Diagnostic significance of nerve cells in human CSF with particular reference to CSF cytology in the brain death syndrome.

Cytological examination of the cerebrospinal fluid (CSF) in 5 cases of the brain death syndrome treated on a respirator revealed the presence of nerve cells (mostly Purkinje cells), massive pleocytosis with many polymorphonuclear leukocytes, and numerous macrophages containing erythrocytes, leukocytes, lipid droplets, and hemosiderin. Portions of connective tissue with well preserved capillaries, and debris which could not be more closely identified, were also found. Neuropathological examination in 4 cases revealed progressive autolysis of brain tissue and displacement of the autolyzed tissue into the subarachnoid space of the spinal canal, partly due to tonsillar herniation. All five patients exhibited clinical signs of brain death and had been placed on respirators for various periods of time. The cytological findings in the CSF, together with the clinical signs of brain death, constitute an intravital morphological indication of brain tissue autolysis.