Transcranial magnetic stimulation-electroencephalogram (TMS-EEG) co-registration offers the opportunity to test reactivity of brain areas across distinct conditions through TMS-evoked potentials (TEPs). Several TEPs have been described, their functional meaning being largely unknown. In particular, short-latency potentials peaking at 5 (P5) and 8 (N8) ms after the TMS pulse have been recently d...

Electromyography is best regarded as an extension of the clinical neurological examination and taken outside this context results are often meaningless and dif®cult to interpret. Test design must be based upon the clinical problem if the most comprehensive and valid information with a minimum number of procedures is to be achieved, and predetermined stereotyped protocols should be discouraged. ...

Oscillatory activity plays a crucial role in corticospinal control of muscle synergies and is widely investigated using corticospinal and intermuscular synchronization. However, the neurophysiological mechanisms that translate these rhythmic patterns into surface electromyography (EMG) are not well understood. This is underscored by the ongoing debate on the rectification of surface EMG before ...

Nerve action potentials recorded over the elbow after stimulation of the wrist were studied in patients with hand amyotrophy of different origin. In amyotrophic lateral sclerosis the amplitude of nerve action potentials does not change significantly even with extreme muscle wasting and loss of motor units.Studies of multisegmental afferent conduction velocities may demonstrate a strictly locali...

This study examines the innervation zone (IZ) in the biceps brachii muscle in healthy subjects and those with amyotrophic lateral sclerosis (ALS) using a 20-channel linear electromyogram (EMG) electrode array. Raster plots of individual waveform potentials were studied to estimate the motor unit IZ. While this work mainly focused on fasciculation potentials (FPs), a limited number of motor unit...

Electromyographic studies in five patients suffering from central core disease are presented. A variable amount of late components of motor unit potentials were found in all of them, as others have found in Duchenne muscular dystrophy. This suggests the existence of collateral innervation of the resultant fragments of the muscular fibre splitting present in this disorder.

39 This study investigated the behaviour of motor units in the semispinalis cervicis 40 muscle. Intramuscular EMG recordings were obtained unilaterally at levels C2 and C5 in 15 41 healthy volunteers (7 women) who performed isometric neck extensions at 5, 10, and 20% of 42 the maximal force (MVC) for 2 min each, and linearly-increasing force contractions from 0 to 43 30% MVC over 3 s. Individua...

The gill withdrawal reflex of Aplysia has been used as a model for studying the neuronal mechanisms of habituation, a behavioral plasticity. We have assessed the contribution of neuromuscular facilitation, an elementary synaptic plasticity, during habituation of the reflex by recording gill muscle potentials, which we show are caused by excitatory junctional potentials. These potentials show sy...

Single motor unit potentials recorded from surface electrodes over the extensor digitorum brevis muscle and evoked by stimulation of the anterior tibial nerve at the ankle were obtained by a computer subtraction method. Their latencies, durations, amplitudes, and areas were measured in control subjects and patients with Duchenne, limb-girdle, facioscapulohumeral, and myotonic muscular dystrophy...