Acute Cerebellitis in a Child With Scrub Typhus
A 9-year-old boy living in the foothills of Himalayas presented with acute onset fever, headache, vomiting and swaying to the left side. There was no history suggestive of seizures, focal deficit, rash, recent immunization, animal or insect bite. On examination, he was febrile, had conjunctival suffusion and icterus. There was no eschar. Neurologic examination revealed horizontal gaze nystagmus and left-sided truncal ataxia. The rest of the systemic examination was normal.
Laboratory investigations revealed leukocytosis (12.2 × 109 cells/L) with predominance of lymphocytes (88%) and with neutropenia (10%) and thrombocytopenia (76 × 109 cells/L). Liver function tests showed elevated transaminase values (aspartate transaminase, 2504 IU/L; alanine transaminase, 1573 IU/L), conjugated hyperbilirubinemia (3.8 mg/dL) and coagulopathy. Lumbar cerebrospinal fluid showed no cells, normal glucose (94 mg/dL) and protein (56 mg/dL). Gram stain was negative, and the culture was sterile. Cerebrospinal fluid polymerase chain reaction for herpes simplex virus DNA was negative. Investigations for hepatotropic viruses and Epstein-Bar virus were negative. He was treated with cefotaxime, acyclovir, lactulose and rifaximin, but he continued to have persistent fever spikes and neurologic worsening.
In view of the child residing in an endemic area, the possibility of scrub typhus was considered, and he was treated with oral doxycycline. IgM enzyme-linked immunosorbent assay (InBios International Inc., Seattle, WA; optical density (OD) value, 1.014; positive >0.5 OD value), and real-time polymerase chain reaction for scrub typhus was positive. An magnetic resonance imaging of brain showed area of focal altered signal area in left cerebellar tonsil (Fig. 1). Within 48 hours, he became afebrile, elevated transaminases and conjugated hyperbilirubinemia showed a gradual decline and the cerebellar symptoms subsided in a week.
Scrub typhus is an emerging infectious disease, and cases have been reported from 23 states of India.2 Neurologic involvement is seen in about 10%–60% of cases with scrub typhus, with meningitis or meningoencephalitis being the commonest presentation.3 Isolated cerebellitis is rare, and only a handful of cases have been described in adult patients.4,5 Unilateral cerebellar signs were present in our case, and An magnetic resonance imaging of brain showed T2 hyperintense signal within the left cerebellar tonsil. Invasion of vascular endothelial cells by rickettsiae and diffuse inflammation of vascular lining result in neurologic manifestations. Focal vasculitis in the brain, lymphocytic infiltration of the blood vessels and perivascular spaces are reported on autopsy of patients with scrub typhus. Abnormalities in neuroimaging include infarction, edema, meningeal enhancement and prominent perivascular spaces. A knowledge of endemicity, high index of suspicion, multisystem involvement and elevated IgM enzyme-linked immunosorbent assay titers against O. tsutsugamushi led to timely diagnosis and management.