Classification of Movement Disorders

Abstract

Movement disorders characteristically result from dysfunction at the level of the basal ganglia and are classified into two broad groups: hypokinetic and hyperkinetic movement disorders. Patients with hypokinetic movement disorders have reduced movements, such as rigidity and akinesia/bradykinesia, which are primarily reported in the context of rigid-akinetic forms of Parkinson disease. Hyperkinetic movement disorders are characterised by excessive movements and include a wide range of motor manifestations, including tremor (rhythmic oscillatory movements), chorea (abrupt, purposeless, dance-like movements), athetosis (continuous, writhing movements, often involving the extremities and occasionally combined with chorea: ‘choreoathetosis’), tics (sudden, repetitive movements and vocalisations expressed following a sensory urge), dystonia (slow, twisting movements and abnormal postures caused by sustained or intermittent muscle contractions), myoclonus (brief shock-like jerks due to the sudden contraction or relaxation of one or more muscles), mannerisms (gestures and peculiar movements that individualise a person and are not usually considered bothersome), and stereotypies (patterned, repetitive, seemingly purposeless movements or utterances typically present in the context of autism spectrum disorders). Both neurodegenerative (Parkinson disease, Huntington disease) and neurodevelopmental (Tourette syndrome) movement disorders often present with specific behavioural symptoms which have a deep impact on patients’ health-related quality of life and highly benefit from a comprehensive neuropsychiatric approach.