Slow Sensory Nerve Conduction Velocity Research Articles

Clinical, neuroelectrophysiological and muscular pathological analysis of chronic progressive external ophthalmoplegia.

The aim of the present study was to explore the clinical, neuroelectrophysiological and muscular pathological characteristics of chronic progressive external ophthalmoplegia (CPEO) and to improve the understanding of CPEO. Clinical manifestations, neuroelectrophysiology and pathological features of muscle biopsies from 12 patients with CPEO were retrospectively analyzed. The average age of onset for the 12 patients (6 males and 6 females) was 17.2 years. All patients had different degrees of blepharoptosis. A total of 11 patients experienced ocular dyskinesia, but diplopia was rare. Electrophysiological testing in 12 patients revealed abnormal changes in 6 patients, including 4 patients with a myogenic lesion, 1 patient with a neurogenic lesion, and 1 patient with mixed myogenic/neurogenic lesions. Two patients had slow sensory nerve conduction velocity. Muscle biopsies in 12 patients demonstrated ragged-red, irregular and broken fibers in 11 patients through Gomori trichrome and hematoxylin and eosin (H&E) staining, increased lipid levels in some muscle fibers in 4 patients through Οil Ρed O staining and abnormal distribution of type I and II muscle fibers in 3 patients through ATPase staining. Electron microscopy in 5 patients showed an increased number of mitochondria and abnormal mitochondrial aggregation between submucosa and myofibrils in 4 patients. These findings suggest that the possibility of CPEO should be considered if patients present with obvious extraocular muscle paralysis without diplopia. Furthermore, the identification of ragged-red fibers by Gomori trichrome and H&E staining of muscle biopsies from patients is an important basis for the diagnosis of CPEO.

Potential Risk of Developing Peripheral Neuropathy in Heavy Motor Vehicle Driving: A Cross-sectional Study

Introduction: There is a growing concern regarding increasing road traffic accidents due to overburdened drivers, which also affect their general health. Drivers maintain the extreme position of arm, forearm, and legs which during distant journeys may put increased constraint on nerves passing in forearm and legs in addition to the vibrations transmission i.e., Hand Arm Vibration Syndrome (HAVS) and Foot Transmitted Vibration (FTV). Aim: To find out if chronic repeated movements at wrist and foot along with vibration transmitted from steering wheel and pedals influence the nerve conduction parameters and to find out which nerves are more prone to neurological conduction defects. Materials and Methods: A cross-sectional study was conducted over a period of two years in Neurophysiology Lab, Department of Physiology, JN Medical College, Aligarh Muslim University, Aligarh, Uttar Pradesh, India. Mean peak sensory and motor latency, mean motor and sensory Nerve Conduction Velocity (NCV), Sensory Nerve Action Potential (SNAP) and Compound Muscle Action Potential (CMAP) of median, ulnar and common peroneal nerve in Professional Heavy Vehicle Drivers (PHVD) was compared with non-drivers using Medicaid System’s (Electromyography) EMG/ (Nerve Conduction Velocity) NCV equipment with Neuroperfect Software. Student’s unpaired t-test was used to assess the significance of difference in nerve conduction study findings. Results: Heavy vehicle drivers showed slow Sensory Nerve Conduction Velocity (SNCV) (drivers: 51.40±3.30, non-drivers: 53.66±3.60 in right hand p-value 0.0001) and (drivers: 52.51±3.78, non-drivers: 53.87±3.61 in left hand p-value=0.0145) and increase in sensory latency (drivers: 3.71±0.72, non-drivers: 2.89±0.56 in right hand p-value<0.0001 and drivers: 3.4±0.81 non-drivers: 2.76±0.70 in left hand p-value <0.0001) of median nerve. Ulnar nerve sensory latency was prolonged (drivers: 2.98±0.52, non-drivers: 2.76±0.42 in right hand p-value 0.0021 and drivers: 2.97±0.42, non-drivers: 2.80±0.65 in left hand p-value 0.0386) and sural nerve sensory latency was prolonged (drivers: 3.05±0.55, non-drivers: 2.78±0.54 in right leg p-value=0.0011 and drivers: 2.92±0.45, non-drivers: 2.69±0.40 in left leg p-value 0.0004).There was no significant difference in Motor Nerve Conduction Velocity (MNCV), motor latency, SNAP and CMAP of median, ulnar and common peroneal nerve among heavy vehicle drivers in comparison to non-drivers. Conclusion: We conclude that pressure and vibrations transmitted at hand and foot along with repeated movements at forearm wrist and pedals leads to more neurological conduction defects in median nerve than in ulnar and sural nerve. Flexibility in delivery time, incorporating judicious breaks in duty, better ergonomics design may help in improving work conditions of drivers.

Associations between hand anthropometric measurements, and degree of severity of carpal tunnel syndrome in Suez Canal area, Egypt

Background: Carpal tunnel syndrome (CTS) is considered as the most commonly reported peripheral nerve entrapment syndrome resulting from compression of the median nerve at the wrist level. Many studies have investigated the association between anthropometric characteristics and the degree of severity of the disease. Most literature supports a causal association between overweight and CTS; moreover, there is strong evidence that anatomical characteristics of the hand-wrist system may change the risk, and perhaps the severity of CTS. The aim of this study was to investigate the association between hand anthropometric measurements in patients with CTS and severity of the disease. Methodology: A cross-sectional study was conducted among patients with CTS (n = 600). For this purpose, a brief questionnaire and physical examination were done; hand dominance also was recorded. Body and hand anthropometric measurements were performed and recorded followed by electrodiagnostic testing at the same visit. Results: Patients had significantly prolonged distal latency, prolonged peak latency, lower compound muscle action potential and sensory nerve action potential amplitudes, and slower sensory nerve conduction velocity. Patients had significantly higher wrist depth, higher wrist ratio (WR), shorter palm length, shorter hand length, and lower hand ratio. Correlations of WR and wrist depth were also found. Conclusion: Anthropometric characteristics of the wrist and hand are significantly correlated with CTS. These measurements could be used in certain occupations to screen for those individuals who have increased liability to develop CTS.

Use of Nerve Conduction Velocity to Assess Peripheral Nerve Health in Aging Mice.

Nerve conduction velocity (NCV), the speed at which electrical signals propagate along peripheral nerves, is used in the clinic to evaluate nerve function in humans. A decline in peripheral nerve function is associated with a number of age-related pathologies. While several studies have shown that NCV declines with age in humans, there is little information on the effect of age on NCV in peripheral nerves in mice. In this study, we evaluated NCV in male and female C57Bl/6 mice ranging from 4 to 32 months of age. We observed a decline in NCV in both male and female mice after 20 months of age. Sex differences were detected in sensory NCV as well as the rate of decline during aging in motor nerves; female mice had slower sensory NCV and a slower age-related decline in motor nerves compared with male mice. We also tested the effect of dietary restriction on NCV in 30-month-old female mice. Dietary restriction prevented the age-related decline in sciatic NCV but not other nerves. Because NCV is clinically relevant to the assessment of nerve function, we recommend that NCV be used to evaluate healthspan in assessing genetic and pharmacological interventions that increase the life span of mice.

The resuits and value of single fiber electromyography in the diagnosis of CTS

Objective To analysis and evaluate the results of single fiber electromyography (SFEMG) in the diagnosis of carpal tunnel syndrorne (CIS). Methods According to results acquired by routine nerve conduction studies, 14 clinically diagnosed CTS patients (20 sides) were divided into 2 groups. In group Ⅰ(10 sides) although there was slowing of sensory nerve conduction velocity (SNCV) across the wrist, latency of the compound muscle action potential (CMAP) of abductor pollieis brevis (APB) was normal. In group Ⅱ(10 sides) in sdditiun to slow SNCV, CMAP latency of APB was more than 4.3 ms. Another 10 normal volunteers served as control. SFEMG was done to all the study subjects to obtain fiber density (FD) of the abductor pollicis brevis and mean of consecufive difference (MCD). Results Preoperative SPEMG showed that MCD of group Ⅰ was 67.86 μs on average, being 27.47 μs longer than that of the control group. MCD of group Ⅱ was 83.36μs on average, 42.97μs longer comparing to the control group. FD of abductor pollicis brevis was higher in both group Ⅰ and Ⅱ, with an increase of 0.46 and 0.60, respectively. MCD and FD in CTS patients were significanfly higher than those of normal control. MCD of group Ⅱ was significantly greater than MCD of group Ⅰ. However there was no significant difference in FD of both groups. Conclusion SFEMG provides more objective and direct evidence for the diagnose of Carpal tunnel syndrome, especially for cases in early stage. Key words: Carpal tunnel syndrome; Diagnosis; Single fiber electromyography

Neuromuscular Abnormalities in Ataxia Telangiectasia: A Clinical, Electrophysiological and Muscle Ultrasound Study

Thirteen classical ataxia telangiectasia (A-T) patients, varying in age from 1 to 25 years, were studied clinically, electrophysiologically as well as by muscle ultrasound to chart the development and spectrum of neuromuscular abnormalities in A-T. The most prominent finding was a progressive axonal sensorimotor polyneuropathy, apparent by electromyography and muscle ultrasound from the age of 8 years and becoming clinically discernible around 12 years of age. Before the age of 8 years decreased tendon reflexes and slightly slowed sensory nerve conduction velocities could already be observed. With routine electrophysiological techniques the severe polyneuropathy precludes conclusions about the presence of anterior horn cell loss in older patients.

Protective Effect of Erythropoietin and Its Carbamylated Derivative in Experimental Cisplatin Peripheral Neurotoxicity

Antineoplastic drugs, such as cisplatin (CDDP), are severely neurotoxic, causing disabling peripheral neuropathies with clinical signs known as chemotherapy-induced peripheral neurotoxicity. Cotreatment with neuroprotective agents and CDDP has been proposed for preventing or reversing the neuropathy. Erythropoietin given systemically has a wide range of neuroprotective actions in animal models of central and peripheral nervous system damage. However, the erythropoietic action is a potential cause of side effects if erythropoietin is used for neuroprotection. We have successfully identified derivatives of erythropoietin, including carbamylated erythropoietin, which do not raise the hematocrit but retain the neuroprotective action exerted by erythropoietin. We have developed previously an experimental chemotherapy-induced peripheral neurotoxicity that closely resembles CDDP neurotoxicity in humans. The present study compared the effects of erythropoietin and carbamylated erythropoietin (50 microg/kg/d thrice weekly) on CDDP (2 mg/kg/d i.p. twice weekly for 4 weeks) neurotoxicity in vivo. CDDP given to Wistar rats significantly lowered their growth rate (P < 0.05), with slower sensory nerve conduction velocity (P < 0.001) and reduced intraepidermal nerve fibers density (P < 0.001 versus controls). Coadministration of CDDP and erythropoietin or carbamylated erythropoietin partially but significantly prevented the sensory nerve conduction velocity reduction. Both molecules preserved intraepidermal nerve fiber density, thus confirming their neuroprotective effect at the pathologic level. The protective effects were not associated with any difference in platinum concentration in dorsal root ganglia, sciatic nerve, or kidney specimens. These results widen the spectrum of possible use of erythropoietin and carbamylated erythropoietin as neuroprotectant drugs, strongly supporting their effectiveness.

Electrodiagnostic features of hereditary neuropathy with liability to pressure palsies.

Because diagnosis of hereditary neuropathy with liability to pressure palsies (HNPP) frequently is missed or delayed, we looked for electrodiagnostic features that raise suspicion of the disorder by making comparisons with two more common diseases that mimic it electrophysiologically: chronic inflammatory demyelinating polyneuropathy (CIDP) and diabetic polyneuropathy. A retrospective review of the neuromuscular laboratory database was performed. Nine HNPP subjects, 22 with CIDP and 49 with diabetic polyneuropathy. Of all the HNPP nerves studied, abnormally slow sensory nerve conduction velocity (SNCV) was found in 93%, prolonged distal motor latencies (DML) in 78%, slow motor nerve conduction velocity in 31%, and prolonged F-wave latencies in 90%. Mean SNCV for HNPP was 85.6%+/-10.6% of the lower limit of normal and significantly slower than for CIDP (114.3%+/-20.1%; p<0.0001) or diabetes (108.1%+/-14.8%; p<0.0001). Excluding the carpal tunnel site from the analysis did not alter this observation: Mean DML were more prolonged in HNPP, even without median nerve data in the analysis (118.5%+/-31.0% of the upper limit of normal), than in CIDP (103.2%+/-31.6%; p<0.05) or diabetes (86.3%+/-18.3%; p<0.0001). Mean HNPP motor nerve conduction velocity was within normal limits. According to findings, hereditary neuropathy with liability to pressure palsies (HNPP) has a distinctive background polyneuropathy independent of superimposed entrapment neuropathy. It is characterized by diffuse sensory nerve conduction velocity (SNCV) slowing and prolongation of distal motor latencies with relatively infrequent and minor reduction of motor nerve conduction velocities. This indicates disproportionate distal conduction slowing in the disorder.

Tarsal tunnel syndrome: Electrophysiological study

Tarsal tunnel syndrome (TTS) is a rare compression neuropathy of the posterior tibial nerve. Typical symptoms are burning pain and paresthesia in the toes and along the sole of the foot. The presence of Tinel's sign and objective sensory loss in the territory of any of the terminal branches of the posterior tibial nerve are diagnostically helpful. The terminal latency and sensory nerve conduction velocity in medial and lateral plantar nerves were studied in 20 normal controls and 21 cases of TTS in 17 patients. Prolonged terminal latency was observed in 11 cases, with TTS, while sensory nerve conduction abnormality (either absent nerve potential or slow sensory nerve conduction velocity) was found in 19. The sensory nerve conduction velocity in the lateral and medial plantar nerves is a superior objective diagnostic index of TTS.