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Show Photo and Video Essay Section Editors: Kimberly M. Winges, MD Michael J. Gilhooley, MA, MB, BChir, DPhil Scrub Meningoencephalitis Associated With Ocular Bob and Downbeat Nystagmus—A Report of Two Cases Kiruthiga Sugumar, MD, DNB (Paed.), Vishnu Mohan, MD (Paed.), Ananthanarayanan Kasinathan, MD, DM (Paed. Neurology), Bobbity Deepthi, MD (Paed.), Dhandapany Gunasekaran, BSc, MBBS, MD (Paed.) S crub typhus is the most common worldwide zoonoses, caused by a Rickettsial organism, transmitted by the bite of a trombiculid mite. The clinical presentations of scrub typhus vary from nonspecific febrile illness to lifethreatening multiorgan dysfunction. Scrub meningoencephalitis, the most common central nervous system manifestation, presents with seizures, altered mentation, and rarely with cranial nerve palsies. We report 2 cases of scrub meningoencephalitis, who presented with abnormal ocular movements, with a dramatic response to treatment. Case 1: A 3-year-old developmentally normal male child who was previously asymptomatic, presented with a history of high-grade fever for 7 days, multiple episodes of nonbilious vomiting for 5 days, and worsening sensorium for the past 4 days. The mother noticed that the child was incessantly crying, with minimal response and poor eye contact for the past 2 days. He subsequently developed 2 episodes of generalized tonic-clonic seizures, on day 7 of illness. There was no significant family history or any recent travel or drug/toxin ingestion. At admission, he was febrile with a Glasgow Coma Scale (GCS) of 11/15. On detailed examination, an eschar was noted over the left neck region, along with significant nontender right cervical lymphadenopathy and soft hepatomegaly. Neurologic examination revealed positive meningeal Journal of Neuro-Ophthalmology 2023;43:e85–e86 doi: 10.1097/WNO.0000000000001688 © 2022 by North American Neuro-Ophthalmology Society Department of Pediatrics, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India. The authors report no conflicts of interest. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www. jneuro-ophthalmology.com). Address correspondence to Dhandapany Gunasekaran, BSc, MBBS, MD (Paed.), Department of Pediatrics, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry605006, India; E-mail: drguna007@gmail.com Sugumar et al: J Neuro-Ophthalmol 2023; 43: e85-e86 signs, right upper motor neuron facial palsy, bilateral brisk deep tendon reflexes, and extensor plantar response. A striking finding during examination was the presence of a classical downbeat nystagmus (See Supplemental Digital Content, Video 1, http://links.lww.com/WNO/A619). A provisional diagnosis of meningoencephalitis was made, and the empirical treatment was begun. In view of the above findings, scrub meningoencephalitis was kept as the primary differential in this case. The initial laboratory reports supported the primary diagnosis-neutrophilic leukocytosis (12 · 109/L; 75% neutrophils), thrombocytopenia (1.2 ·109/L), hyponatremia (123 mEq/L), and hypoalbuminemia (23 g/L). Cerebrospinal fluid (CSF) microscopy revealed pleocytosis with a neutrophilic preponderance. Cerebrospinal fluid biochemistry and culture reports were unremarkable. Contrast enhanced computed tomography of the brain was not suggestive of any abnormalities. Although, serum immunoglobulin M (IgM) testing for scrub typhus was negative, polymerase chain reaction (PCR) was reported positive in CSF, thus confirming the diagnosis of scrub meningoencephalitis. He had dramatic response to a 10day course of doxycycline, with rapid resolution of all symptoms including nystagmus. He had a normal neurologic examination without any deficit at the time of discharge. Case 2: A 4-year-old previously normal girl presented with a 7-day history of high-grade fever and progressive deepening of sensorium and altered sleep–wake cycle over the last 4 days. History of seizures, recent travel or exanthematous illness was not forthcoming. Family history was uninformative. At admission, child was febrile, irritable, with GCS of 9/15. Bilateral nontender cervical lymphadenopathy and soft hepatomegaly were striking. Neurologic examination revealed axial and appendicular hypotonia with brisk muscle stretch reflexes and a positive Babinski sign. Ocular examination revealed rapid downward movement of both eye balls followed by slow upward movement to the initial midline position characteristic of ocular bobbing (see Supplemental Digital Content, Video, http://links.lww.com/WNO/A620). A provisional diagnosis of e85 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Photo and Video Essay acute encephalitic syndrome/Pontine demyelination was made. Investigations revealed neutrophilic leukocytosis with evident hyponatremia (126 mEq/L) and mild hepatic transaminitis (aspartate aminotransferase- 194 U/L; alanine aminotransferase- 113 U/L). Brain MRI was unremarkable. Cerebrospinal fluid analysis was acellular with elevated protein (1950 mg/L) and normal glucose (58 mg/dL). Cerebrospinal fluid viral panel (herpes/Japanese encephalitis/entero/chikungunya viruses) was negative. Blood IgM ELISA and CSF PCR were strongly positive for scrub typhus. Fourteen-day course of doxycyline combined with oral prednisolone resulted in dramatic improvement of symptoms and ocular bobbing resolved by fifth day of therapy. The child was discharged with an intact neurologic function and no focal deficit. is hypothesized to be spontaneous or induced activity of the vestibulo-oculomotor pathway along the paramedian pontine reticular formation (PPRF). Ocular bobbing has been described with lesions in pons such as hemorrhage, trauma, and glioma; it has also been reported in a 19-year-old girl with biopsy-proven encephalitis (5), but not in a case of scrub typhus so far. Our index child merits attention for 2 reasons. First, immune-mediated pathogenesis involving PPRF presenting with ocular flutter is another presentation of scrub typhus (2). Our cases underline the neurotropism for brainstem in scrub typhus. Second, ocular bobbing, in general, portends a poor prognosis. Our case is exceptional and highlights the good prognosis in scrub typhus when picked up early. INTERPRETATION OF FINDINGS Neurologic involvement in scrub typhus is characterized by a myriad of presentations, of which well-known are seizures, altered sensorium, hemiparesis, cranial nerve palsies, and Guillain–Barre syndrome. The reported ophthalmic involvement in scrub typhus ranges from conjunctival congestion to retinal hemorrhages, cotton wool spots, and optic disc edema (1). However, abnormal ocular movements in scrub typhus are only limited to a few case reports. These include ocular flutter in a 9-year-old child (2), opsoclonus and bilateral gaze evoked nystagmus in an adult (3,4). Our index case 1 presented with vertical nystagmus, but without other signs of brainstem or cerebellum involvement. There was a dramatic response to doxycycline, indicating that the nystagmus was because of the neurotrophic nature of the organism with predilection for the brainstem. Case 2 presented with ocular bobbing, which is the abnormal involuntary movement of the eye characterized by rapid downward fall followed by slow upward drift to the initial midline position. The mechanism for ocular bobbing e86 STATEMENT OF AUTHORSHIP Conception and design: D. Gunasekaran, K. Sugumar, V. Mohan, A. Kasinathan, B. Deepthi; Acquisition of data: D. Gunasekaran, K. Sugumar, V. Mohan, A. Kasinathan, B. Deepthi; Analysis and interpretation of data: N/A. Drafting the manuscript: D. Gunasekaran, K. Sugumar, V. Mohan, A. Kasinathan, B. Deepthi; Revising the manuscript for intellectual content: D. Gunasekaran. Final approval of the completed manuscript: D. Gunasekaran, K. Sugumar, V. Mohan, A. Kasinathan, B. Deepthi. REFERENCES 1. Abroug N, Khochtali S, Kahloun R, Mahmoud A, Attia S, Khairallah M. Ocular manifestations of rickettsial disease. J Infect Dis Ther. 2014 2:140. 2. Kasinathan A, Suthar R, Sahu JK, Sankhyan N, Nallasamy K. Ocular flutter in scrub typhus. J Pediatr. 2019:204:315. 3. Sahu D, Varma VS. Opsoclonus in scrub typhus. J Clin Sci Res. 2017;6:113–116. 4. Kim DE, Lee SH, Park KI, Chang KH, Roh JK. Scrub typhus encephalomyelitis with prominent focal neurologic signs. Arch Neurol. 2000;57:1770–1772. 5. Rudick R, Satran R, Eskin TA. Ocular bobbing in encephalitis. J Neurol Neurosurg Psychiatry. 1981;44:441–443. Sugumar et al: J Neuro-Ophthalmol 2023; 43: e85-e86 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. |