Pattern Differences of Small Hand Muscle Atrophy in Amyotrophic Lateral Sclerosis and Mimic Disorders / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Amyotrophic lateral sclerosis (ALS) and some mimic disorders, such as distal-type cervical spondylotic amyotrophy (CSA), Hirayama disease (HD), and spinobulbar muscular atrophy (SBMA) may present with intrinsic hand muscle atrophy. This study aimed to investigate different patterns of small hand muscle involvement in ALS and some mimic disorders.</p><p><b>METHODS</b>We compared the abductor digiti minimi/abductor pollicis brevis (ADM/APB) compound muscle action potential (CMAP) ratios between 200 ALS patients, 95 patients with distal-type CSA, 88 HD patients, 43 SBMA patients, and 150 normal controls.</p><p><b>RESULTS</b>The ADM/APB CMAP amplitude ratio was significantly higher in the ALS patients (P < 0.001) than that in the normal controls. The ADM/APB CMAP amplitude ratio was significantly reduced in the patients with distal-type CSA (P < 0.001) and the HD patients (P < 0.001) compared with that in the normal controls. The patients with distal-type CSA had significantly lower APB CMAP amplitude than the HD patients (P = 0.004). The ADM/APB CMAP amplitude ratio was significantly lower in the HD patients (P < 0.001) than that in the patients with distal-type CSA. The ADM/APB CMAP amplitude ratio of the SBMA patients was similar to that of the normal controls (P = 0.862). An absent APB CMAP and an abnormally high ADM/APB CMAP amplitude ratio (≥4.5) were observed exclusively in the ALS patients.</p><p><b>CONCLUSIONS</b>The different patterns of small hand muscle atrophy between the ALS patients and the patients with mimic disorders presumably reflect distinct pathophysiological mechanisms underlying different disorders, and may aid in distinguishing between ALS and mimic disorders.</p>

A clinical neurophysiology study of Hirayama disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Hirayama disease is a rare disease characterized by juvenile-onset of asymmetric amyotrophy, of which etiology has not been clarified. The aim of our study was to investigate the clinical and neurophysiologic characteristics of Hirayama disease.</p><p><b>METHODS</b>Neurophysiological tests, including nerve conduction studies (NCS), F-wave and routine electromyography (EMG), were performed in seventy-three patients with Hirayama disease. EMG was selectively performed on upper and lower extremities, sternocleidomast and thoracic paravertebral muscles according to the clinical features of the patients.</p><p><b>RESULTS</b>Abnormal NCS parameters, including decreased compound muscle action potentials or delayed distal motor latency, were found in 34.2% (25/73) and 12.3% (9/73) of the patients, respectively. A total of 24.6% (18/73) of the patients showed decreased F-wave frequency. EMG demonstrated the presence of neurogenic lesions in all patients with spontaneous potentials, prolonged duration or augmentation of amplitude in motor unit potentials (MUPs), or a single pattern of MUP recruitment. About 17.8% (13/73) of the patients showed neurogenic lesions, mostly in the C7-8 level of the cervical cord, only in the upper extremity of affected side, whereas 35.6% (26/73) of the patients possessed lesions in the upper extremities bilaterally. A total of 46.6% (34/73) of patients exhibited abnormalities in the lower extremities, sterno- cleidomast or thoracic paravertebral muscle. Changes in motor NCS were significantly correlated with muscle strength.</p><p><b>CONCLUSIONS</b>EMG detects diffused subclinical neurogenic lesion in a high proportion of patients with Hirayama disease. Results of our study challenge the hypothesis that Hirayama disease is a type of cervical myelopathy.</p>

Nerve conduction studies in patients with dermatomyositis or polymyositis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Involvement of peripheral nerves in dermatomyositis (DM) and polymyositis (PM) is less well known. In the present study we retrospectively analyzed the clinical and electrophysiological records of hospital inpatients with a diagnosis of DM or PM to investigate the association of DM/PM and peripheral neuropathy.</p><p><b>METHODS</b>The data of inpatients diagnosed with DM or PM were collected in Peking Union Medical College Hospital, and 186 patients (118 patients with DM and 68 with PM) were retrospectively analyzed. Nerve conduction studies (NCSs) of the median nerve, ulnar nerve, posterior tibial nerve, and common peroneal nerve were examined simultaneously.</p><p><b>RESULTS</b>There were 71 (38.2%) patients with abnormal NCS findings, 37 (19.9%) with pure motor involvement (decreased compound muscle action potential, CMAP), and 34 (18.3%) with peripheral neuropathy. Of the 34 peripheral neuropathy patients, 14 (7.5%) had polyneuropathy, 1 (0.5%) had multiple mononeuropathy, 16 (8.6%) had carpal tunnel syndrome (CTS), 1 (0.5%) had trigeminal sensory neuropathy, 1 (0.5%) had ulnar sensory neuropathy, and 1 (0.5%) had brachial plexus involvement. The prevalence of malignant disease (3/34, 8.8%), other connective tissue diseases (CTDs) (7/34, 20.6%) and diabetes (6/34, 17.6%) was significantly greater in DM/PM patients with peripheral neuropathy (chi(2) = 15.855, P = 0.000) compared with DM/PM patients without involvement of peripheral nerves (5/115, 4.3% and 7/115, 6.1%, respectively).</p><p><b>CONCLUSIONS</b>Peripheral neuropathy in DM/PM often suggests a complication with cancer, other CTDs, diabetes or CTS. From a practical point of view, NCS for DM/PM may help find the underlying disorders.</p>

Association between DPP6 polymorphism and the risk of sporadic amyotrophic lateral sclerosis in Chinese patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disease characterized by the loss of motor neurons in the spinal cord, brainstem, and cerebral cortex, which results in muscle weakness, atrophy. Sporadic ALS (SALS) accounts for about 90% of ALS cases, but the etiology is largely unknown. Most of the researchers consider it to be a complex disease. There have been several genome-wide association (GWA) studies reporting several single nucleotide polymorphisms (SNPs) which are susceptible to ALS, but no data of Asians (including Chinese) yet. We investigate whether the polymorphism of rs10260404 in DPP6 gene is associated with SALS in Chinese Han origin to compare the ethnic differences between Chinese Han origin and other populations.</p><p><b>METHODS</b>The genomic DNA was extracted from the leukocytes of whole blood samples in 58 Chinese Han patients with SALS and 52 healthy controls. The asymmetric PCR was processed in the presence of an unlabeled probe that contained the rs10260404 locus. The product was genotyped on a light scanner using high resolution melting method and some were confirmed with sequencing.</p><p><b>RESULTS</b>The rs10260404 polymorphism was in Hardy-Weinberg equilibrium in patients and controls. The CC genotype and the C allele were similar in patients compared with healthy subjects and not associated with an increased risk of Chinese SALS patients (chi(2) = 0.29, OR = 1.26, 95% CI 0.55 - 2.87, P > 0.05).</p><p><b>CONCLUSIONS</b>The rs10260404 is not associated with ALS susceptibility in Chinese people with Han origin which may be due to ethnic differences. More study with large number of cases in Chinese population is really necessary.</p>

Value of anal sphincter electromyography, orthostatic hypotension and dizziness in diagnosing multiple system atrophy / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the value of anal sphincter electromyography (ASEMG), orthostatic hypotension (OH), and dizziness in diagnosing multiple system atrophy (MSA).</p><p><b>METHOD</b>The characteristics of ASEMG and OH were compared among patients with dizziness (MSA and non-MSA), patients without OH (MSA and non-MSA), and patients with probable MSA (OH and non-OH).</p><p><b>RESULTS</b>Totally 476 patients underwent ASEMG examinations. Dizziness was the onset symptom in 69 patients. Between the MSA group and non-MSA group, the mean duration of dizziness [(14.6 +/- 2.1) vs. (12.8 +/- 2.0) ms, P < 0.01] and satellite potential occurrence rate [(22.7 +/- 11.8)% vs. (12.2 +/- 8.9)% , P < 0.01] were significantly different, while the OH rate (84.6% vs. 55.2% ) and the difference of the blood pressure between standing and supine positions were not significantly different. In 162 patients with symptom of dizziness, the mean duration of dizziness [(15.3 +/- 2.7) vs. (12.8 +/- 1.9) ms, P < 0.001], satellite potential occurrence rate [(25.4 +/- 12.8)% vs. (13.5 +/- 10.4)%, P < 0.001] , and difference of the diastolic blood pressure [(18.5 +/- 17.0) vs. (11.7 +/- 12.7) mmHg, P < 0.05] were significantly different between the MSA group and non-MSA group, while the normal rate of blood pressure at standing position (60% vs. 41.9%) and the difference of systolic blood pressure were not significantly different. In 146 patients with abnormal blood pressure at standing and supine positions, the mean duration of dizziness [(15.0 +/- 2.4) vs. (12.8 +/- 1.7) ms, P < 0.001] and satellite potential occurrence rate [(22.0 +/- 12.2)% vs. (10.6 +/- 8.5)%, P < 0.001] were significantly different between the MSA group (n = 61) and non-MSA group (n = 85). In 125 patients with probable MSA, the mean duration of dizziness [(15.5 +/- 2.4) vs. (15.9 +/- 2.2) ms, P > 0.05] and satellite potential occurrence rate [(24.3 +/- 12.6)% vs. (22.7 +/- 12.4)%, P > 0.05] were not significantly different between those with OH and those without OH. The rates of dizziness and the percentage of dizziness as the onset symptom were 93.2% and 52.3% in OH group and 44.4% and 8.3% in non-OH group.</p><p><b>CONCLUSIONS</b>ASEMG is better than OH in diagnosing patients with dizziness suspected as MSA. Neurogenic lesion can be found by ASEMG in patients without OH, which is helpful in the early diagnosis of MSA.</p>

Changes of single fiber electromyography in patients with inflammatory myopathies / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To assess the significance of single fiber electromyography (SFEMG) in diagnosis of inflammatory myopathies and the correlation with other assistant examination findings.</p><p><b>METHODS</b>SFEMG were recorded from the extensor digitorum communis of 34 patients with polymyositis or dermatomyositis and compared with the findings of routine electromyography (EMG), serum creatine kinase (CK) determination, and muscle biopsy.</p><p><b>RESULTS</b>SFEMG recordings in 34 patients were all abnormal. The prominent feature was markedly increased fiber density (FD) with normally or mildly increased jitter. FD ranged from 1.0 to 6.0 (2.34 +/- 0.43). Jitter ranged from 5 to 78 micros (41.6 +/- 10.3 micros). The potential pairs with jitter values greater than 55 micros ranged from 0% to 55% (7.7% +/- 11.8%). Block was detected at one recording site in only one patient. Routine EMG demonstrated myogenic lesions in only 24 patients (70.6%). FD was a little higher in the normal-EMG subgroup or the neurogenic-EMG subgroup than myogenic-EMG subgroup but without statistical significance. Elevated CK levels were found in 75% patients (24/32). FD in the normal CK subgroup was significantly higher than that in the elevated CK subgroup (2.62 +/- 0.40 vs. 2.28 +/- 0.40, P < 0.05). Muscle pathologies were consistent with the diagnosis of myositis in 75% (15/20).</p><p><b>CONCLUSION</b>SFEMG is of great value in the diagnosis and disease process understanding of inflammatory myopathies for the clinically suspected patients with normal routine EMG, CK levels, and muscle biopsies.</p>