Effectiveness of Neuromuscular Electrical Stimulation Added to Oral Motor Therapy in Cerebral Palsy

Effectiveness of Neuromuscular Electrical Stimulation Added to Oral Motor Therapy in Children With Cerebral Palsy Experiencing Drooling Problems: A Randomized Controlled Trial

This randomized, controlled, single-blind trial aims to investigate the effectiveness of neuromuscular electrical stimulation (NMES) combined with oral motor therapy in reducing drooling severity among children with cerebral palsy. Participants will be allocated to an intervention group (oral motor therapy plus NMES), a control group (oral motor therapy alone) and a sham group (oral motor therapy with placebo NMES).

Drooling is a common and disabling problem in children with cerebral palsy, adversely affecting health, social participation, and quality of life. Oral motor therapy is frequently used to improve oral control, and neuromuscular electrical stimulation (NMES) has been suggested as an adjunctive treatment to enhance orofacial muscle function.

This randomized, controlled, single-blind study will include children aged 4 to 17 years diagnosed with cerebral palsy and presenting with moderate to severe drooling (Drooling Severity and Frequency Scale score ≥3). Participants will be randomly assigned to one of three groups: oral motor therapy alone, oral motor therapy plus active NMES, and oral motor therapy with sham NMES. The intervention comprises twelve therapy sessions over four weeks, delivered by a trained therapist.

Oral motor therapy involves exercises targeting lips, tongue, cheeks, and jaw, in addition to thermal and tactile stimulation (using brushes, spoons, cold packs, and heat packs). NMES will be applied bilaterally to the masseter muscles and to the orbicularis oris muscle using a Chattanooga NMES device. Sham NMES will simulate the procedure without delivering active stimulation.

Outcome measures will be assessed before and after the intervention and will include both subjective and objective drooling scales: Drooling Severity and Frequency Scale (DSFS), Drooling Impact Scale (DIS), Visual Analog Scale for drooling severity, Drooling Quotient (DQ5), and caregiver reports of bib usage. Orofacial muscle thickness will be measured with ultrasound imaging. Additional assessments will include functional classification systems (GMFCS, MACS, CFCS, VFCS, EDACS, FOIS) and the Pediatric Eating Assessment Tool (PEDI EAT-10).

This study is approved by the Ethics Committee of Istanbul Medipol University.

Inclusion Criteria:

• Diagnosis of cerebral palsy (unilateral/bilateral spastic, ataxic, dyskinetic, or mixed type)
• Presence of drooling control problems
• Age between 4 and 17 years
• Gross Motor Function Classification System (GMFCS) levels 2, 3, 4, or 5
• Stable drooling severity for at least one month prior to enrollment
• Drooling Severity and Frequency Scale (DSFS) score of 3 or higher

Exclusion Criteria:

• Diagnosis of dysphagia
• Use of medications affecting drooling within the past 72 hours
• Upper respiratory tract infection and/or salivary gland infection during the study period
• History of botulinum toxin injection to the salivary glands