title: Cortical recovery of swallowing function in wound botulism.
abstract: BACKGROUND
  Botulism is a rare disease caused by intoxication leading to muscle weakness and rapidly progressive dysphagia. With adequate therapy signs of recovery can be observed within several days. In the last few years, brain imaging studies carried out in healthy subjects showed activation of the sensorimotor cortex and the insula during volitional swallowing. However, little is known about cortical changes and compensation mechanisms accompanying swallowing pathology.
  
  
  METHODS
  In this study, we applied whole-head magnetoencephalography (MEG) in order to study changes in cortical activation in a 27-year-old patient suffering from wound botulism during recovery from dysphagia. An age-matched group of healthy subjects served as control group. A self-paced swallowing paradigm was performed and data were analyzed using synthetic aperture magnetometry (SAM).
  
  
  RESULTS
  The first MEG measurement, carried out when the patient still demonstrated severe dysphagia, revealed strongly decreased activation of the somatosensory cortex but a strong activation of the right insula and marked recruitment of the left posterior parietal cortex (PPC). In the second measurement performed five days later after clinical recovery from dysphagia we found a decreased activation in these two areas and a bilateral cortical activation of the primary and secondary sensorimotor cortex comparable to the results seen in a healthy control group.
  
  
  CONCLUSIONS
  These findings indicate parallel development to normalization of swallowing related cortical activation and clinical recovery from dysphagia and highlight the importance of the insula and the PPC for the central coordination of swallowing. The results suggest that MEG examination of swallowing can reflect short-term changes in patients suffering from neurogenic dysphagia.
authors.affiliation: Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Muenster, Germany. i.teismann@uni-muenster.de
authors.forename: Inga K
authors.initials: IK
authors.lastname: Teismann
authors.forename: Olaf
authors.initials: O
authors.lastname: Steinstraeter
authors.forename: Tobias
authors.initials: T
authors.lastname: Warnecke
authors.forename: Julian
authors.initials: J
authors.lastname: Zimmermann
authors.forename: Erich B
authors.initials: EB
authors.lastname: Ringelstein
authors.forename: Christo
authors.initials: C
authors.lastname: Pantev
authors.forename: Rainer
authors.initials: R
authors.lastname: Dziewas
mesh_terms: D000328:Adult; D001906:Botulism / Q000175:diagnosis* / Q000382:microbiology / Q000503:physiopathology; D002540:Cerebral Cortex / Q000382:microbiology / Q000502:physiology; D003679:Deglutition / Q000502:physiology*; D003680:Deglutition Disorders / Q000175:diagnosis / Q000382:microbiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D020127:Recovery of Function / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*; D014947:Wounds and Injuries / Q000175:diagnosis* / Q000382:microbiology / Q000503:physiopathology