Can age-related hearing loss affect language rehabilitation in aphasic patients?

Abstract

Aphasia is a language disorder caused by left hemispheric lesion, compromising functional recovery. Age-related hearing loss (ARHL) decreases understanding spoken language, and represents a major public health issue despite the little attention received, affecting around 30% of Europeans by the age of 70 years. The populations most susceptible to hearing loss and to aphasia overlap and co-occurrence of both conditions can lead to compounded communication impairment. Our goal was to review existing data about occurrence of ARHL in patients with aphasia, concerning language rehabilitation. A search of PubMed database and selection of eligible studies was performed. We applied a combination of keywords including: age-related hearing loss, aphasia, stroke, peripheral auditory system, hearing aids and language. A total of 94 studies were found, from which 19 met our selection criteria. We found that the assessment of ARHL in aphasic patients remains under-investigated. ARHL is a possible biomarker and modifiable risk factor for cognitive decline, and there is strong cross-sectional association between stroke and hearing loss. Studies support that hearing evaluation should be performed in aphasic patients. Pure tone audiometry can be used as hearing screening in the post-acute phase, and a study showed that 72.82% of patients successfully underwent this test. Speech audiometry can be compromised, but the performance in this exam is largely determined by hearing loss rather than by aphasia, so clinicians should not hesitate to use this tool if patients are able to repeat single words. Therapeutic success in aphasia can be reduced by an existing ARHL, and hearing evaluation is justified in all patients. Despite the evidences, hearing screenings are being conducted only inconsistently with this population. There is a need to develop tools that are easily accessible and validated for aphasia. Moreover, the role of hearing aids in aphasic patients’ rehabilitation remains unclear.