Initial unsolicited report received from literature on 01 June 2018. The following is verbatim from the article: Learning Objective 1: Recognize and treat vaccine derived acute encepalitis CASE: A 62-year-old woman suddenly developed a headache 3 days after receiving the influenza vaccine. The headache worsened and was associated with photosensitivity and vomiting. The next day she was lethargic, and that night, her husband states she sat up in bed and started "speaking in tongues" as if she was "possessed". He brought her to the emergency room where she was extremely disoriented, could not follow commands. Temperature was 101.2F on presentation, but remained afebrile afterward. She had diffuse hyperreflexia with ankle clonus bilaterally; otherwise exam was unremarkable. Serum white blood count was 12.2, ESR 51, CRP 3.40; anti-cardiolipin IgM and beta-2-glycoprotein were elevated. The remainder of serological studies were unremarkable, including anti-NMDA antibodies, tick borne infections, and viral studies. CTA of the head and neck were unremarkable. Lumbar puncture showed protein of 57, 87 white cells, 36 red cells, normal glucose, negative viral studies, and negative oligoclonal bands. MRI brain showed hyperintensities in the bilateral mesial temporal lobes, frontoparietal white matter, and basal ganglia; this was consistent with acute disseminated encephalomyelitis (ADEM). She was treated with IV steroids for 5 days followed by prednisone taper over 1 month. Her mental status improved dramatically each day; score on montreal cognitive assessment (MOCA) test was 19/30 on discharge. At follow up 1 month after presentation, she complained of some problems with short-term memory and balance, but was otherwise back to normal. Examination demonstrated MOCA of 26/30, difficulty with tandem gait, and mild hyperreflexia without clonus; neurologic exam was otherwise normal. Cardiolipin IgM, beta-2-glycoprotein, ESR, CRP all decreased. Repeat MRI demonstrated resolution of diffusion restriction and improvement in the size and number of hyperintensities without new lesions. IMPACT: ADEM is an inflammatory demyelinating disease of the central nervous system. The assumed mechanism is immune-mediated demyelination triggered by infection, or, rarely, vaccination. For most vaccines, incidence rates of ADEM are as low as 0.1 per 100, 000 vaccinated individuals. As such, there have been no large population studies with estimated incidence rates yet. Lesion patterns often seen in ADEM include widespread, multifocal lesions in the white and deep grey matter, as seen in our patient. DISCUSSION: Significant spontaneous recovery is the expected outcome in most cases of vaccine-induced ADEM. Based on the current literature, it is difficult to predict who may be at risk. The risk must be balanced by the fact that influenza infection itselfis a risk factor for ADEM, which is more common than that triggered by the vaccine. We do not advocate avoiding any vaccinations, but wish to promote awareness of this potential complication, as early identification and treatment may improve outcomes, and avoid unnecessary testing and treatment. This case involves 62 years old female patient who was vaccinated with dose of Influenza vaccine (batch number, expiry date, route and site of administration were not reported) on an unspecified date. The patient's medical history and concomitant medication were not reported. On an unspecified date, three days following the vaccination, patient had headache and headache worsened and was associated with photosensitivity and vomiting. On an unspecified date, four days  (Reported as next day) following the vaccination, she was lethargic, and that night, her husband states she sat up in bed and started "speaking in tongues" as if she was "possessed". He brought her to the emergency room where she was extremely disoriented, could not follow commands. Temperature was 101.2F on presentation, but remained afebrile afterward. She had diffuse hyperreflexia with ankle clonus bilaterally; otherwise exam was unremarkable. Serum white blood count was 12.2, ESR 51, CRP 3.40; anti-cardiolipin IgM and beta-2-glycoprotein were elevated. The remainder of serological studies were unremarkable, including anti-NMDA antibodies, tick borne infections, and viral studies. CTA of the head and neck were unremarkable. Lumbar puncture showed protein of 57, 87 white cells, 36 red cells, normal glucose, negative viral studies, and negative oligoclonal bands. MRI brain showed hyperintensities in the bilateral mesial temporal lobes, frontoparietal white matter, and basal ganglia; this was consistent with acute disseminated encephalomyelitis (ADEM). At follow up 1 month after presentation, she complained of some problems with short-term memory and balance, but was otherwise back to normal. Examination demonstrated MOCA of 26/30, difficulty with tandem gait, and mild hyperreflexia without clonus; neurologic exam was otherwise normal. Patient was treated with IV steroids for 5 days followed by prednisone taper over 1 month. Her mental status improved dramatically each day; score on montreal cognitive assessment (MOCA) test was 19/30 on discharge. Cardiolipin IgM, beta-2-glycoprotein, ESR, CRP all decreased. Repeat MRI demonstrated resolution of diffusion restriction and improvement in the size and number of hyperintensities without new lesions. On an unspecified date patient was recovered from ankle clonus bilaterally and fever (Temperature was 101.2F) and recovering from other events. On an unspecified date, patient was discharged from hospital. List of documents held by sender: none.; Sender's Comments: This case concerns an adult patient who experienced a multitude of symptoms after vaccination with INFLUENZA vaccine. The events were judged to be symptoms and sequelae of 'Acute disseminated encephalomyelitis'. The time to onset is compatible. There is, however, no information regarding patient's past history, medical condition at time of vaccination nd lab tests do not rule out alternate etiologies. Based upon the reported information, the role of the vaccine cannot be assessed.