Decline of compound muscle action potentials and statistical MUNEs during Wallerian degeneration.

AIM OF THE STUDY: In two previous studies, we found that the compound muscle action potential (CMAP) amplitude loss was significantly higher than the loss of estimated motor unit numbers in the course of Wallerian degeneration (WD). In order to overcome some drawbacks of the method previously used, we performed a similar CMAP vs MUNE comparison by using the statistical motor unit number estimation (MUNE) method. PATIENTS AND METHODS: Initial electrophysiological studies on 6 patients were performed between 22 and 98 hours after the injuries; it was possible to make repeated examinations, four times in 1 nerve, twice in 1 nerve and three times in 4 nerves, before the eventual complete disappearance of the CMAPs. RESULTS: The transected/intact (T/I) side CMAP ratios declined steeply as WD evolved. They were significantly lower than the relatively stable MUNE ratios 48 hours after the injury. CONCLUSION: This study, performed with the use of statistical MUNE, strengthens our previous observation by the incremental method that might have some relevance to the pathophysiology of early WD. CMAP amplitude loss that is more than expected from the amount of axonal degeneration may indicate a considerable amount of inactive muscle fibers in the motor units innervated by the nerve fibers, which are undergoing degeneration but still retain their excitability. Although technical sources of error cannot be totally excluded, our findings could more likely be explained by the failing of neuromuscular synapses in an asynchronous order before complete unresponsiveness of the motor unit ensues.

Sexual dysfunction in women with migraine versus tension-type headaches: a comparative study.

The aim of this study was to compare the incidence of sexual dysfunction between patients with tension-type headaches (T), migraines (M) and healthy controls (C) in order to investigate the relationship between sexual dysfunction and the features of headaches. The population comprised of 44 patients with M, 30 with T and 30 with C. They have completed Arizona Sexual Experiences Scale (ASEX), Visual Analog Scale. The number of sexual activities over the past 30 days and the frequency of masturbation behavior in C were considerably higher than those in the headache groups. The averages for ASEX item no. 1, 2, 3 and 4 were significantly higher in those with M versus C; and both the subscales and total scores of ASEX were also higher in those with T than C. The mean score for ASEX item no. 3 and the total ASEX score were significantly higher in T versus M. In both headache groups, no significant relationship was observed between headache features and ASEX. The present study showed that patients with either M or T do experience problems in several aspects of sexuality compared with C. Further research is essential to augment our understanding of the sexual dysfunction in this field.

Motor unit number estimation in transected peripheral nerves.

OBJECTIVES: To study motor unit number estimation (MUNE) in acutely transected peripheral nerves, and to retest our previous observation which had revealed a discordance between the loss of compound muscle action potential (CMAP) size and decrease in MUNE during Wallerian degeneration. METHODS: In eight patients with nine transected median or ulnar nerves, a total of 18 electrophysiological studies were performed before the complete nerve degeneration ensues. CMAP recordings and incremental MUNE studies were performed by stimulation of the nerves at the wrist level and recording from the appropriate hand muscles. The same studies repeated on the contralateral side. RESULTS: Injury side to intact side ratios of the MUNEs were significantly higher than the CMAP ratios. Mean step areas in MUNE studies were found to be lower on the transected sides after 72 hours post-injury. DISCUSSION: These findings support the existence of an electrophysiologically observable asynchrony in neuromuscular synapse dysfunction during Wallerian degeneration.

Cortical excitability in Duchenne muscular dystrophy.

OBJECTIVE: To investigate the probable cortical excitability changes in DMD by electrophysiological means. METHODS: Sixteen cases with DMD, 10 age-matched control children (CC) and 10 healthy adult volunteers (AC) were studied with a transcranial magnetic stimulation (TMS) test battery composed of central conduction time, cortical silent period and paired TMS paradigm. RESULTS: There were no significant differences between DMD and CC groups except for lower amplitude motor responses in DMD cases. These two groups showed a similar pattern of excitability with less short interval intracortical inhibitions and shorter silent period durations as compared to the AC subjects. CONCLUSIONS: The electrophysiological tests performed in our DMD patients did not reveal abnormalities caused particularly by the disorder. SIGNIFICANCE: TMS excitability studies performed in DMD boys may not provide findings other than those related to the developmental age.

Botulinum toxin A in the treatment of spasticity - An open label study.

PURPOSE: To assess the efficacy of botulinum toxin type A in spasticity in upper-motor neuron syndromes. METHODS: Twenty-three patients with spasticity resulted from stroke-related hemiplegia, transverse myelitis and multiple sclerosis took part in the study. Following the history and physical examinations of the patients, injections of botulinum toxin-A were applied. The dose ranged from 80 to 400 mouse unit (MU) depending on the size of the muscle injected. In all patients, spasticity, spasms and pain were measured using the Ashworth Scale, Spasm Frequency Score, and Visual Analogue Scale prior to the therapy, at the 1st week, 1st month and 3rd month of the therapy. RESULTS: In all patients, botulinum toxin type A led to a significant decrease in spasticity, spasms and pain after the 1st week, 1st and 3 rd months of the treatment when compared to the baseline values (p<0.001). No significant side effects or complications were observed. CONCLUSION: Our results have demonstrated that botulinum toxin type A is effective in the management of patients with spasticity due to stroke-related hemiplegia, transverse myelitis and multiple sclerosis, without major adverse effects.