Can strep throat cause ataxia?

Strep Throat and Ataxia: Relationship and Clinical Implications

Yes, strep throat can cause ataxia through post-streptococcal autoimmune mechanisms that affect the central nervous system, particularly the cerebellum and basal ganglia. 1

Post-Streptococcal Neurological Manifestations

• Post-streptococcal autoimmune disorders can affect the central nervous system, with the basal ganglia being particularly vulnerable, leading to various movement disorders including ataxia 2
• Group A beta-hemolytic streptococcal (GABHS) infections can trigger aberrant immune responses where antibodies produced against streptococcal antigens cross-react with neuronal tissues 1
• This immune-mediated mechanism is similar to what occurs in Sydenham's chorea, which is a well-established post-streptococcal neurological disorder 1

Clinical Presentation and Diagnosis

• Ataxia following strep throat typically presents as acute or subacute onset of uncoordinated voluntary movements, which may manifest as:

  • Unsteady gait
  • Dysmetria (inability to judge distance in muscular acts)
  • Dysdiadochokinesis (inability to perform rapid alternating movements)
  • Nystagmus 3

• When evaluating a patient with ataxia and suspected strep throat connection:

  • Look for history of recent pharyngitis with fever, tonsillar exudates, and cervical adenopathy 4
  • Consider timing: post-infectious ataxia typically develops within days to weeks after the streptococcal infection 3
  • Assess for other neurological signs that might indicate cerebellar involvement 3

Diagnostic Approach

• For patients presenting with acute ataxia and suspected post-streptococcal etiology:
  • Confirm recent streptococcal infection through throat culture (gold standard) or rapid antigen detection testing 5
  • Consider serological tests for streptococcal antibodies (ASO titers, anti-DNase B) 1
  • Brain MRI is the preferred imaging modality to evaluate for cerebellar involvement or other intracranial pathology 6
  • CT imaging may be considered when MRI is not immediately available 6

Management Considerations

• Treatment approach for post-streptococcal ataxia includes:
  • Complete eradication of streptococcal infection with appropriate antibiotics:
    • Penicillin or amoxicillin for 10 days is first-line therapy 4
    • First-generation cephalosporins for patients with non-anaphylactic penicillin allergy 4
  • Supportive care as most post-infectious ataxia cases are self-limiting 6
  • In severe or persistent cases, immunomodulatory therapies may be considered 1

Important Clinical Pitfalls

• Do not mistake post-streptococcal ataxia for other causes of acute cerebellar dysfunction such as:

  • Acute cerebellitis of other infectious etiologies
  • Posterior fossa tumors
  • Toxic ingestions
  • Acute disseminated encephalomyelitis 3

• Post-streptococcal neurological manifestations may be part of a broader spectrum of pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) 1

• Failure to recognize and treat the underlying streptococcal infection could potentially lead to other post-streptococcal complications such as rheumatic fever 5

• The prognosis for post-streptococcal ataxia is generally favorable, with most cases resolving completely, though some may have a more protracted course 1