Electrical stimulation may be useful and safe in alleviating dysphagia — difficulty swallowing — and the accompanying medical issues in children with cerebral palsy, according to new research.
The study, “Is sensory-level electrical stimulation effective in cerebral palsy children with dysphagia? A randomized controlled clinical trial,” was published in the journal Acta Neurologica Belgica.
Dysphagia is common among children with cerebral palsy. In addition to learning how to perform specific swallowing movements, treatment of dysphagia generally involves strengthening the oropharyngeal (mouth and throat) muscles through exercises as well as dietary and nutritional changes.
Ways to stimulate the oropharyngeal muscles, such as thermal, tactile, and pressure stimulation, are being explored to improve patients’ swallowing ability. But evidence supporting these methods is imprecise.
Recently, electrical stimulation has been used to treat children with cerebral palsy. However, the techniques (intensity, frequency, duration, and location) and efficacy of electrical stimulation have not been consistent. There is a lack of standardization for studies on electrical stimulation as a therapy for oropharyngeal symptoms.
There are three phases of swallowing — oral, pharyngeal, and esophageal. Certain muscle groups have been shown to be related to these phases, with the suprahyoid and infrahyoid muscles linked to the pharyngeal phase and masseter muscles to the oral.
Studies have shown that oral phase disorders are more common in children with cerebral palsy than pharyngeal phase disorders. However, electrical stimulation research has mostly focused on the pharyngeal phase. This is problematic because the phases of swallowing are interconnected and sequential — the pharyngeal phase depends on the oral phase and the esophageal phase depends on the pharyngeal phase. Therefore, an effective oral phase is critical to improving dysphagia.
Researchers at the University of Health Sciences in Ankara, Turkey, investigated the effects of sensory-level electrical stimulation treatment associated with improvement of the oral phase of swallowing.
The team applied electrical stimulation to bilateral masseter muscles — those involved in chewing and located in the mandible — at the lowest current level, combined with conventional dysphagia treatment in 102 participants — children ages 2-6 with cerebral palsy with oropharyngeal dysphagia symptoms.
Electrical stimulation was performed for 30 minutes a day, five days a week, for four weeks. Patients had two surface electrodes placed on the jaw.
This research was done in a randomized controlled clinical trial, meaning that the children were randomly grouped to receive or not receive electrical stimulation in addition to conventional dysphagia treatment.
A significant difference in dysphagia levels was observed only in the group that had received sensory-level electrical stimulation.
“Our results showed that the sensory-level electrical stimulation combined with traditional dysphagia rehabilitation methods achieved significantly more improvement in swallowing functions such as drooling, tongue movements, chewing, eating large food ability, feeding duration, dysphagia symptom severity and dysphagia level compared to control group — those participants who did not receive electrical stimulation,” researchers stated.
Based on these results, researchers think sensory-level electrical stimulation can be used to treat children with cerebral palsy who have oropharyngeal dysphagia symptoms without causing discomfort or risk of aspiration.
The researchers will now need to examine the long-term effects of sensory-level electrical stimulation in children with cerebral palsy and other conditions.