Effects of neuromuscular electrical stimulation on the masticatory muscles and physiologic sleep variables in adults with cerebral palsys : a novel therapeutic approach

Abstract

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.