Search results for "nerve conduction"
showing 10 items of 45 documents
Increased risk of sensory neuropathy in workers with chloracne after exposure to 2,3,7,8-polychlorinated dioxins and furans
1999
Objective - The existence of a peripheral neuropathy after exposure to polychlorinated dioxins (PCDD) is still discussed, as studies concerning dioxin effects on the peripheral nervous system are rare and contradictory. Material and methods - Clinical and neurophysiological examinations (motor conduction velocity of the peroneal nerve, sensory conduction velocities of the sural and ulnar nerves) were made in 156 dioxin exposed workers (42 with, 114 without cloracne) from one pesticide producing plant. Because of known risk factors for peripheral neuropathy, 7 workers with and 28 without cloracne were excluded from further analysis. Results - Workers with chloracne had a significantly higher…
Central motor conduction time by magnetic stimulation of the cortex and peripheral nerve conduction follow-up studies in Friedreich's ataxia.
1998
A follow-up clinical study, peripheral motor and sensory nerve conduction velocities and central motor conduction by magnetic stimulation of the cortex were performed in 13 patients with classical Friedreich's ataxia (FA) phenotype, for a period of 9-12 years. Clinical worsening was unrelated to peripheral nerve abnormalities. The amplitude of the nerve action potentials and delayed conduction velocity remained unchanged for several years. Central motor conduction times were abnormal in all patients. Clinical conditions worsened significantly between successive examinations with significant increments in threshold and significant decrement of the amplitude of motor evoked potentials. The re…
Analysis of F-wave in metabolic neuropathies: a comparative study in uremic and diabetic patients.
1987
Motor nerve conduction study along the entire length of the ulnar and tibialis posterior nerves was carried out in 30 diabetics compared with 30 uremic patients and 30 control subjects. The conduction in the proximal and the distal nerve segments was evaluated by the determination of the M and F latencies, MNCV (between the stimulus sites), FWCV (between the spinal cord and the stimulus sites), and F-ratio (conduction time ratio of proximal to distal segment). In both groups of patients the lower limbs appear much more involved than the upper, where the ulnar nerve is more commonly affected in uremic than in diabetic patients. In diabetic neuropathy the motor conduction abnormalities are di…
Evoked potential study in facio-scapulo-humeral muscular dystrophy.
1997
Nerve conduction velocities (NCVs), somatosensory (SEPs) and auditory evoked potentials (BAEPs) were recorded in 9 patients with facio-scapulo-humeral dystrophy (FSHD) and in 20 age-matched controls. In FSHD patients a significant increase of the nerve distal sensory latencies and of the absolute SEP latencies revealed a subclinical involvement of the afferent sensory pathways, as well as the abnormal slowing of the later components of the BAEPs, pointed to a central auditory dysfunction. Moreover all patients underwent brain MRI that showed the presence of white matter hyperintense lesions in 4 of them (44%). No correlations were found between individual or total number of SEP and BAEP abn…
Changes of sensory conduction velocity and refractory periods with decreasing tissue temperature in man.
1977
Changes with temperature of maximum sensory nerve conduction velocity as well as absolute and relative refractory periods were tested in 14 human subjects. Corresponding to previously published findings maximum conduction velocity decreased with cooling following a Q10 of +1.4. The absolute and relative refractory periods were increased by cooling, the Q10 being -3.1 and -3.35 respectively. There was a tendency showing a more pronounced temperature effect at low temperatures. The Q10 and the steepness of the regressionline changed at the level of 26.9 degrees C, but were significant for the relative refractory period only.
Evaluation of carpal tunnel syndrome in patients with polyneuropathy
1997
The difference between the median nerve latency to the second lumbrical muscle and the ulnar nerve latency to the second interosseous muscle (L-I DIFF) was tested in a prospective study to discriminate whether prolonged distal motor latency of the median nerve in patients with polyneuropathy (PNP) reflects an additional carpal tunnel syndrome (CTS). We investigated 92 patients (107 hands) with CTS, 30 patients (34 hands) with PNP, 22 patients (27 hands) with CTS and coexisting PNP (PNP+CTS), and 77 controls (87 hands). L-I DIFF was significantly prolonged in both the CTS and PNP+CTS patients as compared to PNP patients and controls. It proved to be the most specific test to differentiate be…
Impaired refractory periods of peripheral sensory nerves in multiple sclerosis.
1978
Maximum conduction velocity and relative refractory period (RRP) of median nerve sensory fibers were studied in 36 patients diagnosed as having multiple sclerosis (MS) and in 31 controls. Maximum conduction velocity did not differ in the two groups, but the RRP was significantly prolonged in MS patients. Increased RRP is observed mainly when peripheral nerve myelin is abnormal or damaged. Our findings support the assumption that peripheral nerve myelinated fibers are usually involved in MS.
Sympathetic Vasomotor Response of the Radial Artery in Patients With Diabetic Foot Syndrome
2003
OBJECTIVE—Neurophysiological assessment of the peripheral autonomic system is characterized by various limitations. An alternative approach to laser Doppler and venous plethymography is the assessment of the sympathetic vasomotor response of the radial artery obtained by continuous wave Doppler sonography. Nomogram data have been established and demonstrate the temporary disappearance of diastolic flow after coughing or deep inspiration. RESEARCH DESIGN AND METHODS—We assessed the sympathetic vasomotor response in 25 patients (mean age 64 years, range 43–76) with diabetic foot syndrome. The Doppler data were correlated with nerve conduction studies of the median and peroneal nerve, the exte…
Clinical neurophysiology and imaging of nerve injuries: preoperative diagnostic work-up and postoperative monitoring
2015
Peripheral nerve injuries are a heterogeneous group of lesions that may occurs secondary to various causes. Several different classifications have been used to describe the pathophysiological mechanisms leading to the clinical deficit, from simple and reversible compression-induced demyelination, to complete transection of nerve axons. Neurophysiological data localize, quantify, and qualify (demyelination vs . axonal loss) the clinical and subclinical deficits. High-resolution ultrasound can demonstrate the morphological extent of nerve damage, fascicular echotexture (epineurium vs . perineurium, focal alteration of the cross-section of the nerve, any neuromas, etc. ), and the surrounding t…
Long-Lasting Cranial Nerve III Palsy as a Presenting Feature of Chronic Inflammatory Demyelinating Polyneuropathy
2015
We describe a patient with chronic inflammatory demyelinating polyneuropathy (CIDP) in which an adduction deficit and ptosis in the left eye presented several years before the polyneuropathy. A 52-year-old man presented with a 14-year history of unremitting diplopia, adduction deficit, and ptosis in the left eye. At the age of 45 a mild bilateral foot drop and impaired sensation in the four limbs appeared, with these symptoms showing a progressive course. The diagnostic workup included EMG/ENG which demonstrated reduced conduction velocity with bilateral and symmetrical sensory and motor involvement. Cerebrospinal fluid studies revealed a cytoalbuminologic dissociation. A prolonged treatmen…