Abstract
Background We report a diagnostically challenging case of acute disseminated encephalomyelitis with prominent meningeal involvement on neuraxial imaging. This case demonstrates the utility of plasma exchange, even in a delayed setting, for functional recovery.
Case A 62-year-old male traveller from Vietnam presented with three days of fever, myalgia and confusion. His condition deteriorated rapidly despite empirical treatment for infective meningoencephalitis, with flaccid quadriparesis and hypoxic respiratory failure requiring invasive ventilation. His CSF was floridly inflammatory with no positive microbiology and equivocal oligoclonal bands. Neuraxial MRI showed multiple periventricular deep white matter lesions, some exhibiting diffusion restriction and faint contrast-enhancement, a prominent C5/6 contrast-enhancing cord lesion, and extensive leptomeningeal enhancement and thickening, which progressed over two weeks with more numerous contrast-enhancing brainstem and cord lesions. The aetiology remained elusive despite extensive CSF and blood studies, bone marrow biopsy, nontargeted meningeal biopsy, and imaging including whole-body FDG-PET. He received empirical anti-tuberculosis antimicrobials, and pulse methylprednisolone followed by intravenous corticosteroids. He regained upper limbs’ function but remained paraplegic. Serial imaging six weeks later demonstrated persistent gadolinium-enhancing, FDG-avid cord lesions. Therapeutic plasma exchange was performed despite the delay since presentation, and resulted in significant partial recovery in lower limbs’ strength with markedly decreased neuraxial inflammation on imaging.
Conclusion Early prominent meningeal involvement posed significant diagnostic and management challenges in this case of acute disseminated encephalomyelitis. It also demonstrates that even in the delayed setting, where imaging evidence of neuraxial inflammation persists, therapeutic plasma exchange may provide benefit.
