Functional (psychogenic) movement disorders – Clinical presentations

Abstract

Functional or psychogenic movement disorders are common and disabling, and sometime difficult to diagnose. The history and physical exam can give positive features that will support the diagnosis, which should not be based solely on exclusion. Some clues in the history are sudden onset, intermittent time course, variability of manifestation over time, childhood trauma, history of other somatic symptom and secondary gain. Anxiety and depression are common, but not necessarily more than the general population. On examination, distraction and suggestibility may be present. There are specific signs that should be looked for with different types of movements. For example, with tremor, change in frequency over time and entrainment are common features. With myoclonus, the movements might be complex in type with long latencies to stimulus induced jerks. Gait disorders show good balance despite claims to the contrary. Functional dystonia still remains a challenging diagnosis in many circumstances, although fixed dystonia is one sign more likely to be functional.

Neurological and spinal manifestations of the Ehlers–Danlos syndromes

“…The authors suggested that movement avoidance may have been adopted to avoid pain, and in time resulted in fixed dystonia. The etiology of the fixed dystonia has also been variously attributed to peripheral injury [van Rooijen et al, ], and psychogenic movement disorder [Hallett, ].…”

“…Neurological evaluation and EEG to rule out seizure should be performed. The diagnosis of psychogenic movement disorder has been met with some skepticism [Palmer et al, ], but is distinguished from malingering, and thought to result from psychological causes [Hallett, ]; it is characterized by involuntary, disabling movements, abrupt in onset, a waxing/waning course, changes in the nature of the movement over time, worsening with stress, anxiety or depression, and improvement with distraction; they are difficult to diagnose and treat. Prognosis for improvement is better in patients with a shorter duration of illness [Lang, ].…”

Post‐traumatic Functional Mirror Movements in Klippel‐Feil Syndrome

“…The cause of hyperhidrosis in our patient is not clear, and we speculate that it was another functional symptom. Our case reiterates that careful history taking and physical/neurologic examination are key to ascertaining the correct diagnosis in patients with functional movement disorders and that sometimes laboratory findings, such as KFS in our patient, can be misleading.…”

Clinical Pearls in Tremor and Other Hyperkinetic Movement Disorders

“…27 Some of the positive criteria that help define psychogenic tremor and other functional movement disorders are listed in ►Table 9. 28 Functional tremors are often entrainable (brought to a specific rhythm). This can be demonstrated by having the patient tap the hand or flex and extend the wrist of the opposite hand at various frequencies.…”