Stroke is the most common neurological condition and a leading cause of disability; almost two-thirds of stroke survivors leave the hospital with a disability.1 Stroke can also affect all levels of the hearing pathway, from the inner ear to the central hearing tracts, and may result in various types of hearing impairment, such as peripheral hearing loss, disordered auditory processing, and cortical deafness.2 Stroke patients with hearing impairment have poor physical recovery after being discharged to the community.3 In addition, hearing loss may double the risk of developing dementia after vascular factors are controlled,4 yet it is one of the few modifiable risk factors for dementia.5 Hearing difficulties in this population can have adverse effects on patients’ communication and rehabilitation after stroke, yet identifying hearing impairment in stroke patients is often neglected.
HEARING ASSESSMENT IN STROKE PATIENTS
Performing a detailed audiological assessment of all stroke patients would be a laborious process and may not be practical. As such, a preliminary hearing screening program is needed. By having a hearing screening protocol in place, the full audiological assessment can be reserved for those who fail the initial hearing screening. To facilitate early identification of peripheral hearing loss and central auditory processing disorder in stroke survivors, we recently validated a two-tier hearing screening protocol using a handheld hearing screener and two validated hearing questionnaires that could be used in stroke units. In our recent article published in the Frontiers in Neurology Journal,6 we also recommended an appropriate referral model for stroke patients with hearing impairment. This study is the first step toward addressing the complex hearing needs of stroke patients in a systematic manner. Our aim was to support these patients’ communication needs and long-term recovery after stroke, and improve their quality of life. This approach may also possibly delay the onset of post-stroke dementia.
HEARING SCREENING IN STROKE PATIENTS
We evaluated three hearing screening tools for the identification of hearing impairment in stroke patients: (1) a handheld hearing screener for the determination of peripheral hearing loss, (2) the modified Amsterdam Inventory for Auditory Disability (AIAD), a questionnaire on specific auditory complaints and a tool for identifying auditory processing disorder, and (3) the Hearing Handicap Inventory for Elderly (HHIE), a sensitive and specific tool for identifying hearing loss.
We conducted these hearing screening tests in 42 stroke patients at three to 12 months after their stroke because hearing impairment is stable at this point.7 We then performed a full audiological assessment to identify and categorize the patient's hearing profile into one of the following: (a) normal hearing, (b) peripheral hearing loss, (c) central auditory processing disorder, or (d) a combination of peripheral and central hearing impairment. We chose pure-tone audiogram as the gold standard for the handheld hearing screener and information from different comprehensive audiological tests for the hearing questionnaires.6 Finally, we calculated the sensitivity and specificity to evaluate the accuracy of these screening tools in the diagnosis of hearing impairment.6 The results are summarized in Table 1.
RECOMMENDED HEARING SCREENING PROTOCOL
Handheld hearing screeners are not intended to determine hearing thresholds; rather, they are used to determine the possibility of an individual presenting with hearing loss.8 Self-reported inventories are standardized questionnaires used to characterize a complex clinical picture, and use of such questionnaires to screen for hearing impairment has been an attractive option because they don't require any costly equipment. Furthermore, these hearing screening tools do not require audiology expertise and can be administered with minimal time.10 Our study found that the handheld hearing screener demonstrated the highest sensitivity (93%) and specificity (100%), making it a reliable tool in identifying stroke patients who need detailed assessment for peripheral hearing loss.6 We also found that adding the AIAD questionnaire can help identify a significant proportion of patients who need further central auditory evaluation. Thus, we recommended a hearing screening protocol for stroke patients (see Fig. 1 for stroke patients in the chronic stage). This protocol can help identify patients with high levels of perceived hearing difficulties who need additional evaluation, thereby promoting optimal outcomes from post-stroke rehabilitation. To learn more, check out our full study recently published in Frontiers in Neurology.6
1. State of the Nation, stroke statistics [Internet]. Stroke association. 2017 [cited 15November 2019]. Available from: https://www.stroke.org.uk/sites/default/files/state_of_the_nation_2017_final_1.pdf
2. Koohi N, Vickers DA, Lakshmanan R, et al. Hearing Characteristics of Stroke Patients: Prevalence and Characteristics of Hearing Impairment and Auditory Processing Disorders in Stroke Patients. Journal of the American Academy of Audiology
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3. Landi F, Onder G, Cesari M, et al. Functional decline in frail community-dwelling stroke patients. European journal of neurology : the official journal of the European Federation of Neurological Societies
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4. Savva GM, Stephan BC; Alzheimer's Society Vascular Dementia Systematic Review Group. Epidemiological studies of the effect of stroke on incident dementia: a systematic review. Stroke
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6. Koohi, N., Vickers, D. A., Utoomprurkporn, N., Werring, D. J., & Bamiou, D. E. (2019). A Hearing Screening Protocol for Stroke Patients: An Exploratory Study. Frontiers in neurology
, 10, 842. doi:10.3389/fneur.2019.00842
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8. American Speech-Language-Hearing Association 1997. Guidelines for Audiological Screening
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9. Yueh B, Collins MP, Souza PE, et al. Long-term effectiveness of screening for hearing loss: the screening for auditory impairment-which hearing assessment test (SAI-WHAT) randomized trial. J Am Geriatr Soc
. (2010) 58: 427-434.