Abstract
Background: Acute disseminated encephalomyelitis (ADEM) is a rare, immune-mediated demyelinating disorder of the central nervous system (CNS). It is typically monophasic and most frequently affects children, but adult presentations, though uncommon, can be fulminant and associated with poor outcomes. Diagnosis in adults is often challenging due to overlapping clinical features with infectious and autoimmune processes.
Case presentation: We report the case of a previously healthy 37-year-old woman who presented with one week of right upper limb numbness and severe brachial pain radiating to the neck. Initial suspicion was brachial neuritis or thoracic outlet syndrome. The following day, she developed high-grade fever (>39 °C), chills, sore throat, and dyspnea. On admission, she was hypotensive with an absent carotid pulse, requiring cardiopulmonary resuscitation, intubation, and inotropic support. Arterial blood gas analysis showed hypercarbic respiratory failure with pH 7.19, arterial carbon dioxide partial pressure (PaCO2) 58 mmHg, and a lactate level of 6.2 mmol/l. Chest radiograph revealed bilateral fluffy opacities. Neurologically, she developed refractory generalized seizures. The electroencephalogram (EEG) showed diffuse epileptiform activity. Magnetic resonance imaging (MRI) of the brain revealed subtle bilateral parietal T2 hyperintensities with diffusion restriction, while spinal MRI showed longitudinal hyperintensities from C1 to D3. Laboratory workup revealed markedly elevated procalcitonin (>100 ng/dl), normal thyroid-stimulating hormone (TSH) (0.383 µIU/ml), and negative viral and bacterial serologies. Serum myelin oligodendrocyte glycoprotein (MOG) antibody was weakly positive at 1:10. Despite administration of intravenous immunoglobulin over three days and escalation of antiseizure therapy, her sensorium did not improve. Progressive sepsis with metabolic acidosis, dyselectrolytemia, coagulopathy, and diffuse cerebral edema ensued. Repeat imaging showed early uncal herniation. Despite maximal intensive care, she suffered cardiac arrest and expired.
Conclusion: This case underscores the fulminant course of adult-onset ADEM, which may initially mimic peripheral or systemic illness, delaying diagnosis. Even with timely immunotherapy and intensive supportive care, outcomes can be fatal. The weak MOG antibody positivity highlights potential overlap syndromes and the limitations of current therapeutic strategies. Further research into advanced immunomodulatory therapies and approaches to manage malignant cerebral edema is warranted.
Yalini Suppu Saravanan, Devasena Srinivasan, Viswanathan Pandurangan
