Delayed neurological deterioration with an unknown cause subsequent to surgery for intraspinal meningiomas.

Delayed neurological deterioration in the absence of direct cord insult following surgical decompression is rare, but severe post-operative complication occurs in chronically compressive spinal disorders. In the present study, the clinical medical records and radiological findings of 10 patients who underwent surgical removal of intraspinal meningiomas and then experienced delayed post-operative neurological deterioration were reviewed. The cases are presented with consideration of the possible underlying mechanisms. There were five male and five female patients, with a mean age of 46.8 years. The mean duration of illness from the onset of symptoms to diagnosis was 42.8 months. Seven tumors were located in the thoracic region and three in the cervical region of the spine. The tumors compressed the cord severely and gross total removal was achieved in all cases. Immediately subsequent to the surgery, all patients were able to move all extremities, but the onset of the neurological deterioration occurred at post-operative hours 3-8 in all cases (mean, 5 h post-surgery). In four cases, radiological examination revealed an area of high signal changes intrinsic to the cord on T2-weighted images, but without residual compression. The mean follow-up period was 49.6 months. Nine patients reported a marked recovery in status compared with the pre-operative presentation during the several weeks to months following surgery. The surgical removal of intraspinal meningiomas may lead to delayed and severe neurological deterioration in the post-operative period in the absence of direct mechanical cord insult. Ischemia-reperfusion injury may be one potential etiology of this deterioration. Recognition of the neurological deficit following surgical excision of intraspinal meningiomas may improve pre-operative patient counseling and merits further study for the determination of the precise pathophysiology.