Dengue-Associated Encephalopathy With Multiple Cranial Neuropathies and Multisystem Involvement in a Patient With Epilepsy: A Comprehensive Case Report With Longitudinal Multimodality Imaging

Dengue fever is a common arboviral infection in tropical and subtropical regions. Neurological involvement is uncommon but increasingly recognized, and may mimic stroke, post-ictal deficits, thrombotic thrombocytopenic purpura, or sepsis-associated encephalopathy. We report a 45-year-old Lebanese woman with epilepsy who presented after a short febrile illness with dysuria initially treated as a urinary tract infection. She was later found in a post-ictal state with frothy oral secretions and urinary incontinence, febrile to 40°C and hypotensive to 70/50 mmHg. Neurological examination revealed reduced consciousness, abnormal rightward gaze, right-sided neck dystonia, nystagmus, left lower motor neuron facial palsy, suspected left sixth nerve palsy, and left-sided hemiparesis. Brain MRI and MR venography showed no acute infarction or venous sinus thrombosis. During admission, her platelet count fell from 200 × 10⁹/L to 23 × 10⁹/L, with an international normalized ratio of 2.6 and elevated D-dimer. Creatine kinase, troponin, and creatine kinase-myocardial band (CK-MB) were markedly raised, and echocardiography showed an ejection fraction of 35-40%, consistent with myocarditis. Dengue IgM was positive on Day 5 of illness. She was treated in the intensive care unit with hemodynamic support, empiric antibiotics, and pulse corticosteroids. Her neurological and laboratory findings improved gradually over a 14-day admission, including seven days in intensive care, and she was discharged home neurologically intact (modified Rankin Scale 1). Dengue should be considered in patients with acute febrile illness and unexplained neurological deficits, particularly in endemic settings. Early recognition is important because dengue can present with encephalopathy, cranial neuropathies, and multisystem dysfunction despite unremarkable neuroimaging.