A spinal cerebrospinal fluid (CSF) leak is an underdiagnosed cause of a debilitating headache that is treatable. A spinal CSF leak occurs when a tear or hole occurs in the spinal dura and the CSF leaks out. When this fluid volume is reduced, there is less fluid available to support the normally floating brain inside the skull. The resulting sagging of the brain and other structures causes tension on the pain sensitive meninges, vessels and cranial nerves, manifesting as variable headache and other neurological signs and symptoms. When upright, the loss of CSF volume / pressure has a pronounced effect on the brain and causes symptoms to worsen.
A leak can be spontaneous or occur from trauma or a medical procedure i.e. lumbar puncture, lumbar cathetrisation or spinal surgery. A variety of causes for spontaneous leaks have been identified. Most often from a bone spur or calcified disc tearing a hole in the normal dura or the other common cause is via an enlarged nerve root sleeve cyst, which is an area of thinned weakened aneurysmal dura. These cysts can be related to a number of genetic connective tissue disorders, such as Marfan syndrome or Ehlers-Danlos syndrome, though more often not the case. A rarer, more recently identified lesion is a CSF to venous fistula, where the nerve root drainage connects directly to a small paravertebral venous structure, thus accelerating CSF drainage into the venous system.
Typically, the headache is located at the base of the back of the head, often with neck pain. However, it may be at the front, whole head or to one side. The headache is generally worse shortly after sitting up or standing and improves relatively quickly when laying down, hence it is often referred to as an “orthostatic” or “postural” headache. The pain can range from mild to severe and can feel more like pressure than pain and be accompanied by a heaviness. The headache may not be present (or may be mild) upon awakening and develop in the late morning or afternoon, generally worsening throughout the day.
Other common symptoms which may accompany the headache include nausea and vomiting, neck pain and stiffness, changes in hearing (muffled, underwater, tinnitus), sense of imbalance, sensitivity to light or sound, interscapular pain, brain fog, dizziness or vertigo.
Unfortunately, this condition and the symptoms that accompany it can often be misdiagnosed as migraine, sinusitis, tension headache, post traumatic headache and the new enitity of chronic daily persistent headache, especially in the case of spontaneous CSF Leaks. Over time the positional nature of the symptoms can diminish and further contribute to misdiagnosis.
Initial diagnosis is usually suspected on the clinical presentation. A Brain MRI with contrast is the ideal imaging starting point, most sensitive in detecting the subtle features of intracranial CSF hypotension. However, in 20% of cases this may be entirely normal.
Strong clinical suspicion would then require an MRI spine, if this was readily available or timely referral to a Neuroradiologist for lumbar puncture with opening pressure measurement and CT myelography. Thereafter, depending on these intial diagnostic tests, the patient may be directed to a diagnostic/therapeutic empiric blood patch or more specialised spinal imaging such as dynamic CT myelography and/or digital subtraction myelography, to locate the CSF Leak. The method chosen will depend on the clinical history and initial MRI, myelography (and patch) results.
Unfortunately, leaks are not always detected during imaging (choice and method of imaging technique and/or the nature of intermittent leaks) and may need to be repeated.
Where a leak is suspected initial treatment includes bed rest, fluids and extra caffeine. In some cases, this may resolve the leak.
Invasive treatment may include non-targeted (also referred to as ‘empiric’) and targeted epidural blood patches, where a patient’s blood is drawn and immediately injected into the epidural space, under sterile conditions. This procedure may be repeated several times for the desired results, depending on the causative lesion. Empiric patching involves a large volume of blood introduced into the lumbar and sometimes the lower thoracic epidural space, as well. Where the site of the leak is known or suspected a targeted patch consisting of fibrin sealant with blood or blood alone can be injected as close to the site of the leak as safely possible. Where targeted patching has been successful, but transient, this could be repeated and / or directed to surgery. Where the leak is fast and extensive, with the level confirmed, this patient would be directed to surgery without patching.
Following any treatment including conservative treatment, precautions should be taken to avoided bending, lifting, tilting and straining for a period of time and to avoid anything which may increases intracranial pressure.
Roughly a third of patients experience a complication of treatment known as rebound intracranial CSF hypertension. This occurs where the intracranial CSF pressure is increased and causes potentially severe headache, nausea and vomiting. Rebound Intracranial hypertension or rebound high pressure may require medication or in some severe cases, a therapeutic lumbar puncture to lower intracranial pressure.
CSF leaks are treatable in many instances. Most cases the outcomes are favourable when in experienced hands and detected early. Many patients however do not receive timely or appropriate care and this may effect outcomes. A small proportion of patients continue to have persistent symptoms despite receiving numerous interventions.
FURTHER INFORMATION AND SUPPORT
Spinal CSF Leak Foundation
CSF Leak Association
When to suspect a CSF Leak
Spinal CSF Leak Support Group and Discussion Community
CSF LEAKS (Cerebrospinal Fluid Leak) & Intracranial Hypotension – International Group
CSF Leakers DownUnder – Private Group Australian & NZ Residents
Last Updated: November 2019 by Dr Scott Davies, MB BCh FCRAD(DIAG)SA FRANZCR Diagnostic Neuroradiologist
DISCLAIMER: The information provided is designed to support, not replace, the relationship that exists between a patient / site visitor and his / her existing health care professionals.