability
|-
|Invasive cervical traction (ICT) with fluoroscopy
|Vertical instability
|}

=== Measurements ===
More than twenty radiological measurements have been proposed or used in the diagnosis of CCI. However, three measurements are most commonly used: the [[Grabb-Oakes measurement|Grabb-Oakes]] line, which measures ventral brainstem compression; the [[Clivo-axial angle|Clivo-Axial Angle (CXA)]], which measures brainstem deformity by the [[odontoid]] process; and the Basion Dens Interval, which measures vertical instability ([[cranial settling]]). According to a 2013 consensus statement on the assessment of CCI, a CXA of 135 degrees or less should be considered as "potentially pathological."<ref name=":13">{{Cite web|url=https://bobbyjonescsf.org/csf-video/review-colloq-2014/|title=REVIEW OF THE 2013 CSF RESEARCH COLLOQUIUM & CONSENSUS ON CRANIOCERVICAL INSTABILITY – Bobby Jones CSF|last=CSF|first=Bobby Jones {{!}}|language=en-US|access-date=2019-09-18}}</ref> as it is reported to be uncommon in the healthy population.<ref>{{Cite journal|last=Batista|first=Ulysses C.|last2=Joaquim|first2=Andrei F.|last3=Fernandes|first3=Yvens B.|last4=Mathias|first4=Roger N.|last5=Ghizoni|first5=Enrico|last6=Tedeschi|first6=Helder|date=Apr 2015|title=Computed tomography evaluation of the normal craniocervical junction craniometry in 100 asymptomatic patients|url=https://www.ncbi.nlm.nih.gov/pubmed/25828499|journal=Neurosurgical Focus|volume=38|issue=4|pages=E5|doi=10.3171/2015.1.FOCUS14642|issn=1092-0684|pmid=25828499}}</ref><ref>{{Cite journal|last=Botelho|first=Ricardo Vieira|last2=Ferreira|first2=Edson Dener Zandonadi|date=Oct 2013|title=Angular craniometry in craniocervical junction malformation|url=https://www.ncbi.nlm.nih.gov/pubmed/23640096|journal=Neurosurgical Review|volume=36|issue=4|pages=603–610; discussion 610|doi=10.1007/s10143-013-0471-0|issn=1437-2320|pmc=3910287|pmid=23640096}}</ref><ref>{{Cite journal|last=Bundschuh|first=C|last2=Modic|first2=Mt|last3=Kearney|first3=F|last4=Morris|first4=R|last5=Deal|first5=C|date=1988-07-01|title=Rheumatoid arthritis of the cervical spine: surface-coil MR imaging|url=https://www.ajronline.org/doi/abs/10.2214/ajr.151.1.181|journal=American Journal of Roentgenology|volume=151|issue=1|pages=181–187|doi=10.2214/ajr.151.1.181|issn=0361-803X}}</ref> Others have argued that these radiological measurements are "not accepted internationally as indicating instability."<ref name=":19" />
{| class="wikitable"
|+
!Measurement
!Units
!Description
! scope="col" style="width: 75px;" | Normal Range
! scope="col" style="width: 75px;" | Borderline Range
! scope="col" style="width: 75px;" | Pathological Range
! scope="col" style="width: 75px;" | Alternate Ranges
!Instability Measured
!Pathology Measured
!Refs
|-
|'''Clivo-axial angle (CXA)'''
|Degrees
|Angle between clivus line and the posterior axial line
|170 -150
|149 -136
|≤ 135
|
|More sensitive for horizontal
|Brainstem deformity
|<ref>{{Cite journal|last=Bolognese|first=Paolo|author-link=|author-link2=|author-link3=|author-link4=|author-link5=|date=|title=Videoed Presentation at: ASAP Chiari & Syringomyelia Conference Paolo Bolognese, MD "Complex Chiari, 2014. Timecode 14:28|url=https://www.youtube.com/watch?v=uiyk0Qbx2TQ&t=14m28s|journal=|volume=|issue=|pages=|quote=|via=}}</ref>
|-
|'''Grabb-Oakes'''
|mm
|Distance from the dura to the line drawn from the basion to the posterior inferior edge of the C2 vertebra
|< 6
|≥ 6 and < 9
|≥ 9
|Some use pathological ≥ 8
|More sensitive for horizontal
|Brainstem compression
|<ref>{{Cite journal|last=Bolognese|first=Paolo|author-link=|author-link2=|author-link3=|author-link4=|author-link5=|date=|title=Videoed presentation at: EDS Awareness Educational Series, April 12, 2018. Timecodes: 49:30 and 53:47|url=https://www.youtube.com/watch?v=MsYDA3SXTkg&t=49m30s|journal=|volume=|issue=|pages=|quote=|via=}}</ref><ref name=":9" />
|-
|'''Basion-Axial Interval (BAI)'''
|mm
|Distance from tip of basion to posterior axial line
|< 12
|
|≥ 12
|
|
|
|<ref name=":15">{{Cite journal|last=Henderson|first=Fraser|author-link=|author-link2=|author-link3=|author-link4=|author-link5=|date=|title=Videoed presentation at: Chiari & Syringomyelia Foundation, Patient Conference of Action, June 24, 2018. Timecode: 10:34.|url=https://www.youtube.com/watch?list=WL&v=sEi9AlHQTJc&t=10m34s|journal=|volume=|issue=|pages=|quote=|via=}}</ref>
|-
|'''Basion-Dens interval (BDI)'''
|mm
|Vertical distance between the basion and the dens
|< 12
|
|≥ 12
|Some use pathological ≥ 10
|Vertical
|Cranial settling
|<ref name=":15" /><ref name=":9" />
|-
|'''Translational BAI'''
|mm
|Change in BAI between flexion and extension positions of the head
|< 1
|≥ 1 and ≤ 2
|> 2
|For surgery > 4 needed
|Horizontal
|Skull sliding over spine
|<ref>{{Cite journal|last=Henderson|first=Fraser C.|last2=Francomano|first2=C. A.|last3=Koby|first3=M.|last4=Tuchman|first4=K.|last5=Adcock|first5=J.|last6=Patel|first6=S.|date=2019-01-09|title=Cervical medullary syndrome secondary to craniocervical instability and ventral brainstem compression in hereditary hypermobility connective tissue disorders: 5-year follow-up after craniocervical reduction, fusion, and stabilization|url=https://doi.org/10.1007/s10143-018-01070-4|journal=Neurosurgical Review|language=en|doi=10.1007/s10143-018-01070-4|issn=1437-2320}}</ref><ref name=":0" />
|-
|'''Translational BDI'''
|mm
|Change in BDI between flexion and extension positions of the head
|
|
|
|
|
|
|
|-
|'''Dynamic BDI'''
|mm
|Change in BDI value when the head is pulled upward with traction force of typically up to 35 lbs
|
|
|
|
|Vertical
|Cranial settling
|
|-
|'''Dens Over Chamberlain'''
|mm
|How far tip of the dens extends above Chamberlain's line
|< 2
|≥ 2 and ≤ 3
|≥ 3
|
|Vertical
|Basilar invagination
|<ref>{{Cite journal|last=Hain|first=Timothy C. |author-link=|author-link2=|author-link3=|author-link4=|author-link5=|date=|title=Basilar Invagination, Basilar Impression and Atlantoaxial Subluxation|url=https://www.dizziness-and-balance.com/disorders/central/cerebellar/basilar%20invagination.htm|journal=|volume=|issue=|pages=|quote=|via=}}</ref>
|}
Some of the measurement ranges in the above table are also to be found in the 2nd International CSF Dynamics Symposium Consensus Statement (2013).<ref name=":13" />

=== Traction ===
Manual traction, halo and invasive cervical traction may be used to aid in the diagnosis of CCI. Symptomatic improvement with traction can help determine whether a patient with abnormal measurements will benefit from craniocervical fusion surgery.

== Treatment ==
{{Video|id=https://youtu.be/sEi9AlHQTJc|service=youtube|dimensions=550|description=Dr. Fraser Henderson presents the results a five-year follow-up study.|alignment=right|urlargs=}}
=== Conservative treatment ===
Traditional “conservative” treatments for CCI include rest, pain management, bracing with a cervical collar, and physical therapy to strengthen neck muscles.<ref>{{Cite journal|last=Mathers|first=K. Sean|last2=Schneider|first2=Michael|last3=Timko|first3=Michael|date=Jun 2011|title=Occult hypermobility of the craniocervical junction: a case report and review|url=https://www.ncbi.nlm.nih.gov/pubmed/21628827|journal=The Journal of Orthopaedic and Sports Physical Therapy|volume=41|issue=6|pages=444–457|doi=10.2519/jospt.2011.3305|issn=1938-1344|pmid=21628827}}</ref>

Other, more experimental treatments for CCI include prolotherapy and upper cervical chiropractic.

=== Surgery ===
If non-invasive treatments for CCI fail to work, occipito-cervical fusion (OCF) can be considered.<ref name=":0" /> OCF is a surgery that aims at a biomechanical stabilization of the craniocervical junction. Patients with objective radiological findings, a clinical picture supportive of the diagnosis, a positive response to traction, and who are significantly impaired may be candidates for this surgery. A common method involves internal fixation of the upper spine to the skull by mechanical rods and screws. (However, rod-wire, rigid rod-screws, occipital hooks and cervical claws are all methods currently in use.<ref name=":16">{{Cite journal|last=Resnick|first=Daniel K.|last2=Patel|first2=Nirav J.|last3=Lall|first3=Rishi|date=2010-11-01|title=A Review of Complications Associated With Craniocervical Fusion Surgery|url=https://academic.oup.com/neurosurgery/article/67/5/1396/2563905|journal=Neurosurgery|language=en|volume=67|issue=5|pages=1396–1403|doi=10.1227/NEU.0b013e3181f1ec73|issn=0148-396X}}</ref>) During surgery, titanium hardware is used to fixate the occiput, axis and atlas (i.e., C0 to C2) while rib graft or cadaver bone graft is used to help the bones fuse together. Wire methods are less biomechanically stable than rod methods and have high rates of dural laceration.<ref name=":16" /> Screw and rod fixation methods have lower complication rates and higher rates of successful fusion.<ref name=":18" /> Fusion rates across all hardware methods range from 89 to 100%.<ref name=":16" /> When cervical instability is present below C2, additional vertebrae may also be fused.

==== Outcomes, risks & complications ====
The outcome of OCF is generally favorable with most patients experiencing symptom relief post-surgery.<ref name=":0" /> In a study following following 20 EDS patients five years free O-2 fusion, most reported they were satisfied with the surgery and experienced significant improvements in symptoms such as vertigo, headaches, imbalance, dysarthria, dizziness, and frequent daytime urination. There was, however, only a small increase in objective outcomes such as work resumption, with 60% of patients remaining unable to work or go to school. Participants attributed this to other EDS comorbidities such as POTS, Mast Cell Activation Syndrome, and additional spinal problems.<ref name=":0" />

The complications of OCF can be serious<ref>{{Cite journal|last=Garrido|first=Ben J.|last2=Sasso|first2=Rick C.|date=Jan 2012|title=Occipitocervical fusion|url=https://www.ncbi.nlm.nih.gov/pubmed/22082624|journal=The Orthopedic Clinics of North America|volume=43|issue=1|pages=1–9, vii|doi=10.1016/j.ocl.2011.08.009|issn=1558-1373|pmid=22082624}}</ref> and occur in an estimated 7% to 33% of patients.<ref name=":10" /><ref name=":18">{{Cite journal|last=Winegar|first=Corbett D.|last2=Lawrence|first2=James P.|last3=Friel|first3=Brian C.|last4=Fernandez|first4=Carmella|last5=Hong|first5=Joseph|last6=Maltenfort|first6=Mitchell|last7=Anderson|first7=Paul A.|last8=Vaccaro|first8=Alexander R.|date=Jul 2010|title=A systematic review of occipital cervical fusion: techniques and outcomes|url=https://www.ncbi.nlm.nih.gov/pubmed/20594011|journal=Journal of Neurosurgery. Spine|volume=13|issue=1|pages=5–16|doi=10.3171/2010.3.SPINE08143|issn=1547-5646|pmid=20594011}}</ref><ref name=":11" /><ref>{{Cite journal|last=Ando|first=Kei|last2=Imagama|first2=Shiro|last3=Ito|first3=Zenya|last4=Kobayashi|first4=Kazuyoshi|last5=Yagi|first5=Hideki|last6=Shinjo|first6=Ryuichi|last7=Hida|first7=Tetsuro|last8=Ito|first8=Kenyu|last9=Ishikawa|first9=Yoshimoto|date=Jun 2017|title=Minimum 5-year Follow-up Results for Occipitocervical Fusion Using the Screw-Rod System in Craniocervical Instability|url=https://www.ncbi.nlm.nih.gov/pubmed/28525489|journal=Clinical Spine Surgery|volume=30|issue=5|pages=E628–E632|doi=10.1097/BSD.0000000000000199|issn=2380-0194|pmid=28525489}}</ref><ref name=":16" /> Common complications include screw failure, wound infection, dural tear and cerebrospinal fluid leakage<ref name=":11" /> In some cases revision surgery is needed to treat infection or to remove hardware. Severe complications can include meningitis and accidental injury of the vertebral artery by misplaced screws.<ref name=":17">{{Cite journal|last=Nockels|first=Russ P.|last2=Shaffrey|first2=Christopher I.|last3=Kanter|first3=Adam S.|last4=Azeem|first4=Syed|last5=York|first5=Julie E.|date=Aug 2007|title=Occipitocervical fusion with rigid internal fixation: long-term follow-up data in 69 patients|url=https://www.ncbi.nlm.nih.gov/pubmed/17688049|journal=Journal of Neurosurgery. Spine|volume=7|issue=2|pages=117–123|doi=10.3171/SPI-07/08/117|issn=1547-5654|pmid=17688049}}</ref>

A meta-study of 2274 procedures across 22 studies<ref name=":16" /> found the following complication rates:

{| class="wikitable"
!Complication type
!Prevalence rate
|-
|Hardware failure after fusion non-union
|7%
|-
|Wound infection
|3.8%-11%
|-
|Vertebral artery damage
|1.3%-4.1%
|-
|Dural tears
|0% to 4.2%
|}
Meta-studies place the rate of death from fusion surgery at 0-0.6%.<ref name=":16" /><ref name=":18" />

==== Side effects ====
OCF causes a substantial reduction in the neck’s range of motion, estimated at approximately 40% of total cervical flexion–extension.<ref name=":8">{{Cite journal|last=Ashafai|first=Nabeel S.|last2=Visocchi|first2=Massimiliano|last3=Wąsik|first3=Norbert|date=2019|editor-last=Visocchi|editor-first=Massimiliano|title=Occipitocervical Fusion: An Updated Review|url=https://doi.org/10.1007/978-3-319-62515-7_35|series=Acta Neurochirurgica Supplement|language=en|location=Cham|publisher=Springer International Publishing|pages=247–252|doi=10.1007/978-3-319-62515-7_35|isbn=9783319625157}}</ref>

==== Cost ====
OCF is estimated to cost tens of thousands of dollars, although some insurance schemes fully cover the cost of surgery depending on the country located and neurosurgeons involved.

=== Experimental treatments ===
* '''Stem cell therapy:''' Some clinics offer stem cell therapy in order to regenerate the area, ligaments, connective and other tissues that may be damaged in the area.{{Citation needed|reason=Please name any clinics that offer stem cell therapy for CCI.|date=3 November 2019}}

*'''PRP (Platelet Rich Plasma) therapy''': Some clinics offer PRP therapy in order to help the body regenerate the area.{{Citation needed|reason=Please name any clinics that offer PRP therapy for CCI.|date=4 february 2020}}

== Dysautonomia and CCI in EDS ==
As CCI can lead to a compression of the brainstem, a number of experts believe it contributes to autonomic symptoms such as orthostatic tachycardia, dizziness and pre-/syncope that are frequently seen in patients with Ehlers Danlos Syndromes (EDS). In a 2007 influential paper Milhorat et al. followed-up on patients with Chiari malformation who did not improve with treatment and surgery. The authors discovered that many of these patients suffered from EDS and had other structural abnormalities at the upper spine such as CCI and cranial settling. Milhorat et al. speculated that the resulting compression of the brainstem might be the cause of the autonomic and other symptoms these patients were suffering from.<ref>{{Cite journal|last=Milhorat|first=Thomas H.|last2=Bolognese|first2=Paolo A.|last3=Nishikawa|first3=Misao|last4=McDonnell|first4=Nazli B.|last5=Francomano|first5=Clair A.|date=Dec 2007|title=Syndrome of occipitoatlantoaxial hypermobility, cranial settling, and chiari malformation type I in patients with hereditary disorders of connective tissue|url=https://www.ncbi.nlm.nih.gov/pubmed/18074684|journal=Journal of Neurosurgery. Spine|volume=7|issue=6|pages=601–609|doi=10.3171/SPI-07/12/601|issn=1547-5654|pmid=18074684}}</ref> Neurosurgeons and other EDS specialists have expounded on the connection between CCI and forms of dysautonomia such as postural orthostatic tachycardia syndrome (POTS) in a number of conference presentations. <ref>[https://www.youtube.com/watch?time_continue=735&v=857Jsjsqxjw Craniocervical Instability (Dr Henderson the 2012 EDNF Confrence).] Minute 12.10. </ref><ref>[https://www.youtube.com/watch?v=ntD9NRIvEJ0 Dr Milhorat from The Chiari Institute at the 2005 ASAP.]</ref><ref name=":13" />

== Mechanical basis theory ==
Five ME/CFS patients diagnosed with CCI (some also had EDS) reported to have experienced remarkable improvements and even remission of their ME/CFS symptoms following OCF-surgery.<ref>{{Cite web|url=https://www.mechanicalbasis.org/interviews.html|title=Craniocervical instability, Atlantoaxial Instability, Myalgic Encephalomyelitis, ME, CFS|website=MEchanical Basis|language=en|access-date=2019-06-06}}</ref><ref>{{Cite web|url=https://medium.com/@jenbrea/health-update-3-my-me-is-in-remission-dd575e650f71|title=Health update #3: My ME is in remission|last=Brea|first=Jennifer|date=2019-05-20|website=Medium|access-date=2019-06-03}}</ref> They speculate that mechanical compression of the brainstem due to CCI has the potential to cause characteristic ME/CFS symptoms such as post-exertional malaise<ref>{{Cite web|url=https://www.mechanicalbasis.org/|title=Craniocervical instability, Atlantoaxial Instability, Myalgic Encephalomyelitis, ME, CFS|website=MEchanical Basis|language=en|access-date=2019-06-03}}</ref>, although this theory is currently not supported by scientific evidence. The current literature does not suggest a connection between ME/CFS and CCI. Others have raised concerns about CCI surgery in patients with ME/CFS given the lack of research on OCF in this patient population.<ref>{{Cite web|url=https://www.s4me.info/threads/concerns-about-craniocervical-instability-surgery-in-me-cfs.9638/|title=Concerns about craniocervical instability surgery in ME/CFS|website=Science for ME|language=en-US|access-date=2019-06-03}}</ref>

== Synonyms ==
* Syndrome of Occipitoatlantialaxial Hypermobility<ref name=":1" />
* Hypermobility of the Craniocervical Junction<ref>{{Cite journal|last=Mathers|first=K. Sean|last2=Schneider|first2=Michael|last3=Timko|first3=Michael|date=Jun 2011|title=Occult hypermobility of the craniocervical junction: a case report and review|url=https://www.ncbi.nlm.nih.gov/pubmed/21628827|journal=The Journal of Orthopaedic and Sports Physical Therapy|volume=41|issue=6|pages=444–457|doi=10.2519/jospt.2011.3305|issn=1938-1344|pmid=21628827}}</ref>
* Craniocervical Junction Syndrome

== See also ==

* [[Atlantoaxial instability|Atlantoaxial instability (AAI)]]
* [[Neural strain]]
* [[Chiari malformation]]
* [[Ehlers-Danlos syndrome]]
* [[Intracranial hypertension]]
* [[Tethered cord syndrome]]

== Learn more ==
* [https://www.healthrising.org/blog/2019/02/27/brainstem-compression-chronic-fatigue-syndrome-me-cfs-fibromyalgia-pots-craniocervical-instability/ Could Craniocervical Instability Be Causing ME/CFS, Fibromyalgia & POTS? Pt I – The Spinal Series] - from Health Rising
* [https://www.healthrising.org/blog/2019/05/21/jennifer-brea-chronic-fatigue-mecfs-recovering-story/ Jennifer Brea’s Amazing ME/CFS Recovering Story: the Spinal Series – Pt. II] - From Health Rising
* [https://www.healthrising.org/treating-chronic-fatigue-syndrome/fibromyalgia-craniocervical-instability-survey-effectivness-survey/ ME/CFS and Fibromyalgia Craniocervical Instability Surgery Effectiveness Poll] - From Health Rising

== References ==
{{reflist}}
[[Category:Diagnoses]]

User talk:Rheadw

2019-12-25T23:42:13Z

Rheadw:/* Adding citations in the Visual Editor -- Pyrrhus (talk) 13:24, December 21, 2019 (EST) */

{{Template:Welcome|realName=Rhea DeRose-Weiss|name=Rheadw}}

-- [[User:New user message|New user message]] ([[User talk:New user message|talk]]) 19:36, August 28, 2019 (EDT)

== Adding citations in the Visual Editor -- [[User:Pyrrhus|Pyrrhus]] ([[User talk:Pyrrhus|talk]]) 13:24, December 21, 2019 (EST) ==

Hi Rheadw, it appears you may have problems adding citations using the Visual Editor. If so, you may consult this page: [[Help:Visual editor]]. I hope this helps.
<br>[[User:Pyrrhus|Pyrrhus]] ([[User talk:Pyrrhus|talk]]) 13:24, December 21, 2019 (EST)

===Re: Adding citations in the Visual Editor -- [[User:Rheadw|Rheadw]] ([[User talk:Rheadw|talk]]) 18:42, December 25, 2019 (EST)===

: Replace this text with your reply

I did it several times as described, and it just didn’t save. It may be my phone/browser.

Atlantoaxial instability

2019-12-21T08:36:27Z

Rheadw:/* Diagnosis */ Added rotational measurement and cited.

Atlantoaxial instability (AAI) is characterized by excessive movement at the junction between the atlas (C1) and axis (C2) as a result of either a bone or ligament abnormality.

It can be caused by congenital conditions, inflammatory conditions like [[rheumatoid arthritis]], as a result of physical trauma, or infection.<ref>{{Cite journal|date=2019-11-10|title=Atlantoaxial Instability: Background, Pathophysiology, Etiology|url=https://emedicine.medscape.com/article/1265682-overview}}</ref> It has been associated with Down’s Syndrome, Morquio's syndrome,<ref>{{Cite journal|last=Li|first=Ming-Feng|last2=Chiu|first2=Pao-Chin|last3=Weng|first3=Mei-Jui|last4=Lai|first4=Ping-Hong|date=2010-12-13|title=Atlantoaxial Instability and Cervical Cord Compression in Morquio Syndrome|url=https://jamanetwork.com/journals/jamaneurology/fullarticle/801729|journal=Archives of Neurology|language=en|volume=67|issue=12|pages=1530–1530|doi=10.1001/archneurol.2010.308|issn=0003-9942}}</ref> [[Marfan syndrome]],<ref>{{Cite journal|last=Herzka|first=Andrea|last2=Sponseller|first2=Paul D.|last3=Pyeritz|first3=Reed E.|date=2000-02-15|title=Atlantoaxial Rotatory Subluxation in Patients With Marfan Syndrome: A Report of Three Cases|url=https://journals.lww.com/spinejournal/Abstract/2000/02150/Atlantoaxial_Rotatory_Subluxation_in_Patients_With.22.aspx|journal=Spine|language=en-US|volume=25|issue=4|pages=524|issn=0362-2436}}</ref><ref name=":3">{{Cite journal|last=MacKenzie|first=James MacKintosh|last2=Rankin|first2=Rosslyn|date=2003-12|title=Sudden Death Due to Atlantoaxial Subluxation in Marfan Syndrome|url=https://journals.lww.com/amjforensicmedicine/Abstract/2003/12000/Sudden_Death_Due_to_Atlantoaxial_Subluxation_in.12.aspx|journal=The American Journal of Forensic Medicine and Pathology|language=en-US|volume=24|issue=4|pages=369|doi=10.1097/01.paf.0000097853.26115.bb|issn=0195-7910}}</ref> and [[Ehlers-Danlos syndrome]].<ref>{{Cite web|url=https://europepmc.org/article/med/8596160|title=Europe PMC|website=europepmc.org|access-date=2019-12-10}}</ref><ref>{{Cite journal|last=Henderson|first=Fraser C.|last2=Austin|first2=Claudiu|last3=Benzel|first3=Edward|last4=Bolognese|first4=Paolo|last5=Ellenbogen|first5=Richard|last6=Francomano|first6=Clair A.|last7=Ireton|first7=Candace|last8=Klinge|first8=Petra|last9=Koby|first9=Myles|date=2017|title=Neurological and spinal manifestations of the Ehlers–Danlos syndromes|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/ajmg.c.31549|journal=American Journal of Medical Genetics Part C: Seminars in Medical Genetics|language=en|volume=175|issue=1|pages=195–211|doi=10.1002/ajmg.c.31549|issn=1552-4876}}</ref><ref>{{Cite journal|last=Castori|first=Marco|last2=Morlino|first2=Silvia|last3=Ghibellini|first3=Giulia|last4=Celletti|first4=Claudia|last5=Camerota|first5=Filippo|last6=Grammatico|first6=Paola|date=2015|title=Connective tissue, Ehlers–Danlos syndrome(s), and head and cervical pain|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/ajmg.c.31426|journal=American Journal of Medical Genetics Part C: Seminars in Medical Genetics|language=en|volume=169|issue=1|pages=84–96|doi=10.1002/ajmg.c.31426|issn=1552-4876}}</ref><ref>{{Cite journal|last=Lane|first=D.|date=2006-08-01|title=Anaesthetic Implications of Vascular Type Ehlers-Danlos Syndrome|url=https://doi.org/10.1177/0310057X0603400412|journal=Anaesthesia and Intensive Care|language=en|volume=34|issue=4|pages=501–505|doi=10.1177/0310057X0603400412|issn=0310-057X}}</ref><ref>{{Cite journal|last=Dordoni|first=Chiara|last2=Ciaccio|first2=Claudia|last3=Venturini|first3=Marina|last4=Calzavara‐Pinton|first4=Piergiacomo|last5=Ritelli|first5=Marco|last6=Colombi|first6=Marina|date=2016|title=Further delineation of FKBP14-related Ehlers–Danlos syndrome: A patient with early vascular complications and non-progressive kyphoscoliosis, and literature review|url=https://www.onlinelibrary.wiley.com/doi/abs/10.1002/ajmg.a.37728|journal=American Journal of Medical Genetics Part A|language=en|volume=170|issue=8|pages=2031–2038|doi=10.1002/ajmg.a.37728|issn=1552-4833}}</ref><ref>{{Cite journal|last=Giunta|first=Cecilia|last2=Baumann|first2=Matthias|last3=Fauth|first3=Christine|last4=Lindert|first4=Uschi|last5=Abdalla|first5=Ebtesam M.|last6=Brady|first6=Angela F.|last7=Collins|first7=James|last8=Dastgir|first8=Jahannaz|last9=Donkervoort|first9=Sandra|date=2018-01|title=A cohort of 17 patients with kyphoscoliotic Ehlers–Danlos syndrome caused by biallelic mutations in FKBP14 : expansion of the clinical and mutational spectrum and description of the natural history|url=https://www.nature.com/articles/gim201770|journal=Genetics in Medicine|language=en|volume=20|issue=1|pages=42–54|doi=10.1038/gim.2017.70|issn=1530-0366}}</ref><ref>{{Cite web|url=https://europepmc.org/article/med/2387821|title=Europe PMC|website=europepmc.org|access-date=2019-12-10}}</ref><ref>{{Cite journal|last=Galan|first=Enrique|last2=Kousseff|first2=Boris G.|date=1995-04-01|title=Peripheral neuropathy in Ehlers-Danlos syndrome|url=http://www.sciencedirect.com/science/article/pii/088789949500003X|journal=Pediatric Neurology|volume=12|issue=3|pages=242–245|doi=10.1016/0887-8994(95)00003-X|issn=0887-8994}}</ref><ref>{{Cite journal|last=Wills|first=Brian P. D.|last2=Dormans|first2=John P.|date=2006-04|title=Nontraumatic Upper Cervical Spine Instability in Children|url=https://journals.lww.com/jaaos/Citation/2006/04000/Nontraumatic_Upper_Cervical_Spine_Instability_in.5.aspx|journal=JAAOS - Journal of the American Academy of Orthopaedic Surgeons|language=en-US|volume=14|issue=4|pages=233|issn=1067-151X}}</ref>

It often co-occurs with [[craniocervical instability]] (CCI).

In individuals without predisposing conditions, it is thought to be extremely rare.<ref name=":0">{{Cite journal|last=Lacy|first=Jordan|last2=Gillis|first2=Christopher C.|date=2019|title=Atlantoaxial Instability|url=http://www.ncbi.nlm.nih.gov/books/NBK519563/|location=Treasure Island (FL)|publisher=StatPearls Publishing|pmid=30137847}}</ref>

== Symptoms ==

* Neck pain<ref name=":0" />
* Neck stiffness, torticollis<ref name=":1">{{Cite journal|last=Cohen|first=William I.|date=1998-02-01|title=Atlantoaxial Instability: What's Next?|url=https://jamanetwork.com/journals/jamapediatrics/fullarticle/189216|journal=Archives of Pediatrics & Adolescent Medicine|language=en|volume=152|issue=2|pages=119–122|doi=10.1001/archpedi.152.2.119|issn=1072-4710}}</ref>
* Spasticity<ref name=":0" />
* Radius are symptoms<ref name=":0" />
* Lack of coordination<ref name=":0" />
* Clumsiness<ref name=":0" />
* Gait changes, difficulty with gait<ref name=":0" /><ref name=":1" />
* Sensory deficits<ref name=":0" />
* Neurogenic bladder<ref name=":0" />
* Spasticity, clonus, hyperreflexia<ref name=":0" /><ref name=":1" />
* Paraplegia, quadriplegia<ref name=":0" />
* Muscle weakness<ref name=":2">{{Cite web|url=https://www.orthobullets.com/spine/2049/atlantoaxial-instability|title=Atlantoaxial Instability - Spine - Orthobullets|website=www.orthobullets.com|access-date=2019-12-10}}</ref>
* Decreased hand dexterity<ref name=":2" />
* Blurred vision<ref name=":3" />
* Occipital headache<ref name=":3" />

== Risk factors and causes ==

=== Congenital causes ===

=== Rheumatoid arthritis ===
Chronic inflammation can cause laxity and stretching of the transverse ligament, the formation of a pannus, as well as bone erosion.<ref name=":0" />

=== Grisel’s syndrome ===
Grisel’s syndrome occurs following inflammation of the soft tissue as a consequence of surgery or infection,<ref name=":4" /> frequently an upper respiratory infection. It is primarily seen in patients ages 5-12 but can also be seen in adults.<ref name=":4">{{Cite journal|date=2019-11-10|title=Atlantoaxial Instability: Background, Pathophysiology, Etiology|url=https://emedicine.medscape.com/article/1265682-overview#a3}}</ref> It usually presents with torticollis, neck pain, neck tilt, and stiffness.<ref name=":5">{{Cite journal|last=Fernández Cornejo|first=Víctor J.|last2=Martínez-Lage|first2=Juan F.|last3=Piqueras|first3=Claudio|last4=Gelabert|first4=Amparo|last5=Poza|first5=Máximo|date=2003-06-01|title=Inflammatory atlanto-axial subluxation (Grisel's syndrome) in children: clinical diagnosis and management|url=https://doi.org/10.1007/s00381-003-0749-6|journal=Child's Nervous System|language=en|volume=19|issue=5|pages=342–347|doi=10.1007/s00381-003-0749-6|issn=1433-0350}}</ref> It can often be treated with conservative therapies such as physical therapy, traction, immobilization, antiinflammatories and treatment of any underlying infection.<ref name=":5" />

== Co-morbid conditions ==
AAI can cause vertebrobasilar insufficiency.<ref>{{Cite journal|last=Vinchon|first=Matthieu|last2=Assaker|first2=Richard|last3=Leclerc|first3=Xavier|last4=Lejeune|first4=Jean-Paul|date=1995-04-01|title=Vertebrobasilar Insufficiency Resulting from Traumatic Atlantoaxial InstabilityCase Report|url=https://academic.oup.com/neurosurgery/article/36/4/839/2753933|journal=Neurosurgery|language=en|volume=36|issue=4|pages=839–841|doi=10.1227/00006123-199504000-00027|issn=0148-396X}}</ref>

== Diagnosis ==
AAI diagnosis is based on a neurological exam, reported symptoms, and radiological measurements. An atlantodental (or atlantodens or atlas-dens) interval (ADI) of greater than 3 mm in adults and of greater than 5 mm in children as measured on plain radiography is considered indicative of AAI. The ADI is the distance between the odontoid process and the posterior border of the anterior arch of the atlas. An abnormal degree of rotation of the atlas (C1) on C2 has also been determined to indicate instability.

== Treatment ==

== See also ==
* [[Craniocervical instability]]

== Learn more ==

== References ==
<references />

Intracranial hypotension

2019-08-28T23:38:47Z

Rheadw:/* Treatment for cranial CSF leaks and intracranial hypotension */

Intracranial hypotension is a condition in which there is negative pressure within the brain cavity.<ref>{{Cite web|url=http://neurosurgery.ucla.edu/intracranial-hypotension|title=Intracranial Hypotension - UCLA Neurosurgery, Los Angeles, CA|website=neurosurgery.ucla.edu|access-date=2019-08-27}}</ref>

== Monro-Kellie Hypothesis ==
The [[Monro-Kellie hypothesis]] or doctrine holds that the skull is a closed space, that the volume of the brain, blood, and cerebral spinal fluid together is a fixed amount. "An increase in one should cause a decrease in one or both of the remaining two."<ref name=":0">{{Cite journal|last=Mokri|first=B.|date=2001-06-26|title=The Monro-Kellie hypothesis: applications in CSF volume depletion|url=https://www.ncbi.nlm.nih.gov/pubmed/11425944|journal=Neurology|volume=56|issue=12|pages=1746–1748|doi=10.1212/wnl.56.12.1746|issn=0028-3878|pmid=11425944}}</ref> In intracranial hypotension, the loss of pressure affecting the amount of cerebral spinal fluid in the cavity can in turn cause cerebral abnormalities, often seen in imaging.

In other words, decreased cerebrospinal fluid volume in intracranial hypotension is compensated for by increased blood volume and why intracranial hypotension is characterized by dilated blood vessels in the brain.
== Signs and symptoms ==

=== Cranial cerebrospinal fluid leaks ===
According to Cedars-Sinai<ref>{{Cite web|url=https://www.cedars-sinai.org/health-library/articles.html|title=Articles|website=Cedars-Sinai|language=en-US|access-date=2019-08-28}}</ref>, symptoms include:
* CSF rhinorrhea, a "runny nose" where the drainage is cerebrospinal fluid
* otorrhea, drainage from the ear
* salty or metallic taste in the mouth
* drainage down the back of the throat
* Cutaneous sinus tract drainage
* loss of sense of smell
* change in hearing or ringing in the ears

=== Cerebrospinal fluid leaks located in the spine ===
* positional or orthostatic headache, which may be intense. The headaches are worse when upright and get better lying down. "The headache usually is in the back of the head or base of the skull, but can also occur in the front, sides or all over the head. It is rarely on just one side of the head, and often is described as a 'pulling sensation' from the head to the neck. The severity of the headache can range from mild to very severe and disabling."<ref>{{Cite web|url=https://www.cedars-sinai.org/programs/neurology-neurosurgery/clinical/csf-leak/curable-cause-of-headache.html|title=CSF Leak: A Curable Cause of Headache|website=Cedars-Sinai|language=en-US|access-date=2019-08-28}}</ref>
* migraine
* nausea
* blurred vision
* dementia––"[b]ehavioral variant frontotemporal dementia (bvFTD) is a devastating early onset dementia[,]... and in spontaneous intracranial hypotension, is rare and associated with brain sagging and hypersomnolence"<ref>{{Cite journal|last=Schievink|first=Wouter I.|last2=Maya|first2=M. Marcel|last3=Barnard|first3=Zachary R.|last4=Moser|first4=Franklin G.|last5=Jean-Pierre|first5=Stacey|last6=Waxman|first6=Alan D.|last7=Nuño|first7=Miriam|date=2018-11-01|title=Behavioral Variant Frontotemporal Dementia as a Serious Complication of Spontaneous Intracranial Hypotension|url=https://www.ncbi.nlm.nih.gov/pubmed/29534203|journal=Operative Neurosurgery (Hagerstown, Md.)|volume=15|issue=5|pages=505–515|doi=10.1093/ons/opy029|issn=2332-4260|pmid=29534203|pmc=|quote=|last8=|first8=|author-link=|author-link2=|access-date=|author-link3=|author-link4=|author-link5=|author-link6=|via=}}</ref>
* coma<ref>{{Cite journal|last=Chan|first=Stephen M.|last2=Chodakiewitz|first2=Yosef G.|last3=Maya|first3=Marcel M.|last4=Schievink|first4=Wouter I.|last5=Moser|first5=Franklin G.|date=May 2019|title=Intracranial Hypotension and Cerebrospinal Fluid Leak|url=https://www.ncbi.nlm.nih.gov/pubmed/30926112|journal=Neuroimaging Clinics of North America|volume=29|issue=2|pages=213–226|doi=10.1016/j.nic.2019.01.002|issn=1557-9867|pmid=30926112|pmc=|quote=|last6=|first6=|last7=|first7=|last8=|first8=|author-link=|author-link2=|access-date=|author-link3=|author-link4=|author-link5=|author-link6=|via=}}</ref>

== Diagnosis ==

=== Diagnostic criteria for spontaneous intracranial hypotension with spinal CSF leaks<ref name=":1">{{Cite web|url=http://www.ajnr.org/content/ajnr/37/7/1374.full.pdf|title=Imaging Signs in Spontaneous Intracranial Hypotension: Prevalence and Relationship to CSF Pressure|last=Kranz|first=P.G.|authorlink=|last2=|first2=|authorlink2=|date=July 2016|website=American Journal of Neuroradiology|archive-url=|archive-date=|dead-url=|access-date=August 28, 2019}}</ref> ===
* orthostatic headache
* no recent history of dural puncture
* not attributable to another disorder
* the presence of at least 1 of:
** low opening pressure (less than or equal to 60 mm of H20)
** sustained improvement of symptoms after epidural blood patching
** demonstration of an active spinal CSF leak
** cranial MRI changes of intracranial hypotension (e.g. brain sagging or pachymeningeal enhancement)

== Imaging signs ==
* pachymeningeal enhancement<ref>{{Cite journal|last=Antony|first=Joyce|last2=Hacking|first2=Craig|last3=Jeffree|first3=Rosalind L.|date=Nov 2015|title=Pachymeningeal enhancement-a comprehensive review of literature|url=https://www.ncbi.nlm.nih.gov/pubmed/26264063|journal=Neurosurgical Review|volume=38|issue=4|pages=649–659|doi=10.1007/s10143-015-0646-y|issn=1437-2320|pmid=26264063|pmc=|quote=|last4=|first4=|last5=|first5=|last6=|first6=|last7=|first7=|last8=|first8=|author-link=|author-link2=|access-date=|author-link3=|author-link4=|author-link5=|author-link6=|via=}}</ref>
* brain "sagging" or "sinking"
** low cerebellar tonsils
** brainstem distortion
** Pontine enlargement
** crowding of the posterior fossa
** flattening of the optic chasm
* subdural hygromas (cerebrospinal fluid-filled cysts) and/or subdural hematomas (blood leaking from vessels)
* engorged venous sinuses
* pituitary hyperemia

== Radiologists' mnemonic for spinal CSF leaks: SEEPS ==
Radiologists use the mnemonic, SEEPS, to describe and remember the signs seen in imaging for CSF leaks located in the spine (not cranial CSF leaks):<blockquote>Subdural fluid collection</blockquote><blockquote>Enhancement of pachymeninges (dura)</blockquote><blockquote>Enlargement of veins</blockquote><blockquote>Pituitary hyperemia (engorged pituitary)</blockquote><blockquote>Sagging of brain (including not limited to saggy tonsils)</blockquote>
== Causes ==
Causes of intracranial hypotension are grouped into 3 kinds of cerebrospinal fluid leaks:

''iatrogenic'', which is caused by a medical procedure;

''traumatic'', which is the result of an injury; and

''spontaneous (idiopathic)'', which is "occurring with minimal or no clear precipitant".<ref name=":2">{{Cite web|url=https://spinalcsfleak.org/about-spinal-csf-leaks/causes/|title=Causes|date=2016-11-20|website=Spinal CSF Leak Foundation|language=en-US|access-date=2019-08-27}}</ref>

==== Iatrogenic causes of intracranial hypotension and spinal CSF leaks ====
* lumbar puncture (spinal tap). Spinal CSF leaks can develop after a lumbar puncture. Headaches that can develop are "often known as Post Dural Puncture Headache = PDPH. This is the most common cause of a spinal CSF leak."<ref name=":2" />
* epidural injections
* spine surgery

==== Traumatic causes of intracranial hypotension and spinal CSF leaks<ref name=":2" /> ====
* brachial plexus injuries (nerves extending from the spinal cord)
* spinal injuries
* sports injuries
* falls

==== Spontaneous (idiopathic) intracranial hypotension and spinal CSF leaks ====
Potential causes may include: "lifting small or large items, straining, stretching, positional changes, sporting activities, roller coaster rides and falls. Some of these might be categorized as traumatic.

• Spontaneous spinal CSF leaks may be associated with '''spinal pathology''' such as calcified disc material or bone spurs. These leaks are usually ventral or in front of the spinal cord.

• There is a growing evidence base suggesting that a significant proportion of spontaneous spinal CSF leaks occur as a result of '''preexisting weakness''' of the dura mater. A range of dural defects have been reported at surgery. Electron microscopy of dura has revealed abnormalities in a substantial proportion of cases. Heritable Disorders of Connective Tissue (HDCT) occur at a higher frequency in affected individuals; intracranial hypotension may be the first noted manifestation. Marfan syndrome, Ehlers-Danlos syndrome (both classic and hypermobility type) and Unspecified Heritable Disorders of Connective Tissue have been reported. Patients with spontaneous spinal CSF leaks have been shown to have higher risk of intracranial aneurysms, bicuspid aortic valve and thoracic aortic aneurysms and should be evaluated for HDCT.

Spontaneous spinal CSF leaks are uncommon, but not rare. One estimate of annual incidence is 5 in 100,000, however this has not been well-studied. Unfortunately, misdiagnoses and delayed diagnoses are common in this subset."<ref name=":2" />

== Treatment ==

==== Treatment for spinal CSF leaks and intracranial hypotension ====
According to the Spinal CSF leak foundation, conservative treatment includes "bedrest, oral and IV fluids, oral and IV caffeine" in the absence of severe symptoms.<ref>{{Cite web|url=https://spinalcsfleak.org/about-spinal-csf-leaks/overview/|title=Overview|date=2014-07-14|website=Spinal CSF Leak Foundation|language=en-US|access-date=2019-08-28}}</ref>

Epidural blood patch

Epidural patch with fibrin glue +/- blood

Surgery

== Notable Studies ==
2019, Intracranial Hypotension and Cerebrospinal Fluid Leak.<ref>{{Cite journal|last=Moser|first=Franklin G.|last2=Schievink|first2=Wouter I.|last3=Maya|first3=Marcel M.|last4=Chodakiewitz|first4=Yosef G.|last5=Chan|first5=Stephen M.|date=2019-05-01|title=Intracranial Hypotension and Cerebrospinal Fluid Leak|url=https://www.neuroimaging.theclinics.com/article/S1052-5149(19)30002-4/abstract|journal=Neuroimaging Clinics|language=English|volume=29|issue=2|pages=213–226|doi=10.1016/j.nic.2019.01.002|issn=1052-5149|pmid=30926112}}</ref> ([https://www.neuroimaging.theclinics.com/article/S1052-5149(19)30002-4/abstract Abstract])

2016, Imaging Signs in Spontaneous Intracranial Hypotension: Prevalence and Relationship to CSF Pressure.<ref name=":1" /> ([http://www.ajnr.org/content/ajnr/37/7/1374.full.pdf PDF of full study])

==See also==
*[[Intracranial hypertension]]
*[[Cerebrospinal fluid leak]]

==References==
<references />
[[Category:Neurology]]
[[Category:Neurological disorders]]