ABSTRACT
ABSTRACT The Bereitschaftspotential (BP) is a negative wave observed in EEG retrograde averaging, preceding a motor act. The objective was to study the BP preceding voluntary eyelid blinks in Parkinson's disease (PD) patients during off and on phases of levodopa. Methods Ten PD patients in stages 1 and 2 of the Hoehn & Yahr classification were compared to 18 healthy controls. Artifact-free EEG segments of two seconds preceding the onset of the blink potential were averaged and analyzed, and the statistical significance of the measured amplitudes were evaluated by analysis of variance models. Results The presence of a BP in the PD patients was demonstrated. The mean amplitudes at 0 ms were respectively 0.6 µV and 3.3 µV for the BP patients and the normal controls, respectively. Conclusions The BP amplitudes were significantly smaller in PD patients than normal participants. The amplitudes of the BP were not modified by levodopa.
RESUMO O Potencial de Bereitschafts (PB) é uma onda negativa observada retrogradamente no EEG precedendo um ato motor. Objetivo Estudar o PB precedendo o piscamento palpebral voluntário em pacientes com doença de Parkinson (DP) durante as fases off e on da levodopa. Foram comparados dez pacientes com DP nos estágios 1 e 2 de Hoehn & Yahr com 18 controles saudáveis. Os segmentos de EEG livres de artefatos 2 segundos antes do início do potencial foram calculados e analisados e a significância estatística das amplitudes foi medida por modelos de análise de variância. Resultados A presença de PB nos pacientes com DP foi demonstrada. As amplitudes médias a 0 ms foram respectivamente 0,6 μV e 3,3 μV para os pacientes com DP e controles respectivamente. Conclusões As amplitudes do PB foram significativamente menores nos pacientes com DP do que controles. As amplitudes do PB não foram modificadas pela levodopa.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Blinking/physiology , Levodopa/adverse effects , Contingent Negative Variation/physiology , Motor Cortex/physiology , Movement/physiology , Antiparkinson Agents/adverse effects , Parkinson Disease/physiopathology , Parkinson Disease/drug therapy , Time Factors , Case-Control Studies , Analysis of Variance , Hypokinesia/etiology , Electrodes, Implanted , Electroencephalography , Eyelids/physiologyABSTRACT
BACKGROUND: Fahr's disease (basal ganglia calcification) is characterized by bi hemispherical calcium deposition in basal ganglia, dentate nucleus and semioval center. Its clinical manifestations are a rigid hypokinetic syndrome, mood disorders and cognitive impairment. AIM: To report to the results of a neurological assessment of three siblings with Fahr disease. PATIENTS AND METHODS: Three sisters, aged 55, 56 and 58 years, were studied. All had a rigid hypokinetic clinical picture associated with cerebellar involvement and a cognitive impairment that progressed in 8, 6 and 10 years respectively. Brain CAT scans showed symmetric and extensive calcifications of cerebellar white matter and dentate nuclei, pons, mesencephalon, lenticular nuclei, thalami and semioval centers. Hypoparathyroidism was ruled out. Cognition was assessed with WAIS and Benton tests and Weschler memory scale. The time of reaction to visual stimuli was studied. The processing speed of visual information and the interhemispheric conduction time of such information, were calculated. Cognitive evoked potentials (P 300) were also studied. RESULTS: Cognitive impairment involved verbal and visual-spatial memory, planning, attention and concentration capacities and visual constructive skills. There was a prolongation of reaction time latencies and loss of the normal asymmetry of interhemispheric transmission (without right to left facilitation). P 300 evoked potentials were absent. CONCLUSIONS: These observations suggest that the pathogenesis of cognitive and motor changes in Fahr's disease is based in a dysfunction of cortico basal connections and their interhemispheric relations. This defines a subcortical dementia secondary to mineral deposits in subcortical structures.
Subject(s)
Humans , Female , Middle Aged , Calcinosis/complications , Dementia/etiology , Basal Ganglia Diseases/complications , Hypokinesia/etiology , Cognition Disorders/etiology , Calcinosis/physiopathology , Calcinosis , Dementia , Basal Ganglia Diseases/physiopathology , Basal Ganglia Diseases , Time Factors , Hypokinesia , Siblings , Evoked Potentials, Visual , Tomography, X-Ray Computed , Cognition DisordersABSTRACT
We describe a patient whose initial manifestation of Parkinson's disease was a malfunctioning of a self-winding wristwatch secondary to bradykinesia of his left arm. Andrade and Ferraz reported this sign in 1996, suggesting that it be called the Rolex sign