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Wrist Clonus

Clonus, is usually encountered in the knee or ankle, it is a classic symptom of spasticity occurring as a result of lesions in upper motor neurons.
Wrist clonus significance is that it is much less common and can be confusing and misdiagnosed. Wrist clonus in patients affected with hemiplegia was described in lectures published in 1883 by the French neurologist Jean-Martin Charcot, who called this  phenomenon  as “provoked trepidation” and noticed that .These patients, on raising the paralysed arm, often experience a trembling similar to that which occurs in the lower limb under like circumstances. But the wrist-phenomenon, provoked or spontaneous, is much more uncommon.”
Method of elicitation of wrist clonus
Hyperextend the wrist, sustained pressure is applied.
There is sustained clonic movement of the hand induced by sudden extension of the wrist.