Sheila R. Pratt

Defining aphasia: Some theoretical and clinical implications of operating from a formal definition

Theoretical and philosophical issues related to the need for and criteria of a formal definition of aphasia are discussed. Following a review of several definitions of aphasia and the contrast of two, a formal definition is advanced that meets the specific requirements of a scientific definition: criteria for group membership and the assumed mechanisms for these criteria. The specific criteria for group membership are discussed and the assumed mechanisms are presented. It is argued that this definition (or a well justified alternative) can serve as a first approximation to a general theory of aphasia. It is also claimed that it can inform the research consumer about important but unstated assumptions of researchers as well as provide clinical guidance.

Hearing Sensitivity in Older Adults: Associations with Cardiovascular Risk Factors in the Health, Aging and Body Composition Study

OBJECTIVES: To examine the association between cardiovascular disease (CVD) and its risk factors and age‐associated hearing loss in a cohort of older black and white adults.

Hearing Impairment and Incident Dementia and Cognitive Decline in Older Adults: The Health ABC Study

Background Age-related peripheral hearing impairment (HI) is prevalent, treatable, and may be a risk factor for dementia in older adults. In prospective analysis, we quantified the association of HI with incident dementia and with domain-specific cognitive decline in memory, perceptual speed, and processing speed. Methods Data were from the Health, Aging and Body Composition (Health ABC) study, a biracial cohort of well-functioning adults aged 70-79 years. Dementia was defined using a prespecified algorithm incorporating medication use, hospital records, and neurocognitive test scores. A pure-tone average in decibels hearing level (dBHL) was calculated in the better hearing ear using thresholds from 0.5 to 4kHz, and HI was defined as normal hearing (≤25 dBHL), mild (26-40 dBHL), and moderate/severe (>40 dBHL). Associations between HI and incident dementia and between HI and cognitive change were modeled using Cox proportional hazards models and linear mixed models, respectively. Results Three-hundred eighty seven (20%) participants had moderate/severe HI, and 716 (38%) had mild HI. After adjustment for demographic and cardiovascular factors, moderate/severe audiometric HI (vs. normal hearing) was associated with increased risk of incident dementia over 9 years (hazard ratio: 1.55, 95% confidence interval [CI]: 1.10, 2.19). Other than poorer baseline memory performance (difference of -0.24 SDs, 95% CI: -0.44, -0.04), no associations were observed between HI and rates of domain-specific cognitive change during 7 years of follow-up. Conclusions HI is associated with increased risk of developing dementia in older adults. Randomized trials are needed to determine whether treatment of hearing loss could postpone dementia onset in older adults.

Verbal working memory and its relationship to sentence‐level reading and listening comprehension in persons with aphasia

Background: Working memory (WM) has gained recent attention as a cognitive construct that may account for language comprehension deficits in persons with aphasia (PWA) (Caspari, Parkinson, LaPointe, & Katz, 1998; Martin, Kohen, & Kalinyak‐Fliszar, 2008; Wright, Downey, Gravier, Love, & Shapiro, 2007). However, few studies have investigated individual differences in performance on sentence comprehension tasks as a function of WM capacity in PWA when WM demands are manipulated. Aims: The purposes of the current study were: (1) to examine the relationships among verbal WM, sentence comprehension, and severity of impairment in PWA and (2) to investigate the differential performance of high versus low verbal WM groups on sentence comprehension tasks in which task demands were manipulated by the length of the sentence stimuli, complexity of syntactic structure, and by presentation method which varied the time over which the linguistic material was available for computation. Methods & Procedures: A total of 20 PWA were divided into high and low WM groups based on a listening version of a WM sentence span task. Each participant completed a listening version (CRTT) and three reading versions (CRTT‐R) of the Computerised Revised Token Test as the sentence comprehension tasks. Outcomes & Results: The WM task significantly predicted performance on the CRTT conditions in which information was only temporarily available, thereby imposing greater WM demands on sentence comprehension. The verbal WM task was significantly correlated with aphasia severity and a principal components analysis revealed that the WM task, overall aphasia severity, and overall reading impairment level loaded on a single factor with 76% of shared variance. The low WM groups performance was significantly lower than the high WM group on the CRTT subtests with syntactically more complex structures and on the CRTT conditions with temporally restricted presentation methods. Conclusions: This verbal WM task was significantly and moderately correlated with the overall severity of aphasia as well as with both listening and reading sentence comprehension. The WM group differences emerged only in sentence comprehension tasks with greater WM demands. These results are consistent with the notion that WM effects are most evident when WM capacity is sufficiently taxed by the task demands (e.g., Caplan & Waters, 1999; Just & Carpenter, 1992).

Association of Hearing Impairment and Mortality in Older Adults

BACKGROUND Hearing impairment (HI) is highly prevalent in older adults and is associated with social isolation, depression, and risk of dementia. Whether HI is associated with broader downstream outcomes is unclear. We undertook this study to determine whether audiometric HI is associated with mortality in older adults. METHODS Prospective observational data from 1,958 adults ≥70 years of age from the Health, Aging, and Body Composition Study were analyzed using Cox proportional hazards regression. Participants were followed for 8 years after audiometric examination. Mortality was adjudicated by obtaining death certificates. Hearing was defined as the pure-tone average of hearing thresholds in decibels re: hearing level (dB HL) at frequencies from 0.5 to 4kHz. HI was defined as pure-tone average >25 dB HL in the better ear. RESULTS Of the 1,146 participants with HI, 492 (42.9%) died compared with 255 (31.4%) of the 812 with normal hearing (odds ratio = 1.64, 95% CI: 1.36-1.98). After adjustment for demographics and cardiovascular risk factors, HI was associated with a 20% increased mortality risk compared with normal hearing (hazard ratio = 1.20, 95% CI: 1.03-1.41). Confirmatory analyses treating HI as a continuous predictor yielded similar results, demonstrating a nonlinear increase in mortality risk with increasing HI (hazard ratio = 1.14, 95% CI: 1.00-1.29 per 10 dB of threshold elevation up to 35 dB HL). CONCLUSIONS HI in older adults is associated with increased mortality, independent of demographics and cardiovascular risk factors. Further research is necessary to understand the basis of this association and whether these pathways might be amenable to hearing rehabilitation.

Association of Hearing Impairment with Declines in Physical Functioning and the Risk of Disability in Older Adults

BACKGROUND Identifying factors associated with functional declines in older adults is important given the aging of the population. We investigated if hearing impairment is independently associated with objectively measured declines in physical functioning in a community-based sample of older adults. METHODS Prospective observational study of 2,190 individuals from the Health, Aging, and Body Composition study. Participants were followed annually for up to 11 visits. Hearing was measured with pure-tone audiometry. Physical functioning and gait speed were measured with the Short Physical Performance Battery (SPPB). Incident disability and requirement for nursing care were assessed semiannually through self-report. RESULTS In a mixed-effects model, greater hearing impairment was associated with poorer physical functioning. At both Visit 1 and Visit 11, SPPB scores were lower in individuals with mild (10.14 [95% CI 10.04-10.25], p < .01; 7.35 [95% CI 7.12-7.58], p < .05) and moderate or greater hearing impairment (10.04 [95% CI 9.90-10.19], p < .01; 7.00 [95% CI 6.69-7.32], p < .01) than scores in normal hearing individuals (10.36 [95% CI 10.26-10.46]; 7.71 [95% CI 7.49-7.92]). We observed that women with moderate or greater hearing impairment had a 31% increased risk of incident disability (Hazard ratio [HR] =1.31 [95% CI 1.08-1.60], p < .01) and a 31% increased risk of incident nursing care requirement (HR = 1.31 [95% CI 1.05-1.62], p = .02) compared to women with normal hearing. CONCLUSIONS Hearing impairment is independently associated with poorer objective physical functioning in older adults, and a 31% increased risk for incident disability and need for nursing care in women.

Hearing sensitivity and bone mineral density in older adults: the Health, Aging and Body Composition Study

Bone mineral density (BMD) may be associated with hearing loss in older adults. Demineralization of the cochlear capsule has been associated with hearing loss in those with Paget’s disease of the bone and otosclerosis. Osteoporosis may also result in cochlear capsule demineralization. We hypothesized that lower hip BMD and lower heel ultrasound measurements would be associated with hearing loss in a population-based sample of 2,089 older black and white men and women. Bone parameters and hearing function were measured at the fourth clinical follow-up visit. Audiometric threshold testing was used to measure air- and bone-conduction hearing sensitivity. BMD of the hip and its subregions was measured using dual-energy X-ray absorptiometry. Calcaneal bone measurements [broadband ultrasound attenuation (BUA), speed of sound (SOS) and the quantitative ultrasound index (QUI)] were obtained using heel ultrasound. After adjusting for known hearing loss risk factors, no association was found between hearing and any of the bone measurements in whites and black women. In black men, however, lower hip BMD was associated with higher odds of hearing loss; for each standard deviation decrease in total hip BMD, the odds of hearing loss were 1.41 (95% confidence interval 1.08, 1.83), 1.39 (95% CI 1.07, 1.82) for femoral neck BMD and 1.65 (95% CI 1.26, 2.16) for trochanter BMD. Conductive hearing loss was associated with lower heel ultrasound measurements, though only among white men. The results of this study are mixed and inconclusive. Lower BMD of the hip and its subregions was associated with hearing loss among black men, but not among whites or black women. Lower measurements on heel ultrasound were associated with conductive hearing loss, though only among white men. These results suggest that axial and appendicular bone parameters may be modestly associated with hearing loss in older men, but not in women.

Accuracy of hearing aid use time as reported by experienced hearing aid wearers.

OBJECTIVE The purpose of this study was to investigate the relationship between the amount of time that a person reports wearing his or her hearing aid and the actual time that the hearing aid is worn. Although use time data are used in the analysis and interpretation of investigations concerned with auditory perceptual learning and with user satisfaction, the accuracy of self-reported use time has not been fully investigated. DESIGN The experimental and control group were fit with a hearing aid that has the capability of storing use time data for later analysis. The experimental group was told that the self-reported use time would be verified with a computer analysis of the hearing aid that provides the actual use time. The control group was not informed of the use time validation procedure. The agreement between self-reported and actual use time was compared statistically between groups (knowledge of validation versus no knowledge of validation). RESULTS The experimental group provided accurate self-reported use time whereas the control group showed a significant difference between actual use time and self-reported use time. CONCLUSIONS The results may assist in the interpretation of results of previous investigations that have depended on self-reported use time and in the design of future investigations. For the clinician, the results indicate that relying on a patients self-reported hearing aid use time for documentation of satisfaction or signal processing preference may be misleading.

Comparing connected language elicitation procedures in persons with aphasia: Concurrent validation of the Story Retell Procedure

Background: The Story Retell Procedure (SRP) (Doyle et al., 1998) is a well‐described method for eliciting connected language samples in persons with aphasia (PWA). However, the stimuli and task demands of the SRP are fundamentally different from commonly employed picture description, narrative, and procedural description tasks reported in the aphasia literature. As such, the extent to which measures of linguistic performance derived from the SRP may be associated with those obtained from picture description, narrative, and procedural description tasks is unknown. This research was supported by VA Rehabilitation Research and Development Merit Review Project C3159R “Cognitive and linguistic mechanisms of language performance in aphasia” and the Geriatric Research, Education, and Clinical Center of the VA Pittsburgh Healthcare System. The authors gratefully acknowledge the generous participation of the volunteers for this study and the laboratory assistance of Jennifer Golovin and MaryBeth Ventura. Aims: To assess the concurrent validity of linguistic performance measures obtained from the SRP with those obtained from picture description, narrative, and procedural description tasks by examining the correlations and the magnitude differences across the linguistic variables among the elicitation tasks. Secondarily, we examined the relationship of the percentage of information units per minute (%IU/Min) to other linguistic variables within the SRP and across the other elicitation tasks. Methods and Procedures: This study compared the SRP to six different, frequently used sampling procedures (three sets of picture descriptions, one fairytale generation, one set of narratives, and one set of procedural description tasks) from which the same five verbal productivity, four information content, two grammatical, and two verbal disruption measures were computed. Language samples were elicited from 20 PWA, spanning the aphasia comprehension severity range. Tests of association and difference were calculated for each measure between the SRP and the other sampling methods. Outcomes & Results: Significant and strong associations were obtained between the SRP and the other elicitation tasks for most linguistic measures. The SRP produced either no significant or significantly greater instances of the dependent variable except for the type–token ratio, which yielded a significantly lower value than the other sampling procedures. Conclusions: The findings are interpreted as support for the concurrent validity of the SRP and as evidence that a single form of the SRP will yield a language sample that is generally equivalent in distribution to other sampling procedures, and one that is generally greater in quantity to those typically used to assess connected spoken language in PWA. Additionally, it was found that the %IU/Min metric predicted highly the information content linguistic measures on the SRP as well as on the other elicitation procedures. However, it did not predict well measures of verbal productivity, grammaticality, or verbal disruptions.

Association of Hearing Impairment with Incident Frailty and Falls in Older Adults

Objective: We aimed to determine whether hearing impairment (HI) in older adults is associated with the development of frailty and falls. Method: Longitudinal analysis of observational data from the Health, Aging and Body Composition study of 2,000 participants aged 70 to 79 was conducted. Hearing was defined by the pure-tone-average of hearing thresholds at 0.5, 1, 2, and 4 kHz in the better hearing ear. Frailty was defined as a gait speed of <0.60 m/s and/or inability to rise from a chair without using arms. Falls were assessed annually by self-report. Results: Older adults with moderate-or-greater HI had a 63% increased risk of developing frailty (adjusted hazard ratio [HR] = 1.63, 95% confidence interval [CI] = [1.26, 2.12]) compared with normal-hearing individuals. Moderate-or-greater HI was significantly associated with a greater annual percent increase in odds of falling over time (9.7%, 95% CI = [7.0, 12.4] compared with normal hearing, 4.4%, 95% CI = [2.6, 6.2]). Discussion: HI is independently associated with the risk of frailty in older adults and with greater odds of falling over time.