Lesion analysis of language production deficits in aphasia

Background: Three aspects of language production are impaired to different degrees in individuals with post-stroke aphasia: ability to repeat words and nonwords, name pictures, and produce sentences. These impairments often persist into the chronic stages, and the neuroanatomical distribution of lesions associated with chronicity of each of these impairments is incompletely understood.

Aims: The primary objective of this study was to investigate the lesion correlates of picture naming, sentence production, and nonword repetition deficits in the same participant group because most prior lesion studies have mapped single language impairments. The broader goal of this study was to investigate the extent and degree of overlap and uniqueness among lesions resulting in these deficits in order to advance the current understanding of functional subdivision of neuroanatomical regions involved in language production.

Methods & Procedures: In this study, lesion-symptom mapping was used to determine if specific cortical regions are associated with nonword repetition, picture naming, and sentence production scores. Structural brain images and behavioural performance of 31 individuals with post-stroke left hemisphere lesions and a diagnosis of aphasia were used in the lesion analysis.

Outcomes & Results: Each impairment was associated with mostly unique, but a few shared lesions. Overall, sentence and repetition deficits were associated with left anterior perisylvian lesions, including the pars opercularis and triangularis of the inferior frontal lobe, anterior superior temporal gyrus, anterior portions of the supramarginal gyrus, the putamen, and anterior portions of the insula. In contrast, impaired picture naming was associated with posterior perisylvian lesions including major portions of the inferior parietal lobe and middle temporal gyrus. The distribution of lesions in the insula was consistent with this antero-posterior perisylvian gradient. Significant voxels in the posterior planum temporale were associated with a combination of all three deficits.

Conclusions: These findings emphasise the participation of each perisylvian region in multiple linguistic functions, suggesting a many(functions)-to-many(networks) framework while also identifying functional subdivisions within each region.     

Aphasia LIFT: Exploratory investigation of an intensive comprehensive aphasia programme

Background: Intensive comprehensive aphasia programs (ICAPs) are gaining popularity in the international aphasia rehabilitation community. ICAPs comprise at least three hours of treatment per day over at least two weeks, have definable start and end dates for one cohort and use a variety of formats including individual treatment, group therapy, education and technology to improve language and communication. While intensive treatment approaches have demonstrated equivocal results on impairment-based measures, positive changes on activity/participation measures provide support for ICAPs in rehabilitation of chronic aphasia. Aphasia Language Impairment and Functional Therapy (LIFT) is a research-based ICAP developed for the purpose of evaluating treatment outcomes across the International Classification of Functioning, Disability and Health (ICF) domains.

Aims: The aim of this study was to estimate the magnitude of treatment effects yielded by Aphasia Aphasia LIFT in the domains of language impairment, functional communication and communication-related quality of life (QOL).

Methods & Procedures: Eleven individuals with chronic post-stroke aphasia (mean = 26.9 months) completed Aphasia LIFT. The programme comprised individual impairment-based and functional treatment, group therapy, and computer-based treatment for 40 hours over two weeks (n = 4, LIFT 1) or 100 hours over four weeks (n = 7, LIFT 2). Assessments of confrontation naming, discourse production, functional communication and communication-related quality of life were completed at pre-treatment, immediately post-treatment and six to eight weeks following treatment termination.

Outcomes & Results: Group-level analyses revealed acquisition and maintenance of treatment effects, as evidenced by significant improvement on at least one outcome measure at follow-up in all domains. The most consistent pattern of improvement at an individual level was observed on measures of functional communication and communication-related QOL.

Conclusions: Aphasia LIFT yielded positive outcomes across ICF domains, and in many cases the treatment effect was enduring. These results demonstrate that Aphasia LIFT was successful in meeting the overarching goal of ICAPs, to maximise communication and enhance life participation in individuals with aphasia. Further research into ICAPs is warranted.     

Lexical-semantic representation in bilingual aphasia: Findings from semantic priming and cognate repetition priming

Background: While many studies have investigated the nature of language organisation in monolingual speakers with aphasia, our understanding of bilingual aphasia lags far behind. Only a handful of studies have employed on-line psycholinguistic experimental methods to explore the nature of language representation and processing in bilingual speakers with aphasia. Improving our understanding of how language is organised and processed in bilingual speakers with aphasia is central to the development of effective impairment-level language treatments. Cognate/noncognate representation and semantic representation are two key aspects of bilingual language organisation that are yet to be explored in depth in bilingual speakers with aphasia.

Aims: The present study aimed to investigate (1) whether semantic representation was shared across the two languages of a bilingual speaker with aphasia and (2) whether cognate words would produce a processing advantage relative to noncognate words (as has been found in neurologically-normal younger bilingual adults).

Methods & Procedures: A 70-year-old bilingual Italian/English speaker, who presented with nonfluent aphasia and apraxia of speech, completed two priming experiments: a semantic priming experiment and a cognate repetition priming experiment.

Outcomes & Results: In the semantic priming experiment, the participant demonstrated large priming effects in both within-language conditions and one cross-language condition. The finding of priming in at least one of the cross-language conditions provides some corroboration for shared semantic representation in this bilingual individual with aphasia. In the cognate repetition priming experiment, the participant produced a language-specific cognate advantage in English, for words repeated in the same language. For words repeated in a different language condition (i.e., as their translation equivalent), the participant produced a processing advantage for noncognate words.

Conclusions: The findings of this study provided support for shared semantic representation in bilingual speakers following aphasia; however, the results also suggested that aphasia can disrupt normal lexical access processes. Results in relation to cognate versus noncognate processing suggested that bilingual speakers with aphasia may not, necessarily, always display a cognate advantage. Overall, the present study showed that language processing in bilingual speakers with aphasia is highly complex and is dependent upon the intricate interplay between the speaker’s premorbid language proficiency, inhibitory processing deficits that occur with normal aging and postmorbid language impairment and recovery patterns.     

Effects of neurological damage on production of formulaic language

Early studies reported preserved formulaic language in left hemisphere damaged subjects and reduced incidence of formulaic expressions in the conversational speech of stroke patients with right hemispheric damage. Clinical observations suggest a possible role also of subcortical nuclei. This study examined formulaic language in the spontaneous speech of stroke patients with left, right, or subcortical damage. Four subjects were interviewed and their speech samples compared to normal speakers. Raters classified formulaic expressions as speech formulae, fillers, sentence stems, and proper nouns. Results demonstrated that brain damage affected novel and formulaic language competence differently, with a significantly smaller proportion of formulaic expressions in subjects with right or subcortical damage compared to left hemisphere damaged or healthy speakers. These findings converge with previous studies that support the proposal of a right hemisphere/subcortical circuit in the management of formulaic expressions, based on a dual‐process model of language incorporating novel and formulaic language use.     

Exploring the relation between learning style and cognitive impairment in patients with acquired brain injury

The intensity of aphasia therapy has been a key clinical question. The aim of this case-series study was to compare the outcome of intensive and non-intensive therapy in the relearning of words for people with aphasia. Eight participants took part in a study comparing the intensity of delivery of the therapy. Participants received two courses of the same therapy (each lasting 10 sessions) delivered either intensively or non-intensively. Therapy consisted of confrontation naming with progressive phonemic and orthographic cues. Post-therapy assessments were carried out immediately after the study and one month later. Performance was also monitored during each therapy session. Immediately post-therapy, both types of therapy had improved naming accuracy considerably and there was no significant difference between the two interventions. One month later, seven out of eight participants showed a small yet significant difference in naming accuracy, favouring non-intensive over intense therapy. There were no differences in the learning patterns during the therapy sessions between the intensive and non-intensive therapies. For the majority of people with aphasia post-stroke, both intense and non-intense therapy for anomia leads to improved naming performance. Retention at one-month post therapy is relatively superior after non-intensive therapy.     

How justice can affect jury: Training abstract words promotes generalisation to concrete words in patients with aphasia

Developing language treatments that not only improve trained items but also promote generalisation to untrained items is a major focus in aphasia research. This study is a replication and extension of previous work which found that training abstract words in a particular context-category promotes generalisation to concrete words but not vice versa (Kiran, Sandberg, & Abbott, 2009 Kiran, S., Sandberg, C., & Abbott, K. (2009). Treatment for lexical retrieval using abstract and concrete words in persons with aphasia: Effect of complexity. Aphasiology, 23, 835–853. doi: 10.1080/02687030802588866[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]). Twelve persons with aphasia (five female) with varying types and degrees of severity participated in a generative naming treatment based on the Complexity Account of Treatment Efficacy (CATE; Thompson, Shapiro, Kiran, & Sobecks, 2003 Thompson, C., Shapiro, L., Kiran, S., & Sobecks, J. (2003). The role of syntactic complexity in treatment of sentence deficits in agrammatic aphasia: The Complexity Account of Treatment Efficacy (CATE). Journal of Speech, Language, and Hearing Research, 46, 591–607. doi: 10.1044/1092-4388(2003/047)[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). All participants were trained to generate abstract words in a particular context-category by analysing the semantic features of the target words. Two other context-categories were used as controls. Ten of the twelve participants improved on the trained abstract words in the trained context-category. Eight of the ten participants who responded to treatment also generalised to concrete words in the same context-category. These results suggest that this treatment is both efficacious and efficient. We discuss possible mechanisms of training and generalisation effects.     

Stroke and aphasia quality of life scale in Kannada-evaluation of reliability,validity and internal consistency

Background:

Quality of life (QoL) dwells in a person''s overall well-being. Recently, QoL measures have become critical and relevant in stroke survivors. Instruments measuring QoL of individuals with aphasia are apparently rare in the Indian context. The present study aimed to develop a Kannada instrument to measure the QoL of people with aphasia. Study objectives were to validate Stroke and aphasia quality of life-39 (SAQOL-39) into Kannada, to measure test–retest reliability and internal consistency.

Materials and Methods:

The original English instrument was modified considering socio-cultural differences among native English and Kannada speakers. Cross-linguistic adaptation of SAQOL-39 into Kannada was carried out through forward–backward translation scheme. The scale was administered on 32 people from Karnataka (a state in India) having aphasia. For a direct understanding of the subject''s QoL, scores were categorized into QoL severity levels. Item reliability of the Kannada version was examined by measuring Cronbach''s alpha. Test–retest reliability was examined by calculating the intraclass correlation coefficient (ICC).

Results:

Kannada SAQOL-39 showed good acceptability with minimum missing data and excellent test–retest reliability (ICC = 0.8). Value of Cronbach''s α observed for four items modified in the original version was 0.9 each and the mean α of all Kannada items was 0.9, demonstrating high internal consistency.

Conclusions:

The present study offers a valid, reliable tool to measure QoL in Kannada-speaking individuals with aphasia. This tool is useful in a cross-center, cross-national comparison of QoL data from people with aphasia. This instrument also permits direct translation into other Indian languages as the items are culturally validated to the Indian population. This study promotes future research using the Kannada SAQOL-39.     

非流利型失语症患者命名障碍与语言恢复之间的关系

目的通过对比非流利型失语症患者口语命名障碍与语言功能恢复的关系,探讨非流利型失语症语言功能损伤的环节。为预测失语症的语言功能恢复和失语症的亚分类提供有益的方法。方法选出16例口语图形命名得分相近的非流利型失语症患者,分别进行图形写名、听觉词／图匹配、视觉词／图匹配、听觉图／词核证、视觉图／词核证各项任务检测。2月后根据语言自然恢复程度的不同分为无明显好转组和好转组,比较无明显好转组及好转组上述各项语言命名任务间正确得分有无差异,分析影响语言恢复的机制。所有数据用SPSS13．0软件包处理,检验两项任务间的得分差异用Wilcoxon分析方法,患者间及多项任务间得分差异比较应用KruskabWaUis分析方法。结果语言功能恢复较差的11名患者是源于中心语义系统受损严重,另外4名语言功能恢复较好的患者源于语音输出系统受,两组在听觉词／图匹配、视觉词／图匹配、听觉图／词核证、视觉图／词核证各项任务上得分差异性具有明显统计学意义（P〈0．05）。结论语言损伤环节可能不同：中心语义系统受损者比语音输出系统受损者,语言功能恢复要差,因为语义层高于语音层。