Clonus Reflex Test

Clonus is usually caused by lesions affecting the upper motor neurons in the central nervous system. Conditions such as multiple sclerosis, spinal cord injury, stroke, and cerebral palsy can lead to clonus.

The test involves slightly flexing the patient’s knee, moving the ankle in dorsiflexion and plantarflexion, and then rapidly dorsiflexing the ankle while observing for rhythmic oscillations.

A positive test, indicated by more than 3-4 rhythmic oscillations, suggests hyperreflexia and spasticity due to upper motor neuron lesions. It helps diagnose and assess conditions like multiple sclerosis and spinal cord injuries.