Biomaterial Database

The mixed nerve silent period in normal subjects and patients with amyotrophic lateral sclerosis. 1998

J M Shefner, and E L Logigian

Department of Neurology, SUNY Health Science Center, Syracuse, USA.

The mixed nerve silent period (MNSP) is the period of motor inhibition observed when the mixed nerve innervating a voluntary activated muscle is electrically stimulated. The etiology of the MNSP is multifactorial, with the early and middle phases likely to be related to the effects of antidromic motor nerve activity on peripheral nerve and spinal interneurons. The terminal portion of the MNSP is mediated primarily by small diameter myelinated afferent fibers. The duration and latency of the MNSP vary as a function of both strength of stimulation and level of voluntary activation. In this study, we varied both stimulus strength and exertion, and compared MNSPs in 6 normal subjects with those obtained from 8 patients with amyotrophic lateral sclerosis (ALS). Differences between patients and control subjects included a longer duration of the MNSP in ALS patients, as well as less complete inhibition in the middle phases of the period. The longer duration of the MNSP may reflect an abnormality of sensory motor processing in ALS patients. The physiology underlying the incomplete inhibition is unclear, but may reflect abnormalities in Renshaw cell function.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D009046	Motor Neurons	Neurons which activate MUSCLE CELLS.	Neurons, Motor,Alpha Motorneurons,Motoneurons,Motor Neurons, Alpha,Neurons, Alpha Motor,Alpha Motor Neuron,Alpha Motor Neurons,Alpha Motorneuron,Motoneuron,Motor Neuron,Motor Neuron, Alpha,Motorneuron, Alpha,Motorneurons, Alpha,Neuron, Alpha Motor,Neuron, Motor
D009431	Neural Conduction	The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.	Nerve Conduction,Conduction, Nerve,Conduction, Neural,Conductions, Nerve,Conductions, Neural,Nerve Conductions,Neural Conductions
D009475	Neurons, Afferent	Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.	Afferent Neurons,Afferent Neuron,Neuron, Afferent
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D000368	Aged	A person 65 years of age or older. For a person older than 79 years, AGED, 80 AND OVER is available.	Elderly
D000690	Amyotrophic Lateral Sclerosis	A degenerative disorder affecting upper MOTOR NEURONS in the brain and lower motor neurons in the brain stem and SPINAL CORD. Disease onset is usually after the age of 50 and the process is usually fatal within 3 to 6 years. Clinical manifestations include progressive weakness, atrophy, FASCICULATION, hyperreflexia, DYSARTHRIA, dysphagia, and eventual paralysis of respiratory function. Pathologic features include the replacement of motor neurons with fibrous ASTROCYTES and atrophy of anterior SPINAL NERVE ROOTS and corticospinal tracts. (From Adams et al., Principles of Neurology, 6th ed, pp1089-94)	ALS - Amyotrophic Lateral Sclerosis,Lou Gehrig Disease,Motor Neuron Disease, Amyotrophic Lateral Sclerosis,Amyotrophic Lateral Sclerosis With Dementia,Amyotrophic Lateral Sclerosis, Guam Form,Amyotrophic Lateral Sclerosis, Parkinsonism-Dementia Complex of Guam,Amyotrophic Lateral Sclerosis-Parkinsonism-Dementia Complex 1,Charcot Disease,Dementia With Amyotrophic Lateral Sclerosis,Gehrig's Disease,Guam Disease,Guam Form of Amyotrophic Lateral Sclerosis,Lou Gehrig's Disease,Lou-Gehrigs Disease,ALS Amyotrophic Lateral Sclerosis,Amyotrophic Lateral Sclerosis Parkinsonism Dementia Complex 1,Amyotrophic Lateral Sclerosis, Parkinsonism Dementia Complex of Guam,Disease, Guam,Disease, Lou-Gehrigs,Gehrig Disease,Gehrigs Disease,Sclerosis, Amyotrophic Lateral