Treatment of steroid-unresponsive tumefactive demyelinating disease with plasma exchange.

The authors describe a patient with an isolated, gadolinium-enhancing, biopsy-proven focus of tumefactive demyelination. There was marked clinical improvement with plasma exchange after failure of high-dose i.v. corticosteroids. The post-treatment clinical course correlated with decreasing enhancement and lesion size on MRI. This patient's rapid clinical and MRI response suggests that plasma exchange may be beneficial in this disorder, and could perhaps serve as a diagnostic tool to avoid the need for brain biopsy.