Relationship between functional disorder (disorder) and dissociative neurological disorder and psychogenic disorder
Psychogenic movement disorder, DEF: A rare neurologic disease with the manifestation of an underlying psychiatric illness that cannot be attributed to any known structural or neurochemical disease. The disease presents typically during adolescence or adulthood. Symptoms may include one or several types of abnormal movements seen in organic movement disorders (tremor, dystonia, chorea, bradykinesia, myoclonus, tics, athetosis, ballism, cerebellar incoordination) and also affect speech and gait. Underlying causes fall into three categories: Conversion disorder, somatic symptom disorders or in rare cases factitious disorder.
Functional movement disorder, DEF: The occurrence of abnormal involuntary movements that are incongruent with a known neurologic cause and are significantly improved on neurological exam with distraction or non-physiologic maneuvers. The disorder is defined by its clinical appearance, rather than by any causative speculation.