Severe Traumatic Brain Injuries in Aging Patients. A Light and Electron Microscopic Study

Orlando J. Castejón

Biological Research Institute “Drs. Orlando J. Castejón and Haydee Viloria de Castejón”, Faculty of Medicine, Zulia University, Maracaibo, Venezuela

Dr. Orlando J. Castejón, Biological Research Institute “Drs. Orlando J. Castejón and Haydee Viloria de Castejón”, Faculty of Medicine. Zulia University, Maracaibo, Venezuela.

Keywords: Brain Trauma, Brain Aging, Neurons, Glial Cells, Microscopy

Abstract

We have studied the pathological changes involved on severe and complicated human head traumas associated to subdural hygroma or hematoma in old patients. Light and electron microscopy study of four patients ranging from 58 to 80 years old, with severe brain traumas and associated subdural hygroma and hematoma were examined. Light microscope showed status spongiosus of brain parenchyma, apoptotic, oncotic, autophagic and necrotic nerve cell death types, reactive hypertrophic astrocytes containing lipofucsin granules, dense oligodendrocytes, and degenerated myelinated axons. Electron microscopy of edematous nerve cell cytoplasm exhibited vacuolar enlargement of rough endoplasmic reticulum with detachment of associated ribosomes, nucleus with distended nuclear pores and irregularly dilated nuclear envelope, swollen mitochondria, enlarged extracellular space, degenerated myelinated axons, and synaptic plasticity and degeneration. Satellite perineuronal, interfascicular and perivascular glycogen depleted-and glycogen-rich astrocytes. Astrocytes showed clustered and thin vesicular profiles of smooth endoplasmic reticulum. Lipofucsin-rich astrocytes also were found. The degenerated myelinated axons appeared attached to swollen and ischemic oligodendrocytes. Close examination of the neuropile showed synaptic plasticity and degeneration. Blood brain barrier breakdown was observed featured by increased surface activity of luminalm endothelial cell surface and vesicular and vacuolar transendothelial transport, basement thickening, swollen pericites with dense bodies, and swollen astrocyte end-feet anchored to the outer surface of basement membrane. Multilayered basement membrane separated by thin bands of swollen pericite cytoplasm was found bearing proliferation of collagen fibers. Perivascular dense microglial cells also were also seen. The findings indicate cytotoxic and vasogenic brain oedema, cell death, and neurodegenerative processes leading to neurological and mental diseases.

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