Biomaterial Database

H-reflex changes following spinal cord injury. 1985

J W Little, and E M Halar

Changes in both central synaptic excitability (CSE) and peripheral sensitivity of muscle spindle stretch receptors have been hypothesized to contribute to hyperactive stretch reflexes of spasticity. To assess CSE, the monosynaptic H-reflex to the triceps surae muscles was tested serially over the first six months after traumatic spinal cord injury (SCI). Six clinically complete SCI patients were compared to age-matched control subjects. As a measure of H-reflex excitability, H/M ratios were calculated by dividing maximum H-reflex by maximum M-response amplitude. Analysis of variance over the testing trials showed significant change in H/M ratios for SCI patients (p less than 0.01). T-tests comparing mean H/M ratios at different time periods after SCI revealed a significant increment after three months (p less than 0.01). H-reflex amplitude also increased significantly over this time period (p less than 0.04), but M-response amplitude did not change significantly. These increases in H/M ratio and H-reflex amplitude suggest that an increase in CSE may contribute to the appearance of hyperreflexia after SCI.

UI	MeSH Term	Description	Entries
D009128	Muscle Spasticity	A form of muscle hypertonia associated with upper MOTOR NEURON DISEASE. Resistance to passive stretch of a spastic muscle results in minimal initial resistance (a "free interval") followed by an incremental increase in muscle tone. Tone increases in proportion to the velocity of stretch. Spasticity is usually accompanied by HYPERREFLEXIA and variable degrees of MUSCLE WEAKNESS. (From Adams et al., Principles of Neurology, 6th ed, p54)	Clasp-Knife Spasticity,Spastic,Clasp Knife Spasticity,Spasticity, Clasp-Knife,Spasticity, Muscle
D009133	Muscular Atrophy	Derangement in size and number of muscle fibers occurring with aging, reduction in blood supply, or following immobilization, prolonged weightlessness, malnutrition, and particularly in denervation.	Atrophy, Muscle,Neurogenic Muscular Atrophy,Neurotrophic Muscular Atrophy,Atrophies, Muscle,Atrophies, Muscular,Atrophies, Neurogenic Muscular,Atrophies, Neurotrophic Muscular,Atrophy, Muscular,Atrophy, Neurogenic Muscular,Atrophy, Neurotrophic Muscular,Muscle Atrophies,Muscle Atrophy,Muscular Atrophies,Muscular Atrophies, Neurogenic,Muscular Atrophies, Neurotrophic,Muscular Atrophy, Neurogenic,Muscular Atrophy, Neurotrophic,Neurogenic Muscular Atrophies,Neurotrophic Muscular Atrophies
D010276	Parasympatholytics	Agents that inhibit the actions of the parasympathetic nervous system. The major group of drugs used therapeutically for this purpose is the MUSCARINIC ANTAGONISTS.	Antispasmodic,Antispasmodic Agent,Antispasmodic Drug,Antispasmodics,Parasympathetic-Blocking Agent,Parasympathetic-Blocking Agents,Parasympatholytic,Parasympatholytic Agent,Parasympatholytic Drug,Spasmolytic,Spasmolytics,Antispasmodic Agents,Antispasmodic Drugs,Antispasmodic Effect,Antispasmodic Effects,Parasympatholytic Agents,Parasympatholytic Drugs,Parasympatholytic Effect,Parasympatholytic Effects,Agent, Antispasmodic,Agent, Parasympathetic-Blocking,Agent, Parasympatholytic,Agents, Antispasmodic,Agents, Parasympathetic-Blocking,Agents, Parasympatholytic,Drug, Antispasmodic,Drug, Parasympatholytic,Drugs, Antispasmodic,Drugs, Parasympatholytic,Effect, Antispasmodic,Effect, Parasympatholytic,Effects, Antispasmodic,Effects, Parasympatholytic,Parasympathetic Blocking Agent,Parasympathetic Blocking Agents
D011930	Reaction Time	The time from the onset of a stimulus until a response is observed.	Response Latency,Response Speed,Response Time,Latency, Response,Reaction Times,Response Latencies,Response Times,Speed, Response,Speeds, Response
D012023	Reflex, Monosynaptic	A reflex in which the AFFERENT NEURONS synapse directly on the EFFERENT NEURONS, without any INTERCALATED NEURONS. (Lockard, Desk Reference for Neuroscience, 2nd ed.)	Monosynaptic Reflex
D006181	H-Reflex	A monosynaptic reflex elicited by stimulating a nerve, particularly the tibial nerve, with an electric shock.	H Reflex,H-Reflexes,H Reflexes,Reflex, H
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000293	Adolescent	A person 13 to 18 years of age.	Adolescence,Youth,Adolescents,Adolescents, Female,Adolescents, Male,Teenagers,Teens,Adolescent, Female,Adolescent, Male,Female Adolescent,Female Adolescents,Male Adolescent,Male Adolescents,Teen,Teenager,Youths
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
D013119	Spinal Cord Injuries	Penetrating and non-penetrating injuries to the spinal cord resulting from traumatic external forces (e.g., WOUNDS, GUNSHOT; WHIPLASH INJURIES; etc.).	Myelopathy, Traumatic,Injuries, Spinal Cord,Post-Traumatic Myelopathy,Spinal Cord Contusion,Spinal Cord Laceration,Spinal Cord Transection,Spinal Cord Trauma,Contusion, Spinal Cord,Contusions, Spinal Cord,Cord Contusion, Spinal,Cord Contusions, Spinal,Cord Injuries, Spinal,Cord Injury, Spinal,Cord Laceration, Spinal,Cord Lacerations, Spinal,Cord Transection, Spinal,Cord Transections, Spinal,Cord Trauma, Spinal,Cord Traumas, Spinal,Injury, Spinal Cord,Laceration, Spinal Cord,Lacerations, Spinal Cord,Myelopathies, Post-Traumatic,Myelopathies, Traumatic,Myelopathy, Post-Traumatic,Post Traumatic Myelopathy,Post-Traumatic Myelopathies,Spinal Cord Contusions,Spinal Cord Injury,Spinal Cord Lacerations,Spinal Cord Transections,Spinal Cord Traumas,Transection, Spinal Cord,Transections, Spinal Cord,Trauma, Spinal Cord,Traumas, Spinal Cord,Traumatic Myelopathies,Traumatic Myelopathy