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• Motor disturbance characterised by intermittent lapses of an assumed posture

• Commonly associated with liver failure where it produces the flapping tremor of hepatic encephalopathy

• jerky, irregular flexion-extension movements at the wrist and metacarpophalangeal joints, accompanied by lateral movements of the fingers

• Usually bilateral, absent at rest and asynchronous on each side

• Mechanism is attributed to interference with the inflow of joint position sense to the reticular formation in the brainstem