Cerebrospinal Fluid Leaks and Spontaneous Intracranial Hypotension: Symptoms, Mechanical Triggers, Diagnosis, and Treatment
Cerebrospinal fluid (CSF) is the clear fluid that surrounds and supports the brain and spinal cord. It provides cushioning, buoyancy, and protection to the central nervous system. Around the spinal cord, CSF is contained within protective membranes, including the dura mater, the tough outer covering of the spinal canal. When a tear, hole, abnormal outpouching, or abnormal connection develops in this protective system, cerebrospinal fluid can escape from its normal compartment. Depending on where the defect occurs, a CSF leak can present in very different ways. A spinal CSF leak may cause loss of CSF volume around the brain and lead to spontaneous intracranial hypotension (SIH), while a defect at the skull base may allow CSF to escape through the nose or ear. One of the most characteristic manifestations of a spinal CSF leak is a positional, or orthostatic, headache: symptoms become substantially worse while sitting or standing and improve after lying flat. However, headache is on...