Can new multiple sclerosis (MS) lesions in the brain cause akathisia-like movements?

Can New MS Lesions Cause Akathisia-Like Movements?

New MS brain lesions can theoretically cause akathisia-like movements if they affect specific basal ganglia or dopaminergic pathways, but this is exceptionally rare and not a recognized typical manifestation of MS. When akathisia-like symptoms appear in an MS patient, medication side effects—particularly from antipsychotics, antiemetics, or other dopamine-blocking agents—should be the primary consideration before attributing symptoms to new demyelinating lesions 1.

Understanding MS Movement Disorders

MS can produce a wide spectrum of movement disorders, but the pattern matters:

• Recognized MS-associated movement disorders include tremor, ataxia, restless leg syndrome, parkinsonism, paroxysmal dyskinesias, chorea, and facial myokymia 2, 3
• Akathisia is notably absent from comprehensive reviews of movement disorders in MS, suggesting it is not a characteristic manifestation 2
• MS symptoms arise from demyelination in specific CNS locations, with most lesions occurring in "silent" brain areas causing no detectable symptoms 4

Critical Diagnostic Algorithm

Step 1: Medication Review (First Priority)

• Antipsychotics (haloperidol, chlorpromazine, quetiapine) are the most common cause of akathisia through dopamine receptor blockade 1
• Antiemetics (metoclopramide, domperidone, prochlorperazine, promethazine) frequently induce choreiform movements via dopaminergic mechanisms 1
• Anticholinergic medications (diphenhydramine, hydroxyzine) can contribute to movement disorders 1
• Elderly patients have increased susceptibility to drug-induced movement disorders 1

Step 2: Lesion Location Analysis

• Review MRI to determine if new lesions involve basal ganglia, substantia nigra, or other motor control regions 5
• Most MS lesions are periventricular, juxtacortical, or in white matter tracts—not typically in deep gray matter structures that would cause akathisia 5
• New T2 lesions reflect permanent footprints from focal inflammatory lesions, with symptoms depending on anatomical location 5, 4

Step 3: Consider Alternative Diagnoses

• Systemic lupus erythematosus with antiphospholipid antibodies can mimic MS and cause chorea—this is a critical differential that requires different management 1
• Brain imaging should be performed when focal neurological signs are present to exclude structural causes 1
• Patients with severe brain damage or basal ganglia lesions have substantially increased risk for drug-induced movement disorders 1

Clinical Reasoning Framework

The anatomical mismatch is key: Akathisia involves dopaminergic pathways and basal ganglia circuits, while typical MS lesions predominantly affect periventricular white matter, corpus callosum, juxtacortical regions, and spinal cord 5. The pathophysiology of MS involves demyelination causing conduction blocks and axonal loss, which produces loss-of-function symptoms rather than the hyperkinetic, dopamine-related phenomena seen in akathisia 4.

Management Approach

If akathisia-like movements appear with new MS lesions:

1. Immediately review all medications for dopamine-blocking agents and discontinue or reduce if possible 1
2. Obtain detailed MRI with attention to basal ganglia using T2-weighted and gadolinium-enhanced sequences 5
3. Consider symptomatic treatment with beta-blockers, benzodiazepines, or anticholinergics only after excluding drug causes 6
4. Rule out alternative diagnoses including SLE, antiphospholipid syndrome, and other inflammatory conditions 1

Common Pitfalls to Avoid

• Do not assume all movement disorders in MS patients are MS-related—medication effects are far more common 1
• Do not overlook the temporal relationship: True MS symptoms from new lesions typically correlate with acute inflammatory activity and gadolinium enhancement 5
• Do not miss systemic causes: Antiphospholipid antibodies and SLE require fundamentally different treatment approaches 1
• Do not underestimate polypharmacy effects in patients on multiple CNS-active medications 1

The evidence strongly suggests that while MS produces diverse neurological manifestations, akathisia-like movements point toward medication effects or alternative diagnoses rather than demyelinating lesions 1, 2.