[An interhemispheric subdural abscess (author's transl)]

A subdural abscess which is cinfined to the interhemispheric space alone, which does not extend over the convexity is rare. This is a specific form and is a complication of a common intracranial subdural abscess. It is of great practical importance to determins this uncommon location, and cerebral angiography is most useful. Multiple trephinations or craniotomy for exploration and evacuation must be performed near the midline. A 20 year old female was in a comatose state on admission. There was a flaccid paralysis of the right lower extremity and a dilated left pupil. Examination of the eyegrounds showed bilateral choked discs. Left cerebral angiography revealed the proximal pericallosal artery to be shifted to the right side and the callosomarginae artery was displaced from the midline parallel to the distal pericallosal artery. Although 20 ml of pus was evacuated through the parietal burr hole, which was located a bout 2.5 cm from the midline, she died. At autopsy, a subsural abscess was found in the interhemispheric space. It extended from the frontal pole to the occipital and had a thick membrane which adhered firmly to the falx medially. We could find no other subdural nor intracerebral pus collections. The left cerebral hemisphere was edematous. The superior sagittal sinus had a thick wall and was almost occluded. This dural sinus thrombophlebitis may have developed into the interhemispheric subdural abscess. It is emphasized that this uncommon location for subdural abscess poses a specific problem in clinical practice.