Tactile thermal oral stimulation increases the cortical representation of swallowing.
BACKGROUND
Dysphagia is a leading complication in stroke patients causing aspiration pneumonia, malnutrition and increased mortality. Current strategies of swallowing therapy involve on the one hand modification of eating behaviour or swallowing technique and on the other hand facilitation of swallowing with the use of pharyngeal sensory stimulation. Thermal tactile oral stimulation (TTOS) is an established method to treat patients with neurogenic dysphagia especially if caused by sensory deficits. Little is known about the possible mechanisms by which this interventional therapy may work. We employed whole-head MEG to study changes in cortical activation during self-paced volitional swallowing in fifteen healthy subjects with and without TTOS. Data were analyzed by means of synthetic aperture magnetometry (SAM) and the group analysis of individual SAM data was performed using a permutation test.


RESULTS
Compared to the normal swallowing task a significantly increased bilateral cortical activation was seen after oropharyngeal stimulation. Analysis of the chronological changes during swallowing suggests facilitation of both the oral and the pharyngeal phase of deglutition.


CONCLUSIONS
In the present study functional cortical changes elicited by oral sensory stimulation could be demonstrated. We suggest that these results reflect short-term cortical plasticity of sensory swallowing areas. These findings facilitate our understanding of the role of cortical reorganization in dysphagia treatment and recovery.
Teismann
Inga K
IK
Department of Neurology, University of Muenster, 48149 Muenster, Germany. i.teismann@uni-muenster.de
Steinsträter
Olaf
O
Warnecke
Tobias
T
Suntrup
Sonja
S
Ringelstein
Erich B
EB
Pantev
Christo
C
Dziewas
Rainer
R
D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D003080:Cold Temperature; D003679:Deglutition / Q000502:physiology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009960:Oropharynx / Q000502:physiology*; D010812:Physical Stimulation