Neurological events related to influenza A (H1N1) pdm09
Article first published online: 13 FEB 2014
© 2014 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Influenza and Other Respiratory Viruses
Volume 8, Issue 3, pages 339–346, May 2014
How to Cite
2014) Neurological events related to influenza A (H1N1) pdm09. Influenza and Other Respiratory Viruses 8(3), 339–346.et al. (
- Issue published online: 10 APR 2014
- Article first published online: 13 FEB 2014
- Manuscript Accepted: 8 NOV 2013
- AH1N1 pandemic;
- neurological events
To review neurological complications after the influenza A (H1N1) pdm09, highlighting the clinical differences between patients with post-vaccine or viral infection.
A search on Medline, Ovid, EMBASE, and PubMed databases using the keywords “neurological complications of Influenza AH1N1” or “post-vaccine Influenza AH1N1.”
Only papers written in English, Spanish, German, French, Portuguese, and Italian published from March 2009 to December 2012 were included.
We included 104 articles presenting a total of 1636 patient cases. In addition, two cases of influenza vaccine-related neurological events from our neurological care center, arising during the period of study, were also included.
Main outcome measures
Demographic data and clinical diagnosis of neurological complications and outcomes: death, neurological sequelae or recovery after influenza A (H1N1) pdm09 vaccine or infection.
The retrieved cases were divided into two groups: the post-vaccination group, with 287 patients, and the viral infection group, with 1349 patients. Most patients in the first group were adults. The main neurological complications were Guillain-Barre syndrome (GBS) or polyneuropathy (125), and seizures (23). All patients survived. Pediatric patients were predominant in the viral infection group. In this group, 60 patients (4.7%) died and 52 (30.1%) developed permanent sequelae. A wide spectrum of neurological complications was observed.
Fatal cases and severe, permanent, neurological sequelae were observed in the infection group only. Clinical outcome was more favorable in the post-vaccination group. In this context, the relevance of an accurate neurological evaluation is demonstrated for all suspicious cases, as well as the need of an appropriate long-term clinical and imaging follow-up of infection and post-vaccination events related to influenza A (H1N1) pdm09, to clearly estimate the magnitude of neurological complications leading to permanent disability.