A case of bilateral interhemispheric subdural hematoma

Interhemispheric subdural hematoma (ISDH), although not infrequent in children, has been rarely encountered in adults. Spread of CT, ISDH has been reported sporadically, and so far more than 40 cases have been reported. But bilateral ISDH is an extremely rare lesion, with only 5 cases reported in the literature. We report a sixth case of bilateral ISDH in adults. A 68-year-old woman was admitted because of headache and vomiting. Two days before admission she had fallen, striking her occiput, and had lost consciousness for a few minutes. Neurological examination on admission revealed hyperreflexia of her extremities, especially in her left leg. However, motor weakness was not recognized. There was no fracture visible on the plain X ray films of the skull. Axial CT scan demonstrated a high density lesion along the falx and its extension down over the tentorium. Coronal CT scan also demonstrated a convexo-convex high density lesion beside the falx, and its extension onto the tentorium. Cerebral angiogram showed lateral displacement of the callosomarginal artery, and an avascular area beside the falx and onto the tentorium. After admission she was managed conservatively, but on the 14th day after head trauma, paraparesis and left arm paresis were recognized. This condition deteriorated and she developed an inability to stand. On the 19th day parasagittal craniotomy and evacuation of the hematoma were performed. Her postoperative course was uneventful and she was discharged with no neurological deficits.