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Biomedical subjects

G Miceli

Publications and source records attributed to G Miceli.

At least 55 records · Page 3Linked to original sources

Semantic disorders of auditory language comprehension in right brain-damaged patients.

A test of auditory language comprehension was given to 110 right brain-damaged patients and to 94 normal controls in order to check if patients with lesions of the right (nondominant) hemisphere make a significantly higher number of semantic errors than normals. Confirmation of the hypothesis was obtained, but the relationship between semantic errors and lesion of the right hemisphere did not seem a simple and direct one. In fact, most of the lexical-semantic errors were due to associated variables (such as unilateral spatial agnosia and general mental deterioration) and not to the lesion of the right hemisphere per se. These data do not suggest a specific semantic capacity of the nondominant hemisphere but rather stress the fragility of the lexical-semantic organization at the cortical level.

Brain Damage, Chronic↗

Validity of some neuropsychological tests in the assessment of mental deterioration.

Eighty-three control subjects and 200 patients suspected of diffuse cerebral damage were submitted to the Mental Deterioration Battery. Three independent judges evaluated each patient on the basis of all available data. Only 103 patients, unanimously classed as demented by the three judges were retained. On the basis of controls' performances, the scores obtained by each demented patient in the various tests were corrected for age and educational level. Both single tests and the Battery as a whole discriminated normal controls from demented patients at a very satisfactory level.

Age Factors↗

The relationships between conceptual and semantic-lexical disorders in aphasia.

A nonverbal test of conceptual thinking was administered to 55 normal controls and to 203 patients with monohemispheric brain lesions (74 aphasics and 129 nonaphasic brain-damaged patients), in order to study the relationships between conceptual impairment of aphasic patients and breakdown of the semantic-lexical level of integration of language. A very high number of aphasic patients (54 out of 74) and a limited number of nonaphasic brain-damaged subjects (31 out of 129) obtained a pathological score on the test of conceptual thinking, but only some components of the aphasic symptomatology seemed closely linked to the conceptual disorder. In fact a non-significant relationship was found between conceptual impairment and: ("fluent" or "non-fluent") clinical type of aphasia; severity of aphasic disturbance. On the contrary, a strong relationship was found between conceptual disorder and impairment of the semantic-lexical level of integration of language. These findings seem to show that conceptual disturbance and semantic-lexical troubles are closely linked in aphasia.

Aphasia↗

Constructional apraxia in left brain-damaged patients: a planning disorder?

The aim of the present study was to verify the hypothesis advanced by Hécaen and Assal (1970), that the presence of landmarks can improve the copying performance of left brain-damaged patients, while leaving unchanged that of right brain-damaged patients. Sixty-two control subjects and 196 brain-damaged patients with lesions restricted to the right (N = 84) or to the left (N = 112) cerebral hemisphere were given two tests of copying drawings. In the first task the patients were asked to directly copy a drawing; to perform the second test they were given guiding landmarks. On both tests no difference was found between the performance of the two hemispheric groups. Right-sided patients used a lower number of guiding landmarks, but this occurred only on the half of the drawings contralateral to the side of the lesion and was apparently due to unilateral spatial neglect.

Apraxias↗

Gangliosides in the treatment of mental deterioration. A double-blind comparison with placebo.

Thirty patients showing signs of mental deterioration were submitted to a neuropsychological battery before and after treatment with gangliosides. Their performances were compared, in a double-blind study, with those obtained on the same tests by 30 patients affected by similar degrees of dementia and treated with placebo. The improvement shown on Raven's Coloured Progressive Matrices and on Immediate Visual Memory by the active group was significantly higher than that shown by the placebo group. Furthermore, an evaluation of the overall effect of gangliosides therapy showed a highly significant difference between the active and placebo group, still in favour of the subjects treated with gangliosides. It is concluded that gangliosides may exert a positive effect in the treatment of demential syndromes.

Clinical Trials as Topic↗

A neurolinguistic model for the study of aphasia.

After having briefly discussed some of the most important models that are now used to understand or to classify the aphasic troubles, the authors explain the neurolinguistic model they are actually using to study some aspects of aphasics' verbal and nonverbal behavior. This theoretical model distinguishes proper linguistic from extralinguistic disturbances in the various clinical forms of aphasia. The existence in aphasia of extralinguistic components that might, in some way, influence verbal performances, is accepted by most authors. Much less obvious is the existence, at least in some clinical forms of aphasia, of proper linguistic (competence) disturbances. Our theoretical model assumes that in most clinical forms of aphasia some impairment of the semantic (lexical) structures of language exists, and it maintains that this trouble can be found both at the expressive and at the receptive level, both in verbal and in nonverbal tasks. Th results of some experimental investigations which give some support to this theoretical model, are briefly discussed.

Aphasia↗

Distinctive features of unilateral spatial agnosia in right and left brain-damaged patients.

In order to study the distinctive features of unilateral spatial agnosia shown by right and left brain-damaged patients, a test of copying drawings with guiding landmarks was given to 83 control subjects and to 248 patients affected by right (n = 108) or left (n = 140) hemispheric damage. The test enabled us to obtain a quantitative assessment both of the lines omitted ('omissions') and of the lines wrongly traced ('errors') on the half page contralateral to the damaged hemisphere. Results showed that contralaterally to the hemispheric locus of lesion a clear-cut double dissociation can be found between right and left brain-damaged patients: the former showed a striking tendency to omit the lines lying on the left half of the sheet, whereas the latter tended mainly to trace faulty lines on the right half of the drawings.

Agnosia↗

[Digital agnosia and lesions of the parietal lobe].

130 patients with focal brain damage have been submitted to non-verbal finger identification tasks. The results of this research can be summarized as follows: -when bilateral finger agnosia is studied with non-verbal tasks, no difference can be shown between right and left parietal lesions; -in left brain damaged patients the bilateral form of finger agnosia is generally due to large lesions involving the parietal lobe; -in right brain damaged patients the unilateral form of finger agnosia is almost always due to lesions centered on the parietal region.

Agnosia↗

Pattern of ipsilateral clinical extinction in brain-damaged patients.

A test of double tactile simultaneous stimulation was given to 212 patients affected by focal (178) or diffuse (34) cerebral lesions to study the order of dominance between face, hand, and foot. Both in focal and in diffuse brain-damaged patients, a striking dominance of the face over the hand and foot was found. No significant difference between hand and foot was seen, but a mild prevalence of the foot over the hand was suggested by a cumulative analysis of our results. These findings do not support the hypothesis of a continuous downward gradient of dominance from rostral to caudal regions of the body.

Brain Damage, Chronic↗

Isolated amnesia with slow onset and stable course, without ensuing dementia: MRI and PET data and a six-year neuropsychological follow-up.

Patient EDS presented with an amnesic disorder of insidious onset (4 years) that remained stable and restricted to memory functions over a 10-year course. Repeated neuropsychological evaluations over 6 years showed a moderate-to-severe, stable impairment of long-term memory and of memory for public events, and a milder, stable impairment of autobiographic memory and of short-term memory. Language, perception, praxis and 'frontal' functions were fully preserved. MRI showed atrophy of the right hippocampus, of the right mammillary body and of the sylvian fissure (bilaterally, but more marked on the left). On PET scan, metabolic activity in the mesial temporal structures was significantly reduced on the right and was at lower normal levels on the left. The disorder observed in EDS is similar to that recently reported in other patients. Possible etiologies of the selective amnesia observed in EDS are considered and their implications discussed.

Age of Onset↗