Expanding Neurological Spectrum of Scrub Typhus: A Single-Center Case Series of Cerebral Venous Sinus Thrombosis, Opsoclonus-Myoclonus Syndrome, and Guillain-Barré Syndrome

Scrub typhus, caused by Orientia tsutsugamushi, is hyperendemic across the "tsutsugamushi triangle" and is increasingly recognized as a cause of diverse neurological complications. Although meningoencephalitis and seizures are the most frequently reported central nervous system manifestations, vascular, central autoimmune, and peripheral nervous system complications are increasingly being documented. Three mechanistically distinct neurological syndromes, cerebrovascular, central immune-mediated, and peripheral immune-mediated, can complicate scrub typhus. Each remains individually uncommon, and their co-occurrence at a single tertiary care center within a short temporal window is exceptional. Three patients with serologically confirmed scrub typhus, encountered within a short period at a single tertiary care center in eastern India, are described: (i) scrub typhus-associated cerebral venous sinus thrombosis (CVT) with hemorrhagic venous infarction in a young adult with concurrent severe vitamin B12 deficiency and hyperhomocysteinemia, representing a dual-hit prothrombotic state; (ii) scrub typhus-associated opsoclonus-myoclonus syndrome (OMS) presenting alongside meningoencephalitis and seizures, with opsoclonus and myoclonus becoming clinically prominent as sensorium improved; and (iii) scrub typhus-associated Guillain-Barré syndrome (GBS) presenting as an acute sensorimotor polyradiculoneuropathy with absent late responses and significant cerebrospinal fluid lymphocytic pleocytosis, suggesting overlapping inflammatory radiculitis. All three patients were diagnosed and managed successfully through early recognition, prompt initiation of doxycycline, and condition-specific therapy with anticoagulation, corticosteroids, and intravenous immunoglobulin, respectively, with favorable neurological outcomes. This series illustrates the broad pathophysiological repertoire of neuroscrub typhus and underscores the necessity of maintaining a high index of diagnostic suspicion in endemic regions.