From the neurological and neurosurgical services of the Massachusetts General Hospital, Boston.
Dr. Schwab is associate clinical professor of neurology, Harvard Medical School, and neurologist, Massachusetts General Hospital, Boston.
Dr. Poryali held a Charles E. Merrill Trust Fellowship, Massachusetts General Hospital.
Dr. Ames is research associate, Biological Chemistry Department, Harvard Medical School, and Neurosurgical Service, Massachusetts General Hospital.
The authors are indebted to Dr. Michio Sakanoue for creating and analyzing the plasma ultrafiltrates.
