Acathisia

Definition & Etymology

Acathisia is a movement disorder characterized by a subjective feeling of inner restlessness and a compelling urge to be in constant motion. This manifests as an objective inability to remain still, leading to repetitive movements such as rocking, pacing, or shifting weight. The term is derived from Greek: a- (not) + kathísis (sitting), literally meaning “an inability to sit.”

Clinical Significance

Primarily an extrapyramidal side effect (EPS) of dopamine receptor antagonists like first-generation antipsychotics, acathisia is a major cause of patient distress and medication non-adherence. It can also be caused by antiemetics (e.g., metoclopramide) and some antidepressants. Critically, it is often mistaken for worsening anxiety or psychosis, which can lead to an inappropriate increase of the causative drug, thereby exacerbating the condition. Diagnosis is clinical, based on patient reports and observation, and can be assessed using tools like the Barnes Akathisia Rating Scale (BARS).

Related Conditions

Acathisia is classified with other EPS like dystonia and tardive dyskinesia. It must be differentiated from Restless Legs Syndrome (RLS), which is typically worse at rest and at night. Differential diagnoses also include agitation from psychosis, anxiety disorders, and substance withdrawal. While overwhelmingly drug-induced, similar symptoms can be associated with Parkinson’s disease.

Key Takeaways

• A state of profound motor restlessness and internal unease, primarily caused by dopamine-blocking medications.
• A significant cause of medication non-compliance, often misdiagnosed as worsening psychiatric symptoms.
• Management focuses on adjusting the offending medication, with symptomatic relief from agents like beta-blockers.

Note: This content is for informational purposes only and does not substitute for professional medical advice. Always consult your doctor for diagnosis and treatment.