Electrical brain stimulation can alleviate swallowing disorders after stroke

After stroke, patients often suffer from dysphagia, a swallowing disorder that results in greater healthcare costs and higher rates of complications such as dehydration, malnutrition, and pneumonia. In a new study published in the July issue of Restorative Neurology and Neuroscience, researchers have found that transcranial direct current stimulation (tDCS), which applies weak electrical currents to the affected area of the brain, can enhance the outcome of swallowing therapy for post-stroke dysphagia.

"Our demonstrated that ten daily sessions of tDCS over the affected esophageal of the brain hemisphere affected by the stroke, combined with swallowing training, improved post-stroke . We observed long-lasting effects of anodal tDCS over three months," reports lead investigator Nam-Jong Paik, MD, PhD, of the Department of , Seoul National University College of Medicine, Seoul, South Korea.

Sixteen patients with acute post-stroke dysphagia were enrolled in the trial. They showed signs of swallowing difficulties such as reduced , coughing and choking during eating, and palsy. Patients underwent ten 30-minute sessions of swallowing therapy and were randomly assigned to a treatment or control group. Both groups were fitted with an electrode on the scalp, on the side of the brain affected by the stroke, and in the region associated with swallowing. For the first 20 minutes of their sessions, tDCS was administered to the treatment group and then swallowing training alone continued for the remaining 10 minutes. In the control group, the direct current was tapered down and turned off after thirty seconds. Outcomes were measured before the experiment, just after the experiment, and again three months after the experiment. A patient from each group underwent a at before and just after the treatment to view the effect of the treatment on metabolism.

All patients underwent interventions without any discomfort or fatigue. There were no significant differences in age, sex, stroke lesion site, or extent of brain damage. Evaluation just after the conclusion of the sessions found that dysphagia improved for all patients, without much difference between the two groups. However, at the three month follow-up, the treatment group showed significantly greater improvement than the control group.

In the PET study, there were significant differences in cerebral metabolism between the first PET scan and the second PET scan in the patient who had received tDCS. Increased glucose metabolism was observed in the unaffected hemisphere, although tDCS was only applied to the affected hemisphere, indicating that tDCS might activate a large area of the cortical network engaged in swallowing recovery rather than just the areas stimulated under the electrode.

"The results indicate that tDCS can enhance the outcome of swallowing therapy in post-stroke dysphagia," notes Dr. Paik. "As is always the case in exploratory research, further investigation involving a greater number of patients is needed to confirm our results. It will be important to determine the optimal intensity and duration of the treatment to maximize the long-term benefits."

add to favorites email to friend print save as pdf

Related Stories

Brain stimulation improves dexterity

Oct 27, 2008

Applying electrical stimulation to the scalp and the underlying motor regions of the brain could make you more skilled at delicate tasks. Research published today in the open access journal BMC Neuroscience shows that a non- ...

Recommended for you

Link seen between seizures and migraines in the brain

7 hours ago

Seizures and migraines have always been considered separate physiological events in the brain, but now a team of engineers and neuroscientists looking at the brain from a physics viewpoint discovered a link ...

Neuroscience: Why scratching makes you itch more

13 hours ago

Turns out your mom was right: Scratching an itch only makes it worse. New research from scientists at Washington University School of Medicine in St. Louis indicates that scratching causes the brain to release ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.