Clinical phenomenology and pathophysiology of daytime and nighttime imperative movements

Abstract

Imperative movements have an intermediate position between voluntary and involuntary movements and are also referred to as semi-voluntary, or induced. Their common characteristic is the urge, forcing the patient to perform an action that can have a different duration and degree of complexity - from a short twitch (with tics) to prolonged episodes of general motor restlessness (for example, akathisia or stereotypes). The ability to slow down this movement for a short or longer period of time by volitional effort is associated with the urge to make a movement, which predetermines the patient's perception of the degree of its imperativeness and arbitrariness. All motor syndromes based on an imperative need to make movements (akathisia, tics, restless legs syndrome, some levodopa-induced dyskinesias, tardive dyskinesia, compulsive disorders, stereotypes), despite their differences, can be conditionally combined by the term «akathisia spectrum disorders». In some cases, violent imperative movements are paradoxically combined with hypokinetic disorders, primarily with parkinsonism, which makes the discomfort experienced by patients particularly severe.