What is akathisia?

Akathisia: Definition, Diagnosis, and Management

Akathisia is a medication-induced movement disorder characterized by an intense feeling of inner restlessness and the urge to move, typically accompanied by observable motor restlessness such as rocking while standing or sitting, lifting feet as if marching, and crossing/uncrossing legs. 1

Clinical Presentation

Akathisia presents with both subjective and objective components:

• Subjective symptoms:

  • Inner feeling of restlessness
  • Compelling urge to move
  • Inability to remain still
  • Anxiety

• Objective manifestations:

  • Rocking while standing or sitting
  • Lifting feet as if marching on the spot
  • Crossing and uncrossing legs while sitting
  • Pacing
  • Fidgeting
  • Repetitive foot tapping
  • Rubbing feet together 1, 2

Types of Akathisia

Akathisia can be classified according to onset timing:

• Acute akathisia: Occurs shortly after starting or increasing the dose of causative medication
• Tardive akathisia: Develops after prolonged medication use
• Withdrawal akathisia: Appears when discontinuing causative medication
• Chronic akathisia: Persists over extended periods 2

Common Causes

The most common causes of akathisia include:

1. Antipsychotic medications (both typical and atypical, though first-generation agents carry higher risk) 1
2. Antiemetic agents (particularly those with dopamine-blocking properties) 3
3. Other medications: Tricyclic antidepressants, SSRIs, lithium 4

Differential Diagnosis

Akathisia must be distinguished from:

• Peripheral neuropathies
• Restless legs syndrome (RLS)
• Vascular disease (intermittent claudication)
• Arthritis
• Venous varicosities
• Anxiety disorders 4

Key differentiating features from RLS include:

• RLS typically occurs only when immobile and is relieved by movement
• RLS is most prominent in the evening/night
• RLS is often associated with dysesthesias in affected extremities 4

Unusual Presentations

Akathisia can manifest in less recognized ways:

• Respiratory akathisia: Presents as dyspnea characterized by an inability to breathe in a relaxed manner, with restless respiratory movements like gasping or sighing 5
• Involvement of body segments other than lower limbs 6

Management Approaches

First-line treatments:

1. Reduce dose or switch medication:

   • If possible, lower the dose of the causative medication
   • Consider switching to an antipsychotic with lower EPS risk (e.g., quetiapine or olanzapine) 1

2. Pharmacological interventions:

   • Propranolol (10-30mg two to three times daily) is the most consistently effective treatment for acute akathisia (use cautiously in patients with asthma, diabetes, or cardiovascular disease) 1, 2

Second-line options:

1. Benzodiazepines:

   • Add when beta-blockers fail or subjective distress persists
   • Lorazepam 0.5-2mg as needed (caution: can lead to tolerance and dependence) 1

2. Other agents:

   • Amantadine
   • Clonidine
   • Anticholinergics (e.g., benztropine 1-2mg daily, maximum 6mg daily) 1, 7

3. Less established options:

   • Ritanserin
   • Piracetam
   • Valproic acid
   • Tricyclic antidepressants 2

Special Considerations

• Elderly patients: More sensitive to medication effects; start with lower doses (e.g., benztropine 0.5mg) and titrate slowly 1

• Patients with Parkinson's disease: Extremely sensitive to antipsychotic effects; consider pimavanserin, clozapine, or quetiapine if antipsychotics are needed 1

• High-risk populations: Elderly, very young patients, males, patients with previous history of tremors, patients with previous antipsychotic use, patients on polypharmacy, and those on higher doses of antipsychotics 1

Monitoring

• Regular assessment for abnormal movements using standardized scales like the Abnormal Involuntary Movement Scale (AIMS) every 3-6 months 1

• Monitor for orthostatic hypotension in patients with cardiovascular disease when using anticholinergics 1

• For patients switched to quetiapine, monitor metabolic parameters (blood glucose, lipids, weight) 1