27 - Apraxia

Summary

Historical note

Liepmann assumed that the expression “apraxia” has first been used by Steinthal in the late 19th century denoting that brain-damaged persons sometimes have lost single skills such as handling an instrument (Liepmann, 1920). Liepmann further notes that a disturbance of limb use that is different from paresis and ataxia had repeatedly been reported in the “older” literature (e.g. by Hughlin Jackson). Memorised entities for movements had been entertained by his contemporary colleagues: Wernicke's “movement images” (“Bewegunsgvorstellungen”) as memories for kinesthetic perceptions brought about by the execution of repeated movements and their loss called “motor asymbolia” (“motorische asymbolie”) by Meynert, Nothnagel's “memorised pictures” (“Erinnerungsbilder”) for type and amplitude of movements, and de Buck's “parakinesias” (“parakinésies”); that is, movement alterations that were meant to be caused by an dissociation between movement idea and executed movements. It was, however, Liepmann's contribution to elaborate on the syndrome “apraxia” in a more systematic way. His ideas are still strongly influencing our current clinical classification. Liepmann classified someone as apraxic if she or he executes a requested movement incorrectly or uses an object incorrectly even though he is not or not sufficiently hindered to use her or his limb correctly by paresis or ataxia, and has understood the task – being without comprehension deficit or at least without deficit to comprehend the given task. The apraxic person cannot use (parts of) his body for some purposes at some points in time because learned mechanisms for movements are impaired.