[Spontaneous intracranial hypotension associated with trochlear nerve palsy and bilateral chronic subdural hematoma]

Spontaneous intracranial hypotension (SIH) is a rare disease which is associated with variety of symptoms and signs including cranial neuropathies. Though diplopia occurred reportedly in about one fourth of SIH cases, trochlear nerve palsy has been reported only one case in the literature. A 71-year-old previously healthy male developed postural headache and nausea. After 15 days, he began to have diplopia caused by right trochlear nerve palsy. He consulted our hospital 2 months later because only diplopia was not recovered. Magnetic resonance imaging (MRI) showed bilateral thin chronic subdural hematoma (CSDH), brain sagging and downward brain stem displacement, but not ischemic change in brain stem. We suspected SIH for right trochlear nerve palsy, and he had symptomatic therapy. Two months later, he had burr hole surgery because of disturbance of consciousness and right hemiparesis due to progressive bilateral-CSDH. To say nothing of disturbance of consciousness and right hemiparesis, his trochlear nerve palsy was completely recovered after surgery at once. Follow-up MRI showed brain sagging and downward brain stem displacement were recovered.