CSF hypotension: A review of its manifestations, investigation and management.

Intracranial cerebrospinal fluid (CSF) hypotension usually arises in the context of known or suspected leak of CSF. This can be spontaneous, or due to central nervous system trauma or dural defects created during lumbar puncture or epidural anaesthesia. Spontaneous intracranial hypotension (SIH) is increasingly being recognised as a cause for orthostatic headache or spontaneous subdural haematoma where no other obvious cause is found. We review CSF physiology, the mechanism of symptom generation in CSF hypotension and the investigation and management of the syndrome. Whilst commonly mild and self-limiting, CSF hypotension may result in life threatening complications and is most often treatable. When the syndrome is severe, prolonged or complicated, epidural blood patching (EBP) is the mainstay of treatment.