Psychogenic movement disorders

Abstract

Purpose of review: This review describes the main clinical features of psychogenic (functional) movement disorders and reports recent advances in diagnosis, pathophysiology, and treatment.

Recent findings: The terminology and definition of patients with psychogenic movement disorders remain subjects of controversy; the term "functional" has been used more frequently in the literature in recent years regarding the neurobiological substrate underpinning these disorders. Correct diagnosis of psychogenic movement disorders should rely not on the exclusion of organic disorders or the sole presence of psychological factors but on the observation or elicitation of clinical features related to the specific movement disorder (ie, a positive or inclusionary rather than exclusionary diagnosis). Sudden onset, spontaneous remissions, and variability over time or during clinical examination are useful "red flags" suggestive of a psychogenic movement disorder. Imaging studies have demonstrated impaired connectivity between limbic and motor areas involved in movement programming and hypoactivity of a brain region that compares expected data with actual sensory data occurring during voluntary movement. Treatment of psychogenic movement disorders begins with ensuring the patient's acceptance of the diagnosis during the initial debriefing and includes nonpharmacologic (cognitive-behavioral therapy, physiotherapy) and pharmacologic options.

Summary: Psychogenic movement disorders represent a challenging disorder for neurologists to diagnose and treat. Recent advances have increased understanding of the neurobiological mechanism of psychogenic movement disorders. Treatment with cognitive strategies and physical rehabilitation can benefit some patients. As short duration of disease correlates with better prognosis, early diagnosis and initiation of treatment are critical.

Figures

Figure 9-1

A proposed algorithm for the diagnosis of psychogenic movement disorders. Diagnosis of psychogenic movement disorder is a multistep process that should encompass demonstration of suggestive phenomenologic features, integration with historical data, and support of electrophysiologic testing. Psychopathology (dotted line) should be carefully searched, although it might not always be evident to a neurologist’s evaluation.

Figure 9-2

Electrophysiologic demonstration of tremor entrainment in a patient with psychogenic tremor. Accelerometry recordings from an accelerometer attached to the hand affected by tremor (AccXR) and to the unaffected hand (AccXL). Below are EMG recordings from the affected hand (RFCR = right flexor carpi radialis; RECR = right extensor carpi radialis). Tremor frequency analysis by fast Fourier transformer shows a 7-Hz peak frequency of tremor (from 92.5 to 98.5 ms); finger tapping of unaffected hand at 4 Hz entrained the affected hand at the same frequency (from 103 to 109.5 ms).