(Central) auditory processing disorders

Abstract

Central auditory processing disorder (CAPD) is defined as “a deficit in the perceptual processing of auditory stimuli and the neurobiological activity underlying that processing.”1 (C)APD likely arises from abnormal neural representation of speech and non-speech sounds in the central auditory nervous system (CANS). This type of disorder may occur in pediatric and adult patients with normal hearing or may co-exist with, or occur secondary to, peripheral hearing loss. (C)APD may lead to difficulties in various auditory functions that are important for listening and comprehending spoken language, especially in noisy backgrounds. As such, (C)APD deficits may include difficulty with lateralization, localization, auditory discrimination, auditory pattern recognition, other temporal processing deficits, and more.1 Generally, patients with (C)APD are children presenting with listening problems in the classroom and difficulty in academic pursuits. (C)APD may be associated with learning disorders, especially in the areas of reading, spelling, articulation problems, difficulty following directions, and significant challenges regarding communicating and comprehending.2,3 (C)APD is more common in boys than girls and even more common in children with a significant history of otitis media.4 Roughly 7% of children are estimated to have (C)APD.5 (C)APD must be diagnosed using tools previously shown to have validity for identification of CANS dysfunction.1 Unfortunately, diagnostic tools currently available do not allow evaluation of (C)APD in children below 7 years of age, secondary to variability in the development of the brain and central nervous system. Other common disorders can mimic or co-exist with (C)APD. For example, attention deficit hyperactivity disorder (ADHD), autism, language processing disorder, and various cognitive disorders may lead to listening behaviors similar to those of (C)APD. However, the diagnosis of (C)APD is not appropriate when listening difficulties arise from, or are due to, higher-order, pan-sensory or global disorders, unless concomitant dysfunction in the CANS can be demonstrated.1 Therefore, with respect to pediatric applications, a multidisciplinary team-based approach involving the audiologist, parent(s), physician, speech-language pathologist, teacher, school psychologist, and possibly others is critical to ensure that all behaviors, actions, and observations have been addressed and considered, prior to arriving at a differential diagnosis.1-3