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Biomedical subjects

A Capon

Publications and source records attributed to A Capon.

At least 37 records · Page 2Linked to original sources
PubMed1991

Remote cortical dysfunction in aphasic stroke patients.

We studied the effect of deep-seated left hemispheric lesions on cortical blood flow in 18 right-handed aphasic stroke patients. Regional cerebral blood flow was measured at rest and during the performance of a functional naming test using the two-dimensional xenon-133 inhalation method. Compared with 10 controls, at rest the patients showed regional cortical hypoperfusion in the left frontoparietal region. In the controls, activation patterns from the rest to the test condition involved mainly the left hemisphere areas. In the patients, a lack of blood flow change was observed in several areas that were usually hypoperfused at rest. However, in patients with slight verbal expression disorders there were obvious blood flow increases in other brain regions in both hemispheres. Such cortical functional reorganization and the presence of a remote cortical dysfunction could play a role in the pathophysiology of language disorders.

Aged↗
PubMed1991

[Cerebral crossed diaschisis caused by cerebellar lesion: role of the cerebellum in mental functions].

In 3 patients with a stroke limited to the posterior fossa, regional cerebral blood Flows were measured by the 133 Xe inhalation method (the first two cases) or by the SPECT with HMPAO method (the third case). The first patient had a median and paramedian hematoma of the left cerebellar hemisphere and the left dorsolateral portion of the pons. Remote cerebral hypoperfusion, measured 3 months later, was observed in both frontal premotor regions (but more marked in the right hemisphere) and in a circumscribed area of the right temporal region. The second patient had a right-sided ischaemic lesion of the anterior cerebellar lobe and the mesencephalic tectum. Contralateral parietal and rolandic hypoperfusion, measured 7 weeks after the stroke, was observed. The third patient had on old infarct of the right cerebellar hemisphere. The SPECT, measured 17 years later, showed a left fronto-parieto-temporal hypoperfusion and the absence of perfusion in the right cerebellar hemisphere. Preliminary data of neuropsychological assessment in our patients disclosed impairment in visuo-spatial and constructive organization, memory and learning compatible with the published findings in some patients and animals with predominantly cerebellar damage. These interesting findings should be confirmed in a large number of patients with age, sex, and sociocultural matched controls. In the absence of supratentorial insult, and during the hemodynamical stable phase, crossed cerebello-cerebral diaschisis is suggested in our 3 patients. Although it is too early to draw definite conclusions, our findings may: (1) confirm the functional interconnections between the cerebellum and the cerebrum in man and (2) provide functional basis for the behavioral function impairment reported in patients with cerebellar insult. Further rCBF, metabolism, and pathologic studies on this subject are required to elucidate this issue.

Cerebellar Diseases↗
PubMed1990

Pathogenesis of aphasia in deep-seated lesions: likely role of cortical diaschisis.

In order to study the pathophysiology of language disorders due to deep-seated left-hemisphere lesions not involving the cortex, a population of 43 right-handed stroke patients (29 aphasic) presenting with such lesions was studied clinically and by regional cerebral blood flow measurements (two-dimensional xenon-133 inhalation method). Most of the patients were studied sequentially between the 1st and 3rd months after stroke. Cortical diaschisis did not account for the whole clinical picture: the remote effect on the cortex could explain the occurrence of aphasia and its severity but not the type of aphasia. Furthermore, the clinical improvement observed in most cases was not accompanied by the disappearance of the diaschisis.

Adult↗
PubMed1990

Remote effect of deep-seated vascular brain lesions on cerebral blood flow.

We measured regional cerebral blood flow using the xenon-133 inhalation method, at approximately 1 month after onset, in 60 stroke patients who had no evidence of major carotid artery stenosis or occlusion. Their single lesions (43 infarcts and 17 hematomas) were located in the capsulothalamolenticular region, sparing the cortex. Hemispheric mean cerebral blood flow was reduced on the side of the lesion in 25 patients and on both sides in 20. Regional hypoperfusion was observed in 46 patients (ipsilaterally in 34, bilaterally in 10, and contralaterally in two). Regional hypoperfusion was observed most frequently in the frontal lobe, particularly in the motor and premotor cortices of the prerolandic area. The 46 patients with regional hypoperfusion were compared with the 14 patients without regional hypoperfusion, considering the size and location of the lesion as well as the functional and analytic motor performances. As a rule, the lesion was slightly smaller and more posterior and the functional (p less than 0.001) and analytic (p less than 0.05) motor performances were significantly better in the 14 patients without regional hypoperfusion. Since the xenon-133 inhalation method examines cortical blood flow, we can attribute blood flow reductions resulting from deep-seated lesions to a functional depression akin to diaschisis. Interpretation of the clinical consequences and pathogenesis of this phenomenon requires further sequential and pathologic studies.

Administration, Inhalation↗
PubMed1990

Naftidrofuryl in the treatment of subacute stroke.

In a placebo-controlled, double-blind study, 82 patients in the subacute stage of a disabling stroke were studied to assess the effect on clinical improvement of 600 mg naftidrofuryl against placebo. Forty-two patients were treated with the drug and 40 with placebo, in each case administered for 60 days. All patients received 100 mg aspirin and 300 mg dipyridamole daily and entered a similar program of rehabilitation therapy. At the start and the end of the study, the motor functions of the upper and lower limbs, the ability to walk and to perform daily activities, the comprehension and expression of speech, and the mental progress were assessed with quantitative linear scales. In the group treated with active drug, a greater overall tendency of improvement was observed, reaching statistically significant levels for walking and activities of daily life when compared to placebo-treated patients. Overall improvement was negatively influenced by advancing age, but the statistically significant effect of treatment on walking and daily activities was not interfered with by age. Right-sided lesions showed better improvement under active drug than left-sided lesions. This may be due to a correctional effect of naftidrofuryl on hemispatial neglect.

Acute Disease↗
PubMed1989

Evidence of cortical reorganization in hemiparetic patients.

We studied the mechanisms underlying the recovery of motor function of the hand using a bidimensional xenon-133 inhalation technique to measure regional cerebral blood flow at rest and during the performance of a motor task (test condition). The regional cerebral blood flow patterns under rest and test conditions were compared in normal control and in stroke patients with either a cortico-subcortical or a deep-seated lesion. Functional recovery appears to depend upon cortical reorganization involving both hemispheres, particularly in both parietal regions in the subgroup of patients with cortico-subcortical lesions.

Adult↗
PubMed1986

Assessment of hemispheric dominance for language in crossed aphasia by two atraumatic methods.

In a right handed patient with crossed aphasia, two atraumatic techniques (regional cerebral blood flow measurements during the performance of a linguistic task and dichotic listening test) were used to assess language lateralization. The prominence of rCBF activation patterns in the right hemisphere and the presence of a clear-cut right ear extinction on the dichotic listening test provide evidence that, is this case, the right hemisphere was dominant for language.

Aged↗
PubMed1985

Prognostic value of computed tomography in aphasic stroke patients.

In order to evaluate the prognostic value of CT scan in aphasic stroke patients, a prospective study was performed during the first 3 months of the disease. The severity of the language disorders was assessed by means of a quantitative method. In cortico-subcortical lesions, the verbal expression recovery rate and the final verbal expression and comprehension status depended on the infarct size. No relation was observed between the latter and the verbal comprehension recovery rate. In deep-seated lesions, computed tomography provided no information concerning the prognosis.

Aged↗
PubMed1984

Resting CBF sequential study during recovery from aphasia due to ischemic stroke.

Cerebral blood flow (133Xenon inhalation method) has been studied in 30 aphasic stroke patients at 15, 30, 60 and 90 days after onset. In total aphasia the CBF values are low and the regional hypoperfused areas are extensive. In Broca's, Wernicke's and nominal aphasias, resting CBF measurements do not provide the clinician with useful additional information and clinical improvement can by no means be attributed to a resting CBF rise during the observation period.

Adult↗
PubMed1979

Early diagnosis of multiple sclerosis by combined multimodal evoked potentials: results and practical considerations.

It is shown that using four combined types of evoked potentials one can disclose new localisations in 62.5% of as yet undiagnosed M.S. patients. Brainstem auditory EP recordings must be considered in detail to avoid missing slight anomalies. Blink reflexes yielding bilateral R1 seem to bear the same significance as an augmented latency with respect to the problem of disclosing new localisations.

Brachial Plexus↗
PubMed1979

Study of two cases of aphasia by infarction of the left thalamus, without cortical lesion.

Two patients suffering from a left thalamus infarct were studied over a long period. The precise location of the lesion has been demonstrated by the C.T. scan. In spite of the absence of any cortical lesion, both presented with aphasia and other neuropsychological disorders (left-right confusion, dyscalculia and possible finger agnosia). Their speech disorders although different, had several features in common. The observations were compared with the other cases reported in the literature.

Aged↗
PubMed1976

Changes in regional cerebral blood flows produced by dexamethasone in patients with brain metastases.

Four patients suffering from brain metastases were studied by brain scintigraphy carotid angiography and rCBF measurement, before and after one week of treatment with dexamethasone. It was noted that the neurological signs and the blood perfusion around the tumor were improved but that the volume of the lesion, as judged from the angiogram was unmodified. It is suggested that the corticosteroids reduce tissue pressure before actually diminishing the volume of the brain oedema.

Adult↗