BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease involving both upper and lower motor neurons with no effective cure. Electrophysiological studies have found decremental responses during low-frequency repetitive nerve stimulation (RNS) except for diffused neurogenic activities. However, the difference between ALS and generalized myasthenia gravis (GMG) in terms of waveform features is unclear. In the current study, we explored the variation trend of the amplitudes curve between ALS and GMG with low-frequency, positive RNS, and the possible mechanism is discussed preliminarily. METHODS: A total of 85 ALS patients and 41 GMG patients were recruited. All patients were from Peking Union Medical College Hospital (PUMCH) between July 1, 2012 and February 28, 2015. RNS study included ulnar nerve, accessory nerve and facial nerve at 3 Hz and 5 Hz stimulation. The percentage reduction in the amplitude of the fourth or fifth wave from the first wave was calculated and compared with the normal values of our hospital. A 15% decrease in amplitude is defined as a decrease in amplitude. RESULTS: The decremental response at low-frequency RNS showed the abnormal rate of RNS decline was 54.1% (46/85) in the ALS group, and the results of different nerves were 54.1% (46/85) of the accessory nerve, 8.2% (7/85) of the ulnar nerve and 0% (0/85) of the facial nerve stimulation, respectively. In the GMG group, the abnormal rate of RNS decline was 100% (41/41) at low-frequency RNS of accessory nerves. However, there was a significant difference between the 2 groups in the amplitude after the sixth wave. CONCLUSIONS Both groups of patients are able to show a decreasing amplitude of low-frequency stimulation RNS, but the recovery trend after the sixth wave has significant variation. It implies the different pathogenesis of NMJ dysfunction of these 2 diseases.
Action Potentials ; physiology ; Adult ; Aged ; Amyotrophic Lateral Sclerosis ; physiopathology ; therapy ; Electric Stimulation Therapy ; Electromyography ; Female ; Humans ; Male ; Median Nerve ; physiology ; Middle Aged ; Motor Neurons ; physiology ; Muscle, Skeletal ; physiology ; Myasthenia Gravis ; physiopathology ; therapy ; Retrospective Studies ; Ulnar Nerve ; physiology

Background: Ongoing efforts have been made to identify new neuroimaging markers to track amyotrophic lateral sclerosis (ALS) progression. This study aimed to explore the monitoring value of multimodal magnetic resonance imaging (MRI) in the disease progression of ALS. Methods: From September 2015 to March 2017, ten patients diagnosed with ALS in Peking Union Medical College Hospital completed head MRI scans at baseline and during follow-up. Multimodal MRI analyses, including gray matter (GM) volume measured by voxel-based morphometry; cerebral blood flow (CBF) evaluated by arterial spin labeling; functional connectivity, including low-frequency fluctuation (fALFF) and regional homogeneity (ReHo), measured by resting-state functional MRI; and integrity of white-matter (WM) fiber tracts evaluated by diffusion tensor imaging, were performed in these patients. Comparisons of imaging metrics were made between baseline and follow-up using paired t-test. Results: In the longitudinal comparisons, the brain structure (GM volume of the right precentral gyri, left postcentral gyri, and right thalami) and perfusion (CBF of the bilateral temporal poles, left precentral gyri, postcentral gyri, and right middle temporal gyri) in both motor and extramotor areas at follow-up were impaired to different extents when compared with those at baseline (all P < 0.05, false discovery rate adjusted). Functional connectivity was increased in the motor areas (fALFF of the right precentral gyri and superior frontal gyri, and ReHo of right precentral gyri) and decreased in the extramotor areas (fALFF of the bilateral middle frontal gyri and ReHo of the right precuneus and cingulate gyri) (all P < 0.001, unadjusted). No significant changes were detected in terms of brain WM measures. Conclusion Multimodal MRI could be used to monitor short-term brain changes in ALS patients.
Adult ; Amyotrophic Lateral Sclerosis ; diagnostic imaging ; physiopathology ; Brain ; diagnostic imaging ; Cerebrovascular Circulation ; Disease Progression ; Female ; Humans ; Magnetic Resonance Imaging ; methods ; Male ; Middle Aged ; Multimodal Imaging ; methods ; Prospective Studies

BACKGROUNDSpontaneous potentials in electromyography (EMG) of paraspinal muscles are associated with diaphragm denervation and, therefore, poor respiratory function in amyotrophic lateral sclerosis (ALS) is understandable. EMG changes in the rectus abdominis (RA) display an effect similar to those in paraspinal muscles with respect to the function of lower motor neurons in the thoracic spinal cord. The RA denervation was examined to determine its association with ventilation dysfunction in ALS.

METHODSWe collected the clinical data of 128 patients with sporadic ALS in Department of Neurology of Peking University Third Hospital from 2009 to 2013. EMG, Revised ALS Functional Rating Scale (ALSFRS-R) and forced vital capacity (FVC) were performed in all patients and the differences in the EMG changes in RA between those with and without FVC ≥ 80% were analysed.

RESULTSThe mean FVC value was 83.4% ± 17.1% (range: 45%-131%) of the predicted value. A total of 79 patients displayed FVC ≥80%, and 49 patients displayed FVC <80%. Compared with the patients displaying a normal FVC (60/79, 75.9%), spontaneous activity in RA was significantly different among those patients displaying an FVC <80% (47/49, 95.9%). In addition, spontaneous potentials in RA were more frequently detected in patients exhibiting dyspnea (32/33, 97.0%) than in patients without dyspnea (75/95, 78.9%).

CONCLUSIONSpontaneous potentials in RA are associated with ventilation dysfunction and dyspnea in ALS patients.

Action Potentials ; physiology ; Adult ; Aged ; Aged, 80 and over ; Amyotrophic Lateral Sclerosis ; physiopathology ; Electromyography ; Electrophysiology ; Female ; Humans ; Male ; Middle Aged ; Motor Neurons ; physiology ; Paraspinal Muscles ; physiopathology ; Quadriceps Muscle ; innervation ; Rectus Abdominis ; innervation ; physiopathology ; Young Adult

BACKGROUNDSingle-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.

METHODSTwenty-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.

RESULTSThe 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.

CONCLUSIONCN-jitter and spike number could be used to quantitatively evaluate changes due to denervation-reinnervation in ALS.

Amyotrophic Lateral Sclerosis ; physiopathology ; Electrodes ; Electromyography ; Humans ; Middle Aged ; Needles ; ROC Curve

BACKGROUNDAmyotrophic 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.

METHODSWe 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.

RESULTSThe 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.

CONCLUSIONSThe 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.

Action Potentials ; Adult ; Aged ; Amyotrophic Lateral Sclerosis ; pathology ; physiopathology ; Diagnosis, Differential ; Female ; Hand ; pathology ; Humans ; Male ; Middle Aged ; Muscle, Skeletal ; physiopathology ; Muscular Atrophy ; pathology ; physiopathology ; Retrospective Studies ; Spinal Muscular Atrophies of Childhood ; pathology ; Spondylosis ; pathology

BACKGROUNDIn amyotrophic lateral sclerosis (ALS), repeater F waves are increased. Accurate assessment of repeater F waves requires an adequate sample size.

METHODSWe 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.

RESULTSIn 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.

CONCLUSIONSIncreased 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.

Adult ; Amyotrophic Lateral Sclerosis ; pathology ; physiopathology ; Female ; Humans ; Male ; Middle Aged ; Motor Neurons ; physiology ; Neural Conduction ; physiology ; Sample Size

BACKGROUNDDysfunctional 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.

METHODSWe 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.

RESULTSThe 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.

CONCLUSIONSIn 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.

Adult ; Aged ; Amyotrophic Lateral Sclerosis ; physiopathology ; Female ; Humans ; Male ; Middle Aged ; Motor Neuron Disease ; physiopathology ; Motor Neurons ; physiology ; Neural Conduction ; physiology ; Ulnar Nerve ; physiology

BACKGROUNDThe spectrum of abnormal behaviors in amyotrophic lateral sclerosis/motor neuron disease (ALS/MND) has been described, but its practical meaning, namely its impact on caregiver burden, has not been clearly documented in Chinese population. This study aimed to assess the distribution of abnormal behaviors in Chinese population, and to analyze the relationship between behavior changes and caregiver burden.

METHODSSixty-five patients with ALS/MND have been consecutively enrolled into registry platform of Peking Union Medical College Hospital. An investigation was performed to these patients and their caregivers using the revised ALS function rating scale, Frontal Behavioral Inventory-ALS version, the Frontal Assessment Battery, and the Caregiver Burden Inventory.

RESULTSTwenty-eight (43.1%) patients displayed abnormal behaviors of varying degrees, with one fulfilling the diagnostic criteria of frontotemporal lobe degeneration. Irritability, logopenia, and inflexibility ranked top 3 of abnormal behavior list. Correlation analysis revealed that the degree of behavioral change and frontal cognitive status were significantly associated with caregiver burden, with more extensive impact from disinhibitive behaviors. Analysis of covariance analysis showed that after associated factors were corrected, caregivers of patients with moderate to severe behavior change reported significantly heavier developmental burden, physical burden, and total burden than those with no behavioral change.

CONCLUSIONSNeurobehavioral symptoms could present in around 40% of Chinese patients with ALS/MND, and the distribution of these behaviors was also unique. Besides, abnormal behaviors were highly related to caregivers' burden.

Adult ; Aged ; Amyotrophic Lateral Sclerosis ; physiopathology ; psychology ; Behavioral Symptoms ; physiopathology ; psychology ; Caregivers ; psychology ; Female ; Humans ; Male ; Middle Aged ; Quality of Life

OBJECTIVETo study the clinical presentations of Kennedy disease (KD) and compare the neurophysiological features between KD and amyotrophic lateral sclerosis(ALS).

METHODSNine patients with KD, 13 patients with ALS and 26 normal control subjects were recruited. The clinical presentations of KD were analyzed, and the results of nerve conduction studies and electromyography were compared among the 3 groups.

RESULTSThe rates of tongue atrophy and facial fasciculation were 100% and 88.9%, respectively, in the early course and mid-course of KD, sensory damages might be perceived. 2)The sural nerve sensory nerve action potential (SNAP) was not elicited in 56.3% of the patients with KD, and sural nerve SNAP amplitudes were significantly lower in KD (7.9. ± 3.4 µV) than in ALS patients (20.0 ± 5.2 µV) and normal control subjects (26.1 ± 16.8 µV) (P<0.05).

CONCLUSIONB The onset of clinical presentations mimicking motor neuron disease, appearance of tongue atrophy and facial fasciculation in the early and mid-course, and presence of sensory impairment with a decreased sural nerve SNAP amplitude may suggest the diagnosis of KD and should prompt a genetic test for KD.

Amyotrophic Lateral Sclerosis ; physiopathology ; Bulbo-Spinal Atrophy, X-Linked ; physiopathology ; Electromyography ; Evoked Potentials ; Humans

Amyotrophic Lateral Sclerosis ; pathology ; physiopathology ; Female ; Frontotemporal Dementia ; pathology ; physiopathology ; Humans ; Male ; Middle Aged ; Psychotic Disorders ; pathology ; physiopathology