In 18 out of 164 consecutive patients with carpal tunnel syndrome ongoing spontaneous rhythmic motor unit potentials were found in the lateral thenar muscles. The frequency ranged from 3 to 9 Hz with an average of 6 Hz. The spontaneous rhythmic motor unit potentials appeared to be doublets in many cases. Ischaemia usually caused a marked increase of spontaneous activity within 1 to 2 minutes. D...

SYNOPSIS An on-line computer method is described for the isolation of single motor unit potentials, evoked by stimulation of the anterior tibial nerve at the ankle, from the compound action potential recorded from surface electrodes over the extensor digitorum brevis muscle. The latencies, durations, amplitudes, and areas of the potentials were measured in a group of control subjects and patien...

Recent advances in the technology of recording magnetic fields associated with electric current flow in biological tissues have provided a means of examining action currents that is more direct and possibly more accurate than conventional electrical recording. Magnetic recordings are relatively insensitive to muscle movement, and, because the recording probes are not directly connected to the t...

Use-dependent facilitation of motor-evoked potentials evoked by transcranial magnetic stimulation with repetition of simple movements has been well established. Motor-evoked potentials were recorded from two intrinsic hand muscles before and after blocks of motor practice in which study participants made repeated ballistic pinch responses with either their left or their right hand. Despite simi...

Pathologic progression in amyotrophic lateral sclerosis (ALS) results from motor neuron death, while the clinical expression also reflects the compensatory effects of collateral reinnervation consequent to lower motor neuron loss. In a cross-sectional study of ALS subjects, we made comparisons between motor unit number estimation (MUNE) values and several measures reflecting collateral reinnerv...

We have identified an inhibitory neuron (RPL4) in the right pleural ganglion of Aplysia, which produced hyperpolarization of the sensory and motor neurons involved in the tail withdrawal reflex. Activation of RPL4 significantly reduced the amplitude of excitatory postsynaptic potentials produced in tail motor neurons by action potentials triggered in sensory neurons. This example of heterosynap...