Cerebrospinal fluid leak

A cerebrospinal fluid leak or cerebral spinal fluid leak occurs when a tear or hole happens in the dura mater, the outermost membrane enveloping the brain and spinal cord.

Symptoms of cranial leaks of cerebrospinal fluid

According to Cedars-Sinai, 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

Symptoms of spinal leaks of cerebrospinal fluid

Symptoms of cerebrospinal fluid leaks include positional headaches, 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."

Other symptoms are:

• 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"
• coma

Causes

Leaks can occur after lumbar punctures, epidurals, and surgery.

They can also happen spontaneously.

Risk factors for spontaneous (idiopathic) leaks as well as leaks following procedures include connective tissue disorders such as Ehlers-Danlos syndrome.

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."
• epidural injections
• spine surgery
• Maxillofacial surgery

Traumatic causes of intracranial hypotension and spinal CSF leaks

• 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."

Diagnosis

According to the Spinal CSF Leak Foundation, spinal imaging to aid diagnosis of CSF leaks includes: spinal MRI, MR mylegram, intracathecal gadolinium enhanced spinal MRI, CT myelogram, dynamic CT myelogram, digital subtraction myelogram, and radioisotope cisternogram.

Diagnostic criteria for spontaneous intracranial hypotension with spinal CSF leaks

• 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)

Treatment

Treatments for cranial CSF leaks

According to the Barrow Neurological Institute, conservative treatment for traumatic cranial CSF leaks, depending on several factors, includes, "bed rest and elevation of the head. Patients are encouraged to avoid coughing, sneezing, nose blowing, and any straining that would increase ICP. Stool softeners and laxatives are given as necessary to avoid straining during bowel movements."

Treatments for spinal CSF leaks

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.

• Epidural blood patch
• Epidural patch with fibrin glue +/- blood
• Surgery

See also

• Intracranial hypotension
• Ehlers-Danlos syndrome
• Cerebrospinal fluid