Acute Cerebellitis: A Rare Complication of Scrub Typhus

Abstract

Scrub typhus, caused by Orientia tsutsugamushi, is an emerging zoonotic infection that typically presents as an acute febrile illness. While neurological manifestations are increasingly recognized, cerebellar involvement remains exceedingly rare. We report the case of a 42-year-old man from Uttar Pradesh who presented with high-grade fever, followed by slurred speech and gait ataxia. Clinical examination revealed cerebellar signs, including dysmetria and dysdiadochokinesia. Laboratory testing confirmed scrub typhus via a positive immunoglobulin M enzyme-linked immunosorbent assay, and other infectious and autoimmune etiologies were excluded. Magnetic resonance imaging of the brain and cerebrospinal fluid analysis were normal. The patient was treated successfully with intravenous doxycycline and methylprednisolone, resulting in rapid clinical improvement. This case highlights acute cerebellitis as an atypical but important complication of scrub typhus, underscoring the need for heightened clinical suspicion in endemic areas.

INTRODUCTION

Scrub typhus is a vector-borne illness caused by the Gram-negative bacterium Orientia tsutsugamushi, which is transmitted through mite bites.[1] This rapidly emerging disease primarily affects rural populations but is increasingly spreading to urban areas. It is a major cause of acute undifferentiated fever in Southeast Asia and India.[2] The presentation of scrub typhus can range widely, from mild febrile illness to severe, life-threatening complications. These complications may include hepatic dysfunction, acute renal failure, acute respiratory distress syndrome, myocarditis, disseminated intravascular coagulation, and hemophagocytic syndrome.[3,4,5,6,7,8] With the rising incidence of scrub typhus, there has been an increase in reports of its atypical manifestations. Neurological complications are varied, with meningoencephalitis being the most classic presentation. Other documented complications include transverse myelitis, cranial nerve palsies, and Guillain–Barre syndrome.[9,10,11,12] Acute cerebellitis is a rare neurological complication of scrub typhus. These manifestations are often not recognized or not immediately attributed to scrub typhus due to a low index of suspicion among physicians. Early identification of such complications can facilitate prompt management, thereby reducing both morbidity and financial costs. This case report details a 42-year-old man who was admitted to a tertiary care center in Northern India with fever and cerebellar symptoms.

CASE REPORT

A man in his early 40s, from Uttar Pradesh, presented with a history of continuous high-grade fever for 4 days, unaccompanied by any skin rash. Subsequently, he experienced slurred speech and incoordination, with progressive swaying movements over the past 3 days. There was no previous history of headache, trauma, loss of consciousness, seizures, respiratory distress, or bladder and bowel involvement. On examination, he was conscious, oriented, afebrile, with a pulse rate of 80/min, blood pressure of 96/60 mmHg, and a respiratory rate of 18/min. No petechiae, ecchymosis, eschar, lymphadenopathy, mucocutaneous bleeding, or rash were noted on inspection. Respiratory, cardiovascular, and abdominal examinations were normal. Neurological examination showed signs of cerebellar dysfunction, including broad-based gait ataxia, dysmetria, dysdiadochokinesia, and dysarthria. The knee-jerk reflex was pendular, and there was no sensory involvement. Higher mental functions and cranial nerve examination were normal, and no meningeal signs were noted. The investigations revealed haemoglobin – 13.5 g/dL, a total leukocyte count – 7900 cells/mm³, and thrombocytopenia with a platelet count of 100 × 10⁹/L. Enzyme-linked immunosorbent assay test for scrub typhus serology was positive for scrub typhus immunoglobulin M (IgM) antibodies. Tests for other tropical infections, including dengue fever, malaria, leptospirosis, and chikungunya, were negative. Liver function tests showed transaminases with elevated aspartate aminotransferase (72 IU/L), alanine aminotransferase (105 IU/L), and alkaline phosphatase (97 IU/L). All other biochemical tests were normal. Cerebrospinal fluid (CSF) analysis was also normal (acellular with glucose levels at 69 mg/dL, protein levels at 38 mg/dL, and sterile culture). CSF and blood viral markers for viral encephalitis were negative. Blood and urine cultures were sterile, and magnetic resonance imaging (MRI) of the brain with gadolinium contrast was normal. The autoimmune and paraneoplastic encephalitis panel was sent. The patient was initially treated with pulse intravenous methylprednisolone at a dosage of 1 g/day for 5 days, followed by a tapering course of oral steroids over 4–6 weeks. Concurrently, he was administered antibiotics, specifically doxycycline 100 mg intravenously twice per day for 7 days and ceftriaxone 1 g twice a day for 7 days. Remarkable clinical improvement was observed by the 2^nd day of pulse therapy, with significant resolution of ataxia and dysarthria. At the time of discharge, which occurred after a total hospital stay of 7 days, some residual dysarthria and ataxia were still present. He was discharged after 7 days on oral doxycycline 100 mg twice a day and oral prednisolone 50 mg/day in tapering dose. The patient was seen in the outpatient department and demonstrated notable clinical improvement, with only minimal residual deficits at 14 days and none at 1 month. His autoimmune encephalitis panel (tested for antibodies against NMDA, AMPA1, AMPA2, CASPR, LGI-1, GABAB) and paraneoplastic encephalitis panel (tested for Anti-Hu, Anti-Ri, Anti-Yo, Anti-CV-2, Anti-PNMA2, Anti-amphiphysin, Anti-SOX1, Anti-Tr, Anti-GAD65, Anti-Zic4, Anti-titin, Anti-recoverin) came out to be negative.

DISCUSSION

Scrub typhus primarily affects rural populations in Southeast Asia and India, and its clinical spectrum can range from mild febrile illness to severe complications.[13] The classic neurological manifestation of scrub typhus is meningoencephalitis.[14] However, this case illustrates that scrub typhus can also present with acute cerebellitis, an uncommon but significant neurological complication. Acute cerebellitis has been underreported in the context of scrub typhus, possibly due to low clinical suspicion and the varied presentation of the disease. Several published articles have documented atypical neurological presentations of scrub typhus, emphasizing the need for increased clinical awareness. For instance, a study by Mahajan and Mahajan (2017) described cases of scrub typhus presenting with acute cerebellitis, characterized by ataxia, dysarthria, and tremors, similar to the present cases.[15] Another report by Alam et al. (2022) detailed a series of patients with scrub typhus who developed various neurological complications, including meningoencephalitis, transverse myelitis, and cerebellitis, highlighting the broad spectrum of central nervous system involvement.[16] In a case report by Mahajan et al. (2016), a patient with scrub typhus developed acute cerebellar ataxia, and treatment with doxycycline led to significant improvement, mirroring the therapeutic response observed in the current case.[17] Furthermore, Karanath et al. (2013) reported a patient with scrub typhus who presented with gait ataxia and dysarthria due to cerebellitis, reinforcing the potential for scrub typhus to cause isolated cerebellar involvement.[18] The patient’s symptoms of slurred speech and incoordination, coupled with cerebellar signs on examination, pointed towards central nervous system involvement. The normal findings on CSF analysis and MRI, along with a positive IgM antibody test for scrub typhus, were pivotal in ruling out other potential causes and confirming the diagnosis. The absence of meningeal signs, trauma, and other systemic symptoms further supported the diagnosis of scrub typhus-related cerebellitis. Treatment with pulse intravenous methylprednisolone and antibiotics, specifically doxycycline and ceftriaxone, resulted in significant clinical improvement. Currently, there are no established guidelines for the use of steroids in rickettsial diseases. Choi et al. reported administering steroids to a patient with rickettsial disease who exhibited progressive neurological symptoms, such as restlessness, ophthalmoplegia, and upper limb paralysis, and noted significant improvement without the development of new complications.[19] Recognizing atypical presentations, such as acute cerebellitis, can lead to timely diagnosis and treatment, reducing morbidity and preventing long-term sequelae. Given the rising incidence of scrub typhus and its expanding geographical distribution, understanding its varied clinical presentations is essential for effective management and improved patient outcomes.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.