Recording of single fiber electromyography in patients with peripheral facial palsy

Electrodiagnostic studies in the management and prognosis of neuromuscular disorders

Prognosis remains a neglected aspect of modern medical care and research, behind diagnosis and treatment. The very term "electrodiagnosis" implies as much. Despite this, much has been published regarding the use and benefit of electrodiagnostic techniques in assessing prognosis and assisting in management of patients after the diagnosis has been established. This information is often hidden or otherwise not emphasized. This review summarizes the literature regarding the use of such techniques for prognosis and management of disorders of lower motor neurons, peripheral nerves, neuromuscular transmission, and muscle.

Investigation of skeletal muscle denervation and reinnervation using magnetic resonance spectroscopy

OBJECTIVE

To determine changes in skeletal muscle metabolism after nerve transection and repair and to correlate metabolic changes with functional recovery.

STUDY DESIGN AND SETTING

Male Wistar rats were divided into 6 experimental groups plus a control group. The posterior tibial nerve was transected and reapproximated. At varying times after surgery (1, 2, 4, 6, or 8 weeks) animals were sacrificed, the gastrocnemius muscle was harvested, and proton nuclear magnetic resonance (NMR) spectroscopy was performed. Functional recovery was measured using the sciatic function index.

RESULTS

Animals undergoing nerve repair all showed functional recovery whereas the nonrepaired nerve group did not. Concentration of glucose and lactate increased after denervation and then returned toward normal. Choline concentration decreased and then returned toward normal. In animals not undergoing nerve repair, the metabolic abnormalities persisted and showed no sign of recovery over the 8-week observation period.

CONCLUSIONS

1H NMR spectroscopy is a potentially useful tool to study changes in skeletal muscle metabolism after motor nerve injury.

SIGNIFICANCE

NMR spectroscopy is rapidly developing into a clinically useful tool. High-field magnets have improved resolution and data acquisition. Basic experiments, such as those described here, will help guide the use of NMR spectroscopy in clinical medicine and will also lead to a better understanding of basic mechanisms of nerve injury and repair.