Peripheral Neuropathy in Multiple Sclerosis: An Electrophysiologic Study in Iranian Patients.

Multiple sclerosis (MS) is the most common cause of disability after trauma in young adults in Northern Hemisphere; it imposes a major burden on the affected young people. A significant association between MS and demyelinating peripheral neuropathy which might be due to common pathogenesis for the central and peripheral nerves demyelination has been reported in several studies. We aimed to assess if there is any peripheral nervous system involvement in a sample of Iranian MS population. Extensive nerve conduction studies (NCS) were conducted in 20 MS patients according to McDonald criteria, and 20 age and gender matched healthy appearing controls. The F-wave ratio was calculated through placing the minimum amount of F-wave proximal latency after 10 stimuli and median or tibial nerves compound motor action potential (CMAP) proximal latency in the corresponding formula. Data were compared between groups. Finally, we found the significantly lower median and tibial nerves conduction velocities (NCV) in MS patients than healthy controls (P=0.008 and 0.003 respectively, Independent Samples t-test). Also, tibial NCV had a significant statistical correlation with Kurtzke's expanded disability scale score (EDSS) as patients with higher EDSS had lower tibial NCV (Pearson's correlation coefficient, r2=0.8). No statistical relationship was found between MS subtypes and NCS parameters. Although we found some electrodiagnostic abnormalities in Iranian MS patients in comparison to the healthy participants, these differences were small and inconclusive. More extensive well-designed electrodiagnostic studies for evaluation of peripheral nervous system involvement and its probable pattern in these patients seems to be needed.

Test-retest reliability of transcarpal sensory NCV method for diagnosis of carpal tunnel syndrome.

BACKGROUND: Carpal Tunnel Syndrome (CTS) is the most frequent entrapment neuropathy affecting the upper extremity. There are a variety of electrodiagnostic methods available for documenting median neuropathy in CTS. In some studies, determining the sensory NCV across the palm-wrist segment has been introduced as the most sensitive diagnostic procedure for CTS. The aim of this study was to investigate the test-retest reliability of transcarpal median sensory NCV method for the diagnosis of CTS. MATERIALS AND METHODS: Twenty-three patients with clinical symptoms of CTS were tested two times by two different practitioners in one session and again by the first practitioner after one week. Stimulation of the median nerve was performed in the wrist and palm, with a conduction distance maximum of 7 cm, reliabilities of median nerves sensory nerve action potential latencies with stimulation at wrist and palm (W-SNAP, P-SNAP) and its transcarpal NCV were assessed with intraclass correlation coefficient (ICC). RESULTS: Comparison of the obtained values, which were done by two practitioners in one session showed ICC of W-SNAP latency, P-SNAP latency and transcarpal NCV of 0.93, 0.88 and 0.87, respectively and values that were done by one practitioner in two sessions with one-week interval showed ICC of 0.60, 0.50 and 0.47, respectively. CONCLUSION: Our findings suggest excellent interpractitioner test-retest reliability of transcarpal median sensory NCV method for diagnosing CTS.

Efficacy of botulinum toxin type a for treating chronic low back pain.

BACKGROUND: Low back pain is a major cause of disability and can result in substantial morbidity and high healthcare costs. Botulinum toxin has been used successfully to alleviate pain for a number of conditions caused by muscle contractions or spasms. OBJECTIVES: The aim of this study was to investigate the efficacy of botulinum toxin type A (BoNT-A; Dysport®, Ipsen, UK) for treating chronic low back pain (CLBP). PATIENTS AND METHODS: This was a single-blind, randomized clinical trial study. Fifty patients with CLBP received either BoNT-A (40 Ipsen units per injection) or saline in 5 sites in the paraspinal muscles (n = 25 per group). A visual analogue system (VAS) was used to measure pain levels at baseline and at 4 and 8 weeks post-injection. Disability was assessed using the Oswestry low back pain disability questionnaire at baseline and at 8 weeks post-injection. RESULTS: After 4 weeks, 76% of patients in the BoNT-A group reported pain relief compared to 20% in the saline group (P < 0. 005). Additionally, greater pain relief was experienced by patients in the BoNT-A group at 8 weeks (64% vs. 12%; P < 0. 001). By week 8, significant functional improvement (a minimum two-grade improvement between baseline and post-treatment assessments) was demonstrated in a higher number of patients receiving BoNT-A than in the saline group (68% vs. 12% , respectively; P < 0. 005). Patients experienced only minor side effects. CONCLUSIONS: BoNT-A improves CLBP with a low incidence of side effects and can be used as a therapeutic tool in the management of these patients.