DELAYED FIBROTIC OBLITERATION OF THE SPINAL SUBARACHNOID SPACE AFTER CEREBRAL ANEURYSMAL SUBARACHNOID HEMORRHAGE

Abstract

Widespread fibrotic obliteration of the spinal subarachnoid space after cerebral aneurysmal subarachnoid hemorrhage (SAH) is rare. A 57-year-old woman presented with the gradual development of a spastic paraparesis. Two years earlier, she experienced a cerebral aneurysmal SAH that was successfully managed with endovascular coiling. However, the SAH was complicated by transient aseptic meningitis and hydrocephalus. Magnetic resonance imaging and computed tomographic myelography at the time of admission 2 years after SAH revealed widespread cystic obliteration of the thoracic subarachnoid space. Through an extensive laminoplasty, multiple non-communicating fibrotic cysts, intimately adherent to the pia, were found to have obliterated the spinal subarachnoid space. A full communication between all cysts and the subarachnoid space was ultimately established using a Fogarty catheter. The cerebrospinal fluid was clear and colorless, with normal microscopy. Histopathological examination revealed non-specific fibrosis with scattered lymphocytes and uniform hemosiderosis. In addition to precipitating leptomeningeal fibrosis within the convexity subarachnoid space and/or arachnoid granulations (causing delayed hydrocephalus), cerebral aneurysmal SAH may also rarely elicit widespread symptomatic fibrotic obliteration of the spinal subarachnoid space. Such cases seem to be characterized by a posterior circulation, Fisher Grade 3 to 4, aneurysmal SAH, and, when circumscribed and cystic, seem amenable to surgical decompression.