Neurodevelopmental disorder is an umbrella term comprising many muscular, skeletal, metabolic, endocrinal, systemic, and immune-related diseases, which are caused due to the improper/inaccurate development of the central nervous system. Most of these disorders are highly prevalent, but some express rarely in human beings. Such disorders with least prevalence rates are known as rare neurodevelopmental disorders. The sensory system is affected in all individuals with these rare neurodevelopmental disorders, although to a varying extent. Sensory processing in terms of hearing loss is reported by many researchers in many rare neurodevelopmental disorders, but the pathophysiology of audiological findings are seldom investigated. In this chapter, the authors highlight the possible relationship between underlying cause and the resultant audiological symptoms in some of the rare neurodevelopmental disorders. Further, the research studies on the audiological profiling in such disorders are discussed.
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The present chapter is a review of the hearing loss in children with neurodevelopmental disorders. The chapters focus on the incidence and prevalence of hearing impairment/auditory processing disorders; and pathophysiology of hearing impairment in such disorders. Available research literature explains the relationship between hearing loss and some common neurodevelopmental disorders. However, such researches with reference to some of the rare neurodevelopmental disorders are limited. In the present chapter, the authors attempted to list the nature and pathophysiology of hearing loss in some of the rare neurodevelopmental disorders. Such information is essential for appropriate assessment and timely and adequate rehabilitation of children with some rare neurodevelopmental disorders.
Neurodevelopmental disorders (NDD) are a heterogeneous group of diseases which affects the development of the central nervous system (Sontheimer, 2015). According to DSM-5 classification (American Psychiatric Association, 2013), the neurodevelopmental disorders may be classified into intellectual developmental disorders, communication disorders, autism spectrum disorders, attention deficit hyperactive disorder, specific learning disorder, and motor disorder (Grohol, 2013). The cognitive, behavioral and sensory processing may be affected in these disorders (Ataalla, 2015).
Cognitive impairments are central to all NDD (Gathercole & Alloway, 2006). Tranel and Haan (2007) stated that impairments of attention are common in a wide array of these disorders. Inhibition control, orientation and selective attention were reported to be impaired in children with such disorders (Cornish, Scerif, & Karmiloff-Smith, 2007). Memory impairment is also common in children with NDD (Alloway & Gathercole, 2006). Other domains of cognition including thinking, reasoning, meta-cognitive abilities, learning, etc., are also affected in most of the children with NDD, although to a varying degree. Because of the cognitive, motor, sensory and intellectual impairment, socio-behavioral development is also affected in children with NDD. Such children are at greater risk of developing anxiety-emotional problems and have the poor peer relationship, lower social esteem, and interpersonal problems (Arim, Kohen, Garner, Lach, Brehaut, MacKenzie, & Rosenbaum, 2015). Academic underachievement is secondary to socio-behavioral impairments in children with NDD (Bruce, 2011).
Sensory processing in terms of visual, somatosensory, proprioceptive, kinesthetic, and hearing abilities are affected in children suffering from most of these disorders to a varying extent. Hearing function in terms of absolute hearing sensitivity and auditory processing abilities are impaired in children with NDD (Katbamna & Crumpton, 2011). Profuse research literature addressing the presence of hearing impairment in children with different neurodevelopmental disorders like autism (Lachowska, Pastuszka, Łukaszewicz-Moszyńska, Mikołajewska, & Niemczyk, 2016; Rosenhall, Nordin, Sandström, Ahlsén, & Gillberg, 1999; Worley, Matson, & Kozlowski, 2011), Asperger’s syndrome (Kancherla, Van Naarden Braun, & Yeargin-Allsopp, 2013), William’s syndrome (Marler, Elfenbein, Ryals, Urban, & Netzloff, 2005), Alstrom syndrome (Frölander, Möller, Rudner, Mishra, Marshall, Piacentini, & Lyxell, 2015), Rett syndrome (Pillion, Rawool, Bibat, & Naidu, 2003), other pervasive developmental disorders (Cruz, Vicaria, Wang, Niparko, & Quittner, 2012; Psillas & Daniilidis, 2003; Tanaka, Adachi, Asanuma, & Sakata, 2011), attention deficit hyperactive disorders (Kelly, Kelly, Jones, Moulton, Verhulst, & Bell, 1993; Mueller & Tomblin, 2012; Munir, 2016; Redmond, Ash, & Hogan, 2015; Riccig & Hynd, 1996; Schmithorst, Plante, & Holland, 2014), and specific learning disability (Edwards, 2010; Hersher, 1980; Keller, Tillery, & McFadden, 2006; Miller & Kiani, 2008; Yeates, 1998), is available.