Anonymous
Not logged in
Talk
Contributions
Create account
Log in
Search
Editing
Grabb-Oakes measurement
From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history
Namespaces
Page
Discussion
More
More
Page actions
Read
Edit
Edit source
History
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
The [[Grabb-Oakes measurement]] (pB-C2 line) is a measure of the encroachment by the [[odontoid process]] into the upper spinal canal ([[basilar invagination]]) and thus, potential ventral [[brainstem compression]].<ref>{{Cite web | title = Grabb-Oakes Line| url = https://www.ispn.guide/glossary/grabb-oakes-line/|website=The ISPN Guide to Pediatric Neurosurgery|access-date=2019-09-02|language=en-US}}</ref> It is used to aid in the diagnosis of [[craniocervical instability]].<ref>{{Cite journal | title = A Dual Approach for the Management of Complex Craniovertebral Junction Abnormalities: Endoscopic Endonasal Odontoidectomy and Posterior Decompression with Fusion | url =http://www.sciencedirect.com/science/article/pii/S2590139719300043|journal=World Neurosurgery: X | date = 2019-04-01|issn=2590-1397 | pages = 100010|volume=2|doi=10.1016/j.wnsx.2019.100010 | first = Andrew F. | last = Alalade | first2 = Elizabeth | last2 = Ogando-Rivas | first3 = Jonathan | last3 = Forbes | first4 = Malte | last4 = Ottenhausen | first5 = Rafael | last5 = Uribe-Cardenas | first6 = Ibrahim | last6 = Hussain | first7 = Prakash | last7 = Nair | first8 = Kurt | last8 = Lehner | first9 = Harminder | last9 = Singh}}</ref> == Measurement == The pB-C2 line is the distance in milimeters from the dura to the line drawn from the basion to the posterior inferior edge of the C2 vertebra. == Clinical significance == The pB-C2 line was first proposed by Grabb, et al. as a means of quantifying ventral brainstem compression in pediatric and young adult patients with [[Chiari malformation]].<ref name=":0">{{Cite journal | title = Ventral Brain Stem Compression in Pediatric and Young Adult Patients with Chiari I Malformations| url = https://academic.oup.com/neurosurgery/article/44/3/520/2859195|journal=Neurosurgery | date = 1999-03-01|issn=0148-396X | pages = 520–527|volume=44|issue=3|doi=10.1097/00006123-199903000-00050|language=en | first = W. Jerry | last = Oakes | first2 = Timothy B. | last2 = Mapstone | first3 = Paul A. | last3 = Grabb}}</ref> They found that in patients with pB-C2 lines less than 9mm, [[posterior fossa decompression surgery]] alone was sufficient to improve symptoms. However, following decompression surgery, patients with pB-C2 lines greater than 7mm (n=19) remained mildly symptomatic and those with measurements greater than 9mm (n=11), moderately symptomatic. In the latter group, treatment directed at improving the retroflexed odontoid was necessary.<ref name=":0" /> A second pediatrics study found that even among those with “normal” Grabb-Oakes measurements, higher measurements were correlated with a greater incidence of post-operative headache.<ref>{{Cite journal | last = Wellons | first = John C. | last2 = Tulipan | first2 = Noel | last3 = Tomycz | first3 = Luke | last4 = Shannon | first4 = Chevis N. | last5 = Day | first5 = Matthew A. | last6 = Dewan | first6 = Michael C. | last7 = Ladner | first7 = Travis R. | date = 2015-02-01 | title = Evaluating the relationship of the pB–C2 line to clinical outcomes in a 15-year single-center cohort of pediatric Chiari I malformation | url =https://thejns.org/view/journals/j-neurosurg-pediatr/15/2/article-p178.xml|journal=Journal of Neurosurgery: Pediatrics|language=en-US|volume=15|issue=2 | pages = 178–188|doi=10.3171/2014.9.PEDS14176|issn=1933-0715}}</ref> A consensus statement formed at the second International CSF Dynamics Symposium of the Chiari and Syringomyelia Foundation in 2013, proposed that a Grabb-Oakes measurement greater than 9mm, or in some cases, 8mm, could be seen as “potentially pathological.”<ref>{{Citation | title = Dr. Paolo Bolognese presents Chiari I Malformation, EDS, and Craniocervical Instability| url = https://www.youtube.com/watch?v=MsYDA3SXTkg|language=en|access-date=2019-09-02}}</ref><ref>{{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> == Epidemiology == As compared to the [[clivo-axial angle]], there has been less work done to establish the average Grabb-Oakes measurement in the general population or in various patient cohorts. === Pediatrics === In Grabb et al.’s pediatric study, healthy control participants (n=12) had an average Grabb-Oakes measurement of 3.1mm, while the average for those with Chiari Malformations (n=40) was 7.0mm.<ref name=":0" /> === Adults === A study of the Grabb-Oakes measurement in 125 healthy adults found a mean of 6.5 ± 2.1mm, range of 0–11.2mm. The authors argue that normal ranges for adults are probably higher than those established in pediatric patients, and that the pediatric literature should not be used for establishing surgical values in adults.<ref>{{Cite journal | last = Shah | first = Lubdha M. | last2 = Bisson | first2 = Erica F. | last3 = Besachio | first3 = David A. | last4 = Khaleel | first4 = Ziyad L. | date = 2014-02-01 | title = Estimation of odontoid process posterior inclination, odontoid height, and pB–C2 line in the adult population: Clinical article| url = https://thejns.org/view/journals/j-neurosurg-spine/20/2/article-p172.xml|journal=Journal of Neurosurgery: Spine|language=en-US|volume=20|issue=2 | pages = 172–177|doi=10.3171/2013.10.SPINE13405}}</ref> However, another study of 100 asymptomatic adults found a similar mean, 6.7 ± 1.0mm, range of 4.2–10.2mm. Only one person in this study had a Grabb-Oakes measurement greater than 9mm,<ref>{{Cite journal | last = Tedeschi | first = Helder | last2 = Ghizoni | first2 = Enrico | last3 = Mathias | first3 = Roger N. | last4 = Fernandes | first4 = Yvens B. | last5 = Joaquim | first5 = Andrei F. | last6 = Batista | first6 = Ulysses C. | date = 2015-04-01 | title = Computed tomography evaluation of the normal craniocervical junction craniometry in 100 asymptomatic patients| url = https://thejns.org/view/journals/neurosurg-focus/38/4/article-pE5.xml|journal=Neurosurgical Focus|language=en-US|volume=38|issue=4| pages = E5|doi=10.3171/2015.1.FOCUS14642|issn=1092-0684}}</ref> the common pathological cutoff, suggesting a Grabb-Oakes measurement greater than 9mm is quite rare in the general population. == See also == * [[craniocervical instability]] * [[Chiari malformation]] ==Learn more== ==References== {{reflist}} [[Category:Tests]]
Summary:
Please make sure your edits are consistent with
MEpedia's guidelines
.
By saving changes, you agree to the
Terms of use
, and you irrevocably agree to release your contribution under the
CC BY-SA 3.0 License
and the
GFDL
. You agree that a hyperlink or URL is sufficient attribution under the Creative Commons license.
Cancel
Editing help
(opens in new window)
Templates used on this page:
Template:Citation
(
edit
)
Template:Cite journal
(
edit
)
Template:Cite web
(
edit
)
Template:Main other
(
edit
)
Template:Reflist
(
edit
)
Module:Check for unknown parameters
(
edit
)
Module:Citation/CS1
(
edit
)
Module:Citation/CS1/COinS
(
edit
)
Module:Citation/CS1/Configuration
(
edit
)
Module:Citation/CS1/Date validation
(
edit
)
Module:Citation/CS1/Identifiers
(
edit
)
Module:Citation/CS1/Utilities
(
edit
)
Module:Citation/CS1/Whitelist
(
edit
)
Module:No globals
(
edit
)
Navigation
Navigation
Skip to content
Main page
Browse
Become an editor
Random page
Popular pages
Abbreviations
Glossary
About MEpedia
Links for editors
Contents
Guidelines
Recent changes
Pages in need
Search
Help
Wiki tools
Wiki tools
Special pages
Page tools
Page tools
User page tools
More
What links here
Related changes
Page information
Page logs