A 39-year-old female patient with no antecedent comorbidities presented to the emergency department of Mayotte hospital with fever at 38.7  C associated with chills, headache, cervical pain, and asthenia of 4 days' duration. She received symptomatic treatment and was discharged.
Five days later, she returned to the emergency unit for acute urine retention in a context of an altered mental state. Clinical examination revealed that she had altered consciousness without fever or neck stiffness. CBC revealed WBC 7500/muL, platelets 356,000/muL and hemoglobin 7.4 g/dL and CRP was 15 mg/L. The results of other biological analysis showed that C-Reactive Protein level was 15 mg/L. Cerebral angiogram did not show any abnormality. A lumbar puncture was performed, the direct examination and culture were negative. However, cerebrospinal fluid (CSF) analysis revealed total leukocyte count 132 cells/muL with a lymphocyte predominance (lymphocytes: 83 %), and elevated level of CSF protein at 79 mg/dL. CSF glucose was within normal limits. The serum PCR dengue serotype 1 performed during her first admission to the emergency department was positive.
She started IV ceftriaxone 4 g per day and amoxicillin 100 mg/kg per day and aciclovir 10 mg/kg/8 h. Due to a deterioration of her neurological state, she was admitted to the intensive care unit. A second lumbar puncture was performed which found an increased number of WBC 7500/muL with a neutrophils predominance (neutrophils: 92 %), red blood cells (2350 cells/muL), the CSF glucose level was 121 mg/dL and CSF protein level was 494 mg/L. Direct examination and the culture of the CSF were again negative.
The injected brain scan showed no visible abnormality or suspect contrast at the meningeal or parenchymal level
A cranial transdoppler and another repeated after five days showed normocapnia. The electroencephalography (EEG) did not show any signs leading to metabolic or toxic encephalopathy diagnosis. A magnetic resonance imaging (MRI) of her brain was performed and showed lesions of the anterior part of the soft bulb, the left cerebellar peduncles and of the midbrain (bilaterally) in the posterior cerebral fossa which appear as hyperintense signals. After injection, there is a nodular contrast enhancement of the anterior bulbar lesion. Hyperintense signal on T2 fluid attenuated inversion recovery sequence (FLAIR) on the supra-tentorial level (Fig. 1).
Analysis of the CSF in search of different germs such as Dengue Virus, Zoster Varicella Virus, Herpes Simplex Virus using PCR. Detection of bacterial genes using 16 s RNA of Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Strepto B, Listeria monocytogenes, or Mycobacterium tuberculosis using culture were performed and negative. In the blood, serology of Cytomegalovirus, Epstein-Barr Virus, Human Immunodeficiency Virus, hepatitis C virus, hepatitis B virus, Treponema Palladium and Human Herpesvirus 6 and several blood cultures were negative. Electrophoresis of plasma proteins was performed and showed polyclonal hyper-gamma globulin without a monoclonal peak. A transthoracic echocardiography did not show any valvular vegetation.
Following a multidisciplinary meeting with the participation of an infectious disease specialist, neuroradiologist, neurologist, neurosurgeon and resuscitator, we concluded that the diagnosis of acute multifocal encephalomyelitis (ADEM) post dengue was the most plausible considering the anamnesis and the imaging (MRI). Therefore, she started an additional treatment using prednisone 2 mg/kg/day for 5 days, then at 1 mg/kg/day. A repeated cerebro-medullary MRI was performed and found an increase number of contrasts enhancing lesions at the level of the brain and spinal cord (Fig. 2). On day 3 of treatment, the patient presented persistent episodes of dysautonomia due to bulbar impairment. A transcranial doppler showed a non-reactive bilateral mydriasis without flux, associated with loss of brain stem reflex. The diagnosis of brain death was confirmed by brain scanner with injection. She was declared died.