[A case of distal aneurysms of bilateral posterior inferior cerebellar arteries].

A case of aneurysms of bilateral distal posterior inferior cerebellar arteries (PICAs) is reported. A 61-year-old man experienced a sudden onset of headache and nausea and was admitted to a hospital immediately. His neurological examination showed no abnormalities, but headache and nausea continued in spite of conservative treatment. The patient was referred to our hospital two days after the onset and the neurological examination revealed slight dysmetria of the right upper extremity. A computed tomography (CT) scan demonstrated a round and heterogeneous high density mass at the cerebellar vermis and some blood coagula at the fourth ventricle and vermis. Angiography showed two aneurysms of the bilateral distal PICAs: The right aneurysm was at the cortical segment and the left one was at the telovelotonsillar segment. The patient underwent a suboccipital craniectomy and both aneurysms were clipped successfully. Sleepiness and headache continued postoperatively due to hydrocephalus. After ventricular drainage he soon recovered without having V-P shunt and was discharged with no neurological deficits. Aneurysms of bilateral distal PICAs are very rare and only three cases have been reported in the literature. The etiology, clinical symptom, CT finding and prognosis in the literature reviewed were briefly discussed.