Paraspinal elicited somatosensory evoked potentials in the detection of spinal cord lesions / 中华神经科杂志

Objective To explore the role of somatosensory evoked potentials elicited by paraspinal stimulation in the detection of spinal cord lesions.Methods Patients with clinically suspected spinal cord lesions underwent somatosensory evoked potentials(SEPs)and spinal cord conduction velocity(SCCV)test using paraspinal stimulating method.96 patients aged 15 to 75 years old with suspected spinal cord lesions of various aetiologies were tested.36 patients had demyelinating disease of the spinal cord,26 had sub-acute combined degeneration of the spinal cord,19 had myelopathy,10 had acute myelitis,5 had spinal cord corhpression.Results Paraspinal stimulation elicited somatosensory evoked potentials were Performed on all 96 patients,68 of whom underwent spinal MRI as well.SEPs and SCCV were found abnormal in a high ratio in all kinds of spinal cord lesions ; in general,78 among the 96 patients had abnormal SEPs with a sensitivity of 81.25%.27 out of 36 with demyelinating disease of the spine had abnormal SEPs with a sensitivity of 75.00%,23 out of 26 with subacute combined degeneration of the spinal cord had abnormal SEPs with a sensitivity of 88.46%,8 out of 10 with acute myelitis had abnormal SEPs,15 patients with myelopathy having abnormal findings,all 5 patients with spinal cord compression had abnormal SEPs.42 of 68 patients undergoing MRI revealed to be abnormal,in which 35 patients also had abnormal SEPs.The other 26 patients had normal spinal MRI,in which 21 patients had abnormal SEPs.Conclusions Paraspinal stimulation somatosensory evoked potentials and spinal cord conduction velocity may objectively document the abnormalities of electrophysiology,which occurs earlier than those of anatomy and radiological finds, therefore it may detect the dysfunction of spinal cord at an early stage.It is even more useful in the detecting of the metabolic myelopathy,which can hardly be detected by MRI.This technique is simple,inexpensive, and maybe useful in the diagnosis for patients with suspected spinal cord lesions.

Pathogenesis and electrodiagnosis of cubital tunnel syndrome / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cubital tunnel syndrome is a well-recognized clinical condition and is the second most common peripheral compression neuropathy. This study was designed to investigate the causes of cubital tunnel syndrome by surgical means and to assess the clinical value of the neurophysiological diagnosis of cubital tunnel syndrome.</p><p><b>METHODS</b>Twenty-one patients (involving a total of 22 limbs from 16 men and 5 women, aged 22 to 63, with a mean age of 49 years) with clinical symptoms and signs indicating a problem with their ulnar nerve underwent motor conduction velocity examinations at different sites along the ulnar nerve and examinations of sensory conduction velocity in the hand, before undergoing anterior transposition of the ulnar nerve.</p><p><b>RESULTS</b>Electromyographic abnormalities were seen in 21 of 22 limbs [motor nerve conduction velocity (MCV) range (15.9 - 47.5) m/s, mean 32.7 m/s] who underwent motor conduction velocity examinations across the elbow segment of the ulnar nerve. Reduced velocity was observed in 13 of 22 limbs [MCV (15.7 - 59.6) m/s, mean 40.4 m/s] undergoing MCV tests in the forearms. An absent or abnormal sensory nerve action potential following stimulation was detected in the little finger of 14 of 22 limbs. The factors responsible for ulnar compression based on observations made during surgery were as follows: 15 cases involved compression by arcuate ligaments, muscle tendons, or bone hyperplasia; 2 involved fibrous adhesion; 3 involved compression by the venous plexus or a concurrent thick vein; 2 involved compression by cysts.</p><p><b>CONCLUSIONS</b>Factors inducing cubital tunnel syndrome include both common factors that have been reported and rare factors, involving the venous plexus, thick veins, and cysts. Tests of motor conduction velocity at different sites along the ulnar nerve should be helpful in diagnosis cubital tunnel syndrome, especially MCV tests indicating decreased velocity across the elbow segment of the ulnar nerve.</p>

Value of sympathetic skin response test in the early diagnosis of diabetic neuropathy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Diabetic neuropathy is common in diabetes mellitus. The early stage of diabetic neuropathy is often symptomless and difficult to be treated. The aim of this study was to assess the correlation between the results of the sympathetic skin response (SSR) test and the development of diabetic neuropathy, and explore the use of SSR as an objective basis for the early diagnosis of diabetic neuropathy.</p><p><b>METHODS</b>The latencies and amplitudes of initiation and of the N and P waves were determined by SSR testing of the extremities of 80 diabetic patients and 30 healthy controls.</p><p><b>RESULTS</b>The latencies of initiation and of the N and P waves were significantly (P <0.001) longer in diabetic patients than in the controls, while there was no significant difference in the amplitudes (P >0.05). All but two patients (97.5%) demonstrated abnormal SSR in at least one limb.</p><p><b>CONCLUSIONS</b>SSR can detect early dysfunction of the small sympathetic fibers in people affected by diabetes mellitus, and may be a useful electrophysiological test for the early diagnosis of diabetic neuropathy.</p>