Neurological manifestation as presenting feature of dengue infection.

Neurological manifestation as the presenting feature of dengue infection is rare. This is a brief description of five children 5 months to 11 years with presenting features as seizures or altered sensorium. Bleeding manifestations were seen in two. Cerebrospinal fluid examination was normal in all. All were diagnosed as per WHO definition of dengue hemorrhagic fever and managed as per standard protocol. Serology (IgM dengue) or nonstructural protein 1 antigen was positive in all.

Introduction

Dengue virus infection has varying clinical manifestation ranging from asymptomatic infection to life threatening hemorrhagic fever and dengue shock syndrome (DSS). Viruses are of four types 1–4 and belong to family flaviviradae. The association of dengue infection with unusual neurological manifestation was first reported by Sanguansermsri et al.[1] Dengue encephalitis has high morbidity and mortality, there are only a few reports.[2] Dengue is known to cause neurological manifestation in 3–6% cases but presentation as a neurological sign or symptom is rare. We present five children who either presented as altered sensorium or seizures with fever of varied duration and were diagnosed as dengue infection.

Case Reports

Five children aged 5 months to 11 years presented with fever of 1–10 days duration. The clinical profile and laboratory investigation of these children can be seen in Tables 1 and 2. Initial presentation of three cases was seizure. Two had altered sensorium at presentation and subsequently manifested as shock. Cerebrospinal fluid (CSF) examination of all five cases was normal. All five cases have normal blood urea and serum electrolytes. Of five cases, four have low platelet count, but none required platelet transfusion. All five cases were dengue IgM or nonstructural protein 1 (NS1) positive.

Table 1

Clinical profile of cases

Table 2

Laboratory profile of cases

Case one was a 5-month-old female who presented with fever of 10 days with multiple episodes of seizures and petechial spots over trunk and both limbs. Her platelet count was low and dengue IgM was positive. The second case was a 11-year-old female who presented with altered sensorium and multiple episode of blood mixed vomiting with fever of 1-day duration. Her dengue NS1 was positive, and CSF examination was normal.

All five cases were given intravenous fluids as per WHO guidelines. All five were discharged successfully without having any residual morbidity.

Discussion

Neurological manifestation as a feature of dengue infection is rare. The association of dengue infection with unusual neurological manifestation was first reported by Sanguansermsri et al.[1] Numerous neurological manifestation are reported such as encephalopathy, encephalitis, Guillain–Barre syndrome, transeverse myelitis, acute disseminated encephalomyelitis and myositis. Most widely reported of these is encephalopathy (incidence 0.5–6.2%).

Involvement of central nervous system (CNS) has always been thought to be secondary to vasculitis with resultant fluid extravasation, cerebral edema, hypoperfusion, liver failure and/or renal failure. Thus, the condition has been referred to as dengue encephalopathy. Encephalitis or direct involvement of the brain by the virus was unlikely.[3] However, recent evidence is in favor of dengue neurotropism because of dengue virus.[4] Dengue IgM antibodies have been discovered in CSF of encephalopathy patients, which suggest that dengue virus is capable of CNS infection.

Most case series on dengue encephalitis suggest that patients with disease have a higher tendency to develop dengue hemorrhagic fever (DHF)/DSS. The neurological recovery was complete in most of these patients, although they had increased the incidence of DHF/DSS. Mortality in cases of dengue encephalitis is increased not due to the encephalitis per se which usually has a benign course, but due to increased incidence of DHF/DSS.[5]

Hence during an epidemic of dengue or in areas endemic to dengue infection dengue virus infection should be kept as a possibility in the differential diagnosis in children presenting with fever, altered sensorium and seizures.