Atypical neuroimaging in rabies encephalitis: A case report of concurrent cerebral venous sinus thrombosis in a nine-year-old patient.

Human rabies is a fatal viral encephalitis that presents a profound diagnostic challenge in the absence of a known history of animal exposure. We report the case of a 9-year-old boy from Morocco who presented with fever, seizures, psychomotor agitation, hypersalivation and hydrophobia, despite no reported history of an animal bite or scratch. Brain magnetic resonance imaging (MRI) served as a critical diagnostic tool, strongly suggesting rabies encephalitis by revealing classic bilateral symmetric grey matter hyperintensities in the thalami and temporal lobes. Concurrently, MRI revealed an atypical and rare macrovascular finding: extensive cerebral venous sinus thrombosis of the right transverse and sigmoid sinuses, which likely accounted for additional asymmetric white matter changes. A nuchal skin biopsy analyzed via reverse transcription polymerase chain reaction confirmed the presence of rabies virus RNA. Despite aggressive neurocritical care and therapeutic anticoagulation, the patient's condition deteriorated, and he passed away on day 9 of admission. This case underscores the dual role of MRI in acute encephalitis: guiding early etiological diagnosis of rabies and identifying concurrent, clinically significant macrovascular complications like cerebral venous sinus thrombosis.