The Phenomenology of Movement Disorders

Abstract

Although advances in neuropathology and molecular genetics provide increasingly more complex classification schemes for the conditions we define as movement disorders, it is the phenomenological clues that should guide a clinician’s initial impression and tailored work-up of an individual patient. Indeed, the characteristics of the abnormal movement provide a framework upon which to construct a differential diagnosis, guide ancillary testing, and consider therapeutic interventions. Movement disorders emerge by impairments in planning, controlling, or executing movement [1] and are classically divided into those causing an excess of movement (hyperkinetic) or a paucity of voluntary and automatic movements (hypokinetic) [2]. The label of “movement disorder” can refer to the specific phenomenology of a movement (e.g., dystonia) or to a syndrome combining several different abnormal movements (e.g., Huntington’s disease which can contain chorea, dystonia, etc). We will focus this chapter on the former, the characterization of the phenomenology of individual movements, in order to provide the basic building blocks upon which to define the more complex syndromes detailed in subsequent chapters.