Biomedical subjects
Publications and source records attributed to P Nichelli.
A series of 224 patients with organic mental deterioration, including 129 patients with presumptive Alzheimer dementia, is described chiefly from the neuropsychological standpoint. Several methodological problems arising from research on dementia are discussed.
A short neuropsychological test battery designed to measure language, memory and visuospatial abilities was administered to 217 patients with reversible ischemic attacks. Patients were tested twice: the first time more than one month, but less than one year, from the last ischemic episode, and the second time three years later. A comparison between the first and the second testing session did not disclose any significant worsening. The degree of atherosclerosis and the occurrence of further ischemic episodes during the follow-up period were found to be unrelated to change in performance at the test battery. These results seems to challenge the hypothesis that multi-infarct dementia may follow apparently reversible, or even clinically silent, ischemic episodes.
A new procedure to test colour discrimination in the parafoveal field is described. This method was used on 25 healthy controls and 25 subjects having a definite clinical or laboratory-supported diagnosis of multiple sclerosis, with or without a previous history of optic neuritis. The test proved to be sensitive in detecting visual dysfunction even in some patients in whom the standard technique of pattern-reversal evoked potential recordings yielded a normal result.
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Neuropsychological deficits following mild head injury have been reported recently in the literature. The purpose of this study was to investigate this issue with a strict methodological approach. The neuropsychological performance of 50 mildly head injured patients was compared with that of 50 normal controls chosen with the case-control approach. No conclusive evidence was found that mild head injury causes cognitive impairment one month after the trauma.
Heavy drinkers (more than 2 liters of wine per day), without clinical evidence of brain dysfunction, moderate drinkers (1 liter of wine per day) and control subjects (no more than 250 cc of wine per day) were given the Progressive Matrices test and two learning tests, one tapping verbal memory and the other spatial memory. Heavy drinkers' performance was significantly worse than that of the other groups on the Progressive Matrices test and the spatial learning test. With a more lenient method of analysis, the difference between heavy drinkers and controls on the verbal learning test and that between moderate drinkers and controls on the Progressive Matrices test were also significant. When the influence of intelligence on memory performance was partialled out by covarying memory scores for Progressive Matrices scores, all differences on the verbal learning test disappeared whereas the spatial learning test still discriminated heavy drinkers from mild drinkers and controls. The bearing of these findings on the continuum of impairment hypothesis and the right hemisphere vulnerability hypothesis is discussed.
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A sixty-year old patient had inferior nasal visual field defect in both eyes associated with papilledema. After pseudotumor cerebri was diagnosed and the appropriate treatment begun, the papilledema disappeared, but the visual field defect persisted. This case suggests a revision of the classical concepts concerning the pathogenesis of binasal defects from intracranial causes and emphasizes the risk of loss of vision inherent in long-standing papilledema.
The aim of this study was to investigate the relationship between visual field differences in tachistoscopic recognition of visuo-spatial patterns and overall proficiency in the two sexes. The results demonstrated a left visual field advantage in males but not in females. A female subgroup showed opposite rather than lacking visual field superiorities without affecting speed and accuracy of performance. These data warn against explaining differences in performance in the two sexes in terms of different hemispheric asymmetries.
Two patients presenting with hemiataxia and hemiparesis on the same side are described. Both had CT scan evidence of an infarct located in the posterior limb of the contralateral internal capsule.
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The ability to carry out movements on imitation was assessed with a 24-item test in uniterally hemisphere-damaged patients. On the basis of a cutoff score derived from the performances of 100 control patients, 20% of the right brain-damaged patients were calssified as apraxic. Most right brain-damaged patients were only mildly defective, but a few showed a striking impairment. In left brain-damaged patients apraxia was not only more frequent, but also much more severe and was nearly always associated with aphasia. However, the correlation between the motor and the language disorder was not particularly high, and the link between the two symptoms was thought to be dependent on the contiguity of the underlying nervous structures.
The performance of unilateral brain-damaged patients on recognition of random shapes was investigated by means of two different experiments. In experiment I interitem similarity and number of response-choice alternatives were varied to evaluate their possible influence on the subjects' performance. In experiment II stimulus exposure time was varied, In both experiments left brain-damaged patients with visual field defect obtained lower scores than control subjects. Right brain-damaged patients with visual field defect obtained scores significantly lower than controls only in the brief exposure condition.
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A 27-year-old woman had been suffering from recurring episodes of left-sided migraine since the age of 5. When 14 years old, a diplopia on looking to the left followed each episode; its length progressed with time and eventually became permanent. On examination a left abducens palsy was found. Arteriography failed to reveal the presence of aneurysm or other vascular anomalies.
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