7.2.3 Headache attributed to spontaneous intracranial hypotension

Previously used terms:
Headache attributed to spontaneous low CSF pressure or primary intracranial hypotension; low CSF-volume headache; hypoliquorrhoeic headache.

Description:
Orthostatic headache caused by low cerebrospinal fluid (CSF) pressure of spontaneous origin. It is usually accompanied by neck stiffness and subjective hearing symptoms. It remits after normalization of CSF pressure.

Diagnostic criteria:
A. Any headache fulfilling criterion C
B. Low CSF pressure (<60 mm CSF) and/or evidence of CSF leakage on imaging
C. Headache has developed in temporal relation to the low CSF pressure or CSF leakage, or has led to its discovery
D. Not better accounted for by another ICHD-3 diagnosis.

Comments:
7.2.3 Headache attributed to spontaneous intracranial hypotension cannot be diagnosed in a patient who has had a dural puncture within the prior month.

The headache in patients with spontaneous CSF leaks or spontaneously low CSF pressure may resemble 7.2.1 Post-dural puncture headache, occurring immediately or within seconds of assuming an upright position and resolving quickly (within 1 minute) after lying horizontally. Alternatively it may show delayed response to postural change, worsening after minutes or hours of being upright and improving, but not necessarily resolving, after minutes or hours of being horizontal. While there is a clear postural component in most cases of 7.2.3 Headache attributed to spontaneous intracranial hypotension, it may not be as dramatic or immediate as in 7.2.1 Post-dural puncture headache. The orthostatic nature of the headache at its onset should be sought when eliciting a history, as this feature may become much less obvious over time.

While autologous epidural blood patches (EBPs) are frequently effective in sealing CSF leaks, the response to a single EBP may not be permanent, and complete relief of symptoms may not be achieved until two or more EBPs have been performed. However, some degree of sustained improvement, beyond a few days, is generally expected. In some cases, sustained improvement cannot be achieved with EBPs and surgical intervention may be required.

In patients with typical orthostatic headache and no apparent cause, after exclusion of postural orthostatic tachycardia syndrome (POTS) it is reasonable in clinical practice to provide autologous lumbar EBP.

It is not clear that all patients have an active CSF leak, despite a compelling history or brain imaging signs compatible with CSF leakage. Cisternography is an outdated test, now infrequently used; it is significantly less sensitive than other imaging modalities (MRI, CT or digital subtraction myelography). Dural puncture to measure CSF pressure directly is not necessary in patients with positive MRI signs such as dural enhancement with contrast.

The underlying disorder in 7.2.3 Headache attributed to spontaneous intracranial hypotension may be low CSF volume. A history of a trivial increase in intracranial pressure (eg, on vigorous coughing) is sometimes elicited. Postural headache has been reported after coitus: such headache should be coded as 7.2.3 Headache attributed to spontaneous intracranial hypotension because it is most probably due to CSF leakage.