Development and Standardization of Western Aphasia Battery-Revised in Tamil

Abstract

Western Aphasia Battery (WAB) (Kertesz, 1982; 2020) is a standardized published quantification tool used in the assessment of language in individuals with aphasia. India has the third-highest stroke prevalence in Asia after China and Japan. Tamil Nadu is one of the highly populated states in India, which has an increasing stroke incidence rate (Jebasingh & Sivanesan, 2017). Validation on the Tamil version of the original Western Aphasia Battery (WAB) can be developed but recently, Kertesz and Raven (2006) introduced the WAB-Revised (WAB-R) which included several important changes; the short version of the test (Bedside record form), a new task (Supplemental writing and reading), and new test items based on the clinician feedback as well as maintaining a scoring system to derive aphasia quotient, cortical quotient, and a newly added Language quotient. Hence the present project aimed to develop by adapting the WAB-R (English version) in the Tamil language and standardize the Western Aphasia Battery- Revised (WAB-R) in the Tamil language by considering 60 neuro-typical individuals and 77 persons with aphasia. The investigator used the direct translation and reverse translation methods introduced by Brislin (1970) by a Speech-Language Pathologist and linguist. Thus, the objectives were 1). To develop by adapting the WAB-R (English version) into the Tamil language as WAB-R in Tamil. 2). To assess language aspects by administering the newly adapted WAB-R in Tamil by considering normal controls and patients with a history of Cerebrovascular Accident (CVA) or brain injury and thus implement the standardization process. 3). To differentiate between the normal control and patients with a history of CVA or diagnosed as Aphasia with reference to the scores obtained on the administration of WAB-R in Tamil and thus implement the validation process. A comparison of the mean value of parameters in Record Form 1 and Record Form 2 demonstrated better performance for neuro-typical individuals compared to persons with aphasia. More number of parameters were affected in persons with Global aphasia and the least affected were persons with anomic aphasia. With reference to the WAB-R Tamil parameters, there was no significant age and gender difference for neuro-typical individuals. Whereas, there was a significant difference between gender and age for subtypes of aphasia, male performing poorer than females and younger age range performing better than older age range. The possible major reasons for the above findings could be the overall AQ showing a slight reduction of mean scores with the age increases and this finding is in concordance with the previous findings (Chengappa & Kumar, 2008; Keshree et al. 2013; Kim & Na, 2010). The lateralization analysis provided the results of males exhibiting left-lateralized activation in Exner's area during handwriting, while females exhibited bilateral Yang et al (2019). The reason for significant less performance in older age groups were identified that older adults exhibit less gray matter volume in comparison to young adults, the prefrontal cortex is particularly susceptible to gray matter atrophy (Good et al., 2001; Jernigan et al. 2001; Raz et al., 1997, 2004; Resnick et al., 2003). The foremost reason for this is the extent of pathology in these various aphasia types, the small lesion size is Anomia and the most extended and widespread lesion is in Global aphasia. The norms are provided in this study with a very good insight into the importance of language assessment using WAB-R Tamil and its use in the classification of aphasia. It is important to consider the language-specific test in the diagnosis of persons with aphasia.