| Part oneDistribution of Fasciculations in Different Regions of Patients with Amyotrophic Lateral Sclerosis under UltrasoundObjective:As an important hint for early diagnosis of amyotrophic lateral sclerosis(ALS),muscle fasciculations have attracted extensive attention.Due to non-invasion and higher sensitivity than needle electromyography,ultrasound has become an important method to observe fasciculations.This study aimed to investigate the fasciculations under ultrasound in different regions of ALS patients and its relationship with clinical factors,so as to explore the distribution pattern of fasciculations in ALS.Methods:113 ALS patients were recruited and their clinical data were collected.Ultrasound was performed on bulbar(geniohyoid,masseter,frontal muscle,sternocleidomastoid,trapezius),cervical(proximal flexors and extensors in upper limb,distal flexors and extensors in upper limb,abductor pollicis brevis,abductor digiti minimi,first interosseus,C5-C7 paraspinal muscles),thoracic(T2,T6 and T10 paraspinal muscles,T6 and T10 rectus abdominis),lumbosacral(proximal flexors and extensors in lower limb,distal flexors and extensors in lower limb,L1-L5 paraspinal muscles,S1-S5 paraspinal muscles)regions.The intensity of fasciculations was divided into five grades based on fring frequency and number in the involved muscle groups.Results:The fasciculation grade in cervical muscle groups was the highest(2[0-3]),followed by lumbosacral(1[0-3]),thoracic(0[0-1])and bulbar(0[0-1])muscle groups(P<0.05).The fasciculation grade in lumbosacral paraspinal muscle groups was the highest(0[0-3]),followed by thoracic(0[0-1])and cervical paraspinal muscle groups(0[0-0])(P<0.05).In cervical region,the fasciculation grade in the proximal(2[1-4])and distal(2[0-4])muscle groups in upper limb was the highest,followed by hand muscle groups(1[0-2])and cervical paraspinal muscle groups(P<0.05).In lumbosacral region,fasciculation grade in the proximal muscle groups in lower limb(2[1-3])was the highest,followed by the distal muscle groups in lower limb(1[0-2])and lumbosacral paraspinal muscle groups(P<0.05).Among the muscle groups affected from limb,the fasciculation grade of muscle groups in region of onset was the highest.Except the cervical paraspinal muscle groups,the fasciculation grade of muscle groups in region of onset from proximal site to distal site accorded with the trend from high to low.Fasciculations were most common in muscle groups that muscle strength grade was 2-4 and with mild-to-moderate atrophy.Conclusion:(1)Fasciculations in ALS patients were most common in cervical region,followed by lumbosacral region,while were relatively less common in thoracic and bulbar region.The distribution of fasciculations from proximal to distal site accorded with a certain pattern.Fasciculations were most common in proximal limb,followed by distal limb,and paraspinal regions.In paraspinal muscles,fasciculations were most common in lumbosacral region,followed by thoracic region,and less common in cervical region.(2)Fasciculations were most common in region of onset in ALS patients affected from limb,and the proximal-to-distal fasciculations follow a more-to-less distribution pattern in region of onset,but not in non-onset region.(3)Fasciculations were related to muscle strength and the degree of atrophy in ALS patients.Fasciculations were most common in muscle groups that muscle strength grade was 2-4 and with mild-to-moderate atrophy.Part two Electrophysiological,Ultrasonographic and Pathological Studies for Two-level Transsynaptic Degeneration of Motor System in Rats after StrokeObjective:Trans-synaptic degeneration(TSD)is widely demonstrated in the nervous system.After stroke,there is electrophysiological and pathological evidence of lower motor neuron damage in the affected limb,which is a common model for studying TSD of the motor system.The mechanism of TSD is currently not fully understood.In this study,a rat model of middle cerebral artery occlusion(MCAO)was established.Electrophysiology and ultrasound was performed on the normal and paralyzed hindlimbs,and pathological study was performed on the spinal cord and hindlimb muscles.We aimed to determine whether there was secondary lesion in the spinal motor neuron after stroke and to observe the change in both sides of muscles,exploring the potential mechanism.Methods:The rats were divided into pre-stroke group,24-hour stroke group,4-7 days after stroke group,12-14 days after stroke group and normal control group.Motor nerve conduction,F wave and fasciculation under ultrasound was performed on normal and paralyzed side of the rats.The spinal cord and hindlimb muscle specimens were collected.Spinal cord motor neuron degeneration was shown by NF200 staining.The activation of spinal microglia was shown by Ibal staining.The activation of ERK in spinal cord and muscles was shown by pERK staining.The muscle atrophy was shown by the muscle fiber diameter.Results:The CMAP amplitude of the paralyzed side was significantly lower than that of the normal side at 4-7 days after stroke(34.20±6.93mv vs 43.22±3.65mv,P<0.05),and was significantly lower than that before the stroke(34.20±6.93mv vs 44.25±4.90)(P<0.05).There was no significant difference in the frequency of F wave and fasciculation grade among these groups.The pathological study of spinal cord showed that the number of motor neurons on the affected side was significantly reduced at 4-7 days(9.00±5.05 vs 11.60±4.39,P<0.05)and 12-14 days(11.14±2.79 vs 14.29±3.09,P<0.05)after stroke compared with the unaffected side.Microglia on the affected side were significantly activated at 4-7 days and 12-14 days after stroke compared with the unaffected side,and were significantly activated at 4-7 days after stroke compared with the normal control group.ERK on the affected side was significantly activated at 12-14 days after stroke compared with the unaffected side.The pathological study of muscle showed that the muscle fiber diameter of the paralyzed side decreased significantly compared with the normal side at 4-7 days(31.61±8.59um vs 39.72±8.17um,P<0.05)and 12-14 days(38.99±9.02um vs 49.27± 15.23um,P<0.05)after stroke.There was no significant activation of the ERK pathway in the paralyzed muscle.Conclusions:(1)In SD rats,electrophysiology showed that the CMAP amplitude of the paralyzed side after stroke was significantly lower than that of the normal side,suggesting that TSD may occur in lower motor neurons after the lesion of upper motor neurons.(2)In SD rats,the neurons in the anterior horn of the affected spinal cord was significantly reduced pathologically,confirming the existence of TSD after stroke.The marked activation of the microglia and ERK pathway may be related to the initiation and progression of TSD.(3)In SD rats,atrophy of the paralyzed muscles was confirmed pathologically,suggesting the possibility for the existence of TSD in muscles after stroke. |
PDF Full Text Request