Medical Terms for Uncontrolled Movements in the Right Lower Extremity
Uncontrolled movements in the right lower extremity are most commonly classified as chorea, which refers to irregular, rapid, and non-stereotyped movements that flow randomly, giving an appearance of "dance" or dancing movements during gait. 1
Types of Involuntary Movements
Chorea: Characterized by irregular, rapid, and non-stereotyped movements that flow randomly. When affecting only one side of the body (such as the right lower extremity), it is specifically termed hemichorea 1, 2
Hemiballism: Refers to more violent, high-amplitude, flinging or flailing movements typically affecting one side of the body. Often considered an extreme form of chorea, predominantly affecting proximal limb muscles 3, 4
Dystonia: Involves prolonged abnormal muscle contractions causing twisting and repetitive movements or abnormal postures 5
Athetosis: Characterized by slower and more twisted movements compared to chorea 1
Myoclonic jerks: Brief, shock-like involuntary movements that can be mistaken for seizure activity 5
Distinguishing Features
Chorea and ballism movements are involuntary, non-rhythmic, and unpredictable 1, 3
Unlike tics, choreiform movements cannot be voluntarily suppressed and are typically of longer duration 6
Choreiform movements differ from tremors in that they are irregular rather than rhythmic 5
Asterixis (negative myoclonus) involves brief lapses of sustained posture rather than active movements 5
Common Causes of Unilateral Involuntary Movements
Structural lesions: Strokes, tumors, or cavernous angiomas affecting the basal ganglia, particularly the contralateral side 2, 4
Metabolic disorders: Particularly notable is non-ketotic hyperglycemic hyperosmolar state (NKHHS) in diabetic patients, which can cause hemichorea-hemiballism 3, 7
Medication-induced: Certain medications, particularly antipsychotics, can cause extrapyramidal symptoms including tardive dyskinesia 8
Genetic disorders: Conditions like Huntington's disease or benign hereditary chorea can present with choreiform movements 6
Diagnostic Approach
Brain MRI is the recommended imaging modality for patients with chorea to identify structural causes 1
In cases of acute onset, particularly with unilateral presentation, stroke should be considered as a potential cause 4
For diabetic patients with acute-onset chorea, T1-weighted MRI may show characteristic high-intensity signals in the basal ganglia 7
Genetic testing may be indicated for suspected hereditary causes 1
Treatment Considerations
Treatment should target the underlying cause when identified 2, 3
For symptomatic management of choreiform movements, dopamine-blocking agents like haloperidol may be effective 8, 2
Caution is needed with antipsychotic medications as they can cause extrapyramidal symptoms including tardive dyskinesia with long-term use 8
Patients receiving neuroleptic treatment should be monitored periodically for the development of tardive dyskinesia 6
For metabolic causes like diabetic chorea, correction of the underlying metabolic abnormality is the primary treatment 3, 7
Clinical Pitfalls
Unilateral involuntary movements may be misdiagnosed as seizures or psychogenic in origin 5
In acute presentations, stroke affecting the frontoparietal region should be considered even without direct involvement of the subthalamic nucleus 4
Rapid correction of blood glucose in diabetic patients can sometimes trigger choreiform movements 7
Tardive dyskinesia can persist or even emerge after discontinuation of antipsychotic medications 8