Transmission electron microscope study of human hydrocephalic cerebral cortex.

Cortical biopsies of 17 patients with diagnosis of hydrocephalus and associated pathology were examined under the transmission electron microscope to study alterations of neurons, neuroglial cells, extracellular space and capillary wall. Nerve cells showed moderate and severe swelling as well as dilation of endoplasmic reticulum canaliculi and perinuclear cistern, edema and degenerative changes of Golgi apparatus, variable degrees of mitochondrial swelling and fragmentation of plasma membrane. The neighbouring neuropil showed notable enlargement of extracellular space and signs of synaptic degeneration characterized by swollen pre- and postsynaptic endings, clumping of spheroidal synaptic vesicles and detachment of glial synaptic ensheathment. The astrocytes exhibited edematous changes and phagocytic activity. Oligodendroglial cells appeared normal in certain cases and in others showed moderate hydropic changes. Evidences of oligodendrocyte mitotic divisions were not found. Numerous myelin figures were observed in some undifferentiated nerve cells. The capillary wall showed evident signs of blood-brain barrier dysfunction featured by increased endothelial vesicular and vacuolar transport, open interendothelial junctions and focal capillary basement membrane thickenings.