Upper motor neuron lesion

Unstable bladder or detrusor instability, characterised by uninhibited, unstable contractions of the detrusor which may be of unknown aetiology or secondary to an upper motor neuron lesion or bladder neck obstruction. 

Parasympathomimetic drugs, e.g. bethanechol, car-bachol and distigmine, may be used to stimulate the detrusor when the bladder is h5 otonic, e.g. due to an upper motor neuron lesion. Distigmine, which is an anticholinesterase, is preferred but, as its effect is not sustained, intermittent catheterisation is also needed when the hypotonia is chronic. 

Graham DH. Monitoring neuromuscular block may be unreliable in patients with upper-motor-neuron lesions. Anesthesiology 1980 52(l) 74-5. 

Indications Spasticity caused by an upper motor neuron lesion like MS Common drug examples ... 

Scissors gait In scissors gait the legs are adducted, crossing alternately in front of one another. Both lower limbs are spastic, and there is spasm ofthe adductor muscles at the hipjoints, often accompanied by pronounced compensatory motions ofthe trunk and upper extremities. Bilateral upper motor neuron lesions, advanced cervical spondylosis, or multiple sclerosis may produce this gait pattern. 

Ataxic hemiparesis constitutes about 10% of cases. It is the combination of corticospinal and ipsilateral cerebellar-like dysfunction affecting the arm and/or leg. It includes a syndrome in which there is little more than dysarthria and one clumsy hand. The lesion is usually in the pons, internal capsule or cerebral peduncle. Dysarthria, with or without upper motor neuron facial weakness, may also be a lacunar syndrome with similar lesion localization as ataxic hemiparesis, but there are other localizing possibilities as well. 

Obviously, in complete upper-motor neuron paraplegics (thoracic level SCI patients), no EMG occurs below the level of the lesion, since the lower-extremity neurons do not fire. However, under FES, action potentials arise at the stimulated motor neurons. These produce action potentials similar to those in... 

Motor pathways in the brain consist of an upper motor neuron and a lower motor neuron. The upper motor neuron is located in the cerebral cortex and the lower motor neuron in the brain stem. A lesion of the upper motor neuron will result in muscle weakness or paralysis, with no muscle atrophy early and a disuse atrophy developing after a period of time. If a body part is bilaterally represented in the cortex, this would not be as noticeable. Increased muscle tone may be present along with increased tendon reflexes. The lower motor neuron is located in the brain stem. A lesion of the lower motor neuron is generally manifested as muscle weakness, flaccid paralysis, loss of reflexes, and an atrophy of the muscles. 

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