Neurological complications in dengue infection: a review for clinical practice

Central and Peripheral Nervous System Manifestations Associated with Dengue Illness

Dengue illness, caused by the dengue viruses, continues to be a major global health concern, with increasing incidence and the emergence of severe manifestations such as neurological complications. An overview of the current understanding of dengue epidemiology, clinical manifestations, and research priorities is presented here. Dengue transmission has escalated in recent years, exacerbated by factors such as vector expansion, climate change, and socioeconomic challenges. The clinical spectrum of dengue ranges from mild febrile illness to severe manifestations, including hemorrhagic fever and neurological complications. Neurological manifestations of dengue, once considered rare, are now increasingly reported, encompassing encephalitis, myelitis, and Guillain-Barré Syndrome, among others. Diagnosis primarily relies on laboratory methods such as RT/PCR, NS1 antigen detection, and serological assays. Despite advancements in understanding the dengue pathogenesis, there remains a critical need for effective vaccines, antiviral drugs, improved surveillance methods, predictive models for disease severity, and long-term studies on post-Dengue sequelae. Integrated programs and holistic approaches to dengue control are essential for mitigating its impact. Addressing these research priorities will be pivotal in combating dengue and reducing its global burden.

Network-based approach for drug repurposing against mpox

The current outbreak of mpox presents a significant threat to the global community. However, the lack of mpox-specific drugs necessitates the identification of additional candidates for clinical trials. In this study, a network medicine framework was used to investigate poxviruses-human interactions to identify potential drugs effective against the mpox virus (MPXV). The results indicated that poxviruses preferentially target hubs on the human interactome, and that these virally-targeted proteins (VTPs) tend to aggregate together within specific modules. Comorbidity analysis revealed that mpox is closely related to immune system diseases. Based on predicted drug-target interactions, 268 drugs were identified using the network proximity approach, among which 23 drugs displaying the least side-effects and significant proximity to MPXV were selected as the final candidates. Lastly, specific drugs were explored based on VTPs, differentially expressed proteins, and intermediate nodes, corresponding to different categories. These findings provide novel insights that can contribute to a deeper understanding of the pathogenesis of MPXV and development of ready-to-use treatment strategies based on drug repurposing.

A Critical Analysis of Intracranial Hemorrhage as a Fatal Complication of Dengue Fever

Dengue fever is the most rapidly spreading mosquito-borne virus in the world, infecting about 100 million individuals. A rare but possibly dangerous consequence of dengue illness is intracranial hemorrhage (ICH). Currently, the pathogenesis of ICH is unknown. A number of studies have found a variety of risk factors for ICH in dengue. In addition, studies have reported the use of emergency surgery while monitoring thrombocytopenia in the therapy of dengue ICH. This review enumerates the potential predictors of ICH in dengue, discusses the use of brain imaging, and mentions the possibility of emergency surgery.

A mouse model of peripheral nerve injury induced by Japanese encephalitis virus

Japanese encephalitis virus (JEV) is the most important cause of acute encephalitis in Eastern/Southern Asia. Infection with this virus also induces peripheral nerve injury. However, the disease pathogenesis is still not completely understood. Reliable animal models are needed to investigate the molecular pathogenesis of this condition. We studied the effect of Japanese encephalitis virus infection in C57BL/6 mice after a subcutaneous challenge. Limb paralysis was determined in mice using behavioral tests, including a viral paralysis scale and the hanging wire test, as well as by changes in body weight. Nerve conduction velocity and electromyography testing indicated the presence of demyelinating neuropathy of the sciatic nerve. Pathological changes in neural tissues were examined by immunofluorescence and transmission electron microscopy, which confirmed that the predominant pathologic change was demyelination. Although Western blots confirmed the presence of the virus in neural tissue, additional studies demonstrated that an immune-induced inflammatory response resulted in severe never injury. Immunofluorescence confirmed the presence of Japanese encephalitis virus in the brains of infected mice, and an inflammatory reaction was observed with hematoxylin-eosin staining as well. However, these observations were inconsistent at the time of paralysis onset. In summary, our results demonstrated that Japanese encephalitis virus infection could cause inflammatory demyelination of the peripheral nervous system in C57BL/6 mice.

Spontaneous acute subdural hematoma in dengue fever: Case report and review of the literature

Introduction and importance

A very uncommon dengue fever consequence is subdural hematoma. IgG positivity, increased AST, and ALT levels may all be risk factors for bleeding in dengue fever patients.

Case presentation

We report the case of a 65-year-old man who presented with dengue fever symptoms and developed altered consciousness and focal neurological deficits. The findings of the tests showed thrombocytopenia, increased AST and ALT, positive anti-dengue IgG, and subdural hematoma on brain imaging. The urgent operations were completed satisfactorily.

Clinical discussion

Dengue-related intracerebral haemorrhage is still a complicated condition. Thrombocytopenia and leukopenia are the first symptoms that point to dengue. Some risk factors, such as thrombocytopenia and increased AST and ALT, have been identified as bleeding factors in dengue fever. For a possible intracerebral haemorrhage, radiological imaging should be performed. In an emergency neurosurgery setting, thrombocyte administration could be used to monitor thrombocytopenia.

Conclusion

Subdural hematoma is a possible dengue fever complication. If the patient's symptoms with thrombocytopenia and elevated liver enzymes indicate the possibility of intracranial haemorrhage, immediate radiological imaging should be performed.

•

Elevated AST and ALT as a risk factor of intracranial bleeding in dengue fever

•

Immediate radiological imaging to the patients with positive IgG and intracranial haemorrhage symptoms.

•

Emergency surgical intervention should be conducted depending on patient's status with thorough care in hematologic profile.

Comprehensive characterization of human-virus protein-protein interactions reveals disease comorbidities and potential antiviral drugs

The protein-protein interactions (PPIs) between human and viruses play important roles in viral infection and host immune responses. Rapid accumulation of experimentally validated human-virus PPIs provides an unprecedented opportunity to investigate the regulatory pattern of viral infection. However, we are still lack of knowledge about the regulatory patterns of human-virus interactions. We collected 27,293 experimentally validated human-virus PPIs, covering 8 virus families, 140 viral proteins and 6059 human proteins. Functional enrichment analysis revealed that the viral interacting proteins were likely to be enriched in cell cycle and immune-related pathways. Moreover, we analysed the topological features of the viral interacting proteins and found that they were likely to locate in central regions of human PPI network. Based on network proximity analyses of diseases genes and human-virus interactions in the human interactome, we revealed the associations between complex diseases and viral infections. Network analysis also implicated potential antiviral drugs that were further validated by text mining. Finally, we presented the Human-Virus Protein-Protein Interaction database (HVPPI, http://bio-bigdata.hrbmu.edu.cn/HVPPI), that provides experimentally validated human-virus PPIs as well as seamlessly integrates online functional analysis tools. In summary, comprehensive understanding the regulatory pattern of human-virus interactome will provide novel insights into fundamental infectious mechanism discovery and new antiviral therapy development.

Emerging tropical neurological infections

A large majority of neurological infections remain undiagnosed worldwide. Emerging and re-emerging infections are likely to be responsible for a significant proportion of these. Over the last two decades, several new organisms producing neurological infection and the neurotropic potential of many other known pathogens have been identified. Large outbreaks caused by re-emerging pathogens such as Chikungunya virus, Zika virus and Ebola virus have led to better delineation of their neurological manifestations. Recognition of the pandemic potential of emerging pathogens and an improved understanding of their host-vector-environment interactions would help us be better prepared to meet these emerging threats.

An unusual case of acute motor axonal neuropathy (AMAN) complicating dengue fever

Neurological complications are increasingly being reported in dengue fever, and the dengue virus is now recognized as a neurotrophic virus. The damage caused by inflammatory cytokines in the febrile phase and molecular mimicry in the recovery phase is responsible for these neurological manifestations. We report such an unusual neurological complication occurring in a 27-year-old female in the recovery phase of dengue fever, who developed an acute onset of ascending symmetric weakness of all four limbs without any sensory, autonomic, cerebellar, or cranial nerve involvement. She was diagnosed as having an acute motor axonal neuropathy (AMAN) variant of Guillain-Barre syndrome (GBS) based on a nerve conduction study (NCS) showing axonal neuropathy and contrast-enhanced magnetic resonance imaging (CE-MRI) showing root enhancement at the region of the cauda equina. She was treated with intravenous immunoglobulin (IVIG) and showed full recovery from symptoms with treatment. Our case highlights the importance of being aware of such rare neurological complications in dengue fever. Early detection and rapid initiation of treatment can lead to the complete reversal of neurological deficits.

Correlation of serotype-specific strain in patients with dengue virus infection with neurological manifestations and its outcome

INTRODUCTION

Neurological manifestation of dengue virus infection is a rare entity. Serotypes commonly associated with neurological manifestation are DENV-2 and DENV-3. We plan to detect the serotypes related to the neurological presentation in dengue infection and its correlation with different neurological complications and outcome.

METHODS

In this case-control study, consecutive dengue cases with different neurological manifestations were enrolled along with age and sex-matched controls (dengue patients without neurological complication). Serotyping using RT-PCR of samples of cases and controls were done. Level of correlation was analyzed with various parameters and outcomes.

RESULTS

In cases out of 33 samples, 6 sample serotypes were detected, which were composed of DENV-1 (n = 2) and DENV-2 (n = 4). In controls, DENV-1 (n = 5), DENV-2 (n = 6), and DENV-3 (n = 3) were detected. When statistically correlated, no significant association was found in cases and controls with dengue virus serotype. The frequency of serotype 2 was higher in hypokalemic paralysis cases than non-hypokalemic paralysis cases and the difference was significant (p < 0.05). The outcome was good (mRS < 3) in all the cases where serotypes were detected, but on statistical correlation, it was not found significant (p > 0.05).

CONCLUSION

DENV-1 and DENV-2 are associated with neurological manifestation of dengue infection, which is different from the existing literature, where DENV-2 and DENV-3 are reported. The detection of DENV serotype will help in predicting and best management of neurological complication. The serotype 2 of dengue virus is more commonly associated with dengue-associated hypokalemic paralysis than other neurological complication (p < 0.05). There is no significant association of serotypes with outcome or mortality.

Hydrocephalus secondary to dengue encephalitis in an infant: case report

BACKGROUND

Dengue is the leading cause of mosquito-borne viral infection. It is responsible for high morbidity and mortality in children living in endemic areas. Nowadays, neurological complications are progressively referred to and include a broad spectrum of symptoms. It can be secondary to metabolic alterations, direct invasion by the virus, and enhanced autoimmune response.

CASE PRESENTATION

Here, we report a rare case of hydrocephalus secondary to dengue encephalitis. A 13-day-old boy was diagnosed with dengue. He evolved with seizures and impaired consciousness being diagnosed with encephalitis. After clinical treatment, he was discharged fully recovered. Three months later, he presented with signs and symptoms of intracranial hypertension. Brain MRI revealed hydrocephalus secondary to acquired aqueduct stenosis. The patient underwent an endoscopic third ventriculocisternostomy.

CONCLUSION

Dengue infection is a differential diagnosis for acute febrile neurological impairment in children from endemic areas. Follow-up should be offered after dengue encephalitis to detect possible late-onset complications, as hydrocephalus.

A Case Series of Severe Dengue with Neurological Presentation in Children from a Colombian Hyperendemic Area

Dengue transmission is sustained in Colombia with increasing prevalence mainly in children. This work aimed to describe a case series of children diagnosed with dengue presenting neurological disease in Huila Province of Colombia. Eleven pediatric febrile patients confirmed for dengue disease and presenting neurological signs were studied in the University Hospital of Neiva, Huila Province. Clinical and laboratory findings, CSF cytochemical analysis, neurology images, and serology and molecular studies were performed. Viral RNA was detected in all patients' sera by RT-PCR. Nine out of 11 were primary infections. Tonic-clonic seizures (73%), consciousness alterations (27%), irritability (27%), and ataxia (18%) were the most frequent neurological signs. None of the patients had plasma leakage, hypovolemic shock, or liver disease, confirming the encephalitis diagnosis. Diagnostic images did not show abnormal findings, but neither bacterial nor fungal infections were detected in CSF analysis. All patients survived without sequelae except for one patient that presented ataxia for months. In conclusion, we described a group of children with neurological signs during severe dengue disease as the main finding, indicating the importance to including dengue as a differential diagnosis in neurological patients from endemic areas.

Use of Cerebrospinal Fluid for the Diagnosis of Neuroinvasive Dengue, Zika, and Chikungunya: A 19-year systematic review

INTRODUCTION

Cerebrospinal fluid analysis contributes to the diagnosis and neuropathogenesis of neuroinvasive arboviruses. Neurological complications caused by dengue, Zika, and chikungunya infections have high clinical relevance because of their high potential to cause death or neurological deficits. We aimed to evaluate the use of cerebrospinal fluid assays for diagnostic support in neurological disorders associated with dengue, chikungunya, and Zika infections.

METHODS

A systematic review was carried out by searching the electronic databases LILACS, PubMed, Scopus, and Embase for articles written in English, Portuguese, or Spanish in the last 19 years. Published studies were reviewed using the terms "dengue," "Zika", "chikungunya", alone or in combination with "cerebrospinal fluid" in the period from 2000 to 2019.

RESULTS

A total of 98,060 studies were identified; of these, 1.1% (1,041 studies, 58,478 cases) used cerebrospinal fluid assays for neurological investigations. The most frequent neurological disorders included encephalitis (41.4%), congenital syndromes (17%), and microcephaly associated with Zika virus infections (8.9%). Neuroinvasive disorders were confirmed in 8.03% of 58,478 cases by specific cerebrospinal fluid analyses. The main methods used were IgM-specific antibodies (66%) and reverse transcription-polymerase chain reaction (10%). The largest number of scientific papers (29%) originated from Brazil, followed by India (18.4%) and the United States (14.4%).

CONCLUSIONS

Although cerebrospinal fluid analysis is of great importance for increasing neurological diagnostic accuracy and contributes to the early diagnosis of neuroinvasive dengue, chikungunya, and Zika infections, it is underused in routine laboratory investigations worldwide.

Case report: Mononeuritis multiplex in the course of dengue fever

Background

Dengue fever usually presents as a self-limiting acute febrile illness with worsening thrombocytopenia, with a small minority of patients developing hemorrhagic or life-threatening complications. Organ specific manifestations like myocarditis, acalculous cholecystitis, encephalitis has been described but are uncommon presentations. Even more rarely, such manifestations are the presenting complaint of Dengue fever. In this case report, we highlight a case of Dengue fever where unrelated neuropathies were the presenting complaint.

Case presentation

An elderly man presents with 1 day of diplopia and left foot drop, associated with 2 days history of fever. A decreasing white cell count (WBC) and platelet on the 2nd day of admission prompted Dengue virus to be tested and a positive NS-1 antigen was detected, confirming the diagnosis of Dengue fever. He was treated with supportive treatment with a short duration of intravenous fluids recovered uneventfully and was discharged 6 days after admission with almost full resolution of diplopia and partial resolution of left foot drop. Left foot drop recovered completely 2 weeks later.

Conclusion

Neurological manifestations can be the presenting symptoms in Dengue fever, a diagnosis which should be borne in mind when such symptoms present in patients from endemic areas or in returning travellers from these areas.

Acute disseminated encephalomyelitis after dengue

Dengue fever, transmitted by Aedes aegypti mosquitoes, is one of the most common vector-borne disease. Its incidence is increasing steadily worldwide, becoming a major public health problem in the tropical and subtropical zone. Neurological manifestations after dengue are not very common and acute disseminated encephalomyelitis (ADEM) following dengue infections is rare with a few cases documented in literature. Clinical characteristics and typical lesions of ADEM on magnetic resonance imaging (MRI) of brain along with serologic positivity for dengue usually confirm the diagnosis. We report a case of ADEM which developed as a neurological complication of dengue during an epidemic in a 39-year-old woman.

Flavivirus Infection Associated with Cerebrovascular Events

Arthropod-borne viruses (arboviruses) of the genus Flavivirus are distributed globally and cause significant human disease and mortality annually. Flavivirus infections present a spectrum of clinical manifestations, ranging from asymptomatic to severe manifestations, including hemorrhage, encephalitis and death. Herein, we describe 3 case reports of cerebrovascular involvement in patients infected by dengue and Zika viruses in Sao Jose do Rio Preto, São Paulo State, Brazil, a hyperendemic area for arbovirus circulation, including dengue, yellow fever, chikungunya and Saint Louis encephalitis viruses. Our findings highlight the potential threat that unusual clinical manifestations may pose to arbovirus disease management and recovery.

Fatal Dengue Cases Reveal Brain Injury and Viral Replication in Brain-Resident Cells Associated with the Local Production of Pro-Inflammatory Mediators

Dengue is an arboviral disease caused by dengue virus (DENV), which is transmitted to humans by Aedes aegypti mosquitoes. Infection by DENV most commonly results in a mild flu-like illness; however, the disease has been increasingly associated with neurological symptomatology. This association draws attention to further investigations on the impact of DENV infection in the host's central nervous system. Here, we analyzed brain samples of three fatal dengue cases that occurred in 2002 during an outbreak in Rio de Janeiro, Brazil. Brain tissues of these cases were marked by histopathological alterations, such as degenerated neurons, demyelination, hemorrhage, edema, and increased numbers of astrocytes and microglial cells. Samples were also characterized by lymphocytic infiltrates mainly composed of CD8 T cells. DENV replication was evidenced in neurons, microglia and endothelial cells through immunohistochemistry and in situ hybridization techniques. Pro-inflammatory cytokines, such as TNF-α and IFN-γ were detected in microglia, while endothelial cells were marked by the expression of RANTES/CCL5. Cytoplasmic HMGB1 and the production of nitric oxide were also found in neurons and microglial cells. This work highlights the possible participation of several local pro-inflammatory mediators in the establishment of dengue neuropathogenesis.

Coronary Artery Spasms Mimicking Acute ST-Elevation Myocardial Infarction in Dengue Haemorrhagic Fever

Dengue is an arboviral febrile illness endemic in many tropical and subtropical regions with frequent epidemics. Although most cases are self-limiting, progression into dengue haemorrhagic fever can have dire outcomes. The course can also be complicated by infrequent occurrence of unusual clinical manifestations which are increasingly recognized. We describe the case of a 16-year-old previously healthy girl diagnosed with dengue, who went on to develop severe ischaemic-type central chest pain towards the end of the critical phase of dengue haemorrhagic fever. Urgent investigation revealed acute ST-segment elevations in the high lateral leads of a surface electrocardiogram which completely reverted to normal within 2 hours, associated with elevated cardiac biomarkers but normal findings on transthoracic 2D echocardiography. She was managed with high-dose statins, nitrates, and pain relievers and made an uneventful recovery without any further episodes. The possible explanation for the presentation was focal myocarditis leading to coronary artery spasms.

Unusual clinical manifestations of dengue disease - Real or imagined?

The disease caused by each of the four serotypes of dengue virus (DENV) have plagued humans since last century. Symptoms of dengue virus (DENV) infection range from asymptomatic to dengue fever (DF) to severe dengue disease (SDD). One third of the world's population lives in regions with active urban DENV transmission, and thousands of serologically naïve travelers visit these areas annually, making a significant portion of the human population at risk of being infected. Even though lifelong immunity to the homotypic serotype is achieved after a primary DENV infection. Heterotypic DENV infections may be exacerbated by a pre-existing immune memory to the primary infection and can result in an increased probability of severe disease. Not only, age, comorbidities and presence of antibodies transferred passively from dengue-immune mother to infants are considered risk factors to dengue severe forms. Plasma leakage and multiple organ impairment are well documented in the literature, affecting liver, lung, brain, muscle, and kidney. However, unusual manifestation, severe or not, have been reported and may require medical attention. This review will summarize and discuss the increasing reports of unusual manifestations in the clinical course of dengue infection.

Spontaneous intracranial hemorrhage associated with dengue fever: An emerging concern for general physicians

Dengue fever (DF) is an arboviral disease caused by a positive-sense RNA virus of the genus Flavivirus. The overall incidence of DF has increased exponentially worldwide over the last three decades. The atypical clinical manifestations of DF grouped under expanded dengue syndrome (EDS), have also been reported more frequently for the last decade. These unusual manifestations are usually associated with coinfections, comorbidities, or complications of prolonged shock. Intracranial hemorrhage (ICH) is one of the rare manifestations of the central nervous system involvement by dengue as a part of EDS. The pathogenesis and treatment of this manifestation also remain controversial. Therefore, we report a case of a previously healthy 65-year-old female who developed ICH as a part of EDS along with a brief review of literature.

A novel p53 paralogue mediates antioxidant defense of mosquito cells to survive dengue virus replication

Mosquito cells allow dengue viruses (DENVs) to undergo replication without causing serious deleterious effects on the cells, leading to advantages for dissemination to other cells. Despite this, increased accumulation of reactive oxygen species (ROS) is usually detected in C6/36 cells with DENV2 infection as shown in mammalian cells. Uniquely, oxidative stress caused by the ROS is alleviated by eliciting antioxidant defense which leads to protection of mosquito cells from the infection. In the present study, a novel p53 paralogue (p53-2) was identified and proved to be regulated in C6/36 cells with DENV2 infection. With a gene-knockdown technique, p53-2 was demonstrated to transcribe catalase which plays a critical role in reducing ROS accumulation and the death rate of infected cells. Ecologically, a higher survival rate of mosquito cells is a prerequisite for prosperous production of viral progeny, allowing infected mosquitoes to remain healthy and active for virus transmission.

Neurocognitive impairment with hepatitis C and HIV co-infection in Southern Brazil

Although cognitive impairment has been well documented in human immunodeficiency virus (HIV) and hepatitis C virus (HCV) mono-infections, research on neurocognitive effects is limited in the context of HIV/HCV co-infection. The aims of this study were to explore the interplay between HIV and HCV infections in the expression of neurocognitive impairment (NCI), and to examine the differences in test performance between HIV/HCV co-infected and HIV or HCV mono-infected patients. A total of 128 participants from Southern Brazil underwent a comprehensive neuropsychological (NP) battery comprising 18 tests. Participants were grouped according to their serological status: HCV mono-infected (n = 20), HIV mono-infected (n = 48), HIV/HCV co-infected (n = 12), and HIV-/HCV-uninfected controls (n = 48). The frequencies of HIV subtypes B and C between the HIV mono-infected and HIV/HCV co-infected groups were comparable. There was greater prevalence of neuropsychological impairment among all three infection groups compared with the uninfected control group, but no statistically significant differences among mono- and co-infected groups were found. HCV infection was associated with cognitive deficits, independently of liver dysfunction. HCV infection did not show an additive effect on neurocognitive function among HIV+. NCI was independent of HCV RNA on peripheral blood, CSF, and hepatic injury. While we did not find additive global effect, in the present study, there was some evidence of additive HIV/HCV co-infection effects in speed of information processing, executive function, and verbal fluency domains when comparing the co-infected group with the other three groups. NP impairment was not dependent on HCV subtypes.

Neurological Manifestations of Dengue Infection

Dengue counts among the most commonly encountered arboviral diseases, representing the fastest spreading tropical illness in the world. It is prevalent in 128 countries, and each year >2.5 billion people are at risk of dengue virus infection worldwide. Neurological signs of dengue infection are increasingly reported. In this review, the main neurological complications of dengue virus infection, such as central nervous system (CNS), peripheral nervous system, and ophthalmic complications were discussed according to clinical features, treatment and possible pathogenesis. In addition, neurological complications in children were assessed due to their atypical clinical features. Finally, dengue infection and Japanese encephalitis were compared for pathogenesis and main clinical manifestations.

Rapidly Resolving Weakness Related to Hypokalemia in Patients Infected With Dengue Virus

OBJECTIVES

Dengue is a mosquito-borne disease caused by arbovirus and well known for its typical fever with thrombocytopenia syndrome. Acute hypokalemic quadriparesis is a rare presentation of dengue with uncertain pathogenesis. We aim to describe the clinical and biochemical characteristics of rapidly resolving weakness related to hypokalemia in patients infected with dengue virus.

METHODS

A retrospective review of the records of patients with diagnosis of dengue-associated hypokalemic weakness was performed. Demography, clinical, biochemical characteristics, and outcome of the patients were recorded during acute phase of illness.

RESULTS

Our study cohort comprised 12 patients and all were males from urban dwelling. The median age was 34.5 years (range, 18-50). Presentation was acute onset rapidly worsening pure motor quadriparesis preceded by short lasting febrile episode. Weakness ranged from 2/5 to 4/5 on Medical Research Council (MRC) scale with generalized hyporeflexia or areflexia. The baseline serum potassium was mean ± SD (2.7 ± 0.48 mmol/L). All patients showed elevation of liver transaminases and elevated creatine phosphokinase level. Weakness improved in 24-72 hours in all patients with correction of serum potassium.

CONCLUSIONS

Dengue-associated acute hypokalemic paralysis is an underrecognized entity having favorable outcome. It should be suspected in patients presenting as acute pure motor quadriparesis after febrile illness in dengue endemic areas.

Acute Necrotizing Encephalopathy of Childhood Secondary to Dengue Infection: A Case Report from Pakistan

Acute necrotizing encephalopathy of childhood (ANEC) is a rare condition mainly affecting children with a distinct clinico-radiologic pattern. Initially thought to be secondary to respiratory viral infections, there have been more insights to the pathogenesis of ANEC including genetics. We present a case of a girl who developed this condition with classical clinico-radiologic findings of ANEC secondary to severe dengue infection and could not survive. We report this case with the aim to raise awareness about this fatal complication of dengue infection as dengue has become a global health-care problem.

Acute disseminated encephalomyelitis complicating dengue infection with neuroimaging mimicking multiple sclerosis: A report of two cases

Acute disseminated encephalomyelitis (ADEM) complicating dengue infection is still exceedingly rare even in endemic countries such as Malaysia. Here we report two such cases, the first in an elderly female patient and the second in a young man. Both presented with encephalopathy, brainstem involvement and worsening upper and lower limb weakness. Initial magnetic resonance imaging (MRI) of the brain was normal in the first case. Serum for dengue Ig M and NS-1 was positive in both cases. Cerebrospinal fluid (CSF) showed pleocytosis in both with Dengue IgM and NS-1 positive in the second case but not done in the first. MRI brain showed changes of perpendicular subcortical palisading white matter, callosal and brainstem disease mimicking multiple sclerosis (MS) in both patients though in the former case there was a lag between the onset of clinical symptoms and MRI changes which was only clarified on reimaging. The temporal evolution and duration of the clinical symptoms, CSF changes and neuroimaging were more suggestive of Dengue ADEM rather than an encephalitis though initially the first case began as dengue encephalitis. Furthermore in dengue encephalitis neuroimaging is usually normal or rarely edema, haemorrhage, brainstem, thalamic or focal lesions are seen. Therefore, early recognition of ADEM as a sequelae of dengue infection with neuroimaging mimicking MS and repeat imaging helped in identifying these two cases. Treatment with intravenous steroids followed by maintenance oral steroids produced good outcome in both patients.

Guillain-Barré syndrome complicating dengue fever: Two case reports

Guillain-Barré syndrome is a rare neurological manifestation associated with dengue infection. More common antecedent infections include Campylobacter jejuni and Cytomegalovirus infection. Here, we report two cases of Guillain-Barré syndrome complicating dengue infection.

Deadly intracranial bleed in patients with dengue fever: A series of nine patients and review of literature

INTRODUCTION

Dengue fever is a global pandemic threat with increasing incidence. To date, there are no cures and the effectiveness of dengue vaccines is still uncertain. World Heath Organization introduced expanded dengue syndrome to include unusual presentations of dengue fever including severe neurologic complications. One of the deadly complications is intracranial hemorrhage (ICH).

METHODOLOGY

We collected data of patients with ICH diagnosed via a plain computed tomography of the brain (CT brain) with thrombocytopenia and positive Dengue virus type 1 nonstructural protein (NS1) antigen test or positive dengue serology IgM from January 2014 till June 2015 at our center. Nine patients were included and all 20 other remaining patients reported in literature so far are discussed.

DISCUSSION

We found that all patients in our center requiring neurosurgical intervention died. Another interesting observation is that detection of Dengue IgG usually meant more severe ICH and poorer outcomes. From our series, platelet levels did not seem to influence the outcome.

CONCLUSION

We recommend that for early detection of ICH, Dengue IgG should be routinely screened and a high index of suspicion be maintained. Future research should be focused on determining predictors of ICH in patients with dengue fever so that preventive steps can be taken as mortality is high and no treatment seems beneficial at the moment once severe ICH occurs.

A Two-Year Review on Epidemiology and Clinical Characteristics of Dengue Deaths in Malaysia, 2013-2014

Background

Dengue infection is the fastest spreading mosquito-borne viral disease, which affects people living in the tropical and subtropical countries. Malaysia had large dengue outbreaks in recent years. We aimed to study the demographics and clinical characteristics associated with dengue deaths in Malaysia.

Methods

We conducted a retrospective review on all dengue deaths that occurred nationwide between 1^st January 2013 and 31^st December 2014. Relevant data were extracted from mortality review reports and investigational forms. These cases were categorized into children (<15 years), adults (15–59 years) and elderly (≥60 years) to compare their clinical characteristics.

Results

A total of 322 dengue deaths were reviewed. Their mean age was 40.7±19.30 years, half were females and 72.5% were adults. The median durations of first medical contact, and hospitalization were 1 and 3 days, respectively. Diabetes and hypertension were common co-morbidities among adults and elderly. The most common warning signs reported were lethargy and vomiting, with lethargy (p = 0.038) being more common in children, while abdominal pain was observed more often in the adults (p = 0.040). But 22.4% did not have any warning signs. Only 34% were suspected of dengue illness at their initial presentation. More adults developed severe plasma leakage (p = 0.018). More than half (54%) suffered from multi-organ involvement, and 20.2% were free from any organ involvement. Dengue deaths occurred at the median of 3 days post-admission. Dengue shock syndrome (DSS) contributed to more than 70% of dengue deaths, followed by severe organ involvement (69%) and severe bleeding (29.7%).

Conclusion

In Malaysia, dengue deaths occurred primarily in adult patients. DSS was the leading cause of death, regardless of age groups. The atypical presentation and dynamic progression of severe dengue in this cohort prompts early recognition and aggressive intervention to prevent deaths.

Trial Registration

National Medical Research Registry (NMRR, NMRR-14-1374-23352)

Dengue infection, especially severe dengue, affected more of adults from working age groups in the society. They can present with non-specific symptoms mimicking many other febrile illnesses, or severe symptoms suggestive of sepsis, with low suspicion of dengue. The clinical progression in severe dengue can be dynamic and sometimes unanticipated, whereby patients can deteriorate rapidly in a short period of time and succumb to death. Although children tend to have central nervous system involvement, where they presented with confusion and/ or seizure, and more elderly had heart involvement, the primary cause of dengue death, dengue shock syndrome, did not differ across different age groups.

Current neurological observations and complications of dengue virus infection

Dengue, a mosquito-borne flavivirus and fastest growing tropical disease in the world, has experienced an explosion of neurologic case reports and series in recent years. Now dengue is a frequent or leading cause of encephalitis in some endemic regions, is estimated to infect one in six tourists returning from the tropics, and has been proven to have local transmission within the continental USA. High documentation of neurologic disease in recent years reflects increases in overall cases, enhanced clinical awareness and advances in diagnostics. Neurological aspects of dengue virus, along with epidemiology, treatment, and vaccine progress, are presented.

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.

Advances and new insights in the neuropathogenesis of dengue infection

Dengue virus (DENV) infects approximately 390 million persons every year in more than 100 countries. Reports of neurological complications are more frequently. The objective of this narrative review is to bring up the advances in the dengue neuropathogenesis. DENV can access the nervous system through blood-brain barrier disturbance mediated by cytokine. The blood-cerebrospinal fluid (CSF) barrier seems to be also involved, considering the presence of the virus in the CSF of patients with neurological manifestations. As for neurotropism, several studies showed the presence of RNA and viral antigens in brain tissue and CSF in humans. In murine model, different virus mutations were associated to neurovirulence. Despite the advances in the dengue neuropathogenesis, it is still necessary to determine a more appropriate animal model and increase the number of cases of autopsy. The detection of neurovirulence markers may contribute to establish a prognosis, the disease control and vaccine development.