Differentiation Between Amyotrophic Lateral Sclerosis and Mimics Using Quantitative Analysis of Fsciculation with Muscle Ultrasound.

Objective To determine the diagnostic accuracy of the intensity of fasciculation evaluated by muscle ultrasound in the differential diagnosis of amyotrophic lateral sclerosis (ALS). Methods We prospectively recruited patients who had ALS and neuropathy-radiculopathy attending Peking Union Medical College Hospital from 2017 to 2020. Healthy adults from a community were recruited as healthy controls. Muscle strength was assessed using the Medical Research Council (MRC) scale. At the first visit to the hospital, patients were assessed for maximal grade of fasciculations, total fasciculation score, and fasciculation grade in 16 muscle groups of bilateral upper and lower limbs using ultrasonography. The sensitivity and specificity of maximal grade of fasciculations, total fasciculation score, and fasciculation grade for the diagnosis of ALS were assessed by receiver operating characteristic analyses. Results The percentage of limb muscles with a maximal fasciculation grade higher than grade 2 in ALS patients and neuropathy-radiculopathy patients was 84.9% and 9.8%, respectively (χ2 = 172.436, P < 0.01). Of the 16 limb muscles detected, the total fasciculation score [median (interquartile range)] was 29 (15, 41) in ALS patients and 3 (0, 8) in neuropathy-radiculopathy patients (Z = 9.642, P < 0.001). Remarkable fasciculations were seen in ALS patients whose muscles with a MRC score ranging from 2 to 4, followed by patients with MRC score 5, and then in those with MRC score 0 and 1. The sensitivity and specificity of total fasciculation score for diagnosis of ALS were 80.6% and 93.4%, respectively (cut-off value 14). In patients with ALS, for muscles with MRC score 4 and 5, the percentage of muscles with fasciculation grades ≥ 3 was 42.3% and 24.1% respectively, while in neuropathy-radiculopathy patients, the percentage for muscles with MRC score 4 and 5 was only 1.7% and 0, respectively. Conclusion A combined analysis of fasciculation intensity and MRC score of the limb muscles may be helpful for differential diagnosis of ALS.

13,14-seco-Withanolides from Physalis minima with Potential Anti-inflammatory Activity.

Four new 13,14-seco-withanolides, minisecolides A - D (1 - 4), together with three known analogues 5 - 7, were isolated from the whole plants of Physalis minima. The structures of new compounds were determined on the basis of spectroscopic analysis, including (1) H-, (13) C-NMR, 2D-NMR (HMBC, HSQC, ROESY), and HR-ESI-MS. Evaluation of all isolates for their inhibitory effects on nitric oxide (NO) production was conducted on lipopolysaccaride-activated RAW264.7 macrophages. Compounds 2, 3, 5, and 6 showed inhibitory activities, especially for compound 5 with IC50 value of 3.87 µm.

Clinical recommendations for perioperative immunotherapy-induced adverse events in patients with non-small cell lung cancer.

Perioperative adjuvant treatment has become an increasingly important aspect of the management of patients with non-small cell lung cancer (NSCLC). In particular, the success of immune checkpoint inhibitors, such as antibodies against PD-1 and PD-L1, in patients with lung cancer has increased our expectations for the success of these therapeutics as neoadjuvant immunotherapy. Neoadjuvant therapy is widely used in patients with resectable stage IIIA NSCLC and can reduce primary tumor and lymph node stage, improve the complete resection rate, and eliminate microsatellite foci; however, complete pathological response is rare. Moreover, because the clinical benefit of neoadjuvant therapy is not obvious and may complicate surgery, it has not yet entered the mainstream of clinical treatment. Small-scale clinical studies performed in recent years have shown improvements in the major pathological remission rate after neoadjuvant therapy, suggesting that it will soon become an important part of NSCLC treatment. Nevertheless, neoadjuvant immunotherapy may be accompanied by serious adverse reactions that lead to delay or cancellation of surgery, additional illness, and even death, and have therefore attracted much attention. In this article, we draw on several sources of information, including (i) guidelines on adverse reactions related to immune checkpoint inhibitors, (ii) published data from large-scale clinical studies in thoracic surgery, and (iii) practical experience and published cases, to provide clinical recommendations on adverse events in NSCLC patients induced by perioperative immunotherapy.

A Comprehensive Analysis of 2013 Dystrophinopathies in China: A Report From National Rare Disease Center.

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive neuromuscular disorders caused by mutations in DMD. A high-quality database of DMD/BMD is essential not only for clinical practice but also for fundamental research. Here, we aimed to build the largest Chinese national dystrophinopathy database using the National Rare Diseases Registry System of China. Peking Union Medical College Hospital (PUMCH) was the National Rare Diseases Center of China. This research involved 2013 patients with dystrophinopathies, whose diagnoses were confirmed; they were registered and followed up at PUMCH from March 2011 to December 2018. Family history, clinical signs, and treatment data were reported for patients with DMD and BMD at different rates. All six serum biochemical indexes could accurately distinguish between DMD and BMD patients. Copy number variations were the most frequent mutation type (79.2% in DMD and 84.3% in BMD), of which large deletions accounted for 88.4 and 88.6%, large duplications accounted for 11.6 and 11.4% in DMD and BMD, respectively. An exon deletion hotspot, located in exons 45-54, was observed in DMD, and intron 44 was the most frequent deletion starting point (26.5%). Duplication and single nucleotide variations appeared to be uniformly distributed among all exons. Eleven patients were identified to have ultrarare mutation types. Eleven other patients suffered from two separate mutations simultaneously, some of which may have taken place via dependent mechanisms. Thus, we have established the largest hospital-based Chinese dystrophinopathy database via the National Rare Diseases Registry System. This study provides valuable information for further diagnostic and therapeutic studies of dystrophinopathy.

[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 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.

The Awaji criteria increases the diagnostic sensitivity of the revised El Escorial criteria for amyotrophic lateral sclerosis diagnosis in a Chinese population.

OBJECTIVES: The accurate and early diagnosis of amyotrophic lateral sclerosis (ALS) is important for extending the life expectancy of patients. However, previous studies that have assessed the diagnostic sensitivities of the Awaji criteria (AC) and the revised El Escorial criteria (rEEC) in patients with ALS have been inconsistent, most of them were consensual regarding the advantage of Awaji over conventional criteria. Our study sought to compare the roles of AC and rEEC in the diagnosis of ALS. METHODS: Data from a total of 294 consecutive patients with ALS were collected between January 2014 and August 2015 in the Peking Union Medical College Hospital. The clinical and electrophysiological records of 247 patients were eventually analyzed. The primary outcome measures were the sensitivities of the AC and rEEC for the diagnosis of ALS. RESULTS: The sensitivity of probable or definite ALS as diagnosed with the AC (78%) was greater than that of the rEEC (36%, P <0.001). Following the application of the AC, 103 of the 147 patients categorized as probable ALS-laboratory supported from the rEEC were upgraded to probable or definite ALS, and 44 were downgraded to possible ALS. CONCLUSIONS: Our data demonstrated that the AC exhibited greater diagnostic sensitivity than the rEEC in a Chinese ALS population. The use of the AC should be considered in clinical practice.

Effectiveness of repetitive transcranial magnetic stimulation (rTMS) after acute stroke: A one-year longitudinal randomized trial.

AIMS: To evaluate the effectiveness of repetitive transcranial magnetic stimulation (rTMS) on motor recovery after stroke using a prospective, double-blind, randomized, sham-controlled study. METHODS: Patients with unilateral subcortical infarction in the middle cerebral artery territory within 1 week after onset were enrolled. The patients were randomly divided into an rTMS treatment group and a sham group. We performed high-frequency rTMS or sham rTMS on the two groups. Motor functional scores were assessed pre- and post-rTMS/sham rTMS and at 1 month, 3 months, 6 months, and 1 year after stroke onset. The scores included the National Institutes of Health Stroke Scale (NIHSS), Barthel Index (BI), Fugl-Meyer Assessment Upper Limb/Lower Limb (FMA-UL/LL), modified Rank Score (mRS), and the resting motor threshold (RMT) of the hemiplegic limb. RESULTS: At baseline, no significant differences were found between the two groups for motor functional scores. On the second day after rTMS treatment, score improvements of the NIHSS, BI, FMA-UL in the real treatment group were more significant than those in the sham group. In addition, similar results were obtained at 1 month. However, at 3 months, 6 months, and 1 year after onset, no significant differences in improvement were observed between the two groups, except for the FMA-UL score improvement. CONCLUSION: rTMS facilitates motor recovery of acute stroke patients, and the effect can last to 1 month, except the function improvement on upper extremities could last for 1 year. A single course of rTMS in the acute stage may induce the improvement of upper extremities function lasted for 1 year.

Quantitating Changes in Jitter and Spike Number Using Concentric Needle Electrodes in Amyotrophic Lateral Sclerosis Patients.

BACKGROUND: Single-fiber electromyography (SFEMG) has been suggested as a quantitative method for supporting chronic partial denervation in amyotrophic lateral sclerosis (ALS) by the revised EI Escorial criteria. Although concentric needle (CN) electrodes have been used to assess jitter in myasthenia gravis patients and healthy controls, there are few reports using CN electrodes to assess motor unit instability and denervation in neurogenic diseases. The aim of this study was to determine whether quantitative changes in jitter and spike number using CN electrodes could be used for ALS studies. METHODS: Twenty-seven healthy controls and 23 ALS patients were studied using both CN and single-fiber needle (SFN) electrodes on the extensor digitorum communis muscle with an SFEMG program. The SFN-jitter and SFN-fiber density data were measured using SFN electrodes. The CN-jitter and spike number were measured using CN electrodes. RESULTS: The mean CN-jitter was significantly increased in ALS patients (47.3 ± 17.0 µs) than in healthy controls (27.4 ± 3.3 µs) (P < 0.001). Besides, the mean spike number was significantly increased in ALS patients (2.5 ± 0.5) than in healthy controls (1.7 ± 0.3) (P < 0.001). The sensitivity and specificity in the diagnosis of ALS were 82.6% and 92.6% for CN-jitter (cut-off value: 32 µs), and 91.3% and 96.3% for the spike number (cut-off value: 2.0), respectively. There was no significant difference between the SFN-jitter and CN-jitter in ALS patients; meanwhile, there was no significant difference between the SFN-jitter and CN-jitter in healthy controls. CONCLUSION: CN-jitter and spike number could be used to quantitatively evaluate changes due to denervation-reinnervation in ALS.

Rapidly Progressive Polyneuropathy in a Patient With Monoclonal Gammopathy: A Case Report of POEMS Syndrome and Beyond.

Neuropathy, the dominant clinical feature of POEMS syndrome, is typically distal, symmetric, and slowly progressive with demyelinating changes. After a gradual proximal spread, it usually results in severe muscle weakness and functional disabilities. Cases characterized by acute onset polyneuropathy are rarely described. In the present report, we describe a 32-year-old male diagnosed as POEMS syndrome, but presenting with a rapidly evolving polyneuropathy. Detailed clinical, electrophysiological, and genetic studies revealed a coexisting underdiagnosed inherited axonal neuropathy, namely Charcot-Marie-Tooth disease 2A2. The patient received lenalidomide-based chemotherapy and consolidated by autologous stem cell transplantation for his POEMS syndrome, which improved the neurological disability. In most conditions, only 1 cause is responsible for a patient's polyneuropathy. However, an insidious inherited neuropathy can be overlooked, when an acquired condition is present. The case illustrated here, to the best of our knowledge, is the first one with coexistent axonal type Charcot-Marie-Tooth disease and POEMS syndrome, suggesting that an unrecognized inherited neuropathy may change the disease course of a further acquired neuropathy.

Cerebral Functional Reorganization in Ischemic Stroke after Repetitive Transcranial Magnetic Stimulation: An fMRI Study.

AIMS: Our study aimed to figure out brain functional reorganization evidence after repetitive transcranial magnetic stimulation (rTMS) using the resting-state functional magnetic resonance imaging (rsfMRI). METHODS: Twelve patients with unilateral subcortex lesion in the middle cerebral artery territory were recruited. Seven of them received a 10-day rTMS treatment beginning at about 5 days after stroke onset. The remaining five received sham treatment. RsfMRI and motor functional scores were obtained before and after rTMS or sham rTMS. RESULTS: The rTMS group showed motor recovery according to the behavioral testing scores, while there was no significant difference of motor functional scores in the sham group before and after the sham rTMS. It proved that rTMS facilitates motor recovery of early ischemic stroke patients. Compared with the sham, the rTMS treatment group achieved increased functional connectivity (FC) between ipsilesional M1 and contralesional M1, supplementary motor area, bilateral thalamus, and contralesional postcentral gyrus. And decreased FC was found between ipsilesional M1 and ipsilesional M1, postcentral gyrus and inferior and middle frontal gyrus. CONCLUSION: Increased or decreased FC detected by rsfMRI is an important finding to understand the mechanism of brain functional reorganization. The rTMS treatment is a promising therapeutic approach to facilitate motor rehabilitation for early stroke patients.

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.

Effects of transcranial magnetic stimulation on motor cortical excitability and neurofunction after cerebral ischemia-reperfusion injury in rats.

OBJECTIVE: To clarify the effects of repetitive transcranial magnetic stimulation (rTMS) on rat motor cortical excitability and neurofunction after cerebral ischemia-reperfusion injury. METHODS: After determined awake resting motor threshold (MT) and motor evoked potentials (MEPs) of right hindlimbs, 20 Sprague-Dawley rats were subjected to middle cerebral artery occlusion (MCAO) reperfusion injury, then rTMS were applied to rTMS group (n=10) at different time, while control group (n=10) received no stimulation. A week later, MT and MEPs were evaluated again, as well as neurological deficits and infarct volume. The effects of rTMS and MCAO reperfusion injury on these parameters were analyzed. RESULTS: After MCAO reperfusion, both MT level and neurological deficit scores increased, distinct focal infarction formed, and latency of MEP elongated. Compared with the control group, the increased extent of MT and neurological scores of rats receiving rTMS were significantly lower (P < 0.05), as well as the infarct volumes reduced significantly (P < 0.05). But MEP was not affected by rTMS obviously. There was a positive linear correlation between postinjury MT and infarct volume (r = 0.64, P < 0.05). CONCLUSION: rTMS may facilitate neurofunction recovery after cerebral ischemia-reperfusion. Postinjury MT could provide prognostic information after MCAO reperfusion injury.

Tumor necrosis factor-alpha polymorphism and secretion in myasthenia gravis.

OBJECTIVE: To analyze the relationship between tumor necrosis factor-alpha (TNFalpha) gene promoter -308 polymorphism and myasthenia gravis (MG) in Chinese and analyze secretion of TNFalpha in peripheral blood mononuclear cells (PBMC) in MG patients. METHODS: A biallelic polymorphism at position -308 in the promoter of TNFalpha gene was screened by PCR amplification and NcoI recognition site. One hundred and twenty-three MG cases and 115 healthy controls were included in this study. MG patients were classified to different groups according to clinical type, age at onset, and sex respectively. PBMC were isolated from 20 patients and 20 healthy controls, and then cultured in the presence or absence of phytohemagglutinin (PHA) and acetycholine receptors (AchR). The supernatants were harvested after incubation and stored until TNFalpha was assayed by enzyme-linked immunosorbent assay. RESULTS: The frequency of TNFalpha-308 allele 2 (A) was found significantly increase in MG patients and showed a trend especially in late onset (> or =40 years) and male patients (P < 0.05). The allele A had no relationship with thymic pathogenesis in MG patients. But frequency of allele A was significantly higher in general type than in ocular type (P < 0.05). MG patients had a higher inducible level of TNFalpha by PHA and AchR, and could be down regulated after treatment. CONCLUSION: Polymorphism in TNFalpha gene promoter -308 is associated with onset of MG. The microsatellite allele TNFalpha2 confer risk for the development of MG in Chinese patients. MG patients have a higher inducible level of TNFalpha.

Asynchronization in Changes of Electrophysiology and Pathology of Spinal Cord Motor Neurons in Rats Following Middle Cerebral Artery Occlusion.

BACKGROUND: Motor dysfunction is common in stroke patients. Clinical electrophysiological studies suggest that transsynaptic degeneration occurred in the lower motor neurons, while pathological evidence is lacked. This study aimed to combine the electrophysiological and pathological results to prove the existence of transsynaptic degeneration in the motor system after stroke. METHODS: Modified neurologic severity score, electrophysiological, and pathological assessments were evaluated in rats before middle cerebral artery occlusion (MCAO), and at 24 hours, 7 days, and 14 days after MCAO. Paired and independent-sample t-tests were applied to assess the changes of electrophysiological and pathological data. RESULTS: Compound motor action potential amplitude in the paretic side was significantly lower than the nonparetic side at both 24 hours (61.9 ± 10.4 vs. 66.6 ± 8.9, P < 0.05) and 7 days (60.9 ± 8.4 vs. 67.3 ± 9.6, P < 0.05) after MCAO. Motor unit number estimation of the paretic side was significantly less than the nonparetic side (379.0 ± 84.6 vs. 445.0 ± 89.5, P < 0.05) at 7 days after MCAO. Until 14 days after stroke, the pathological loss of motor neurons was detected. Motor neurons in 14-day MCAO group were significantly decreased, compared with control group (5.3 ± 0.7 vs. 7.3 ± 1.8, P < 0.05). CONCLUSIONS: Both electrophysiological and pathological studies showed transsynaptic degeneration after stroke. This study identified the asynchronization in changes of electrophysiology and pathology. The abnormal physiological changes and function impairment can be detected in the early stage and recovered quickly, while the pathological loss of motor neuron can be detected only in a later stage.

Single-fiber Electromyography in the Extensor Digitorum Communis for the Predictive Prognosis of Ocular Myasthenia Gravis: A Retrospective Study of 102 Cases.

BACKGROUND: Single-fiber electromyography (SFEMG) abnormality in the extensor digitorum communis (EDC) was reported in ocular myasthenia gravis (OMG), which indicated subclinical involvement beyond extraocular muscles in OMG patients. The relationship between the abnormal findings of SFEMG in EDC and the probability for OMG to develop generalized myasthenia gravis (GMG) is unknown. This retrospective study aimed to determine the predictive value of abnormality of SFEMG in EDC of OMG patients. METHODS: One-hundred and two OMG patients underwent standard clinical diagnosis process and SFEMG test in EDC muscle when diagnosed and were clinically followed up for 5 years. The SFEMG data were compared between different clinical groups according to thymus status, onset age, and different outcome of OMG developing. Chances of progressing to GMG were compared between two different groups according to SFEMG and repetitive nerve stimulation (RNS) results, acetylcholine receptor antibody (AchRAb) titer, thymus status, and onset age. RESULTS: Abnormal SFEMG results were observed in 84 (82.4%) patients. The mean jitter, percentage of jitter >55 µs (%), and blocking were higher in OMG patients than in healthy volunteers. There were no statistical differences in jitter analysis between thymoma group and non-thymoma group (P = 0.65), or between the later OMG group and the later GMG group (P = 0.31), including mean jitter, percentage of jitter >55 µs (%), and blocking. Elderly group (≥45 years old) had a higher mean jitter than younger group (t = 2.235, P = 0.028). Total 55 OMG developed GMG, including 47 in abnormal SFEMG group while 8 in normal SFEMG group. There was no statistical difference in the conversion rates between the two groups (χ2 = 0.790, P = 0.140). RNS abnormality, AchRab titer, or onset age had no correlation with OMG prognosis (P = 0.150, 0.070, 0.120, respectively) while thymoma did (χ2 = 0.510, P = 0.020). CONCLUSION: SFEMG test in the EDC showed high abnormality in OMG, suggesting subclinical involvement other than extraocular muscles. Nevertheless, the abnormal jitter analysis did not predict the prognosis of OMG according to clinical follow-up.

Importance of sample size for the estimation of repeater F waves in amyotrophic lateral sclerosis.

BACKGROUND: In amyotrophic lateral sclerosis (ALS), repeater F waves are increased. Accurate assessment of repeater F waves requires an adequate sample size. METHODS: We studied the F waves of left ulnar nerves in ALS patients. Based on the presence or absence of pyramidal signs in the left upper limb, the ALS patients were divided into two groups: One group with pyramidal signs designated as P group and the other without pyramidal signs designated as NP group. The Index repeating neurons (RN) and Index repeater F waves (Freps) were compared among the P, NP and control groups following 20 and 100 stimuli respectively. For each group, the Index RN and Index Freps obtained from 20 and 100 stimuli were compared. RESULTS: In the P group, the Index RN (P = 0.004) and Index Freps (P = 0.001) obtained from 100 stimuli were significantly higher than from 20 stimuli. For F waves obtained from 20 stimuli, no significant differences were identified between the P and NP groups for Index RN (P = 0.052) and Index Freps (P = 0.079); The Index RN (P < 0.001) and Index Freps (P < 0.001) of the P group were significantly higher than the control group; The Index RN (P = 0.002) of the NP group was significantly higher than the control group. For F waves obtained from 100 stimuli, the Index RN (P < 0.001) and Index Freps (P < 0.001) of the P group were significantly higher than the NP group; The Index RN (P < 0.001) and Index Freps (P < 0.001) of the P and NP groups were significantly higher than the control group. CONCLUSIONS: Increased repeater F waves reflect increased excitability of motor neuron pool and indicate upper motor neuron dysfunction in ALS. For an accurate evaluation of repeater F waves in ALS patients especially those with moderate to severe muscle atrophy, 100 stimuli would be required.

F Wave Study in Amyotrophic Lateral Sclerosis: Assessment of Segmental Motoneuronal Dysfunction.

BACKGROUND: Dysfunctional spinal circuit may play a role in the pathophysiology of amyotrophic lateral sclerosis (ALS). The purpose of this study was to use F waves for assessment of segmental motoneuronal excitability following upper motor neuron (UMN) dysfunctions in ALS. METHODS: We studied the F waves of 152 ulnar nerves recorded from abductor digiti minimi in 82 patients with ALS. Two groups of hands were defined based on the presence or absence of pyramidal signs in the same upper limb. The group with pyramidal signs in the upper limbs was designated as the P group, and the group without pyramidal signs in the upper limbs was designated as the NP group. RESULTS: The mean (P < 0.001), median (P < 0.001) and maximum (P = 0.035) F wave amplitudes, mean (P < 0.001), median (P < 0.001) and maximum (P = 0.003) F/M amplitude ratio, index repeating neuron (P < 0.001) and index repeater F waves (P < 0.001) of the P group were significantly increased compared with the NP group. No significant differences were identified for F wave chronodispersion (P = 0.628), mean F wave latency (P = 0.151), minimum F wave latency (P = 0.211), maximum F wave latency (P = 0.199), F wave persistence (P = 0.738), F wave duration (P = 0.152), F wave conduction velocity (P = 0.813) and number of giant F waves (P = 0.072) between the two groups. CONCLUSIONS: In this study, increased F wave amplitude, F/M amplitude ratio and number of repeater F waves reflected enhanced segmental motoneuronal excitability following UMN dysfunctions in ALS.

Single fiber electromyography in the diagnosis of ocular myasthenia gravis: report of 90 cases.

BACKGROUND: The aim of this study was to evaluate single fiber electromyography (SFEMG) in the diagnosis of ocular myasthenia gravis (OMG), compared with repetitive nerve stimulation (RNS) and blood concentration of antibody to acetylcholine receptor (AchRAb). METHODS: SFEMG, RNS and AchRAb titration were measured in 90 patients with OMG (44 men, 46 women). RESULTS: Markedly increased jitter and ratio of block in the frontalis and the extensor digitorum communis (EDC) were observed (83.3% and 61.1%, respectively). The mean jitter was 43.6 +/- 14.5 micros, and the percentages of jitter>55 micros and blocking were 16.9% +/- 19% and 3.5% +/- 9.5% respectively in the EDC. The mean jitter was 64.3 +/- 25.6 micros, and the percentages of jitter > 55 micros and blocking were 33.5% +/- 27.6% and 29.3% +/- 23.2% respectively in the frontalis. The percentage of abnormal RNS was 27.8% (25/90). There was an increased AchRAb titration in 29 (32.2%) of the 90 patients. Increased jitter, blocking was negatively correlated with maximum decrement to RNS (P < 0.01). 11.4% (4/35) of patients with abnormal RNS and 24.1% (7/29) patients with abnormal AchRAb were seen in the patients with normal SFEMG in the EDC. CONCLUSION: SFEMG test showed the highest sensitivity in the diagnosis of OMG. To our knowledge, the three methods (SFEMG, RNS and AchRAb) are complementary in the diagnosis and differential diagnosis of OMG.