Manifestations neurologiques de la dengue

Viral Parkinsonism: An underdiagnosed neurological complication of Dengue virus infection

Dengue virus (DENV) is a flavivirus that is a significant cause of human disease costing billions of dollars per year in medical and mosquito control costs. It is estimated that up to 20% of DENV infections affect the brain. Incidence of DENV infections is increasing, which suggests more people are at risk of developing neurological complications. The most common neurological manifestations of DENV are encephalitis and encephalopathy, and movement disorders such as parkinsonism have been observed. Parkinsonism describes syndromes similar to Parkinson’s Disease where tremors, stiffness, and slow movements are observed. Parkinsonism caused by viral infection is characterized by patients exhibiting at least two of the following symptoms: tremor, bradykinesia, rigidity, and postural instability. To investigate DENV-associated parkinsonism, case studies and reports of DENV-associated parkinsonism were obtained from peer-reviewed manuscripts and gray literature. Seven reports of clinically diagnosed DENV-associated parkinsonism and 15 cases of DENV encephalitis, where the patient met the case criteria for a diagnosis of viral parkinsonism were found. Clinically diagnosed DENV-associated parkinsonism patients were more likely to be male and exhibit expressionless face, speech problems, and lymphocytosis. Suspected patients were more likely to exhibit tremor, have thrombocytopenia and low hemoglobin. Viral parkinsonism can cause a permanent reduction in neurons with consequential cognitive and behavior changes, or it can leave a latent imprint in the brain that can cause neurological dysfunction decades after recovery. DENV-associated parkinsonism is underdiagnosed and better adherence to the case definition of viral parkinsonism is needed for proper management of potential sequalae especially if the patient has an ongoing or potential to develop a neurodegenerative disease.

Dengue Virus (DENV) causes generalized fever in most patients and is transmitted via Aedes aegypti mosquitos. A small proportion of DENV infected patients have neurological complications associated with the critical phase of the illness. The usual neurological manifestations are encephalitis and encephalopathy, but there can also be movement disorders such as parkinsonism. DENV patients with parkinsonism present with tremor, bradykinesia, instability, and rigidity on top of the typical febrile manifestations of the disease. We searched the literature and uncovered 7 cases of clinically diagnosed DENV parkinsonism patients and 15 cases of suspected DENV parkinsonism. We found that the clinically diagnosed patients were more likely to be male, have expressionless face, speech issues and lymphocytosis. The suspected cases often had a diagnosis of encephalitis and were more likely to have tremors, thrombocytopenia, and low hemoglobin.

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.

Viral and Prion Infections Associated with Central Nervous System Syndromes in Brazil

Virus-induced infections of the central nervous system (CNS) are among the most serious problems in public health and can be associated with high rates of morbidity and mortality, mainly in low- and middle-income countries, where these manifestations have been neglected. Typically, herpes simplex virus 1 and 2, varicella-zoster, and enterovirus are responsible for a high number of cases in immunocompetent hosts, whereas other herpesviruses (for example, cytomegalovirus) are the most common in immunocompromised individuals. Arboviruses have also been associated with outbreaks with a high burden of neurological disorders, such as the Zika virus epidemic in Brazil. There is a current lack of understanding in Brazil about the most common viruses involved in CNS infections. In this review, we briefly summarize the most recent studies and findings associated with the CNS, in addition to epidemiological data that provide extensive information on the circulation and diversity of the most common neuro-invasive viruses in Brazil. We also highlight important aspects of the prion-associated diseases. This review provides readers with better knowledge of virus-associated CNS infections. A deeper understanding of these infections will support the improvement of the current surveillance strategies to allow the timely monitoring of the emergence/re-emergence of neurotropic viruses.

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.

Depressive and Anxiety Symptoms among Pediatric In-Patients with Dengue Fever: A Case-Control Study

BACKGROUND

Psychiatric symptoms have been reported in adult patients with dengue fever (DF); however, information on pediatric patients remains inadequate. We sought to identify the prevalence and predictors of depressive and anxiety symptoms and identify other psychiatric symptoms among pediatric patients with DF. This case-control study involved pediatric in-patients (n = 225) who had clinical or serologic-confirmed DF and healthy school-based controls (n = 260). Participants completed the Revised Child Anxiety and Depression Scale (RCADS).

RESULTS

The prevalence of depressive (13.3%) and anxiety (34.2%) symptoms among pediatric patients with DF was significantly (p < 0.001) higher than that among controls (3.5% and 16.2%, respectively). Multiple linear regression analysis found that age, family history of DF, ≤2 days of hospitalization, myalgia, and arthralgia were predictors of increased depressive and anxiety symptoms among the patients. Further, 26.7% of pediatric patients reported irritability, agitation, visual hallucinations, and aggressiveness.

CONCLUSION

Pediatric patients present depressive and anxiety symptoms whose levels were associated with social and clinical factors. However, whether these symptoms are present only during the infection or may still persist after recovery or are brought by children's adverse reactions to hospitalization are unknown, and thus, further studies are needed.

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.

Guillain-Barré Syndrome (42 Cases) Occurring During a Zika Virus Outbreak in French Polynesia

Zika virus (transmitted by mosquitoes) reached French Polynesia for the first time in 2013, leading to an epidemic affecting 10% of the total population. So far, it has not been known to induce any neurological complications, but, a few weeks after the outbreak, an unexpectedly high number of 42 patients presented with Guillain-Barré syndrome.We report the clinical and electrophysiological characteristics of this series. Males predominated with a sex ratio of 2.82 (mean age: 46). All patients (except 2) were native Polynesian. At admission, 55% were able to walk unaided against 38% at nadir, 24% had swallowing troubles (nadir: 45%), 74% had motor weakness of the limbs (nadir: 86%) and deep tendon reflexes were diminished or not found in the vast majority of patients. Mean duration of the progressive phase and of the plateau phase was respectively 7 and 9 days. Thirty-eight percent of the patients were admitted in intensive care unit and 10 patients underwent tracheotomy. Nerve electrophysiological studies at admission showed marked distal motor conduction alterations, which had almost completely disappeared at the 4th month; this pattern was more suggestive of acute motor axonal neuropathy (AMAN) than of acute inflammatory demyelinating polyneuropathy (AIDP). Lumbar puncture showed elevated proteins in 90% of the cases, with cell count always inferior to 50/μL.This epidemic raises several questions, such as the potential existence of interactions between Zika virus and Polynesian HLA system and/or the consequences of several recombination events of this virus. This situation should call for increased vigilance, especially in countries where Aedes mosquitoes are present.

Early Guillain-Barré Syndrome associated with acute dengue fever

Various forms of neurological manifestations are reported in dengue fever. We describe here three cases of concomitant Guillain-Barré syndrome and dengue virus (DENV) infection during the largest DENV-1 outbreak in New Caledonia. Research of viral RNA was positive in both blood and CSF samples. All patients were treated with intravenous polyvalent immunoglobulins and recovered without sequelae within one week.