Effects of sleep deprivation on cortical excitability in patients affected by juvenile myoclonic epilepsy: a combined transcranial magnetic stimulation and EEG study

Transcranial magnetic stimulation, since its introduction in 1985, has brought important innovations to the study of cortical excitability as it is a non-invasive method and, therefore, can be used both in healthy and sick subjects. Since the introduction of this cortical stimulation technique, it has been possible to deepen the neurophysiological aspects of motor activation and control. In this narrative review, we want to provide a brief overview regarding TMS as a tool to investigate changes in cortex excitability in athletes and highlight how this tool can be used to investigate the acute and chronic responses of the motor cortex in sport science. The parameters that could be used for the evaluation of cortical excitability and the relative relationship with motor coordination and muscle fatigue, will be also analyzed. Repetitive physical training is generally considered as a principal strategy for acquiring a motor skill, and this process can elicit cortical motor representational changes referred to as use-dependent plasticity. In training settings, physical practice combined with the observation of target movements can enhance cortical excitability and facilitate the process of learning. The data to date suggest that TMS is a valid technique to investigate the changes in motor cortex excitability in trained and untrained subjects. Recently, interest in the possible ergogenic effect of non-invasive brain stimulation in sport is growing and therefore in the future it could be useful to conduct new experiments to evaluate the impact on learning and motor performance of these techniques.

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Low frequency transcranial magnetic stimulation in subacute ischemic stroke: Number of sessions that altered cortical excitability

Neurorehabilitation ◽

10.3233/nre-203156 ◽

2020 ◽

Vol 47 (4) ◽

pp. 427-434

Author(s):

Mohammed S. El-Tamawy ◽

Moshera H. Darwish ◽

Saly H. Elkholy ◽

Engy BadrEldin S. Moustafa ◽

Shimaa T. Abulkassem ◽

...

Keyword(s):

Ischemic Stroke ◽

Transcranial Magnetic Stimulation ◽

Physical Therapy ◽

Upper Limb ◽

Magnetic Stimulation ◽

Cortical Excitability ◽

Low Frequency ◽

Cortical Reorganization ◽

Therapy Program ◽

Physical Therapy Program

BACKGROUND: Cortical reorganization between both cerebral hemispheres plays an important role in regaining the affected upper extremity motor function post-stroke. OBJECTIVES: The purpose of the current study was to investigate the recommended number of contra-lesion low frequency repetitive transcranial magnetic stimulation (LF-rTMS) sessions that could enhance cortical reorganization post-stroke. METHODS: Forty patients with right hemiparetic subacute ischemic stroke with an age range between 50–65 yrs were randomly assigned into two equal groups: control (GA) and study (GB) groups. Both groups were treated with a selected physical therapy program for the upper limb. Sham and real contra-lesion LF-rTMS was conducted for both groups daily for two consecutive weeks. Sequential changes of cortical excitability were calculated by the end of each session. RESULTS: The significant enhancement in the cortical excitability was observed at the fourth session in favor of the study group (GB). Sequential rate of change in cortical excitability was significant for the first eight sessions. From the ninth session onwards, no difference could be detected between groups. CONCLUSION: The pattern of recovery after stroke is extensive and not all factors could be controlled. Application of LF-rTMS in conjugation with a selected physical therapy program for the upper limb from four to eight sessions seems to be efficient.

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A commonSCN1Asplice-site polymorphism modifies the effect of carbamazepine on cortical excitability-A pharmacogenetic transcranial magnetic stimulation study

Epilepsia ◽

10.1111/epi.12515 ◽

2014 ◽

Vol 55 (2) ◽

pp. 362-369 ◽

Cited By ~ 21

Author(s):

Katja Menzler ◽

Anke Hermsen ◽

Katharina Balkenhol ◽

Caroline Duddek ◽

Hannes Bugiel ◽

...

Keyword(s):

Transcranial Magnetic Stimulation ◽

Magnetic Stimulation ◽

Cortical Excitability

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EEG recording after sleep deprivation in a series of patients with juvenile myoclonic epilepsy

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2005000300003 ◽

2005 ◽

Vol 63 (2b) ◽

pp. 383-388 ◽

Cited By ~ 17

Author(s):

Nise Alessandra de Carvalho Sousa ◽

Patrícia da Silva Sousa ◽

Eliana Garzon ◽

Américo C. Sakamoto ◽

Nádia I.O. Braga ◽

...

Keyword(s):

Sleep Deprivation ◽

Diagnostic Delay ◽

Quantitative Eeg ◽

Juvenile Myoclonic Epilepsy ◽

Myoclonic Epilepsy ◽

Mean Delay ◽

Epileptiform Discharges ◽

Number Of Patients ◽

Syndromic Diagnosis ◽

Eeg Recordings

Seizures in Juvenile Myoclonic Epilepsy (JME) are dependent on the sleep-wake cycle and precipitant factors, among which sleep deprivation (SD) is one of the most important. Still an under diagnosed syndrome, misinterpretation of the EEGs contributes to diagnostic delay. Despite this, a quantitative EEG investigation of SD effects has not been performed. We investigated the effect of SD on EEGs in 41 patients, aged 16-50 yr. (mean 25.4), who had not yet had syndromic diagnosis after a mean delay of 8.2 yr. Two EEG recordings separated by a 48-hour interval were taken at 7 a.m. preceded by a period of 6 hours of sleep (routine EEG) and after SD (sleep-deprived EEG). The same protocol was followed and included a rest wakefulness recording, photic stimulation, hyperventilation and a post-hyperventilation period. The EEGs were analyzed as to the effect of SD on the number, duration, morphology, localization and predominance of abnormalities in the different stages. A discharge index (DI) was calculated. Out of the 41 patients, 4 presented both normal EEG recordings. In 37 (90.2%) there were epileptiform discharges (ED). The number of patients with ED ascended from 26 (70.3%) in the routine EEG to 32 (86.5%) in the sleep-deprived exam. The presence of generalized spike-wave and multispike-wave increased from 20 (54.1%) and 13 (35.1%) in the first EEG to 29 (78.4%) and 19 (51.4%) in the second, respectively (p<0.05 and p<0.01). As to localization, the number of generalized, bilateral and synchronous ED increased from 21 (56.8%) to 30 (81.1%) (p<0.01). The DI also increased; while 8 patients (21.6%) presented greater rate in the routine EEG, 25 (67.6%) did so in the sleep-deprived EEG mainly during somnolence and sleep (p<0.01). Moreover, the paroxysms were also longer in the sleep-deprived EEG. Sleep-deprived EEG is a powerful tool in JME and can contribute significantly to the syndromic characterization of this syndrome.

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