This report provides the first detailed neuropathological study of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐induced parkinsonism in humans. All 3 subjects self‐administered the drug under the impression it was “synthetic heroin” and subsequently developed severe and unremitting parkinsonism, which was L‐dopa responsive, at least in the earlier stages of illness. Survival times ranged from 3 to 16 years. Neuropathological examination revealed moderate to severe depletion of pigmented nerve cells in the substantia nigra in each case. Lewy bodies were not present. In Patients 1 and 2, there was gliosis and clustering of microglia around nerve cells. Patient 3 had a similar picture and also showed large amounts of extraneuronal melanin. These findings are indicative of active, ongoing nerve cell loss, suggesting that a time‐limited insult to the nigrostriatal system can set in motion a self‐perpetuating process of neurodegeneration. Although the mechanism by which this occurs is far from clear, the precedent set by the cases could have broad implications for human neurodegenerative disease.
As theoretically expected, a parallel plate configuration is significantly stronger and stiffer than a perpendicular plate configuration when subjected to sagittal bending forces in a distal humerus fracture model.
Cerebral commissurotomy or the "split-brain" procedure may be a valuable adjunct to anticonvulsants for the control of seizures in people whose epilepsy cannot be relieved by anticonvulsants alone, and who are not candidate for the standard methods of surgery. Corpus callosotomy, a revised form of the usual division of many commissures, is a safer operation and appears to be equally effective. The complex clinical aspects of cure and treatment are emphasized.
A second consecutive series of 12 patients underwent microsurgical "central" commissurotomy (division of the entire corpus callosum and hippocampal commissure) for the relief of previously intractable generalized seizures. This modified operation was found to be safer than the multiple commissurotomies performed in the first series of eight patients and was equally effective. Central commissurotomy was modified further by being performed in two stages, which reduced the length and severity of the "acute disconnection syndrome," a common cause of morbidity in the early postoperative phase. Best results were obtained in patients who were not severely retarded, had signs of unilateral cerebral damage, and included akinetic spells as a prominent form of their generalized seizures. EEG showed that bilateral symmetric discharge became either unilateral or asymmetric after surgery, which emphasized the important role played by the corpus callosum in conducting seizure discharges from one hemisphere to the other.
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