Published on 09/04/2015 by admin
Filed under Neurology
Last modified 09/04/2015
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Limbs
motor
Examination of motor function is divided into:
As with all parts of the examination, attention needs to be paid to the hypotheses thrown up by the history.
Patients with different types of motor disease assume typical positions. It is worth looking at the position of the patient before examining the limbs at closer quarters. For example, a patient whose arm is held with a flexed elbow, wrist and fingers and whose leg is extended at the knee and ankle has a contralateral hemisphere lesion, typically a stroke. The myasthenic patient has an extended neck to overcome the ptosis, and a droopy jaw. The patient with Parkinson’s disease is stooped with flexed elbows.
Look at the bulk of the muscles. Is the bulk normal, decreased (atrophied) or increased (hypertrophied)?
Muscle atrophy is most commonly seen distally in the small muscles of the hands and in the feet and tibialis anterior. Muscle atrophy can be confined to one muscle group or be more generalized. Atrophy usually reflects lower motor neurone abnormalities, though muscles do atrophy from disuse, for example in a longstanding upper motor neurone lesion or with severe muscle disease.
Muscle hypertrophy is much rarer than atrophy. The calves are most commonly affected. This is seen in the Duchenne and Becker muscular dystrophies.
Fasciculations are small movements within the muscle and reflect contraction of a motor unit. These usually indicate a lower motor neurone abnormality. They are widespread in anterior horn cell diseases, typically motor neurone disease. They can occur in the absence of neurological disease, and are quite commonly observed in the calves of people without neurological disease.
This is usually assessed at the wrist, elbow, hip and knee (Fig. 1). The joint is moved through its range, initially slowly and then at increasing speeds.
Neurology An Illustrated Colour Text
