Biomaterial Database

Reciprocal Ia inhibition in spastic paralysis in man. 1978

N Yanagisawa, and R Tanaka

Reciprocal reflex connections were studied in capsular hemiplegia and spastic paresis with spinal cord lesions, using Lloyd's technique. Effects of conditioning stimulation of the tibial or peroneal nerve on the H reflex in the antagonists were examined. Stimulus intensity was controlled with reference to the threshold of the M wave. Weaker stimulation than this threshold was regarded as stimulation of group I afferents. It aroused no subjection sensation in intact subjects. Early and strong inhibition, comparable to Ia inhibition in the cat (Lloyd 1946), was observed from weak stimulation of the tibial nerve on the pre-tibial (flexor) H reflex, but not from the peroneal nerve on the triceps surae (extensor) H reflex in capsular hemiplegia. Alcohol block of extensor motor points resulted in reduction of spasticity without further paralysis in the blocked muscle and a remarkable increase in strength of the antagonist pre-tibial muscles. These results suggest that an extensor spasticity withe flexor weakness, which is common in capsular hemiplegia, may be due to an imbalance of reflex activities via Ia muscle afferents, and that a part of flexor weakness can be restored by "disinhibition' by reduction of Ia inflow from extensor muscles. Ia inhibition was also observed in one third of cases with spinal cord lesions at rest. It returned to normal after recovery from spastic paresis by radical therapy in some cases.

UI	MeSH Term	Description	Entries
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
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
D009433	Neural Inhibition	The function of opposing or restraining the excitation of neurons or their target excitable cells.	Inhibition, Neural
D010243	Paralysis	A general term most often used to describe severe or complete loss of muscle strength due to motor system disease from the level of the cerebral cortex to the muscle fiber. This term may also occasionally refer to a loss of sensory function. (From Adams et al., Principles of Neurology, 6th ed, p45)	Palsy,Plegia,Todd Paralysis,Todd's Paralysis,Palsies,Paralyses,Paralysis, Todd,Paralysis, Todd's,Plegias,Todds Paralysis
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
D012026	Reflex, Stretch	Reflex contraction of a muscle in response to stretching, which stimulates muscle proprioceptors.	Reflex, Tendon,Stretch Reflex,Tendon Reflex
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
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
D006429	Hemiplegia	Severe or complete loss of motor function on one side of the body. This condition is usually caused by BRAIN DISEASES that are localized to the cerebral hemisphere opposite to the side of weakness. Less frequently, BRAIN STEM lesions; cervical SPINAL CORD DISEASES; PERIPHERAL NERVOUS SYSTEM DISEASES; and other conditions may manifest as hemiplegia. The term hemiparesis (see PARESIS) refers to mild to moderate weakness involving one side of the body.	Monoplegia,Hemiplegia, Crossed,Hemiplegia, Flaccid,Hemiplegia, Infantile,Hemiplegia, Post-Ictal,Hemiplegia, Spastic,Hemiplegia, Transient,Crossed Hemiplegia,Crossed Hemiplegias,Flaccid Hemiplegia,Flaccid Hemiplegias,Hemiplegia, Post Ictal,Hemiplegias,Hemiplegias, Crossed,Hemiplegias, Flaccid,Hemiplegias, Infantile,Hemiplegias, Post-Ictal,Hemiplegias, Spastic,Hemiplegias, Transient,Infantile Hemiplegia,Infantile Hemiplegias,Monoplegias,Post-Ictal Hemiplegia,Post-Ictal Hemiplegias,Spastic Hemiplegia,Spastic Hemiplegias,Transient Hemiplegia,Transient Hemiplegias
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man