Neurological complications after H1N1 influenza vaccination: magnetic resonance imaging findings

Abstract

Objective: To report 4 different neurological complications of H1N1 virus vaccination. Method: Four patients (9, 16, 37 and 69 years of age) had neurological symptoms (intracranial hypertension, ataxia, left peripheral facial palsy of abrupt onset, altered mental status, myelitis) starting 4-15 days after H1N1 vaccination. MRI was obtained during the acute period. Results: One patient with high T2 signal in the cerebellum interpreted as acute cerebellitis; another, with left facial palsy, showed contrast enhancement within both internal auditory canals was present, however it was more important in the right side; one patient showed gyriform hyperintensities on FLAIR with sulcal effacement in the right fronto-parietal region; and the last one showed findings compatible with thoracic myelitis. Conclusion: H1N1 vaccination can result in important neurological complications probably secondary to post-vaccination inflammation. MRI detected abnormalities in all patients.Keywords: central nervous system, influenza A virus, H1N1, magnetic resonance imaging, encephalitis after vaccination. RESUMOObjetivo: Relatar quatro diferentes complicações neurológicas da vacina contra o vírus H1N1. Método: Quatro pacientes (9, 16, 37 e 69 anos) tinham sintomas neurológicos (hipertensão intracraniana, ataxia, paralisia facial esquerda de inicio abrupto, estado mental alterado e mielite) iniciando-se 4 a 15 dias após vacinação contra H1N1. RM foi realizada em quatro pacientes na fase aguda e em um paciente na fase crônica. Resultados: Dos quatro pacientes, um apresentou hipersinal em T2 no cerebelo, interpretado como cerebelite aguda; um, com paralisia facial esquerda, tinha realce dos condutos auditivos internos, maior à direita; um tinha hipersinal em T2 no cortex parietooccipital direito; um apresentou sinais compatíveis com mielite torácica. Conclusão: A vacinação contra o H1N1 pode resultar em importantes complicações neurológicas, provavelmente secundárias a inflamação pós-vacinal. A RM detectou anormalidades em todos os pacientes.Palavras-chave: sistema nervoso central, virus influenza H1N1, imagem de ressonância magnética, encefalite pós-vacinal.

A Rare Cause of Childhood Cerebellitis-Influenza Infection: A Case Report and Systematic Review of Literature

“…AC has also been associated with Salmonella typhi, Bordatella pertussis, Borrelia burgdorferi, Mycoplasma, Coxiella burnetii, group A Streptococcus, and Orientia tsutsugamushi. Similar findings have been described in some vaccines [2][3][4][5][6]. It has also been reported to be associated with influenza A and B [7][8][9][10].…”

Acute Cerebellitis Following COVID-19 Vaccination: A Case Report

“…Specifically, we only found three reports of postvaccination cerebellitis which were secondary to influenza vaccine. The first case was a 16-year-old girl 12days after receiving H1N1 vaccine with cortical foci of hyperintensity on FLAIR in the cerebellar hemispheres with significant mass effect on the 4 th ventri-cle (16). The second one was a 66-year-old woman presented with limb and gait ataxia and a history of H1N1 vaccination 3weaks prior to her symptoms.…”

Acute Cerebellitis in Children: A Variable Clinical Entity

“…Interestingly, both chickenpox and vaccination, both common causes of acute cerebellar ataxia, were rare causes of acute cerebellitis: only 2 children had chicken pox prior to acute cerebellitis and 3 cases were attributable to a recent vaccination. [17][18][19][20][21][22][23] Four cases were attributable to drug ingestions (3 cases of opiate toxicity and 1 case of ingestion of the tricyclic antidepressant amitriptylline). [24][25][26][27] When a prodromal illness was reported, the average time from prodromal illness to development of acute cerebellitis was 8.4 days (range 1-43).…”

“…The inflammation preferentially affects the grey matter and the white matter is usually spared, although this is not always the case. 48 Cerebellar inflammation typically appears on MRI as hyper-intense lesions in both cerebellar hemispheres on T2-weighted and fluid-attenuation inversion recovery sequences. Fluid-attenuation inversion recovery sequence uses inversion recovery to null fluid, therefore it suppresses cerebrospinal fluid signal on the MRI image and therefore enhances the contrast between normal and inflamed parenchyma.…”