What is the prognosis for a patient with Tuberculosis (TB) meningitis and altered sensorium?

Prognosis in TB Meningitis with Altered Sensorium

Patients with tuberculous meningitis (TBM) who present with altered sensorium have a significantly worse prognosis, with mortality rates of up to 57% in those with severely altered consciousness (Vellore grade IV) prior to treatment. 1

Prognostic Factors in TBM with Altered Sensorium

Altered mental status is one of the strongest predictors of poor outcomes in TBM. Multiple studies have identified key factors that influence prognosis:

• Severity of altered consciousness:

  • Patients with comatose mental status have 6 times higher odds of mortality (OR 6.0,95%CI 3.6-10.2) 2
  • Mortality varies from 10.5% to 57.1% in patients with altered sensorium prior to surgery 1

• Disease staging: The British Medical Research Council staging system classifies TBM severity 3:

  • Stage I: Alert and oriented with no focal neurological deficits (best prognosis)
  • Stage II: Altered mental status but not comatose
  • Stage III: Glasgow Coma Scale ≤10 (worst prognosis)

• Additional negative prognostic factors when combined with altered sensorium:

  • Advanced age (OR 4.64,95%CI 1.03-24.74) 4
  • Underlying comorbidities (OR 9.75,95%CI 1.58-59.95) 4
  • Leukocytosis (OR 9.74,95%CI 1.67-56.7) 4
  • Presence of seizures (OR 3.3,95%CI 1.2-9.0) 2
  • Delayed or interrupted treatment (OR 5.1,95%CI 2.4-11.2) 2
  • Hydrocephalus (present in up to 85% of cases) 1

Predictors of Neurological Sequelae in Survivors

Even with survival, patients with altered sensorium are at high risk for permanent neurological damage:

• Drowsiness at presentation (OR 4.2,95%CI 2.04-8.82) 2
• Cranial nerve palsy (OR 2.6,95%CI 1.4-4.2) 2
• Hemiparesis/focal weakness (OR 9.3,95%CI 3.8-22.6) 2
• Multiple neurological deficits (OR 7.1,95%CI 2.14-23.38) 2
• Presence of extra-meningeal TB (OR 2.1,95%CI 1.1-4.2) 2

Improving Outcomes in TBM with Altered Sensorium

The key to improving outcomes in TBM patients with altered sensorium includes:

1. Early treatment initiation:

   • Antimicrobial therapy should be started immediately upon clinical suspicion 5, 3
   • Standard regimen includes isoniazid, rifampin, pyrazinamide, and ethambutol for 9-12 months 3, 6

2. Adjunctive corticosteroid therapy:

   • Strongly recommended for all TBM patients, especially those with altered sensorium 3
   • Reduces mortality by approximately 25% (RR 0.75,95% CI 0.65 to 0.87) 3
   • Options include dexamethasone (12 mg/day) or prednisolone (60 mg/day), tapered over 6-8 weeks 3

3. Management of hydrocephalus:

   • Present in up to 85% of TBM cases 1
   • Surgical intervention (ventriculoperitoneal shunt or endoscopic third ventriculostomy) should be considered early for patients with hydrocephalus and symptoms of raised intracranial pressure 1

4. Aspirin as adjunctive therapy:

   • Recommended particularly for patients with moderate to severe disease (stages II and III) 3
   • May reduce mortality and morbidity by preventing infarctions and reducing inflammation 3

Monitoring and Follow-up

For TBM patients with altered sensorium who survive the acute phase:

• Regular neurological assessment
• Follow-up neuroimaging to assess for infarctions and hydrocephalus
• Motor and somatosensory evoked potentials may help objectively document motor and sensory functions in patients with altered sensorium 7

Pitfalls and Caveats

• Delaying treatment while waiting for definitive diagnosis significantly worsens prognosis
• Rapid tapering of corticosteroids may lead to rebound inflammation
• Ethambutol should be used with caution in unconscious patients as visual acuity cannot be tested 3
• Patients on corticosteroids require monitoring for hyperglycemia, gastrointestinal bleeding, and secondary infections 3

In conclusion, while TBM with altered sensorium carries a poor prognosis, early recognition and aggressive management with antitubercular therapy, corticosteroids, and appropriate surgical interventions when indicated can improve outcomes in these critically ill patients.