Spontaneous intracranial hypotension is a very rare cause of headaches that results from a CSF leak. The leak is typically from the thoracic nerve root sleeves.

Risk factors include connective tissue disorders such as Marfan's syndrome.

Key features

• strong postural relationship with the headache generally much worse when upright. Patients may, therefore, be bed-bound

Investigations

• MRI with gadolinium: typically shows pachymeningeal enhancement

Management

• usually conservative
• if this fails an epidural blood patch may be tried