Postinfectious Ocular Flutter–Tremor–Ataxia Syndrome Following Scrub Typhus: A Case Report

Case DesCriptionA 39-year-old female patient came with complaints of fever, highgrade, lasting for 2 days, and 1 week later, the patient noticed generalized tremulousness while walking and developed tremors of all four limbs, which were progressively worsening, and head tremor with unsteadiness and swaying while walking, and rapid, involuntary, jerky, irregular horizontal eye saccadic movements occurring 4-5 times per minute.No history of any weakness of limbs and no history suggestive of any sensory complaints.No history introDuCtion Scrub typhus, caused by Orientia tsutsugamushi, is an acute febrile illness endemic to parts of Asia.The typical presentation is a short febrile illness associated with a pathognomonic cutaneous "cigarette burn" eschar, but neuropsychological features are increasingly being described.Commonly, these include seizures and aseptic meningitis.Rarer neurological syndromes include extrapyramidal features, hearing loss, and opsoclonus.We present a patient with ocular flutter-tremorataxia syndrome, which can be included in the spectrum of opsoclonus-myoclonus-ataxia syndrome (OMAS) as a manifestation of scrub typhus.Opsoclonus-myoclonus-ataxia syndrome is characterized by chaotic, multidirectional saccadic eye movements (opsoclonus), myoclonic jerks, and gait/truncal ataxia.1,2 While pediatric OMAS is often paraneoplastic, adult cases are more frequently autoimmune, paraneoplastic, or postinfectious.1,3 Infectious triggers include Epstein-Barr virus, human immunodeficiency virus (HIV), West Nile virus, influenza, and rickettsial diseases such as scrub typhus.[3][4][5] Opsoclonus is a rare manifestation, seen in about 0.01% of cases.6 This condition usually occurs 1-2 weeks after the infectious episode, but it has been reported as early as the 2nd day of illness.5,7 The diagnosis is primarily clinical, as neuroimaging is usually normal.1,2 A few case reports from India and Southeast Asia describe OMAS occurring within days to weeks after the febrile episode, suggesting an immune-mediated mechanism.5,7 We report a case of postinfectious ocular flutter-tremor-ataxia syndrome following scrub typhus in an adult, with complete resolution after targeted antibiotic and immunosuppressive therapy.