Which of the following is not a feature of Upper Motor Neuron lesion?
Positive babinsky sign
Normal nerve conduction study
Positive sharp waves on EMG
Hyperactive tendon reflexes
Ans. is. 'c' i.e., Positive sharp waves on EMG * Following table compares and contrasts the features of upper motor neuron and lower motor neuron lesionsDifference between upper and lower motor neuron paralysisUpper motor neuron paralysisLower motor neuron paralysis* Muscles affected in groups never individual nuscles.* Atrophy slight and due to disuse.* Spasticity with hyperactivity of the tendon reflexes and* Extensor plantar reflex (Babinski sign)* Fascicular twitches absent* Normal nerve conduction studies; no denervation potentials in E.M.G.* Individual nuscles may be affected.* Atrophy pronounced up to 70% of the total bulk.* Flaccidity and hypotonia of affected muscles with loss of tendon reflexes.* Plantar reflex if present is of normal flexor type* Fasciculation may be present* Abnormal nerve conduction studies; denervation potential (fibrillations, fasciculations positive sharp waves) in E.M.G.* It is clear from the table that presence of fibrillations, fasciculations and positive sharp waves are features of lower motor neuron and not upper motor neuron lesions.
C.N.S.