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Biomedical subjects

J Kulisevsky

Publications and source records attributed to J Kulisevsky.

At least 55 records · Page 3Linked to original sources
PubMed1996

Acute effects of levodopa on neuropsychological performance in stable and fluctuating Parkinson's disease patients at different levodopa plasma levels.

The contribution of dopaminergic systems to cognitive defects in Parkinson's disease and the cognitive effects of levodopa remain controversial. The levodopa plasma levels and the neuropsychological performance of 10 parkinsonian patients with a stable motor response to the drug and 10 matched parkinsonian patients with a 'wearing-off' phenomenon were studied 12 h after levodopa was withdrawn (time zero), and at 1 h and 4 h after an oral dose of levodopa (i.e. at '+1H' and '+4H'), to investigate whether discrete cognitive domains are more sensitive to levodopa in parkinsonian patients with the wearing-off phenomenon. Considering the 20 patients as a whole, levodopa significantly diminished the response time in verbal and visuospatial memory tests, the extradimensional matching test and the Wisconsin card sorting test (WCST), without significantly improving or worsening the patient's accuracy. A significant group-by-time effect was only evident in the WCST; while in stable patients levodopa produced no changes, wearing-off patients significantly reduced the number of categories achieved and had more perseverative errors at +1H, recovering at +4H. These results confirm previous findings of selective adverse effects of levodopa on highly demanding executive tasks in Parkinson's disease and additionally suggest that some previous discrepancies between studies may be accounted for by lack of differentiation between stable and wearing-off conditions. 'Frontal' disturbances on neuropsychological tests with levodopa may become evident only after massive degeneration of the dopamine systems has occurred.

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PubMed1996

Frontal lobe activation during word generation studied by functional MRI.

AIMS: To further delimit the specific verbal operations occurring in the dorsolateral frontal cortex during the generation of words. METHODS: Different verbal fluency tasks guided by distinct specifications (phonological, semantic, or automatic production of words) were used in a functional magnetic resonance study. The study group comprised 10 right-handed normal subjects ranging in age from 23 to 27 years. Functional magnetic resonance images were obtained in a 1.5-Tesla magnet using a spoiled GRASS sequence. RESULTS: Noticeable activation was found during the word generation tasks in the dorsolateral frontal cortex. The region showing the most prominent activation was the posterior part of the left middle frontal gyrus. Nevertheless, the different tasks each had a different activation effect. The phonologically guided generation of words produced the most consistent activation of the middle frontal gyrus, which mainly involved the premotor cortex. CONCLUSION: The results suggest that operations concerned with the generation of sound sequences, rather than the amount of produced words or their semantics, are responsible for sustained focal activity observed in the frontal lobes during verbal fluency tasks.

Adult↗
PubMed1996

Poststroke bipolar affective disorder: clinical subtypes, concurrent movement disorders, and anatomical correlates.

The authors describe 9 patients with bipolar affective disorder associated with cerebrovascular lesions. Eight had negative family histories of affective disorders and late age at onset (after age 40) of manic-depressive symptoms. Only one, with positive family history of affective disorders, developed mood swings before age 40. Clinical subtypes of bipolar disorder and patterns of affective cycling in these stroke patients resembled those previously reported in functional bipolar disorder. Five patients had concurrent hyperkinetic movement disorders, and one depressed patient presented with unilateral left-sided parkinsonism that disappeared during a manic switch. In most patients, bipolar affective disorder was associated with right hemisphere lesions that involved subcortical and midline structures. Findings suggest that damage to frontal-basal ganglia-thalamocortical circuits by subcortical vascular lesions may simultaneously provoke disorders of movement and mood regulation.

Adult↗
PubMed1996

Obsessive-compulsive disorder associated with brain lesions: clinical phenomenology, cognitive function, and anatomic correlates.

We studied the behavioral, cognitive, and neuroimaging characteristics of obsessive-compulsive disorder (OCD) in 13 patients with focal brain lesions (acquired OCD) and compared their clinical features and the severity of obsessive and compulsive (OC) symptoms with patients with idiopathic OCD. Both OCD groups were further compared with matched normal controls on a series of neuropsychological tests. Patients with acquired OCD had a negative familial history and later age at onset of OCD symptoms than patients with idiopathic OCD. The two OCD groups showed relatively similar clinical phenomenology, severity of OC symptoms, and profile of neuropsychological deficits. Compared with normal control subjects, both OCD groups showed cognitive deficits affecting attention, intellectual function, memory, word retrieval, and motor and executive functions. Eight of the 13 patients with acquired OCD had abnormal neurologic examinations, whereas only 3 of the 13 patients with idiopathic OCD had abnormal neurologic examinations. Neuroimaging in the acquired OCD group disclosed a variety of lesions involving exclusively the cerebral cortex (frontal, temporal, or cingulate regions), the basal ganglia, or both. These results suggest that acquired and idiopathic OCDs may share a common pathophysiologic mechanism, and that structural damage to specific frontal-limbic-subcortical circuits plays an important role in the pathogenesis of acquired OCD.

Adult↗
PubMed1996

Neurospectroscopic alterations and globus pallidus hyperintensity as related magnetic resonance markers of reversible hepatic encephalopathy.

In patients with chronic hepatic encephalopathy, proton magnetic resonance spectroscopy can be used to detect specific metabolic abnormalities in the brain; MRI shows a hyperintense globus pallidus on T1-weighted sequences. We investigated the relationship between these two MR findings in a series of 25 patients with the use of quantitative data and a multiple regression analysis model. The cerebral increase in glutamine compounds and the decrease in myoinositol and choline correlated separately with globus pallidus hyperintensity, and each was complementary in accounting for this imaging finding. Such as association suggests that spectroscopic and imaging alterations are two different expressions of the reversible events that occur in the brain of patients with hepatic encephalopathy in that both disappear after liver transplantation. Globus pallidus hyperintensity seems to be a global indicator of the cerebral metabolic disorder, and the spectroscopic pattern denotes the specific metabolic alterations.

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PubMed1996

[Movement disorders and AIDS].

We describe the clinical characteristics, causes and response to treatment in 6 patients with AIDS who presented with abnormal movement disorders between January 1987 and July 1993 in our hospital, 3 with hemiballismus-hemichorea, 1 with athetosis, 1 myoclonia and 1 with "rubric" tremor. Brain imaging showed lesions in the corpus striatum in all the patients. Suspected diagnoses were cerebral toxoplasmosis in 4, cerebral lymphoma in 1 and progressive multifocal leukoencephalopathy in 1. The toxoplasmosis patients showed improvement (2 cases) or disappearance (2 cases) of movements with antiparasitic therapy. Treatment provided no benefit to the patients with leukoencephalopathy and lymphoma. Hemiballismus-hemichorea was the most common movement disorder in AIDS patients. The underlying cause is usually lesions in the basal ganglia arising from toxoplasmosis. If the lesions are so caused, movements may improve with antiparasitic therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Longitudinal evolution of prefrontal leucotomy in Tourette's syndrome.

We report the case of a 69-year-old man with severe Tourette's syndrome (TS) who underwent a bilateral prefrontal leucotomy at the age of 29 years to alleviate coprolalia, copropraxia, and obsessive-compulsive disorder. No improvement was observed during the 5 years after the leucotomy. Tics and associated behavioral abnormalities disappeared thereafter, to recur at age 67. Long-term follow-up of single cases can help to estimate the role of neurosurgery in the treatment of TS.

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PubMed1995

Abnormalities of the Bereitschaftspotential and MRI pallidal signal in non-encephalopathic cirrhotic patients.

In cirrhotic patients, even in the non-encephalopathic state, MRI may show an increased signal in globus pallidus in T1-weighted sequences, the clinical significance of which is still poorly characterized. A dysfunction of the motor circuit of the basal ganglia might be predicted if the increased MRI signal expressed alterations in the globus pallidus activity. We compared the Bereitschaftspotential (BP) in 15 non-encephalopathic cirrhotic patients and 15 age-matched controls and found that the amplitude of the early component and the peak negativity of the BP before the electromyogram onset were significantly reduced in the patient group. The intensity of the pallidal signal was related to the plasma ammonia level but the amplitudes of the BP were not related to the pallidal signal or to ammonia. These findings indicate that a defective activity of the cortical areas implicated in the preparation of movement, not specifically related to the pallidal signal, can be present in cirrhotic patients, even in the non-encephalopathic state.

Adult↗
PubMed1995

Levodopa does not aggravate postural tremor in Parkinson's disease.

Characterization of postural tremor in Parkinson's disease (PD) is incomplete. It was suggested to be an exaggerated physiological tremor and to be enhanced by the action of levodopa. We compared the magnitude of postural tremor to the magnitude of rest tremor and to plasma levodopa levels in 20 PD patients, 10 with stable motor response to oral levodopa, and 10 with the wearing-off phenomenon. Tremor assessment included motor scores of the Unified Parkinson's Disease Rating Scale and accelerometric measurements. Accelerometric data showed that the absolute power of both rest and postural basal dominant tremor frequencies significantly diminished with the increase in plasma levodopa levels and increased with their decrease. Tremor frequencies were also significantly changed by levodopa, which slowed rest tremor and increased postural tremor dominant frequency. This latter, however, did not reach the 8- to 12-Hz frequency band said to be typical of exaggerated physiological tremor. No significant differences between groups were found in their tremor response to levodopa. This study shows that the net postural tremor exhibited by PD patients is improved by levodopa, that levodopa does not augment tremor in the 8- to 12-Hz range, and that this effect is independent of the patient's motor response pattern of oral levodopa.

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PubMed1995

Persistence of MRI hyperintensity of the globus pallidus in cirrhotic patients: a 2-year follow-up study.

We investigated the long-term persistence and short-term stability of globus pallidus (GP) hyperintensity on T1-weighted MRI in 19 cirrhotic patients. After a mean interval of 25.8 months, the hyperintensity of the GP persisted in 17 patients. Hyperintensity disappeared in two patients with hepatocarcinoma, indicating that hyperintensity can revert to normal in circumstances other than liver transplants. Ten patients participated in a 6-month study with repeated evaluations of GP signal intensity, plasma ammonia levels, and selected neuropsychological tests. The GP signal was fairly stable during the follow-up, and the variables considered maintained significant relationships. GP hyperintensity appears as a stable indicator of the functional status of cirrhotic patients.

Adult↗
PubMed1995

Motion of the cerebellar tonsils in Chiari type I malformation studied by cine phase-contrast MRI.

We studied the effects on CSF dynamics at the foramen magnum and the clinical significance of the abnormal tonsillar motion in 14 patients with Chiari type I malformation and 14 control subjects using cine phase-contrast MRI. Dynamic MRI consisted of axial and sagittal cine phase-contrast sequences. CSF and tonsillar motion were qualitatively and quantitatively evaluated, and the subarachnoid space at the foramen magnum measured. In Chiari patients, cine phase-contrast MRI detected the abnormal pulsatile motion of the cerebellar tonsils, which produced a selective obstruction of CSF flow from the cranial cavity to the spine. The amplitude of the tonsillar pulsation and the severity of the arachnoid space reduction were associated with the symptom of cough-strain headache, but not with the presence of syringomyelia. The finding of abnormal valve dynamics of the cerebellar hernia revealed by cine phase-contrast MRI conforms to the pathophysiologic mechanisms suggested in pressure register studies and opens a new possibility in the presurgical assessment of Chiari patients with exertional symptoms.

Adult↗
PubMed1994

Double-blind trial of flumazenil in hemiballismus.

Three patients with hemiballismus received intravenous flumazenil and placebo in a double-blind cross-over study aimed to investigate whether an antagonistic action at the level of the GABA-benzodiazepine receptors may improve choreoballistic movements. No clinical benefit was seen.

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