|Year : 2020 | Volume
| Issue : 3 | Page : 301-303
Dengue encephalitis in children “Not an uncommon entity but is rarely thought of”: A case report
Sai Chandar Dudipala, Prashanthi Mandapuram, Laxman Kumar Chinma
Department of Pediatrics, Prathima Institute of Medical Sciences, Karim Nagar, Telangana, India
|Date of Submission||05-Jan-2020|
|Date of Decision||08-Mar-2020|
|Date of Acceptance||19-Mar-2020|
|Date of Web Publication||06-Nov-2020|
Dr. Sai Chandar Dudipala
Department of Pediatrics, Prathima Institute of Medical Sciences, Karim Nagar, Telangana.
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Dengue fever is a common viral infection in the tropical areas, especially in India. The clinical manifestations of dengue infection are broad-spectrum, ranging from asymptomatic to life-threatening dengue shock syndrome. Usually, the dengue virus does not cause neurologic manifestations, but recently this has been documented in some cases. However, there is increasing evidence for dengue viral neurotropism, suggesting there may be an element of direct encephalitis in some dengue patients. Here we are reporting a case of dengue encephalitis in a 2-year-old female child from rural India who was presented with a history of fever, altered sensorium, and seizures. Blood test results of dengue immunoglobulin M (IgM) antibodies were positive. Cerebrospinal fluid analysis showed lymphocytic pleocytosis with elevated proteins and normal glucose. Neuroimaging was normal. In addition, other causes of encephalitis were ruled out by appropriate laboratory investigations. Our case highlights that dengue encephalitis may present even in the absence of neuroimaging findings with classical clinical signs. Hence, dengue encephalitis should be considered in the differential diagnosis of fever with altered sensorium and seizures, especially in areas where dengue fever is endemic.
Keywords: Encephalitis, neurotropism, seizures
|How to cite this article:|
Dudipala SC, Mandapuram P, Chinma LK. Dengue encephalitis in children “Not an uncommon entity but is rarely thought of”: A case report. J Pediatr Neurosci 2020;15:301-3
| Introduction|| |
Dengue fever is a common viral infection in the tropical areas, especially in India, caused by dengue virus. The clinical manifestations of dengue infection are broad-spectrum, ranging from asymptomatic to life-threatening dengue shock syndrome. Usually, the dengue virus does not cause neurologic manifestations, but recently this has been documented in some cases. However, there is increasing evidence for dengue viral neurotropism, suggesting there may be an element of direct encephalitis in some dengue patients. In the literature, so many case reports and case series are published regarding dengue viral neurotropism in adults and pediatric population, but the pathogenesis of neurotropism is poorly understood. In the present case, dengue encephalitis is presented with a normal neuroimaging.
| Case Report|| |
A 2-year-old female child from rural area with normal birth and developmental history was admitted in a local hospital with history of fever for 5 days. She had altered sensorium for 1 day and one episode of generalized tonic-clonic seizure for 10 min; hence, she was referred to our tertiary pediatric hospital in Karim Nagar district of Telangana, India. No history of rash or recent vaccination or any toxin ingestion was reported.
On examination in emergency room, child was stuporous. She was hemodynamically stable without any respiratory compromise. Fundus examination was normal with no meningeal irritation signs. On the basis of the complaints and examination, meningitis or viral meningoencephalitis was considered. Due to endemic area and epidemic, suspected dengue encephalitis/Japanese encephalitis was considered.
On laboratory evaluation, liver function test, creatinine, serum electrolytes, blood sugar, serum albumin, and ammonia were normal [Table 1]. Complete blood picture showed 7170 cells/mm3 white blood cells, 2.1 lakhs/mm2 dengue non-structural protein 1 (NS1), and immunoglobulin M (IgM) positive. But blood pictures never showed any leukopenia or thrombocytopenia. To find out the cause for encephalopathy, cerebrospinal fluid (CSF) analysis was performed. CSF showed 90 cells with 80% of lymphocytes, 90.45 mg/dL of protein, and 62 mg/dL of sugar (67% of blood glucose), which was supportive of encephalitis. Electroencephalogram showed generalized slowing suggestive of moderate encephalopathy [Figure 1]. But surprisingly magnetic resonance imaging (MRI) of the brain with contrast was normal. Child was treated with oxygen, intravenous mannitol, levetiracetam, and other supportive measures. Repeated dengue serology showed IgM positive. Dengue CSF polymerase chain reaction was planned, but due to financial issues unable to send. Child was improved and discharged after 7 days of admission. Clinical features, double checked dengue serology positive result, and CSF analysis excluded other causes of encephalopathy, suggestive of dengue encephalitis. Hence we are reporting a case of dengue encephalitis, which is clinically and serologically suggestive of dengue with normal neuroimaging.
|Figure 1: Electroencephalogram (generalized slowing). There is generalized background slowing, consisting mainly of delta frequencies (sensitivity—7.5 µV/mm)|
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| Discussion|| |
Dengue is the most common arthropod-borne viral infection in humans. It is caused by a family of positive, single-stranded, enveloped RNA viruses called Flaviviridae, genus Flavivirus. There are four closely related but antigenically different serotypes of the virus that can cause dengue (DEN-1, DEN-2, DEN-3, and DEN-4). The clinical manifestations of dengue infection are broad-spectrum, ranging from asymptomatic to life-threatening dengue shock syndrome. The incubation period of dengue infection ranges from 3 to 14 days after the bite of infected mosquito, Aedes aegypti. There are three phases that can be seen in the setting of dengue infection: a febrile phase, a critical phase, and a recovery phase. However, the critical phase is not seen in all categories of infection. In 2009, World Health Organization revised the classification with following three categories: dengue without warning signs, dengue with warning signs, and severe dengue.
Neurological signs of dengue infection were first reported in 1976 as atypical symptoms of dengue infection. The incidence rates varied from 0.5% to 20% in recent years., Neurological manifestations associated with dengue infection include encephalopathy and seizures., Dengue is classically thought to be a non-neurotropic virus. The serotypes most frequently implicated in causing neurological manifestations are DEN2 and DEN3. Clinical manifestations include fever, headache, lethargy, and seizures; some patients may have no characteristic features of dengue infection. In such cases, the diagnosis has been supported by serological testing, and/or CSF analysis. The neurological manifestations in dengue have been classified by Murthy into the following three categories: (1) manifestations due to neurotropic effects of virus including encephalitis, meningitis, myositis, and myelitis; (2) systemic complications resulting in encephalopathy, stroke, and hypokalemic paralysis; and (3) postinfectious complications include Guillain–Barré syndrome, optic neuritis, and encephalomyelitis. The classical symptoms of dengue fever such as rash, myalgia, and bleeding manifestations are seen in less than half of patients with encephalitis. Solomon et al. have suggested that dengue should be suspected in all patients with encephalitis from endemic regions even in the absence of typical features.
The criteria for dengue encephalitis are (1) fever, (2) acute signs of cerebral involvement, (3) presence of anti-dengue IgM antibodies or dengue genomic material in the serum and/or CSF, and (4) exclusion of other causes of viral encephalitis and encephalopathy. In the present case, child had fever, seizures, anti-dengue IgM antibodies in serum, and CSF analysis suggestive of viral encephalitis. We also ruled out other causes for encephalitis by appropriate investigations. So the present case satisfied the criteria for dengue encephalitis. Hence we are consistent with dengue encephalitis. Poor sensitivity (0%–73%) of IgM antibodies in CSF for dengue virus makes it a less reliable screening tool. It may confirm but does not exclude the neurological manifestations associated with dengue. Available literature for dengue encephalitis shows very low yield for evidence for detection of dengue in CSF. Hence in our patient, we were not done CSF dengue antibodies.
Neuroimaging of dengue encephalitis showed variable data, with normal findings in most cases. MRI may be normal, or hemorrhages, cerebral edema, and focal abnormalities involving the basal ganglia, hippocampus, and thalamus can be seen. In our patient, MRI of the brain was normal. Prognosis is good for dengue encephalitis with normal neuroimaging.
Neurological manifestations associated with dengue may be treated according to diagnosis. Treatment of dengue viral infection is largely supportive. In the present case, child was treated with antiedema measures, levetiracetam, and intravenous fluids. Child recovered gradually without any neurological sequelae. The prognosis of patients with neurological complication associated with dengue depends on the clinical picture of the disease and ranges between 5% and 30%.
| Conclusion|| |
Dengue encephalitis should be considered in the differential diagnosis of fever and with neurological features even in the absence of other classical signs. Especially in endemic areas, the pediatricians should have a high index of suspicion of this rare presentation of an otherwise common infectious disease.
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Conflicts of interest
There are no conflicts of interest.
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