Bilateral thalamic involvement in dengue infection

Rare case of dengue encephalitis with extensive brain lesions from Pakistan

Dengue infection is common in 129 countries including Pakistan, with an estimated 390 million dengue virus infections per year. Asia accounts for 70% of the actual burden. Clinical signs and symptoms of dengue include a high fever (40°C/104 °F) accompanied by two of the following symptoms during the febrile phase: severe headache, pain behind the eyes, muscle and joint pains, nausea, vomiting, swollen glands and rash. Severe dengue is a potentially fatal complication, due to plasma leaking, fluid accumulation, respiratory distress, severe bleeding or organ impairment. Dengue virus does not usually cause neurological manifestations, unlike other arboviral infections. Encephalopathy is the most common neurological complication. Encephalitis is rare manifestation. We report a rare case of dengue encephalitis from Pakistan, with extensive brain lesions involving the thalamus, cerebellar vermis and frontoparietal periventricular regions. Therefore, we suggest dengue encephalitis should be considered in the differential diagnosis of fever with altered sensorium, especially in Asian countries such as Pakistan where dengue is rampant as dengue encephalitis can be fatal at times.

MRI features in dengue encephalitis: A case series in South Indian tertiary care hospital

Dengue virus, a RNA virus of family Flaviviradae is considered non-neurotropic. Increasing studies and case reports reveal neurological manifestations of dengue virus. In our case series, we have evaluated magnetic resonance imaging (MRI) findings of 3 patients with dengue fever diagnosed by positive dengue NS1 antigen with neurological symptoms, which revealed nonspecific imaging features of dengue encephalitis in two cases and dengue meningoencephalitis in one case. Autopsy findings are also correlated in 2 patients who succumbed to their disease. This case series underlines the consideration of dengue encephalitis in patients of dengue fever with neurological symptoms and relevant imaging findings.

Dengue fever with encephalitis: a rare phenomenon

The clinical profile and presentation of patients with dengue fever may differ from asymptomatic infection to the dreadful complications like dengue shock syndrome. However, neurological complications are very rare. Dengue encephalitis occurs by a direct involvement of central nervous system by the dengue virus which is an extremely rare complication. A 33-year-old man presented with fever, vomiting and severe headache. He had one episode of generalised tonic-clonic seizure followed by an altered sensorium on the day of admission to the hospital. The diagnosis of dengue fever was confirmed by dengue serology (IgM) and (NS1) antigen assay. MRI brain was suggestive of encephalitis. Thus, the patient was treated symptomatically and discharged in stable condition with minimal neurological deficit.

Brain Imaging in Cases with Positive Serology for Dengue with Neurologic Symptoms: A Clinicoradiologic Correlation

BACKGROUND AND PURPOSE

Dengue is a common arboviral disease, which uncommonly involves the brain. There has been a recent surge in dengue cases and dengue-related deaths in tropical countries. The aim of this study was to describe brain imaging findings in patients with dengue infection having neurologic symptoms.

MATERIALS AND METHODS

Thirty-five patients with positive serology for dengue with CNS symptoms undergoing imaging of the brain were included in the study. Clinical, laboratory, and imaging parameters were assessed and correlated to poor outcome.

RESULTS

A Glasgow Coma Scale score of ≤12 at presentation, clinical classification of severe-type dengue, and the presence of acute renal failure were associated with poor outcome. Imaging parameters associated with poor outcome were involvement of the thalami and cerebellar peduncles and the presence of diffusion restriction and hemorrhagic foci in the brain parenchyma.

CONCLUSIONS

Although not specific, dengue infection has imaging findings that can be used to narrow down the differential list and help in prognostication.

Spectrum of findings on magnetic resonance imaging of the brain in patients with neurological manifestations of dengue fever

Objective

To describe the spectrum of magnetic resonance imaging (MRI) findings in patients with neurological manifestations of dengue.

Materials and Methods

We included nine patients with dengue fever (three females and six males; age range, 9–30 years), all of whom presented with neurological manifestations. The MRI examinations, performed in 1.5 T or 3 T scanners, included T1-weighted, T2-weighted, and fluid-attenuated inversion recovery (FLAIR) sequences. Diffusion-weighted imaging with apparent diffusion coefficient mapping was also employed. Fast low-angle shot and susceptibility-weighted gradient-recalled echo sequences, as well as contrast-enhanced T1-weighted scans, were also obtained in order to assess parenchymal enhancement. MRI scans were analyzed for lesion distribution and imaging features.

Results

All patients showed areas of altered signal intensity that appeared as hyperintensity on T2-weighted and FLAIR sequences. The most commonly affected site was the basal ganglia-thalamus complex. Other affected sites were the cerebellum, cerebral cortex, white matter, and brainstem. In all cases, we observed patchy areas of restricted diffusion and focal areas of hemorrhage.

Conclusion

Dengue encephalitis commonly affects the basal ganglia, thalamus, cerebellum, cerebral cortex, and white matter. Therefore, MRI should be an indispensable part of the evaluation of patients with neurological complications of dengue fever.

A rare case of dengue encephalopathy complicating a term pregnancy

BACKGROUND

Dengue fever has an expanded clinical spectrum ranging from an asymptomatic infection to life threatening dengue hemorrhagic fever and refractory shock. Dengue infection in pregnancy can be a diagnostic dilemma, particularly considering the physiological changes in pregnancy and the obstetric complications encountered in clinical practice. Hence the knowledge of its diagnosis and management in its atypical presentations is of paramount importance. Here we report an unusual case of uncomplicated dengue encephalopathy in a term mother, probably the first to be reported from the Indian subcontinent.

CASE PRESENTATION

A 28 year old woman, 37 weeks of pregnancy presented with fever of four days duration. She eventually developed irritability, altered sensorium, somnolence, and unresponsiveness to commands by the 5th day of febrile illness without any circulatory compromise. Physical examination and investigations including serology confirmed dengue fever. After excluding all other possible causes, the transient neurological deterioration was finally attributed to dengue encephalopathy which is an uncommon manifestation of the disease, particularly in pregnancy. Her deteriorated neurological status which had lasted for 6 days improved spontaneously with the convalescence of dengue infection. Cautious fluid management was carried out in correlation to clinical and hematological parameters. The pregnancy was continued uncomplicated till the platelet count had risen to more than 50,000 cells/cumm. She delivered vaginally a healthy male baby.

CONCLUSIONS

Dengue fever in pregnancy is increasingly being encountered due to its rising disease burden. Dengue encephalitis/encephalopathy must be suspected in the differential diagnosis of fever and altered sensorium, even in pregnancy, in the tropical countries where the infection is rampant. Management of dengue infection in term pregnancy is a challenge for both the clinician and obstetrician. Further discussion and research are mandatory to decide on optimal management of these patients, with regard to monitoring, fluid management, and the precise timing and mode of delivery in order to prevent fatal morbidity and mortality to both mother and fetus.

Two Case Reports on Thalamic and Basal Ganglia Involvement in Children with Dengue Fever

There have been increasing numbers of case reports of dengue infection with unusual manifestations. Such unusual manifestations including acute liver failure and encephalopathy could be manifested even in the absence of significant plasma leakage. Further, severe organ involvement including nervous system involvement indicates severe dengue infection. However, neurological manifestations of dengue fever are rare. This is the first case report of dengue infection with thalamic and basal ganglia involvement in Sri Lanka.

Clinico-radiological profile and outcome of dengue patients with central nervous system manifestations: A case series in an Eastern India tertiary care hospital

BACKGROUND AND OBJECTIVE

Dengue, an acute viral disease, transmitted by Aedes mosquitoes, has a variable clinical spectrum ranging from asymptomatic infection to life-threatening dengue hemorrhagic fever and dengue shock syndrome. However, neurological complications, in general, are unusual but have been observed more frequently in the recent past, and some studies highlighted varied neurological complications during the course of illness. Although dengue is classically considered a nonneurotropic virus, there is increasing evidence for dengue viral neurotropism. In this study, we have evaluated clinico-radiological profile and outcome of nine serologically confirmed dengue patients having varied manifestations of central nervous system (CNS) involvement.

MATERIALS AND METHODS

All the consecutive patients presented with neurological complications with positive serology for dengue infection (IgM positivity) in Department of Medicine, in a tertiary care hospital in Eastern India from August 2013 to October 2014 were included in the study. These patients were subjected to a detailed clinical evaluation, laboratory assessment including complete hemogram, coagulation profile, liver function test, serum electrolytes, and routine CSF (Cerebrospinal Fluid) study with the exclusion of other common neuroinvasive pathogens.

RESULTS

Out of 9 patients with neurological complications associated with confirmed dengue infection, 2 (22%) patients had dengue encephalopathy, 5 (56%) patients have dengue encephalitis, 1 (11%) patient had dengue meningitis, and 1 (11%) patient had postdengue immune-mediated CNS involvement.

CONCLUSION

This case series reaffirms the occurrence of varied CNS manifestations in dengue virus infection and underlines the importance of inclusion of dengue in the differential diagnosis of acute encephalitis syndrome.

Findings at brain MRI in children with dengue fever and neurological symptoms

Dengue is a flavivirus of the genus arbovirus with four serotypes, from DEN 1 to DEN 4. There has been an increase in incidence of dengue infection in children in the tropics and subtropics. Dengue has a variable clinical presentation, with many patients being asymptomatic. Its clinical manifestations in children vary from fever and arthralgia to life-threatening dengue hemorrhagic fever and dengue shock syndrome. We describe MRI findings in children with neurological involvement including dengue encephalopathy, acute hypoxic injury and dengue encephalitis. Dengue encephalopathy is usually secondary to multisystem derangement such as shock, hepatitis, coagulopathy and concurrent bacterial infection and is relatively common. Dengue encephalitis from direct neuronal invasion is rare. Nonspecific changes are seen on brain MRI in dengue infection. Clinical and laboratory findings as well as outcome do not necessarily correspond with brain MRI findings.

"Dot sign" in dengue encephalitis

Neuro radiological findings in Dengue encephalitis are non specific. Here we report a case of Dengue encephalitis with transient splenial hyperintensity appearing as dot sign on magnetic resonance imaging of brain.

Acute hemorrhagic encephalitis: An unusual presentation of dengue viral infection

Dengue is a common viral infection worldwide with presentation varying from clinically silent infection to dengue fever, dengue hemorrhagic fever, and severe fulminant dengue shock syndrome. Neurological manifestation usually results from multisystem dysfunction secondary to vascular leak. Presentation as hemorrhagic encephalitis is very rare. Here we present the case of a 13-year-old female admitted with generalized tonic clonic seizures. Plain computed tomography (CT) scan of head revealed hypodensities in bilateral deep gray matter nuclei and right posterior parietal lobe without any hemorrhage. Cerebrospinal fluid (CSF) and serology were positive for IgM and IgG antibodies to dengue viral antigen. Contrast-enhanced magnetic resonance imaging (MRI) revealed multifocal T2 and fluid attenuated inversion recovery (FLAIR) hyperintensities in bilateral cerebral parenchyma including basal ganglia. No hemorrhage was seen. She was managed with steroids. As her clinical condition deteriorated, after being stable for 2 days, repeat MRI was done which revealed development of hemorrhage within the lesions, and diagnosis of acute hemorrhagic encephalitis of dengue viral etiology was made.

Isolated Bell's palsy - an unusual presentation of dengue infection

Dengue fever is a very common arthropod - borne infection in tropical countries. Neurological complications in dengue fever are relatively uncommon and among these, isolated cranial neuropathies have been reported only very rarely. We present an unusual neurological complication of Bell's palsy (lower motor neuron 7 th nerve palsy) associated with dengue infection. To the best of our knowledge, there have been very few documented cases of Flavivirus causing isolated Bell's palsy.

A rare case of dengue encephalitis

Dengue fever has a variable clinical spectrum ranging from asymptomatic infection to life-threatening dengue haemorrhagic fever and dengue shock syndrome. However, neurological complications, in general, are unusual. Dengue encephalopathy is not an unknown entity; however, dengue encephalitis, a direct neuronal infiltration by the dengue virus, is an extremely rare disease. Although dengue is classically considered a non-neurotropic virus, there is increasing evidence for dengue viral neurotropism, suggesting that, in a proportion of cases, there may be an element of direct viral encephalitis. An MRI brain rarely shows focal abnormalities in dengue encephalitis. We report an interesting case of dengue encephalitis during an outbreak in Delhi, India. The diagnosis was confirmed by blood and cerebrospinal fluid dengue serology and (NS1) antigen assay. The case showed extensive lesions involving the midbrain, cerebellum, thalamus and medial temporal region on both sides of the MRI brain, which is an uncommon manifestation of dengue fever.

Unique neurological manifestations of dengue virus in pediatric population: a case series

Dengue infection is endemic in developing countries posing a major public health problem. Clinical manifestations form a broad spectrum and include uncomplicated dengue fever, dengue hemorrhagic fever and dengue shock syndrome. We report three confirmed cases of dengue infection in pediatric population with central nervous system involvement with certain unreported manifestations resulting in diagnostic dilemma. Increasing evidence of neurotropism by dengue virus emphasizes that clinician be aware of such association and consider dengue infection in cases of febrile encephalitis and myelitis in endemic areas. Early diagnosis and appropriate supportive cars can reverse this potentially fatal disease.

An evaluation of the usefulness of neuroimaging for the diagnosis of Japanese encephalitis

Japanese encephalitis virus (JEV) is estimated to cause 30–50,000 cases of encephalitis every year. The disease occurs mainly in rural Asia and is transmitted to humans from birds and pigs by mosquitoes of the genus Culex. JE is diagnosed with antibody testing of the serum and CSF, but this is not available in many hospitals. Neuroimaging abnormalities, particularly thalamic hypodensity on computed tomography (CT) and hyperintensity on T2 weighted magnetic resonance imaging (MRI) have been described in case studies, but their usefulness for diagnosing JE is not known. We have therefore evaluated the usefulness of neuroimaging (CT and MRI) for the diagnosis of JE. The findings of thalamic lesions were compared with the final serological diagnosis in a cohort of 75 patients (children and adults) with suspected CNS infections in Southern Vietnam, a JEV endemic area. Thalamic lesions on CT and/or MRI combined had sensitivity 23% (95% confidence interval 12.9–33.1%), specificity 100%, positive predictive value 100% and negative predictive value 42.1% (95% confidence interval 30.2–53.8%) for a diagnosis of JE in this cohort. Over time, the thalamic lesions resolved in some patients. One patient showed disappearance of lesions on CT followed by reappearance of the lesions some time later, known as the fogging effect. In this setting, the presence of thalamic abnormalities suggested the diagnosis of JE, but their absence did not exclude it.

Dengue Encephalitis Associated with Hydrocephalus

We describe a case of dengue encephalitis with bilateral thalamus and cerebellum involvement. The cerebellar mass effect led to hydrocephalus requiring drainage. The patient recovered completely on follow-up.

Dengue encephalitis

We report a case of dengue fever with features of encephalitis. The diagnosis of dengue was confirmed by the serum antibodies to dengue and the presence of a dengue antigen in the cerebrospinal fluid. This patient had characteristic magnetic resonance imaging brain findings, mainly involving the bilateral thalami, with hemorrhage. Dengue is not primarily a neurotropic virus and encephalopathy is a common finding in Dengue. Hence various other etiological possibilities were considered before concluding this as a case of Dengue encephalitis. This case explains the importance of considering the diagnosis of dengue encephalitis in appropriate situations.