Effects of neuromuscular electrical stimulation on the biomechanics of masseter and temporalis muscle activity, physiological sleep variables, and body fat distribution in patients with Down Syndrome

Abstract

Introduction: Down Syndrome (DS), caused by the chromosome 21 trisomy, is a more frequent genetic abnormality in the population, with one case in each 319 to 1,000 births. Its main phenotypic aspects are intellectual deficiency in varying degrees, short stature, generalized muscular hypotonia, craniofacial dysmorphia, and congenital heart diseases. Other comorbidities may be associated with this abnormality, such as: gastrointestinal, hands/feet, renal and urogenital (cryptorchidism and hypospadias) malformations, overweight and obesity, decrease of sensorial function, respiratory disorders as obstructive sleep apnea (OSA), thyroid dysfunction, leukemia, defects of the immune system, neuropathy leading to dementia as Alzheimer's Disease, and others. Objective: The objective of this research was to evaluate the therapeutic effects of surface neuromuscular electrical stimulation (sNMES) on the biomechanics of masseter and temporalis muscle activity and the physiological sleep variables in young and adult patients with Down syndrome. The distribution of body fat will also be analyzed, before and after the proposed therapy, in order to verify the presence of possible variations. Methodology: Ten (10) subjects of DS research will be selected and submitted to therapy with sNMES. The therapeutic effects on the electrical activities of the masseter (surface portion) and temporal muscles (anterior portion), the amplitude of mouth opening, and the intensity of bite force will be investigated by means of surface electromyography (EMGs), analog caliper and force transducer, respectively. The physiological sleepvariables will be analyzed through the polysomnography - type II (PSG-II); while, distribution of body fat will be measured by means of the anthropometric analysis, including body mass index (BMI), neck circumference, waist circumference, and waist and hip ratio (GCR). These methods of analysis will be performed before and after the proposed therapy.