upper motor neuron paralysis, an injury to or lesion in the brain or spinal cord that causes damage to the cell bodies, axons, or both of the upper motor neurons, which extend from the cerebral centers to the cells in the spinal column. Clinical manifestations include weakness or paralysis; increased muscle tone and spasticity of the muscles involved with little or no atrophy; hyperactive deep tendon reflexes; diminished or absent superficial reflexes; the presence of pathological reflexes, such as Babinski’s and Hoffmann’s reflexes; and no local twitching of muscle groups. Compare lower motor neuron paralysis.
