==== Front Am J Case RepAm J Case RepamjcaserepThe American Journal of Case Reports1941-5923International Scientific Literature, Inc. 3003820910.12659/AJCR.909884909884ArticlesDengue Cerebellitis: A Case Report and Literature Review Khoo Ching Soong ABCDEFDepartment of Medicine, Universiti Kebangsaan Malaysia Medical Center, Cheras, MalaysiaAuthors’ Contribution: A Study Design B Data Collection C Statistical Analysis D Data Interpretation E Manuscript Preparation F Literature Search G Funds Collection Conflict of interest: None declared Corresponding Author: Ching Soong Khoo, e-mail: chingsoongkhoo@gmail.com2018 24 7 2018 19 864 867 09 3 2018 17 5 2018 © Am J Case Rep, 20182018This work is licensed under Creative Common Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)Patient: Male, 60 Final Diagnosis: Dengue cerebellitis Symptoms: Dizziness • fever • headaches • vomiting Medication: — Clinical Procedure: Lumbar puncture Specialty: Neurology Objective: Unusual clinical course Background: Dengue-associated neurological manifestations have recently been on the rise. Cerebellar syndrome complicating dengue fever has rarely been reported in the literature. We present a case report of dengue-associated cerebellar syndrome and performed a literature review to draw attention to this rare neurological complication. Case Report: A 60-year-old man presented with 4 days of fever, myalgia, arthralgia, headaches, and warning symptoms (persistent diarrhea and vomiting). He was admitted with serologically-confirmed dengue fever. He had been well until day 8 of illness, when he developed cerebellar signs and symptoms. The temporal relationship with the recent dengue fever suggested that he had dengue cerebellitis. He recovered well, with no neurological sequelae upon our clinic visit. Conclusions: Dengue cerebellitis is a rare but recognized manifestation, which should be considered in patients from endemic areas of dengue fever who develop cerebellar syndrome. MeSH Keywords: AtaxiaCerebellar DiseasesDengue ==== Body Background The incidence of dengue fever has grown exponentially around the globe in recent years. In Malaysia, dengue fever is a public health threat due to its alarming rise in morbidity and mortality rates. At present, there are 18 688 confirmed patients with dengue infection in Malaysia and 201 have died due to dengue [1]. With the escalating trend of dengue infection, atypical manifestations of dengue fever, such as dengue encephalitis, are also increasingly reported. We report a case of a diabetic patient with cerebellitis associated with dengue fever. Our literature review identified only 4 other similar cases, all from Sri Lanka. Our report underscores the importance of recognizing this rare neurological syndrome associated with dengue fever. Case Report A 60-year-old man presented to the Emergency Department with 4 days of fever, myalgia, arthralgia, headaches, and dengue warning symptoms (persistent diarrhea and vomiting). He lived in a dengue-prone area. He was on treatment for his type II diabetes mellitus, hypertension, dyslipidemia, and a previous stroke. He had presented with left upper limb weakness 5 years ago, which resolved within a few days. He could not recall his brain computed tomography (CT) results and had remained well with modified Rankin scale (mRS) of 0/6 upon discharge. His presenting vital signs, including glucose level, were stable. Apart from petechiae in his lower limbs, his physical examination was unremarkable. Full blood count revealed hemoglobin 15.1g/dL, hematocrit 43%, white blood cell 3.3×109/L, and platelet 81×109/L. His alanine transaminase was 59 U/L. Renal profile was normal. Dengue IgM was detected on day 5 of illness. Blood films for malarial parasites were repeatedly negative. A diagnosis of dengue fever was made and he was managed with intravenous fluids in the ward in view of his warning symptoms. A series of full blood count monitoring is summarized in Table 1. He was well in the ward until day 8 of illness (in recovery phase). He suddenly complained of headaches, giddiness, and vomiting. On examination, he had nystagmus in all directions, bilateral dysmetria more prominent on the left and ataxic gait. His blood pressure was 150–160/80–90 mmHg during this acute episode. A preliminary diagnosis of acute brainstem stroke was entertained given his background of multiple underlying illnesses. The magnetic resonance imaging (MRI) of his brain revealed hyperintense signals at the right corona radiata and left frontal lobe in keeping with old stroke (Figures 1, 2). No abnormal signals were seen in his cerebellum, cerebellopontine angle, midbrain, and pons (Figure 3). His magnetic resonance angiogram (MRA) study was normal. Lumbar puncture was done and his cerebro-spinal fluids (CSF) showed normal opening pressure, cell count, and biochemistry. Dengue PCR (sent on day 9 of illness) was not detected from his CSF. Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae were not isolated from the CSF. Antigens of Cytomegalovirus, Epstein-Barr virus, herpes simplex virus 1 and 2, and varicella zoster virus were not detected by polymerase chain reaction (PCR) from his CSF. He tested negative from his serum for HIV, hepatitis, syphilis, varicella zoster, Epstein-Barr, herpes simplex, and mycoplasma. He was managed with physiotherapy and rehabilitation therapy in the ward for 2 weeks. He was discharged with a walking frame. Twenty days after discharge, he could walk independently and all neurological signs resolved spontaneously. Discussion Dengue fever is a mosquito-borne viral disease transmitted principally by the mosquito Aedes aegypti. Dengue virus is a single-stranded RNA virus with 4 serological types [2]. The clinical manifestations of dengue fever are varied, ranging from self-limited infection to plasma leakage, hemorrhage, shock, or organ failure resulting in death. Atypical syndromes are increasingly recognized, such as neurological manifestations, myocarditis, acute kidney injury and cholecystitis [3]. According to Carod-Artal et al. [4], dengue fever can manifest with neurological features ranging from 0.5% to 21% of the cases presenting at hospital. Neurological manifestations associated with dengue fever can broadly be classified into encephalopathy, encephalitis, neuromuscular, and neuro-ocular complications. Among these manifestations, encephalopathy, encephalitis, Guillain-Barré syndrome, myositis, and maculopathy are commonly reported. Cerebellar syndrome associated with dengue infection was first reported by Weeratunga et al. [5] as a case series in 2013 followed by Withana et al. [6] as a case report in 2014. Our case (the fifth case) and the literature review demonstrate that patients with dengue cerebellar syndrome tend to recover spontaneously without permanent neurological sequelae. The onset of symptoms ranged from 2 days to 2 weeks. Ataxia and bilateral nystagmus were present in all cases. Cerebellar signs resolved from 1 week to 2 months. It is noteworthy that there were no changes in the neuroimaging in all but 1 case. This may suggest a transient inflammation in dengue cerebellitis. Other differences are illustrated in Table 2. The pathogenesis of neurological syndromes remains to be elucidated. Direct invasion of the virus and immune-mediated mechanisms are postulated to cause the neurological sequelae. Several viral infections are reported to cause cerebellitis, such as varicella zoster, Epstein-Barr, herpes simplex, measles, HIV, and coxsackie [7]. Cerebellitis can be primary infective, post-infective, or post-vaccination. Among the 5 cases, 4 (including ours) are likely primary infective and 1 is likely post-infective. Conclusions Dengue-related cerebellitis, although rarely reported, is a recognized neurological manifestation. Clinicians should consider dengue infection as an etiology in patients with fever who live in endemic areas and develop cerebellar syndrome. Dengue cerebellitis can occur in any phase of dengue fever and is self-limiting. Further studies are required to elucidate its pathophysiology. The author would like to thank the staff of the Neurology Unit, Department of Medicine, Universiti Kebangsaan Malaysia Medical Center and Dr Siti Soraya Ab Rahman, Radiologist, from the Islamic Science University of Malaysia for her work in interpreting the MRI images. Conflicts of interest None. Figure 1. T2-weighted brain magnetic resonance imaging (MRI) reveals a hyperintense lesion in the right corona radiata (blue arrow). Figure 2. T2-weighted brain magnetic resonance imaging (MRI) reveals a hyperintense lesion in the left frontal lobe (blue arrow). Figure 3. No abnormal signal intensity in the cerebellum in the T2-weighted brain magnetic resonance imaging (MRI). Table 1. Full blood count trend in the ward. Day of illness Hemoglobin (g/dL) Hematocrit (%) White cell (109/L) Platelet (109/L) Day 4 15.1 43 3.3 81 Day 5 13.7 41.6 3.0 53 Day 6 14.6 42.4 4.3 34 Day 7 14.3 41.3 7.1 66 Day 8 15.8 45.8 8.9 92 Day 9 14.2 40.9 7.5 148 Table 2. Summary of the 5 cases of dengue cerebellar syndrome. Age Sex Phase of presentation Cerebellar signs Dengue serology Brain MRI CSF analysis Duration of complete recovery Weeratunga et al. 40 Female Critical Dysarthria, bilateral nystagmus, bilateral limb and gait ataxia IgM positive (both serum and CSF) Normal Normal 2 months Weeratunga et al. 28 Male Post recovery Bilateral vertical and horizontal nystagmus, gait ataxia IgM positive (both serum and CSF) Normal Normal 1 week Weeratunga et al. 25 Male Febrile Bilateral nystagmus, dysmetria, severe ataxia IgM positive (both serum and CSF) Bilateral and symmetrical T2 hyperintense lesions in the cerebellum Normal 2 weeks Withana et al. 45 Female Febrile Scanning dysarthria, horizontal nystagmus, bilateral dysmetria, dysdiadochokinesia more prominent on the right, ataxia, tendency to fall to the right NS 1 Antigen and IgM positive (serum) Normal Not done 17 days Khoo 60 Male Recovery Nystagmus in all directions, bilateral dysmetria more prominent on the left, ataxia IgM positive (serum); PCR negative (CSF) – taken on D9 of illness Hyperintense signals in the right corona radiata and left frontal lobe suggestive of his previous stroke Normal 34 days ==== Refs References: 1. iDengue 2015. Available from: URL: http://idengue.remotesensing.gov.my/idengue/index.php 2. Cheah WK Ng KS Marzilawati AR A review of dengue research in Malaysia Med J Malaysia 2014 69 A 59 67 25417953 3. Gulati S Maheshwari A Atypical manifestations of dengue Trop Med Int Health 2007 12 9 1087 95 17875019 4. Carod-Artal FJ Wichmann O Farrar J Gascón J Neurological complications of dengue virus infection Lancet Neurol 2013 12 9 906 19 23948177 5. Weeratunga PN Caldera HP Gooneratne IK Spontaneously resolving cerebellar syndrome as a sequelae of dengue viral infection: A case series from Sri Lanka Pract Neurol 2014 14 3 176 78 23840070 6. Withana M Rodrigo C Chang T Dengue fever presenting with acute cerebellitis: A case report BMC Res Notes 2014 7 125 24598036 7. Sawaishi Y Takada G Acute cerebellitis Cerebellum 2002 1 223 28 12879984