Sue Ann Erdman, MA, CCC-A
Increased longevity and the aging of the baby boomer generation will result in a doubling of the population older than 65 by the year 2030. The number of individuals older than 85 is expected to quadruple during the first half of this century, making this cohort the fastest-growing segment of our population. The implications for audiology practice are immense. To address these issues, ASHA Professional Development recently sponsored Audiology 2006, "The Aging Patient: New Perspectives in Audiology Service Delivery." The 3-day web seminar featured an interdisciplinary panel of experts including:
The increasing number of older adults poses challenges and opportunities for audiologists. Market surveys reveal that even now, less than half of the people older than 65 who could benefit from hearing aids actually purchase them. The challenge for audiologists is evident in survey results that indicate older citizens want to remain productive, to stay mentally and physically active, to help others, to socialize, and to learn new things. The challenge is multifaceted inasmuch as other physical and mental constraints influence audiologic outcome. Rowe and Kahn (1997) describe successful, healthy aging as not only avoiding disease and disability, but also as maintaining high cognitive and physical functioning and active involvement in society.
Patricia Kricos discussed the important role audiologists have in each of these areas. Cognitive functioning remains higher in individuals with satisfactory hearing, with or without hearing aids. Communication plays a critical role in ensuring independence, stimulating thinking, maintaining social networks, enhancing well-being, facilitating adaptation to change, and participating in the activities of life (Worral & Hickson, 2003).
Kricos stressed that there is no one description of the older population with hearing loss. She believes recent use of the terms "frisky," "fragile," and "frail" is more apt and descriptive of the status of older patients who may be centenarians or barely 60+. Patients' specific physical or cognitive difficulties should also influence hearing aid selection. Noise reduction technology, for instance, is important due to increased auditory processing difficulties in older adults. Automatic features facilitate overall ease of use, particularly for those with manual dexterity issues. Multiple memories are beneficial, especially for those with diverse, active lifestyles. Additionally, a slower speech-processing algorithm may be helpful for those with cognitive impairment.
Cognitive function includes two kinds of mental activity or intelligence. Fluid mechanics, which involve the speed and accuracy of elementary aspects of sensory-cognitive function such as symbol recognition, can be viewed as basic information processing. Crystallized pragmatics, which are learned complex behaviors such as literacy, professional skills, and social coping mechanisms, reflect intelligence as cultural knowledge. A decrease in fluid mechanics can be seen as early as the mid 20s. Growth of crystallized pragmatics, on the other hand, continues in healthy old age. These differences are key to understanding the cognitive abilities of older patients.
Arthritis is the most common chronic condition among elderly patients and often affects manual dexterity. Dexterity may also be affected by diminished circulation, loss of sensitivity in fingertips, swelling, and a reduced sensitivity to temperature.
Aging results in anatomical and physiological changes to the auditory and balance systems. Stephen Ackley discussed four types of presbycusis and their prevalence: sensory or cochlear are the most common, followed by neural, central, and cochlear conductive. Changes in eustachian tube function may necessitate insertion of PE tubes. Reduced sloughing of epithelial cells in the TM makes it likely that PE tubes will not be extruded naturally as they are in children. Status of the PE tubes should be monitored to determine the need for removal or replacement. Older patients may also report hearing their own heartbeat, the source of which is the carotid artery. The cause is generally high blood pressure, although a glomus jugularis tumor should be ruled out. In either case, medical referral is indicated. Vascular events resulting in sudden hearing loss are also more prevalent among older individuals. Medical treatment within 72 hours of onset maximizes the possibility of restoring hearing. Ackley also discussed diagnostic applications of cortical evoked response (P300) in Alzheimer's disease. The P300 is effective in separating mild and moderate Alzheimer's patients; those with severe Alzheimer's cannot attend to the signal. The P300 can also be used to assess the effectiveness of cholinesterase inhibitors in Alzheimer's patients. Decreased efficiency in sound transmission by the temporal bone can result in cochlear conductive hearing loss and is manifested by an often perplexing air-bone gap on audiograms.
A number of medical conditions commonly experienced by older individuals can accelerate presbycusis. Recent investigations by National Technical Institute for the Deaf researchers have found evidence of accelerated peripheral and central presbycusis for type II diabetics versus nondiabetics. Measures that are dependent on both central/brain and ear components of the auditory system showed significant differences between diabetics and nondiabetics. Hypothyroidism, which becomes more common with age, is also associated with accelerated presbycusis. Robert Frisina and colleagues found that hearing sensitivity and understanding speech in noise were significantly poorer for individuals with hypothyroidism than for matched controls. Presbycusis is also associated with aldosterone levels. Aldosterone regulates sodium and potassium, both of which are critical to cochlear function. Studies of older patients revealed strong correlations between aldosterone levels and pure-tone thresholds and scores for the Hearing in Noise Test, suggesting that aldosterone may have a protective effect on hearing in old age, both peripherally and centrally. Frisina also discussed implications of declines in the auditory efferent feedback system. In all mammals, the efferent system maintains health and proper functioning of the inner ear hair cell system, helps reduce background noise, increases perception of speech and biologically relevant sounds, and is involved in selective attention. The system begins to decline in middle age. The decline in the efferent system results in decreases in the overall health of the inner ear, leading to decreases in hearing sensitivity.
It is estimated that nearly one half of the individuals older than 85 have Alzheimer's or Alzheimer's-type disease. This statistic is especially disturbing given that this is the fastest-growing segment of our population. According to Paul Bell, the most common risk factor for Alzheimer's is not family history. Risk factors include age, gender, head injury, stroke, low education, obesity, diabetes, and—finally—genetics. The progression of Alzheimer's may occur over a period of 3 to 30 years, but most commonly occurs over a 10- to 12-year period. Bell described the progression of Alzheimer's using the seven-stage Functional Assessment Stages of the Global Deterioration Scale by Reisberg et al. (Reisberg, Ferris, de Leon, & Crook, 1982; Reisberg, Ferris, & Franssen, 1985). The progression is the reverse of normal developmental stages, with the ability to handle complex tasks in demanding situations deteriorating first, and loss of the ability to sit and smile occurring at the end.
Bell cautioned against pushing patients to do tasks that are now past their functional capabilities. Audiologists should watch for signs of forgetfulness, such as missed appointments or an inability to find the way out of the building. Simple tests—such as asking the patient to remember five words for several minutes, to count backwards from 100 by sevens, or spell the word "world" backwards—can also be helpful. If symptoms warrant, it is important to speak to a family member, who, in fact, may have been hoping to talk to someone about the patient's behavior. Stress for caregivers increases as Alzheimer's progresses; it is critical that they obtain support and should be encouraged to contact the Alzheimer's Association (24-hour hotline: 800-272-3900). Hearing tests can be very difficult for Alzheimer's patients. Nonetheless, because hearing loss can increase the confusion caused by dementia, improving hearing when possible is encouraged. As Alzheimer's progresses, patients may lose their hearing aids, forget how to insert them, eventually not remember they ever had hearing aids, and become belligerent about using them.
Dual sensory impairment becomes more common with age. Age-related vision and hearing problems develop gradually and may go unrecognized until functioning is significantly impaired. Carren Styka noted that dual sensory impairment is woefully underreported and undiagnosed. Individuals may be reluctant to admit to vision or hearing problems; this reluctance is especially true for individuals experiencing the onset of a second sensory loss. Additionally, specialists in one field are not necessarily familiar with difficulties in other fields. Audiologists should question patients about their eyesight and make referrals to optometrists and ophthalmologists as needed. Common age-related vision problems include cataracts, macular degeneration, glaucoma, and diabetic retinopathy—the leading cause of adult blindness. Styka encouraged audiologists to consider patients' vision throughout their clinical activities. She recommended the following:
Successful aging consists of maintaining a quality of life (QOL) that is acceptable, if not optimal, for each person. Factors associated with health-related quality of life (HRQOL) include physical status and functional abilities, emotional and cognitive status, independence and mobility, social support and networking with friends and family, economic/vocational status, and spiritual well-being. Styka stressed audiologists' role in maximizing HRQOL for individuals with hearing loss as well as for those with dual sensory impairment. QOL measures are used to assess treatment outcome in many fields. Measures that focus on a single disease or disability are more sensitive to change. Global measures can assess broad-based treatment effects; results can be used to contrast the effects of different diseases or disabilities on quality of life. Studies sponsored by the National Council on Aging indicate that compared with individuals with untreated hearing loss, those who have had treatment for hearing loss have better relations at home and at work, better social life, and better self-confidence, all of which may contribute to an improved quality of life.
Audiology, as a profession, must prepare for the growing number of older patients who will require audiologic services and the complexities these individuals present. Graduate programs in audiology will need to emphasize gerontology in their curricula to ensure that graduates have the knowledge and skills necessary to manage older patients. The adjustments in clinical practice will range from philosophical to logistical. Patient management will become increasingly client-centered and interdisciplinary. The inextricable interweaving of hearing, physical health, cognitive functioning, and quality of life highlights the need for a more holistic approach to audiology practice and modifications in how we, as audiologists, view our responsibilities. Audiologists must also address—in addition to a decline in hearing sensitivity—suprathreshold compromises including problems in frequency resolution and temporal processing and deterioration of the central auditory system. Cognition, vision, mobility, and dexterity in older patients are of paramount importance. At the same time, the effects of significant life events and changes in lifestyle and chronic disease and disabilities cannot be overlooked. Although the challenges are enormous, they present myriad opportunities for audiologists.
Sue Ann Erdman is director of ARCCS in Jensen Beach, Florida. Contact her at firstname.lastname@example.org.
Reisberg, B., Ferris, S. H., de Leon, M. J., & Crook, T. (1982). The Global Deterioration Scale for assessment of primary degenerative dementia. The American Journal of Psychiatry, 139, 1136–1139.
Reisberg, B., Ferris, S. H., & Franssen, E. (1985). An ordinal functional assessment tool for Alzheimer's-type dementia. Hospital and Community Psychiatry, 36, 593–595.
Rowe, J. W., & Kahn R. L. (1997). Successful aging. Gerontologist, 37, 433–440.
Worral, L., & Hickson, L. (2003). Communication disability in aging . New York: Thomson Delmar Learning.