110 research outputs found
Combining entacapone with levodopa/DDCI improves clinical status and quality of life in Parkinson's Disease (PD) patients experiencing wearing-off, regardless of the dosing frequency: results of a large multicentre open-label study.
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Pitiríase rubra pilar
No full textTrabalho de Conclusão de Curso - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Departamento de Clínica Médica, Curso de Medicina, Florianópolis, 200
DIFFERENTIAL ACTIVATION OF MOTOR UNITS IN THE WRIST EXTENSOR MUSCLES DURING THE TONIC VIBRATION REFLEX IN MAN
No full textInternational audience1. Single motor unit activity was recorded in the extensor carpi radialis longus and extensor carpi radialis brevis muscles of five healthy human subjects, using metal microelectrodes. 2. Motor units were characterized on the basis of their twitch contraction times and their force recruitment thresholds during voluntary imposed-ramp contractions. 3. The discharge patterns of forty-three motor units were studied during tonic vibration reflex elicited by prolonged (150 s) trains of vibration (30 Hz) applied to the distal tendons of the muscles. The temporal relationships between the individual small tendon taps of the vibratory stimulus and the motor unit impulses were analysed on dot raster displays and post-stimulus time histograms. 4. After tendon taps, the impulses of motor units with long twitch contraction times (mean +/- S.D., 47.2 +/- 10.7 ms) and low recruitment thresholds (0.88 +/- 0.6 N) formed a single narrow peak (P1) with a latency (22.7 +/- 1.4 ms) which was comparable to that of the tendon jerk in the extensor carpi radialis muscles. These motor units were named `P1 units'. On the other hand, the response of motor units with shorter twitch contraction times (31.1 +/- 3.3 ms) and higher recruitment thresholds (3.21 +/- 1.3 N) showed two peaks: a short latency (23.4 +/- 1.3 ms) P1 peak similar to the previous one and a P2 peak occurring 9.4 +/- 1.2 ms later. These motor units were named `P1-P2 units'. 5. When the reflex contraction increased slowly, the P1 peaks of `P1-P2 units' were clearly predominant at the beginning of the contraction, during the rising phase of the motor unit discharge frequency, while the P2 peaks became predominant when the units had reached their maximal discharge frequency. 6. Increasing the tendon vibration frequency (35, 55, 75, 95 Hz) did not modify the `P1 unit' discharge pattern. Due to interference between vibration period and peak latencies, increasing the vibration frequency caused the P1 and P2 peaks of `P1-P2 units' to overlap. 7. Superficial cutaneous stimulation of the dorsal side of the forearm during tendon vibration noticeably decreased the P1 peaks in both types of motor units. In the P2 peaks it could result in either a decrease or an increase but the average effect was a slight increase. 8. When applied 10 s before tendon vibration, cutaneous stimulation considerably suppressed the tonic vibration reflex. 9. The nature of the pathways mediating the P1 and P2 peaks and the effects of cutaneous stimulation are discussed in relation to data obtained from both animal and human experiments. The hypothesis is put forward that during the tonic vibration reflex, the slow and fast motor units are differentially activated on the basis of either a monosynaptic reflex process or mono- and polysynaptic processes, respectively. It is suggested that the monosynaptic pathway plays a major role in tonic vibration reflex initiation at the onset of the tendon vibration and plays a significant role during a maintained reflex contraction. This is contrary to what was previously thought to be the case
Joseph Plenck (1735-1807): autor do primeiro livro de Dermatologia Joseph Plenck (1735-1807): author of the first textbook on Dermatology
No full textWilson Fonseca: crendices e lendas amazônicas para canto e piano
No full textThis paper discusses Wilson Fonseca, one of the most important composers of our Amazon region, due to its history and dedication of a lifetime for music and our culture, being a reference not only in the music field, but also in memory and redemption of history and culture of Santarem. Amazonian legends and superstitions for voice and piano, a topic addressed in this research, is just one of many faces which portrayed the author in his extensive music production.O presente trabalho fala sobre Wilson Fonseca, um dos compositores mais importantes da nossa região amazônica, devido a sua trajetória e dedicação de uma vida inteira a favor da música e da nossa cultura, sendo uma referência não somente no campo musical, mas também na memória e resgate da história e cultura santarena. Crendices e lendas amazônicas para canto e piano, temática abordada nessa pesquisa, é apenas uma das várias faces a qual o autor retratou em sua extensa produção musical
Resonance in subthalamo-cortical circuits in Parkinson's disease
No full textNeuronal activity within and across the cortex and basal ganglia is pathologically synchronized, particularly at 20 Hz in patients with Parkinson's disease. Defining how activities in spatially distributed brain regions overtly synchronize in narrow frequency bands is critical for understanding disease processes like Parkinson's disease. To address this, we studied cortical responses to electrical stimulation of the subthalamic nucleus (STN) at various frequencies between 5 and 30 Hz in two cohorts of eight patients with Parkinson's disease from two different surgical centres. We found that evoked activity consisted of a series of diminishing waves with a peak latency of 21 ms for the first wave in the series. The cortical evoked potentials (cEPs) averaged in each group were well fitted by a damped oscillator function (r 0.9, P < 0.00001). Fits suggested that the natural frequency of the subthalamo-cortical circuit was around 20 Hz. When the system was forced at this frequency by stimulation of the STN at 20 Hz, the undamped amplitude of the modelled cortical response increased relative to that with 5 Hz stimulation in both groups (P 0.005), consistent with resonance. Restoration of dopaminergic input by treatment with levodopa increased the damping of oscillatory activity (as measured by the modelled damping factor) in both patient groups (P 0.001). The increased damping would tend to limit resonance, as confirmed in simulations. Our results show that the basal ganglia–cortical network involving the STN has a tendency to resonate at 20 Hz in Parkinsonian patients. This resonance phenomenon may underlie the propagation and amplification of activities synchronized around this frequency. Crucially, dopamine acts to increase damping and thereby limit resonance in this basal ganglia–cortical networ
Aspects électrophysiologiques des méningoradiculoneuropathies aiguës dans les infections par herpès virus
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