Search results
Results from the WOW.Com Content Network
Hyperreflexia is overactive or overresponsive bodily reflexes. Examples of this include twitching and spastic tendencies, which indicate disease of the upper motor neurons and the lessening or loss of control ordinarily exerted by higher brain centers of lower neural pathways. [citation needed] Spinal cord injury is the most common cause of ...
The upper motor neurons are thought to inhibit the reflex arc, which is formed by sensory neurons from intrafusal fibers of muscles, lower motor neurons (including alpha and gamma motor fibers) and appurtenant interneurons. Therefore, damage to lower motor neurons will subsequently result in hyporeflexia and/or areflexia. [citation needed]
Knee jerk or patellar reflex — a kick caused by striking the patellar tendon with a tendon hammer just below the patella, stimulating the L4 and L3 reflex arcs. Moro reflex , a primitive reflex — only in all infants up to 4 or 5 months of age: a sudden symmetric spreading of the arms, then unspreading and crying, caused by an unexpected ...
Hoffmann's reflex is a deep tendon reflex (spindle fibre) with a monosynaptic reflex pathway in Rexed lamina IX of the spinal cord, normally fully inhibited by descending input. On the other hand, the plantar reflex is more complicated and not a deep tendon reflex, and its pathway is both more complicated and not fully understood. [8]
The saying refers to lower motor neuron symptoms in the upper extremity (arm) and upper motor neurons symptoms in the lower extremity (leg). Health professionals' understanding of impairments in muscles after an upper motor neuron lesion has progressed considerably in recent decades. However, a diagnosis of "spasticity" is still often used ...
There are 3 reflexes in the upper arm that are tested. [1] [2] These are the biceps, triceps and supinator reflex. The reflexes may be abnormally brisk or absent. In the latter, the reflex could be elicited through reinforcement by asking the patient to clench their jaw. [2]
Balance is a partly involuntary and unconscious business, dependent on "spinal reflexes." When provided with appropriate context, these reflexes go into oscillation that is called "clonus," a phenomenon that is familiar to everybody and which is easily produced. (While sitting, place the leg with thigh horizontal and foot supported on the floor.
Symptoms associated with central nervous systems disorders are classified into positive and negative categories. Positive symptoms include those that increase muscle activity through hyper-excitability of the stretch reflex (i.e., rigidity and spasticity) where negative symptoms include those of insufficient muscle activity (i.e. weakness) and reduced motor function. [5]