CLINICAL CORRESPONDENCE Headache caused by alternating intracranial hypertension and intracranial hypotension: a case report.

This article presents a case report on headache caused by alternating intracranial hypertension and intracranial hypotension. The patient was a 21-year-old man who was seen for the evaluation of continuous severe headache. Seven years previously, he developed a severe headache which was associated with vomiting. The headache was so severe as to prevent him from undertaking normal daily activity. Brain CT revealed an arachnoid cyst near the torcular herophili. He received a cystoperitoneal shunt, which abolished the severe headache. On examination, the patient showed a left trochlear nerve palsy and a right peripheral facial nerve palsy. There was no papilloedema on ophthalmological examination. Otherwise, there were no neurological abnormalities.