Spinal Cerebrospinal Fluid Leak
– An Under-recognized Cause of Headache
Connie Deline, MD,
Spinal CSF Leak Foundation
Spontaneous intracranial hypotension, or low cerebrospinal fluid (CSF) pressure inside the
head, is an under-recognized cause of headache that is treatable and in many cases, curable.
Although misdiagnosis and delayed diagnosis remain common, increasing awareness of
this condition is improving the situation for those afflicted.
Frequently, patients with a confirmed diagnosis of intracranial hypotension will report
that they have been treated for chronic migraine or another headache disorder for months
or years. This type of headache rarely responds to medications; however, when treatment
is directed at the appropriate underlying cause, most patients respond well.
Anatomy of Intracranial Hypotension
In almost all cases, intracranial hypotension results from a leak of cerebrospinal fluid at
the level of the spine. Spontaneous CSF leaks located at the level of the skull base that leak
from nose or ear are not causally associated with intracranial hypotension.
Low pressure headache is a term commonly used for the headache resulting from intracranial
hypotension. It is important to note that a significant percentage of patients have normal
cerebrospinal fluid pressure measurements. Our understanding has evolved to recognize
that a low volume of the cerebrospinal fluid is the core problem although pressure is
related to volume.
The cerebrospinal fluid surrounds the brain and spinal cord in one continuous
compartment. One of its many functions is to cushion the fatty brain which floats in
this watery fluid. The fluid is held in place by a tough connective tissue layer called the
dura mater, or simply the dura. A hole or tear of the spinal dura results in the loss of
cerebrospinal fluid volume around the brain and spinal cord, and sinking of the brain
inside the head. When the patient is lying flat, the cerebrospinal fluid pressure in
the head and the spine are equal. However when the individual is upright, the
cerebrospinal fluid pressure in the head is much lower than the pressure in the
lower spine, as with any column of fluid. When a loss of cerebrospinal fluid
volume occurs, this results in a larger than normal drop in pressure in the
head when the patient goes from lying flat to being upright. This pressure
change during positioning explains why symptoms are usually worse when
the patient is upright.
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HeadW ise ®
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Volume 7, Issue 1 • 2018