posure.7,9 Morphologic alterations in the brain were most prominent in the amygdala, temporal cortex, basal ganglia, and pontine nuclei. Swollen perikarya, loss of Nissl substance, and necrosis of nerve cells were seen. Electron microscopy showed zebra bodies and many vacuoles. Cerebral edema with irreversible cell damage also occurred in the amygdala. The cerebellar cortex showed loss of Purkinje cells.
The exact mechanism of neurotoxic action of trimethyltin remains uncertain. Proposed mechanisms include release of endogenous excitotoxins from the heavy metal-containing pathways of the hippocampus,29 elevated extracellular glutamate levels,30 hyperammonemia,31 decreased γ-aminobutyric acid concentration,32 inhibition of Ca2+-ATPase in a concentration-dependent manner thereby interfering with calcium pump and other cAMP (adenosine 3′:5′-cyclic phosphate)-mediated processes in the brain,33 or a reduction in the hippocampal zinc concentration, possibly leading to mossy fiber disinhibition and subsequent hyperexcitation of the hippocampal electrical circuitry.3,34
Trimethyltin is an intermediate by-product in the production of other more commonly used tin products.3 It, thus, still constitutes an occupational hazard for some groups, especially chemists who often seem unaware of the inherent dangers.35 This article documents the acute and long-term neurotoxic effects of exposure in a young man. The detailed serial electroencephalographic and neuropsychological studies provide a basis for estimating the prognosis in such cases.1
Accepted for publication August 26, 1992.
Reprint requests to Department of Neurology, Boston University School of Medicine, 80 E Concord St, P801A, Boston, MA 02118–2394 (Dr Feldman).
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