Influence of activity-induced axonal hypoexcitability on transmission of descending and segmental signals.

In this experiment, the changes in excitability of motor axons produced after natural activity were measured in nine healthy subjects using 1 min of maximal voluntary contractions (MVC) of the abductor digiti minimi (ADM) by studying the relationship between stimulus intensity applied to the ulnar nerve and the size of the ADM compound muscle action potential (CMAP). On cessation of the contraction, there was a prominent right-shift of the input-output curve: the intensity required to produce a control CMAP approximately 60% of maximum, generated a post-contraction response approximately 25% of maximum. Similar changes occurred in the input-output curves obtained by recording the ulnar nerve volley evoked by same test stimulus for CMAP.

Ulnar nerve compression neuropathy at Guyon's canal caused by crutch walking: case report with ultrasonographic nerve imaging.

This report is the first account of Guyon's syndrome after the bilateral use of forearm crutches. Crutch palsy is usually neuropraxic in nature and associated with clinical and electrophysiologic recovery of nerve function, especially if patients are instructed to not bear excessive weight on the wrist. The present case history follows this pattern.

Prulifloxacin as a trigger of myasthenia gravis.

Fluoroquinolones has been rarely associated with exacerbation of myasthenia gravis (MG). We present a case of MG following a treatment with prulifloxacin, a new broad-spectrum oral fluoroquinolone. Fluoroquinolones of any generation may interfere with neuromuscular transmission and should be avoided in patients with MG.

Ulnar sensory nerve impairment at the wrist in carpal tunnel syndrome.

In previous studies, changes in impulse transmission of ulnar motor axons have been documented in patients with carpal tunnel syndrome (CTS). We examined ulnar sensory conduction in 144 CTS hands. In particular, conduction parameters of the dorsal ulnar cutaneous branch (DUC) running outside Guyon's canal were compared with those of the superficial sensory branches (U4 and U5) passing through the canal.

Changes in corticomotor excitability of forearm muscles in relation to static shoulder positions.

We examined whether the recruitment properties of the corticospinal pathway to forearm muscles are influenced by variations of the shoulder joint angle. Flexor carpi radialis (FCR) and extensor carpi radialis (ECR) muscles motor evoked potentials (MEPs) in response to transcranial magnetic stimulation were examined during different static positions of shoulder joint in the horizontal plane: from 30 degrees abduction to 30 degrees adduction. We found that at 30 degrees shoulder adduction, maximum slope and plateau phase of the ECR and FCR input-output relationship (i.