Effects of Neuromuscular Electrical Stimulation on the Masticatory Muscles and Physiologic Sleep Variables in Adults with Cerebral Palsy: A Novel Therapeutic Approach.

Cerebral palsy (CP) is a term employed to define a group of non-progressive neuromotor disorders caused by damage to the immature or developing brain, with consequent limitations regarding movement and posture. CP may impair orapharygeal muscle tone, leading to a compromised chewing function and to sleep disorders (such as obstructive sleep apnea). Thirteen adults with CP underwent bilateral masseter and temporalis neuromuscular electrical stimulation (NMES) therapy. The effects on the masticatory muscles and sleep variables were evaluated using electromyography (EMG) and polysomnography (PSG), respectively, prior and after 2 months of NMES. EMG consisted of 3 tests in different positions: rest, mouth opening and maximum clenching effort (MCE). EMG values in the rest position were 100% higher than values recorded prior to therapy for all muscles analyzed (p < 0.05); mean mouth opening increased from 38.0 ± 8.0 to 44.0 ± 10.0 cm (p = 0.03). A significant difference in MCE was found only for the right masseter. PSG revealed an improved in the AHI from 7.2±7.0/h to 2.3±1.5/h (p < 0.05); total sleep time improved from 185 min to 250 min (p = 0.04) and minimun SaO2 improved from 83.6 ± 3.0 to 86.4 ± 4.0 (p = 0.04). NMES performed over a two-month period led to improvements in the electrical activity of the masticatory muscles at rest, mouth opening, isometric contraction and sleep variables, including the elimination of obstructive sleep apnea events in patients with CP. Trial registration: ReBEC RBR994XFS http://www.ensaiosclinicos.gov.br.

Test-retest reliability of electromyographic variables of masseter and temporal muscles in patients with cerebral palsy.

INTRODUCTION: The aim of this study was to evaluate the reliability of surface electromyography of the masticatory muscles in patients with cerebral palsy. METHODS: Surface electromyography was performed over the masseter and temporal muscles in 15 patients with cerebral palsy with the mandible at rest and during maximum clenching effort in two sessions. The data were analyzed using the root mean square amplitude, mean frequency, median frequency, zero crossings and approximate entropy. RESULTS: In the within-day evaluations, intraclass correlation coefficients were higher (0.80-0.98) for the all electromyography variables and muscles during maximum clenching effort. In the resting position, the coefficients revealed good to excellent reliability (0.61-0.95) for root mean square, mean frequency, median frequency and zero crossings and fair to good reliability (0.53-0.74) for approximate entropy. In the between-day evaluations, the coefficients revealed good to excellent reliability (0.60-0.86) for mean frequency, median frequency, zero crossings and approximate entropy. In the resting position, the coefficients revealed poor to fair reliability (0.23-0.57) for all electromyography variables studied. The root mean square had the highest standard errors during maximum clenching effort (2.37-5.91) and at rest (1.47-6.86). CONCLUSION: Mean frequency, median frequency and approximate entropy are the most reliable variables of surface electromyography signals of the masseter and temporal muscles during maximum clenching effort in individuals with cerebral palsy. These measures can be used to evaluate the function and behaviour of the masticatory muscles in this population following oral rehabilitation and surgical oral procedures as well as for the study the physiology of these muscles.