Exercise with vibration dumb-bell enhances neuromuscular excitability measured using TMS

AIM

The purpose of the study was to examine the effects of exercise without vibration and exercise with vibration (27 Hz) on the cortical silent period (CSP) and cortical motor threshold (CMT) measured using transcranial magnetic stimulation (TMS).

METHODS

In 22 university athletes, a circular coil attached to a TMS stimulator was applied over the contralateral motor cortex of the target forearm. Resting cortical motor thresholds for dominant and non-dominant extremities were measured for each participant. Then, 15 biceps curls (15 flexion and 15 extension movements) were performed with the dominant arm using a single vibration dumbbell with the vibration turned off. On a different day, the same biceps curl protocol was performed with the dumbbell vibrating at 27 Hz (2 mm amplitude). A supra-threshold TMS stimulus (1.5x CMT) was delivered while participants were voluntarily contracting the flexor digitorum sublimus muscle (30% MVC grip strength) to determine cortical silent periods before and after each upper extremity exercise protocol. Cortical motor thresholds were measured at rest and after the vibration exercise protocol.

RESULTS

All subjects completed the study protocol as designed. After TMS, the CSP in the dominant (exercised) extremities increased after exercise without vibration from a resting (pre-exercise) mean of 57.3 ms to 70.4 ms (P<0.05) and after exercise with vibration, the CSP decreased to a mean of 49.4 ms (P<0.02). The CSP in the non-dominant (unexercised) extremities decreased from resting values of 75.6 ms to 69.3 ms (P=0.935) after the exercise-only protocol and decreased to 49.4 ms (P<0.01) after the vibration exercise protocol. The cortical motor threshold in exercised extremities decreased from a resting mean of 41.4 μV to a postvibration exercise mean of 38.6 μV (P<0.01). In non-exercised extremities, the CMT also decreased, from mean of 43.5 μV to 39.9 μV after the vibration-exercise (P<0.01).

CONCLUSION

Vibration exercise enhances bilateral corticospinal excitability, as demonstrated by a shortened cortical silent period and lower cortical motor threshold in both exercised and non-exercised extremities.

Four siblings with achalasia, alacrimia and neurological abnormalities in a consanguineous family

Four siblings with achalasia, alacrimia and other problems involving the autonomic nervous system involvements are reported. Achalasia and alacrimia were present in all of them. Their parents are first cousins and have four other healthy children. Electrophysiological tests showed that autonomic dysfunction has progressed with age. Blood cortisol levels were normal in all four affected children. Depending on those findings of our case and previous reports, we conclude that triple-A syndrome and achalasia, alacrimia with or without neurological abnormalities could be variable manifestations of the same autosomal recessive gene defect.

An electrophysiological investigation of deglutition in man

This article describes a combined electrophysiological and mechanical method used to measure laryngeal movements and related submental EMG activity during swallowing. The mechanical upward and downward movements of the larynx were detected using a piezoelectric sensor while the submental integrated EMG (SM-EMG) was recorded. Measurements were performed in 29 human subjects. The interval between the onsets of the two sensor signal deflections was used as a measure of the time the larynx remained in its superior position during swallowing. In 10 subjects, the cricopharyngeus muscle (CP) of the upper esophageal spinchter showed a continuous tonic EMG activity except during swallowing. All the parameters measured were influenced by the type and volume of the bolus material. The method presented in this study proved its usefulness in the study of the physiology of deglutition as well as in its objective clinical evaluation in patients with dysphagia.

Hand and genital sympathetic skin potentials in flaccid and erectile penile states in normal potent men and patients with premature ejaculation

Sympathetic skin potentials were recorded from the hand and genital region in 14 normal potent men and 18 patients with premature ejaculations. With the penis flaccid the sympathetic skin potentials obtained did not differ significantly in both groups. However, when erection was induced by 50 mg. intracavernous papaverine injection, the genital sympathetic skin potentials were significantly suppressed in all but 3 normal men, while the hand potentials did not change. In subjects with premature ejaculation genital and hand sympathetic skin potentials were suppressed during erection as a generalized bodily reaction except in 1 patient. This phenomenon may indicate that the specific and regional suppression of genital sympathetic activity during erection could not be properly adjusted in patients with premature ejaculation.

Diagnostic value of electrical stimulation of lumbosacral roots in radiculopathies

Needle electrical stimulation of the lumbosacral roots at the laminar level of the Th12-L1 or L1-2 intervertebral spaces were performed in 24 normal subjects and 58 patients with various kinds of lumbar radiculopathy (unilateral L4, L5 and S1 herniated nucleus pulposus and lumber stenosis). The root stimulation method was compared with conventional needle EMG. Lumber electrical stimulation showed root abnormalities objectively in 80% of patients while the diagnostic value of needle EMG was 65%. Therefore, electrical root stimulation is superior to routine EMG for localizing lumbar root involvement. However, the only needle EMG demonstrated the root pathology in 7 cases (12%) and single electrophysiological abnormality was found by the root stimulation in 16 cases (27%). Thus, both electrophysiological methods should be complementary to each other in evaluation of the lumbar radioculopathy.

Comparison of magnetic coil stimulation and needle electrical stimulation in the diagnosis of lumbosacral radiculopathy

Electrical stimulation (ES) of lumbosacral nerve roots using a needle electrode inserted to the laminar level at the midline of Th12-L1 or L1-2 intervertebral interspace, was compared with magnetic stimulation using a 9-cm diameter coil (MCS) at the L3-4 or L4-5 spine levels, Compound muscle action potentials (CMAP) were superficially recorded from homologous muscles in both sides in 15 normal control subjects and in 20 patients with lumbosacral radiculopathy. Soleus muscles were used for S1, tibialis anterior (TA) for L5, and rectus femoris (RF) muscles for L4 roots. According to the clinical or radiological diagnosis (CAT, MRI and/or myelography) conventional needle EMG was capable to localise the root lesion in 16 of 20 patients (80%) and ES localised the root involvement in 18 of 20 patients (90%); the diagnostic value of MCS was lower, about 65% (13 of 20 patients). Although ES is uncomfortable and invasive, it is superior to needle EMG in localising unilateral or multiple lumbosacral root involvement. At present, MCS is not suitable for the diagnosis of lumbar radiculopathy.

Calcification of basal ganglia associated with pontine calcification in four cases: a radiologic and genetic study

We describe 4 brothers with calcification of basal ganglia, pons and dentate nuclei. An abnormal iron metabolism was found in one case. The radiological, pathogenetic and genetic aspects of this disease are discussed.