Acute hemorrhagic leukoencephalitis after seasonal influenza vaccination

Excerpt

A previously healthy 70-year-old man was admitted to the emergency department for acute headache and confusion, 3 days after a seasonal influenza revaccination with alpharix^®, a tetravalent inactivated influenza vaccine. Clinical examination revealed a left hemiparesis with hyperthermia (39 °C) and temporal disorientation. The serum laboratory data showed a leukocytosis (16.550 white blood cells/mm³, 90% of neutrophils) with increased C reactive protein at 167 mg/L (normal value < 10). The cranial computerized tomography was unremarkable. Cerebrospinal fluid (CSF) examination revealed 199 white blood cells/mm³ with neutrophilic predominance (71%), normal glucose and increased protein content at 1.74 g/L (N < 0.45). Empirical treatment for acute infectious meningoencephalitis was started, including ceftriaxone (4 g/day), ampicilline (12 g/day), acyclovir (10 mg/kg every 8 h), and methylprednisolone (125 mg/day). However, the neurological status continued to deteriorate on the following days, requiring his transfer to the Intensive Care Unit. On day 5 after admission, he developed a deep coma with quadriparesis, extension plantar responses, Cheyne–Stokes respiration, bilateral myosis, absent oculo-cephalic reflexes, and bilateral decerebration. Bacterial cultures remained sterile. CSF-HSV polymerase chain reaction and autoimmune serologies were negative. Diffuse slow delta waves were identified on electroencephalogram recording. The brain magnetic resonance imaging (MRI) showed diffuse white matter lesions, extending to the corpus callosum and the posterior brain stem, with ischemic and hemorrhagic components in the periventricular and callosal regions (Fig. 1). These MRI findings were suggestive of acute hemorrhagic leukoencephalitis (AHL). The control CSF was acellular and xanthochromic due to a very high protein content at 8.53 g/L. Transoesophagal echocardiography was unremarkable. The anti-infectious therapy was discontinued. High doses of methylprednisolone (1 g per day) and repeated plasma exchanges were given. However, his neurological condition did not improve. He developed multi-organ failure and died 3 weeks later. No autopsy was performed.

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