Asterixis

Abstract

Asterixis is a type of negative myoclonus characterized by irregular lapses of posture of various body parts. It is an uncommon but important sign in clinical neurology. Initially described as a “liver flap,” its utility encompasses a galaxy of neurological and nonneurological situations. Asterixis has a rich history. Despite being described over 70 years ago, its exact pathogenesis remains unknown. Its significance as a tool for the evaluation and prognosis of encephalopathies has been suggested. This review presents its history, clinical implications and its significance.

Myoclonic Disorders

“…Negative myoclonus consists of irregular lapses of muscle activity and posture. Pathological negative myoclonus can be tested by extending the arms and dorsiflexing the wrists, or at the hips in a supine position with knees bent and feet resting on the bed, leaving the legs to fall to the sides [ 132 ]. Negative myoclonus can also produce a wobbling gait or sudden postural lapses (“bouncy gait”), for example after cerebral hypoxia [ 5 ].…”

Hepatic Encephalopathy and Nutrition Influences: A Narrative Review

“…NH 3 also acts as a neurotoxic agent by increasing the resting membrane potential and inhibiting outward chloride pumps in the neurons, which leads to suppression of inhibitory postsynaptic potential formation and neuronal depolarization. This explains the development of asterixis in patients with HE; asterixis is defined as flapping movement at the wrist observed by extending the arms, dorsiflexing the wrists, and spreading the fingers (ie, similar to stopping traffic), resulting in irregular myoclonic lapses of hand and wrist posture . As glutamine hydrolysis plays an important role in increased mitochondrial NH 3 and ROS formation, 2 glutaminase haplotypes have been identified to be associated with overt HE development in cirrhotic patients …”

Severe asterixis due to hypermagnesemia in chronic renal failure: a case report

“…Asterixis is a type of negative myoclonus characterized by sudden irregular lapses of posture of various body parts due to involuntary interruption in muscle contraction [ 1 , 2 ]. Flapping tremor or liver flap, a type of asterixis, associated with liver disease is well-known.…”

“…Flapping tremor or liver flap, a type of asterixis, associated with liver disease is well-known. However, it occurs in many disorders systemically in impaired visceral functions, drug intoxications, and dyselectrolytemia, and unilaterally in focal brain lesions (Table 1 ) [ 1 ]. Therefore, full examinations are necessary for detecting the causative disorders.…”

“…As dyselectrolytemia causing asterixis, hypomagnesemia, and hypokalemia have been described [ 1 , 2 ]. With reference to hypermagnesemia, it causes depression of nerve and muscle functions consisting of decreased tendon reflexes, muscle flaccid paralysis, and impaired consciousness terminating in coma [ 3 ].…”