Neuromuscular Electric Stimulation in Rehabilitation of Dysphagia in pediatric Patients with Cerebral Palsy

Abstract

Cerebral palsy (CP) is a chronic movement disorder resulting from an abnormal development or injury in the immature brain. Children with CP demonstrate various movement disorders, including muscle weakness, abnormal postural responses, coordination failure, and slow muscle contraction, which cause functional problems, including abnormal gait (Shkedy Rabani et al., 2014), hand dysfunction (Klingels et al., 2012), and dysphagia (Arvedson, 2013). Swallowing problems which is a common problem in CP were included in the spectrum of disorders of movement and posture development and were accepted as one of the core features of CP (Kim, 2013). A number of international studies, some of which are dated, have reported the prevalence of dysphagia in children with CP, with ranges between 13 to 99% (Calis et al., 2008; Parkes, 2010; Kim et al., 2013; Benfer et al., 2013). Children with CP have a difficulty recognizing oral sensation for localization of the input, because the sensory threshold is different from normal so it is difficult to determine where the stimulation occurs within the oral area, including the lips, cheeks, tongue, and oral plates (arvedson,2013).The touch and pressure receptors of the tongue and oral-cavity surfaces transmit sensory information to the brainstem and cerebral cortex to guide tongue shape and pharyngeal pressure according to bolus volume and viscosity (Song, 2015). The ASHA NOMS is a multidimensional clinical tool developed to assess supervision, diet level and severity of dysphagia, and represents functional status, which is rated on a scale from 1 to 7(Song et al., 2015). Swallowing disorders can be evaluated by a Video fluoroscopic swallow study (VFSS) that provides dynamic visualization of oral, pharyngeal and upper esophageal phases of swallowing. It has been the accepted "gold standard" investigation for several years but has significant drawbacks, including the time constraints set by the use of ionizing radiation and the problems posed by the cumbersome equipment in mimicking the child's normal feeding situation (Dodrill and Goza, 2015). Ultrasonography has been suggested as an alternative or additional investigation of oral motor function in children with CP as a portable, non-invasive, and radiation free technique. US imaging provided useful information with regard to the oral cavity and the soft tissue structures, capturing the silent features of tongue/hyoid/palate activity and bolus transport across the tongue and through the hypo pharyngeal area impairment (Hsiao et al., 2012). Fiber optic Endoscopic Evaluation of Swallowing (FEES) offers detailed information of pharyngeal phase of swallowing and of the relative functions of the upper airways and upper digestive tract (Sitton et al., 2011). Oral sensory stimulation by speech therapists has been applied to improve the feeding ability in children with CP (Arvedson et al., 2010b). Electrical stimulation is one of the most crucial tools in rehabilitation of swallowing to restore muscle use by depolarizing the nerves that are responsible for motor innervation to a particular muscle or particular muscle fibers (Ianessa et al., 2012). A few previous studies have suggested that Neuro Muscular Electrical Stimulation (NMES) might provide positive effects on swallowing function in paediatric patients (Christiaanse et al., 2011; Rice, 2012 & Song, 2015).However, there remains a lack of studies investigating the effects of NMES on oral functions related to feeding in CP with dysphagia (Song, 2015).