[Clinical features and genetic diagnosis of Kennedy disease].

OBJECTIVE: To outline the clinical features of Kennedy disease in Chinese patients. METHODS: The peripheral blood was collected from the male lower motor neuron disease patients of our inpatients and outpatients from July 2005 to September 2008. Then the genome DNA was extracted and the target gene amplified by polymerase chain reaction and sequenced. The clinical data of positive samples were analyzed and summarized. RESULTS: The number of expanded CAG repeats of 12 patients ranged from 43 to 57. And the number of CAG repeats was inversely correlated with the age of onset (r = -0.756, P < 0.005). The first symptom of all of these patients was extremity weakness. The progression of disease was slow. One of the patients died from pneumonia. And the whole disease course lasted for 14 years. CONCLUSION: As an adult onset degenerative disease with a slower clinical progression, Kennedy disease has its own characteristics of inheritance pattern and natural course. It can be accurately diagnosed by androgen receptor gene analysis.

[A clinical, electromyographic, and magnetic resonance imaging study of cervical spondylotic myelopathy: analysis of 96 cases].

OBJECTIVE: To investigate the clinical, electromyographic, and magnetic resonance imaging (MRI) manifestations of the patients with cervical spondylotic myelopathy (CSM) and the correlation among them. METHOD: 96 CSM patients, 56 males and 40 females, aged 53 (2/32-72), underwent electromyography (EMG) of the deltoid muscle (C5), biceps muscle of arm (C6), common extensor muscle of fingers (C7), and short abductor muscle of thumb and abductor muscle of little finger (C8-T), and MRI of the cervical vertebrae before surgical treatment. The clinical symptoms were graded according to the Japanese Orthopaedic Association (JOA) scoring system. The correlation among the JOA score, MIR classification, and EMG manifestation was analyzed. RESULTS: EMG showed that 61 of the 96 patients (64%) with root injury at C5, 6, 7, and 8. Those positive in EMG showed higher severity in MRI (Z=2.863, P=0.004). The JOA score was not correlated with the degree of spinal cord compression demonstrated by MRI and the EMG results. CONCLUSION: The root injury rate is high in the CSM patients. The patients positive in EMG have severe MRI results. No clear correlation is between the severity of clinical symptom and MRI of cervical vertebrae and root injury demonstrated by EMG. Hence, treatment should be considered by integration of EMG, MRI and JOA scores.

[Value of anal sphincter electromyography, orthostatic hypotension and dizziness in diagnosing multiple system atrophy].

OBJECTIVE: To explore the value of anal sphincter electromyography (ASEMG), orthostatic hypotension (OH), and dizziness in diagnosing multiple system atrophy (MSA). METHOD: 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). RESULTS: 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. CONCLUSIONS: 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.

[Clinical value of blink reflex:analysis of 548 patients].

OBJECTIVE: To evaluate the clinic value of blink reflex (BR). METHODS: BR test was conducted among 584 patients with facial spasm (161 cases), face or upper extremities numbness (120 cases), Bell's palsy (102 cases), trigeminal neuralgia (31 cases), ptosis (30 cases), multiple cranial palsy or brain stem lesion (28 cases), cerebral vascular disease (19 cases), lateral face atrophy (16 cases), Guillain-Barré syndrome (13 cases), connective tissue disease (12 cases), diabetic peripheral neuropathy (12 cases), head trauma (11 cases), definite or suspected multiple sclerosis (10 cases), Meige syndrome (9 cases), Parkinson's disease (5 cases), or motor neuron disease (5 cases). RESULTS: 279 out of the 584 patients (47.77%) showed abnormal BR results. By analyzing of waveform, latency period and difference of bilateral side of BR test, the different BR changes caused by either peripheral damage to trigeminal nerve and facial nerve or by brain stem damages were distinguished. CONCLUSION: As one convenient test, BR helps locate the lesion of trigeminal nerve or facial nerve and has highly diagnostic value to the lesion of brain stem, even to the subclinical lesion at the early time of some disease without any symptoms. When the BR results are coordinated with those by brain stem auditory evoked potential, the abnormality of brain stem function can be found and located earlier in some situation that can result to brain stem damage such as MS and systematical disease. Coordination of BR with radionuclide study or single-fiber electromyography helps increase the differential diagnosis of spasm of eyelid and MG.

[Clinical and electrophysiological characteristics of myasthenia gravis with thymoma: analysis of 72 patients].

OBJECTIVE: To investigate the clinical and electrophysiological characteristics of myasthenia gravis with thymoma (MGT). METHODS: The clinical and repetitive nerve stimulation (RNS) data of 72 patients with MGT, 36 males and 36 females, and 63 patients with myasthenia gravis without thymoma (NMGT) were analyzed retrospectively. RESULTS: The onset age of 52 of the 72 MGT patients (72.2%) was 35-59. The average onset age of the MGT patients was 39.5, older than that of the NMGT patients (29.4 yrs), and the course of the MGT patients was 13.1 months, shorter than that of the NMGT patients (29.1 months)The attack rate of the males was not significantly different than that of the females. The proportion of generalized presentation type among the MGT patients was 72.8%, higher than that among the NMGT patients (66.7%), particularly concerning the respiratory muscle (20.8% vs. 9.5%). The average time interval between the onset of symptoms and respiratory or bulbar muscle involvement of the NMGT patients were 12 and 7 months respectively, both remarkably shorter than those of the NMGT patients (26.4 and 11.6 months respectively). The abnormal RNS test yield rate of the MGT patients was 86.9%, higher than, however, not significantly that of the NMGT patients (75.0%). 97.2% of the thymoma and mediastinal abnormality could be detected through computed tomography (CT) scan on thymus. The positive rate of AchRab titer of the MGT patients was 50.0%, not significantly different from that of the NMGT patients (52.4%). CONCLUSION: MGT is common in middle-aged people, both male and female. The Course is quickly progressive and generalized skeletal muscles, particularly respiratory muscles, are more involved in the MGT patients than in the NMGT patients. RNS study is a sensitive tool to identify MGT. AchRab may not be the specific antibody for recognizing MGT. CT scan is useful in differentiating thymoma preoperatively.

Pattern Differences of Small Hand Muscle Atrophy in Amyotrophic Lateral Sclerosis and Mimic Disorders.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Changes of single fiber electromyography in patients with inflammatory myopathies.

OBJECTIVE: To assess the significance of single fiber electromyography (SFEMG) in diagnosis of inflammatory myopathies and the correlation with other assistant examination findings. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

[Clinical and neurophysiological features of 700 patients with diabetic peripheral neuropathy].

OBJECTIVE: To study the clinical and electrophysiological features of diabetic peripheral neuropathy in 700 patients to elucidate the relationships between them and evaluate the value of electromyography in the diagnosis of diabetic peripheral neuropathy. METHODS: Standard sensory and motor nerve conduction studies were performed in the 700 patients, sensory nerve conduction velocity (SCV), amplitude of sensory nerve action potential (SNAP), distal motor latency (DML) and amplitude of compound muscle action potential (CMAP) of median nerve, ulnar nerve, posterior tibial nerve and common peroneal nerve were studied simultaneously. Needle electromyogram (EMG) test was performed in 239 patients. RESULTS: (1) The most common symptoms of peripheral neuropathy were numbness and pain in limbs, while impaired or lost tendon reflexes were the most common abnormal signs in lower limbs. (2) The abnormal rate of nerve conduction studies was 72.4% in the 700 patients. Slow SCV, prolonged DML and decreased amplitude of SNAP and CMAP were detected. (3) More severe abnormal nerve conduction was found in lower limbs than in upper limbs. The abnormal degree was more severe in sensory nerve than in motor nerve and severity was more in amplitude than in conduction velocity (P < 0.05). (4) Abnormal motor and/or sensory nerve conduction was detected in 67.3% of the patients with clinical manifestations of neuropathy and 5.1% patients without signs or symptoms of neuropathy, while motor or sensory nerve conduction was normal in 27.6% patients with manifestations of neuropathy. Needle EMG showed neurogenic lesion in 4.6% of the patients with normal motor and sensory nerve conduction. (5) polyneuropathy is the most common type of diabetic neuropathy and carpal tunnel syndrome the next. CONCLUSIONS: The most common clinical and electrophysiological manifestation of diabetic neuropathy is sensory disturbance, which is more severe in lower limbs. The electrophysiological changes are not always accordant with clinical manifestations. Subclinical diabetic peripheral neuropathy can be detected by electrophysiological tests, which are useful to verify the range and extent of the nerve lesion involved in the early stage of diabetic peripheral neuropathy. Needle EMG is not recommended for screening diabetic neuropathy.

[Phrenic radix conduction time in inflammatory demyelinating polyneuropathy patients].

OBJECTIVE: To investigate the features and application of phrenic radix conduction time (PRCT) in inflammatory demyelinating polyneuropathy (IDP) patients. METHODS: Distal motor latency (DML) was recorded by stimulating phrenic nerve electrically and phrenic nerve root magnetically in 20 IDP patients with surface electrodes at intercostal space. The difference of the two DML was calculated and compared with those recorded previously from 61 sides in 31 healthy control subjects. RESULTS: PRCT of the IDP patients was longer than that of the controls, and it correlated with the severity of clinical dyspnea. The abnormal rate of PRCT was higher than the incidence of clinical dyspnea. CONCLUSIONS: PRCT could reflect the functional status of the spinal roots related to respiration in IDP patients at an electrophysiological level. It correlates well with the degree of clinical dyspnea. Its detection is helpful to find out the subclinical dyspnea in IDP patients.

A clinical neurophysiology study of Hirayama disease.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Nerve conduction studies in patients with dermatomyositis or polymyositis.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Association between DPP6 polymorphism and the risk of sporadic amyotrophic lateral sclerosis in Chinese patients.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.