Alyssa Sachs Abstracts
Alyssa Sachs
Ph.D. Candidate
Cognitive Science GIDP
American Speech-Language-Hearing Association (ASHA) Convention
Boston, Massachusetts
November 15-17, 2018
Although many studies document improvement in language and naming abilities in individuals with aphasia, there is limited information regarding long-term recovery. We examined language recovery in a heterogeneous sample of 112 individuals with aphasia over an average of three years. Performance on the Western Aphasia Battery and the Boston Naming Test revealed significant improvement over time.
Main Argument:
In the first few months after injury, individuals with aphasia experience the greatest amount of recovery due to physiological restitution (Kertesz, 1984), compared to more modest changes during the chronic stage (Basso, et al., 1979; Kertesz & McCabe, 1977). Among the most common and persistent deficits is anomia, or word retrieval difficulty (Benson, 1979). Hundreds of treatment studies have examined recovery and outcomes for individuals with chronic aphasia (Moss & Nicholas, 2006; Robey, 1998) with a large subset focusing on lexical retrieval treatment. The majority of these studies focus on change relative to specific treatment approaches over short time periods. It is surprising that few studies document long-term recovery of language or naming ability in aphasia, so there is limited information regarding extent and rate of recovery as well as prognostic indicators. In practice, it is relatively unclear how much change can be expected for individuals with chronic aphasia over long periods of time.
The Western Aphasia Battery (WAB; Kertesz, 1982) and Boston Naming Test (BNT; Kaplan, Goodglass, & Weintraub, 1983) are two widely used quantitative measures of language and naming abilities, respectively. Both of these assessments have been used in aphasia treatment studies to measure initial severity and/or response to treatment. The purpose of this study was to examine language and naming performance in chronic aphasia over long periods mof time using WAB aphasia quotient (AQ) scores and BNT scores. We aimed to provide benchmarks for recovery and identify possible predictive factors of long-term improvement.
Procedures:
We conducted a retrospective analysis of data collected in clinical and research contexts at the University of Arizona between 1985 and 2018. From the available data, we identified 155 individuals with at least two WAB administrations who participated in individual and/or group treatment. We excluded 43 individuals who a) had comorbid neurological or health issues, b) were diagnosed with progressive neurodegenerative disease, c) were missing data (e.g., demographic information), or d) were considered non-aphasic with an initial aphasia quotient (AQ) of 93.8 or higher. This resulted in a total of 112 participants with WAB AQ scores for analysis, and 52 of these individuals had multiple BNT scores available to examine trajectory of naming improvement over time. The average age at the first test was 61.9 years (range = 23.2 – 83.4), with 14.88 years of education (range = 9 – 20). The mean time post onset (TPO) of aphasia at the first WAB administration was 1.74 years (range = 0.25 – 9.82). On average, individuals were followed for 2.99 years from initial to final WAB administrations (range = 0.24 – 12.41). The average initial AQ score was 61.26 (out of 100; 4.5 – 93.8), and the average initial BNT score was 27.46 (out of 60; 0 – 57).
For this study, we examined long-term language and naming recovery independent of specific treatments. In other words, we aimed to characterize change over time in a heterogeneous group of individuals who all sought rehabilitation services in a university setting, and who received treatments that varied in type and intensity. We determined overall improvement by calculating the difference between the final and initial AQ and BNT scores. A hierarchical regression model was implemented to examine the predictive value of age (at first test), education, time post onset (years), initial severity, and elapsed time (years) relative to change in AQ and BNT scores.
Results & Discussion:
The average overall improvement for the entire cohort was +6.52 AQ points (SD = 8.3) and +5.83 BNT points (SD = 7.5). We used initial AQ scores to establish severity groups prior to analysis (mild > 80; moderate 34 – 79.9; severe < 34). With respect to initial severity, all three groups demonstrated positive change in AQ and BNT scores. Individuals in the moderate group had the greatest average gain of +9.91 AQ points (SD = 9.12) and +7.52 BNT points (SD = 8.6). Individuals in the mild group had more modest average gain over time (+2.26 AQ, SD = 3.27; +4.05 BNT, SD = 6.13), and those who were considered severe at the initial administration had average gains of +6.39 in AQ (SD = 9.38) and +5.20 on the BNT (SD = 6.38). The strongest predictors of AQ change were age at the first WAB administration and initial severity as measured by an individual’s first AQ score, such that younger age and a lower initial AQ score were associated with the greatest change over time. Initial severity was also a significant predictor of BNT change, along with time post onset at initial testing. Lower initial BNT scores and an earlier time post onset were associated with greater change on the BNT. Overall, these findings demonstrate the potential for significant improvement in language and naming ability over time for people with chronic aphasia. These findings are relevant for those who continue to participate in some sort of behavioral intervention.
Abstract for Lay Audience
Aphasia is an acquired language disorder that negatively impacts an individual’s ability to communicate with others. It is caused by damage (e.g., stroke, gunshot wound) to the left hemisphere of the brain. Aphasia can affect both comprehension and production of spoken and written language. Additionally, a universal characteristic of aphasia is difficulty with naming (anomia). Individuals with aphasia commonly describe anomia as the feeling of knowing what they want to say, but not being able to say it. While aphasia can range in severity based on extent and location of damage, all individuals experience difficulty with spoken and written communication, making it difficult to participate in everyday activities or maintain a healthy quality of life.
Individuals with aphasia experience spontaneous recovery in the first few months following injury, with more modest improvement in language ability during the chronic stage (defined as greater than 3-months post injury). Hundreds of treatment studies have examined recovery for individuals with chronic aphasia, with a large subset focusing on treatment for naming difficulties. The majority of these studies focus on change relative to specific treatment approaches over short time periods. Few studies document long-term recovery of language or naming ability in aphasia, so there is limited information regarding the magnitude and rate of recovery as well as predictors of improvement. With this in mind, it is relatively unclear how much change can be expected for individuals with chronic aphasia over long periods of time. The purpose of this study was to examine language and naming performance in chronic aphasia over long periods of time using scores from two standardized assessments of language and naming abilities: the Western Aphasia Battery (WAB) and the Boston Naming Test (BNT). We aimed to provide benchmarks for recovery and identify possible predictive factors of longterm improvement. To accomplish this, we conducted a retrospective analysis of data collected in clinical and research contexts at the University of Arizona over the past 30 years. We identified a total of 112 individuals with aphasia who met inclusion criteria and had at least two WAB scores for analysis. Of this cohort, 52 individuals had multiple BNT scores available to examine naming improvement over time. All individuals participated in individual and/or group treatment that targeted a variety of language skills (e.g., naming, spoken production, comprehension). The average overall improvement for the entire cohort was +6.52 WAB points and +5.83 BNT points. These were found to be statistically significant and clinically meaningful indices of change on these assessments. We identified several predictors of overall change in language and naming ability, including initial severity of aphasia, age at the first test, and time post onset of aphasia. With the data from our statistical analyses, we created prediction equations that will allow clinicians to use demographic information and performance on the WAB or BNT to predict an individual’s expected trajectory of change in language and naming abilities. Our findings demonstrate the potential for significant improvement over time for people with chronic aphasia. Since all of our participants received some sort of behavioral intervention, our findings also provide support for continued treatment in the chronic stage of aphasia, which is often difficult to justify for this population given strict healthcare and insurance policies. Overall, we were able to clarify expectations for recovery in the months and years following onset of aphasia and provide clinicians with meaningful information that will allow them to better support individuals with aphasia.