Age: 75.0
Sex: F
Vaccine: FLUX
Symptoms: Acute disseminated encephalomyelitis, Anaesthesia, Brain stem syndrome, C-reactive protein increased, CSF lymphocyte count increased
Clinical narrative: Case number PHHY2011CA86216 is an initial literature report received on 27 Sep 2011. Authors presented a case of acute disseminated encephalomyelitis (ADME) following influenza vaccination. This case refers to a 75-year-old female patient. Her past medical history included non-insulin dependent diabetes mellitus type 2, dyslipidemia, hypertension, hypothyroidism and a seronegative arthropathy. She had no other recent illness, history of tuberculosis, or travel history in the preceding 24 months. She had never previously received influenza vaccination. She was vaccinated with an inactivated seasonal influenza vaccine (manufacturer and batch number: Unknown) on an undetermined date in 2008. She presented with a 20 day history of headache, malaise, fatigue, intractable hiccups, nausea and vomiting in Nov 2008. It was reported that the symptoms began evolving 2 days following receipt of vaccination. She developed left hemiparesis 20 days post-immunization (PI) and by 29 days PI had progressed to hemiplegia and hemianesthesia of the left side. She then became encephalopathic and developed brainstem involvement with a left abducens palsy, dysarthria, right hemiparesis, and incontinence. Her neurological exam demonstrated bilateral spastic tone, brisk reflexes and extensor plantar responses. Magnetic resonance imaging of the brain and spine demonstrated a long segment of T2 hyperintensity extending from the caudal medulla down the entire length of the cervical cord terminating at T6. Spinal cord expansion was presented throughout this segment, maximal at C5/C6. Skip lesions were also present through the rest of the spinal cord down into the conus medullaris. Patchy enhancement was presented on postgadolinium sequences throughout. The remainder of the brain MRI was within normal limits for her age (non-specific white matter changes). Her cerebrospinal fluid demonstrated lymphocytic pleocytosis (white blood cell count of 208/micro L), comprised 56% neutrophils, 29% lymphocytes and 15% monocytes, and elevated protein of 911 mg/L. A comprehensive parainfectious workup and rheumatologic panel were negative apart from an elevated CRP of 37.4 mg/L. CSF pathology was negative for malignant cells. Her clinical and radiologic findings fulfilled published criteria for ADEM according to the Brighton Collaboration Encephalitis Working Group. Despite treatment with broad-spectrum antibiotics, acyclovir, methylprednisolone and plasma exchange therapy (7 treatments in 14 days), the patient continued to deteriorate to quadriplegia and required intubation secondary to hypercapneic respiratory failure, she developed pneumonia and passed away 70 days PI. Authors stated that seeing as the patient passed away 70 days PI and did not attain the minimum 3 months follow-up duration required to document a monophasic pattern of illness and fulfill a level 1 of diagnostic certainty, her case meets a level 2 of diagnostic certainty for ADEM. Although CSF findings are not included in the abovementioned diagnostic definition of ADEM, the CSF pleocytosis and elevated protein in this patient are useful indicators of central nervous system inflammation. Authors also stated that brainstem dysfunction may serve as a poor prognostic indicator. When assessing post-vaccination adverse events it is always difficult to separate causality from a temporal coincidence, however, in accordance with the World Health Organization's causality assessment criteria it is 'very likely' that in this case disease was caused by the administration of vaccine.