Differential Diagnosis for Periodic Limb Movements While Awake

• Single Most Likely Diagnosis
  • Restless Leg Syndrome (RLS): Characterized by an irresistible urge to move the legs, usually accompanied by uncomfortable sensations. Periodic limb movements during wakefulness are a common feature of RLS, making it the most likely diagnosis.
• Other Likely Diagnoses
  • Periodic Limb Movement Disorder (PLMD): Although more commonly associated with sleep, some patients may exhibit periodic limb movements during wakefulness. This condition is similar to RLS but lacks the urge to move.
  • Akathisia: A movement disorder characterized by a feeling of inner restlessness and a compelling need to be in constant motion, often seen as a side effect of antipsychotic medication.
  • Dystonia: A neurological disorder that causes involuntary muscle contractions, leading to repetitive movements or abnormal postures. Some forms of dystonia can present with periodic limb movements.
• Do Not Miss Diagnoses
  • Neurodegenerative Diseases (e.g., Parkinson's Disease): While less common, certain neurodegenerative diseases can present with periodic limb movements. Missing these diagnoses could lead to delayed treatment and significant morbidity.
  • Vascular or Structural Lesions: Rarely, periodic limb movements can be a symptom of a vascular or structural lesion in the brain or spinal cord. Identifying and treating these conditions promptly is crucial to prevent further damage.
• Rare Diagnoses
  • Huntington's Disease: A rare genetic disorder that causes progressive damage to the brain, leading to motor dysfunction, including chorea, which can manifest as periodic limb movements.
  • Wilson's Disease: A genetic disorder that leads to copper accumulation in the brain and liver. Neurological symptoms, including movement disorders, can occur, though periodic limb movements are not a primary feature.
  • Toxic or Metabolic Disorders: Certain toxins or metabolic imbalances can cause movement disorders, including periodic limb movements. These are rare but important to consider, especially in the context of exposure history or systemic illness.