Eligibility CriteriaInclusion criteria of normal controls:
- normal neurological examination
- no history of stroke
- no active neurological disorder
Inclusion criteria of hemispheric stroke patients:
- a single cerebral hemispheric stroke
- swallowing difficulty: detected by bedside swallow assessment by a physician while admitting to the rehabilitation unit.
Inclusion criteria of these brain stem stroke patients:
- a single brain stem stroke without prior stroke history
- swallowing difficulties: detected by bedside swallow assessment by a physician while admitting to the rehabilitation unit
- multiple brain lesions due to one episode of stroke
- impaired communication ability due to cognition deficit
- other central or peripheral neurological deficit leading to swallowing difficulty.
- use of an electrically sensitive biomedical device (eg. cardiac pacemaker)
- metal clip in the brain
- pneumonia at the time of enrollment.