Atypical complication of western equine encephalitis: central hypoventilation syndrome.

Case description: A 49-year-old male patient, a rural worker, presented with a two-day history of fever. Initial treatment for suspected community-acquired pneumonia was followed by the development of confusion and signs of meningeal irritation. Western Equine Encephalitis Virus infection was confirmed. The patient required prolonged intensive care due to central hypoventilation syndrome, a complication not previously described for this condition.

Clinical findings: The patient exhibited hypercapnia-related encephalopathy, with MRI revealing pontine lesions. Respiratory drive testing confirmed central hypoventilation. Peripheral muscular strength was preserved, ruling out muscular or peripheral neurological involvement. Persistent metabolic alkalosis secondary to failed ventilator weaning attempts was noted.

Treatment and outcome: Treatment included mechanical ventilation, nocturnal invasive ventilation, and acetazolamide to address post-hypercapnic metabolic alkalosis. Gradual improvement led to successful decannulation after 46 days. At the 30-day follow-up, the patient reported full independence and returned to work, maintaining stable respiratory function and acid-base balance.

Clinical relevance: This case highlights central hypoventilation syndrome as a rare but significant complication of Western Equine Encephalitis Virus infection. The administration of acetazolamide proved effective in managing metabolic alkalosis, supporting its potential role in similar cases. Further investigation is needed to better understand this complication and to establish evidence-based management strategies.