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Biomedical subjects

C Monaca

Publications and source records attributed to C Monaca.

9 recordsLinked to original sources
PubMed2006

The effect of repetitive transcranial magnetic stimulation on dystonia: a clinical and pathophysiological approach.

Dystonia is characterized by sustained muscle contraction, which frequently causes repetitive, twisting movements or abnormal posture. The precise pathophysiological mechanisms of dystonia are still unknown. Several studies did demonstrate that, although motor cortex hyperexcitability appears to be responsible for abnormal co-contraction and overflow to adjacent muscles, plasticity mechanisms and integrative sensorimotor processing are also likely to be involved in this condition. Current dystonia treatments are based on oral medication, injection of botulinum toxin and, in a low proportion of cases, bi-pallidal deep brain stimulation. However, treatment outcome is generally disappointing. A few researchers have reported the application of repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex or the premotor cortex, with the goal of decreasing motor cortex hyperexcitability. This article reviews all studies using this technique in dystonia and discusses rTMS therapeutic impact and its possible mechanisms of action in this indication. Currently, the premotor cortex seems to be the best target for rTMS in dystonia. Rather than merely reducing the hyperexcitability of the primary motor cortex, this technique's clinical benefit seems to result from modifications in plasticity and restoration of sensorimotor integration. The corollary technique for chronic rTMS is electrical cortical stimulation. Even though this new therapeutic tool may have therapeutic promise, more studies are required to confirm it. In particular, we need to broaden our knowledge of rTMS impact on the various forms of dystonia and to optimize target localization.

Dystonia↗
PubMed2006

Vigilance troubles in Parkinson's disease: a subjective and objective polysomnographic study.

BACKGROUND AND PURPOSE: To assess the prevalence of vigilance disorders in Parkinson's disease patients, relate the observed phenomena to potential causes and confirm these troubles with polysomnographic analysis. PATIENTS AND METHODS: A questionnaire was used to gather information on demographic data, previous and current treatments, disease characteristics, sleep and vigilance troubles. Somnolence was measured using the Epworth Sleepiness Scale (ESS). Nocturnal polysomnography (PSG) and multiple sleep latency tests (MSLT) were performed for a sample of parkinsonian patients. RESULTS: Two hundred twenty-two parkinsonian patients completed the questionnaire, and 36 patients had objective analyses. Of the patients, 43.2% had an ESS score >10, and 28.4% reported somnolence in the hour after taking dopaminergic drugs, whereas 6.8% reported unintended sleep episodes. In view of questionnaire data, these vigilance disorders may be partly explained not only by the impact of nocturnal sleep disorders (e.g. sleep apnea syndromes) but also by dopaminergic therapy (especially with dopaminergic agonists). With PSG and MSLT results, we have shown a significant correlation between mean sleep latency and ESS score. Patients with unintended sleep episodes have severe sleepiness in MSLT compared with others patients. CONCLUSIONS: Vigilance disorders are frequently observed in Parkinson's disease. We recommend informing patients of the risk of occurrence of such conditions, notably for patients with unintended sleep episodes and with sleepiness in the hour after taking dopaminergic drugs.

Aged↗
PubMed2004

Effects of bilateral subthalamic stimulation on sleep in Parkinson's disease.

OBJECTIVE: Sleep disturbances are frequently observed in Parkinson's disease (PD). Bilateral chronic subthalamic nucleus (STN) stimulation is an alternative treatment for advanced PD. Improvements in motor disturbances after STN stimulation are well documented and seem to be associated with better sleep quality, even though the objective effect on sleep structure remains unclear. We have therefore studied the sleep/wakefulness cycle before and after surgical treatment in 10 consecutive parkinsonian patients. METHODS: Subjective sleep quality and sleep recordings were evaluated one month before and three months after initiation of STN stimulation. After surgery, the recordings were performed under two conditions: with stimulation (the "on" condition) and-if patients had given their consent-in the absence of stimulation (the "off" condition). RESULTS: With STN stimulation, subjective and objective sleep qualities were improved. Total sleep time, sleep efficiency and the durations of deep slow wave sleep and paradoxical sleep increased significantly. When stimulation was absent, sleep disturbances were similar to those observed before surgery. CONCLUSION: Chronic STN stimulation is associated with a sleep improvement, which can be explained in part by the concomitant decrease in motor disturbances but also by the reduction in dosages of antiparkinsonian medication. However, we can not exclude a direct effect of STN stimulation on sleep regulatory centres.

Aged↗
PubMed2004

[Management of restless legs and periodic movements of sleep].

INTRODUCTION: Restless legs syndrome and periodic leg movements in sleep are frequently observed, often in association. Misdiagnosis of these two conditions is common. STATE OF ART: Physical examination can provide the diagnosis of restless legs syndrome but polysomnography recording must be performed to confirm the presence of periodic leg movements. Dopaminergic pathways are implicated in the pathophysiology of these two syndromes and the same treatment is given: dopaminergic agents, benzodiazepines, opioids and/or antiepileptic drugs. PERSPECTIVES AND CONCLUSION: Treatment provides an improvement in quality-of-life for these patients.

Anticonvulsants↗
PubMed2001

Does post-movement beta synchronization reflect an idling motor cortex?

After the completion of a voluntary movement, a synchronization of cortical beta rhythms is recorded over the contralateral central region, which is assumed to reflect the termination of the motor command. In order to test this hypothesis, we compared in eight healthy subjects the synchronization of EEG beta rhythms following active and passive index extension. The passive movement was also performed after deafferentation by ischaemic nerve block in three subjects. Beta synchronization was present in all subjects after both active and passive movements, and disappeared under ischaemia in all three subjects. Post-movement beta synchronization can not solely be explained by an idling motor cortex. It may also, at least in part, reflect a movement-related somatosensory processing.

Adult↗
PubMed2001

Relationship between leuko-araiosis and blood pressure variability in the elderly.

Although leuko-araiosis is a common finding on computed tomographic (CT) scans of the brain, its pathogenesis remains uncertain. To investigate the association between blood pressure (BP) disturbances and leuko-araiosis, we retrospectively reviewed CT scans and 24-hour ambulatory blood pressure monitorings of 79 elderly patients (57 women and 22 men; mean age: 83.3 +/- 6.4 years). Of the 79 patients, 50 were demented (30 had Alzheimer's disease and 18 vascular dementia) and 29 were not demented. The leuko-araiosis score (LA score) was determined by using Rezek's scale. To evaluate short-term variation of BP, we determined (1) the variability of systolic and diastolic BPs (SBP, DBP; within-subject standard deviation of all readings over a 24-hour period), (2) the coefficient of variability (variability of BP/mean BP) and (3) the maximal variation of BP (difference between the maximum and minimum 24-hour BPs). Higher LA scores were associated with higher SBPs in 24-hour, diurnal and nocturnal periods, higher maximal variation of SBP, greater variability of SBP during 24-hour, diurnal and nocturnal periods and greater coefficient of variability of SBP during sleep. Our study suggests that elevations and short-term variations of SBP may contribute to the pathogenesis of white matter lesions in elderly persons.

Aged↗