Maximising recovery from aphasia with central and peripheral agraphia: The benefit of sequential treatments.

Maximal recovery from acquired language impairment may require progression from one behavioural treatment protocol to the next in order to build upon residual and relearned cognitive-linguistic and sensory-motor processes. We present a five-stage treatment sequence that was initiated at one year post stroke in a woman with acquired impairments of spoken and written language. As is typical of individuals with left perisylvian damage, she demonstrated marked impairment of phonological retrieval and sublexical phonology, but she also faced additional challenges due to impaired letter shape knowledge and visual attention. The treatment sequence included (1) written spelling of targeted words, (2) retraining sublexical sound-to-letter correspondences and phonological manipulation skills, (3) training strategic approaches to maximise interactive use of lexical, phonological, and orthographic knowledge, (4) lexical retrieval of spoken words, and finally (5) sentence-level stimulation to improve grammatical form of written narratives. This Phase II clinical study documented positive direct treatment outcomes along with evidence of a significant reduction in the underlying deficits and generalisation to untrained items and language tasks. Improvements on a comprehensive assessment battery were realised as functional gains in everyday written and spoken communication, including improved lexical retrieval and grammatical complexity of written narratives. This case provides a valuable example of the cumulative therapeutic benefit of sequential application of theoretically motivated treatment protocols.

The neural substrates of improved phonological processing following successful treatment in a case of phonological alexia and agraphia.

Phonological deficits are common in aphasia after left-hemisphere stroke, and can have significant functional consequences for spoken and written language. While many individuals improve through treatment, the neural substrates supporting improvements are poorly understood. We measured brain activation during pseudoword reading in an individual through two treatment phases. Improvements were associated with greater activation in residual left dorsal language regions and bilateral regions supporting attention and effort. Gains were maintained, while activation returned to pre-treatment levels. This case demonstrates the neural support for improved phonology after damage to critical regions and that improvements may be maintained without markedly increased effort.

The nature and treatment of phonological text agraphia.

Phonological alexia and agraphia are written language disorders characterised by disproportionate difficulty reading and spelling nonwords in comparison to real words. In phonological alexia, it has been shown that, despite relatively accurate reading of words in isolation, text-level reading deficits are often marked and persistent. Specifically, some individuals demonstrate difficulty reading functors and affixes in sentences, a profile referred to as phonological text alexia. In this paper, we demonstrate an analogous manifestation of the phonological impairment on text-level writing and suggest the term "phonological text agraphia". We examined four individuals with phonological alexia/agraphia who also showed disproportionate difficulty writing well-formed sentences in comparison to their grammatical competence in spoken utterances. Implementation of a phonological treatment protocol resulted in significantly improved sublexical phonology skills as well as improvements in grammatical accuracy of written narratives. These findings support the notion of a common phonological impairment underlying nonword reading/spelling deficits and sentence-level difficulties.

Dysfunctional visual word form processing in progressive alexia.

Progressive alexia is an acquired reading deficit caused by degeneration of brain regions that are essential for written word processing. Functional imaging studies have shown that early processing of the visual word form depends on a hierarchical posterior-to-anterior processing stream in occipito-temporal cortex, whereby successive areas code increasingly larger and more complex perceptual attributes of the letter string. A region located in the left lateral occipito-temporal sulcus and adjacent fusiform gyrus shows maximal selectivity for words and has been dubbed the 'visual word form area'. We studied two patients with progressive alexia in order to determine whether their reading deficits were associated with structural and/or functional abnormalities in this visual word form system. Voxel-based morphometry showed left-lateralized occipito-temporal atrophy in both patients, very mild in one, but moderate to severe in the other. The two patients, along with 10 control subjects, were scanned with functional magnetic resonance imaging as they viewed rapidly presented words, false font strings, or a fixation crosshair. This paradigm was optimized to reliably map brain regions involved in orthographic processing in individual subjects. All 10 control subjects showed a posterior-to-anterior gradient of selectivity for words, and all 10 showed a functionally defined visual word form area in the left hemisphere that was activated for words relative to false font strings. In contrast, neither of the two patients with progressive alexia showed any evidence for a selectivity gradient or for word-specific activation of the visual word form area. The patient with mild atrophy showed normal responses to both words and false font strings in the posterior part of the visual word form system, but a failure to develop selectivity for words in the more anterior part of the system. In contrast, the patient with moderate to severe atrophy showed minimal activation of any part of the visual word form system for either words or false font strings. Our results suggest that progressive alexia is associated with a dysfunctional visual word form system, with or without substantial cortical atrophy. Furthermore, these findings demonstrate that functional MRI has the potential to reveal the neural bases of cognitive deficits in neurodegenerative patients at very early stages, in some cases before the development of extensive atrophy.

Positive changes to written language following phonological treatment in logopenic variant primary progressive aphasia: Case report.

Phonological impairment contributes to deficits in repetition and spoken naming in logopenic variant Primary Progressive Aphasia (lvPPA), but weakened phonology can also affect written language skills. In this experimental case report, we demonstrate phonological text agraphia in a 71-year-old woman in the early stages of lvPPA that undermined her ability to write meaningful, grammatical sentences. We investigated the therapeutic value of a rigorous treatment protocol to strengthen phonological manipulation skills coupled with transcranial direct current stimulation (tDCS). Intervention took place 5 days a week for 2 weeks with active tDCS, followed by a 2-month rest period, and then a second period of phonological treatment with sham tDCS. Over the course of treatment, our participant demonstrated improved phonological transcoding and manipulation skills as well as marked improvement in the proportion of grammatically well-formed, meaningful written narratives. Improvements in spelling and letter selection were also observed. Treatment gains were documented during phonological intervention in both active tDCS and sham treatment phases and were maintained 2 months after the conclusion of intervention. Importantly, improvements were observed in the context of a progressive disorder. These data present compelling evidence regarding the impairment-based approach that targets compromised phonological skills, presenting opportunity for improving functional written communication skills relevant to the everyday lives of individuals with lvPPA.

Common predictors of spoken and written language performance in aphasia, alexia, and agraphia.

Language performance requires support from central cognitive/linguistic abilities as well as the more peripheral sensorimotor skills to plan and implement spoken and written communication. Both output modalities are vulnerable to impairment following damage to the language-dominant hemisphere, but much of the research to date has focused exclusively on spoken language. In this study we aimed to examine an integrated model of language processing that includes the common cognitive processes that support spoken and written language, as well as modality-specific skills. To do so, we evaluated spoken and written language performance from 87 individuals with acquired language impairment resulting from damage to left perisylvian cortical regions that collectively constitute the dorsal language pathway. Comprehensive behavioral assessment served to characterize the status of central and peripheral components of language processing in relation to neurotypical controls (n = 38). Performance data entered into principal components analyses (with or without control scores) consistently yielded a strong five-factor solution. In line with a primary systems framework, three central cognitive factors emerged: semantics, phonology, and orthography that were distinguished from peripheral processes supporting speech production and allographic skill for handwriting. The central phonology construct reflected performance on phonological awareness and manipulation tasks and showed the greatest deficit of all the derived factors. Importantly, this phonological construct was orthogonal to the speech production factor that reflected repetition of words/non-words. When entered into regression analyses, semantics and phonological skill were common predictors of language performance across spoken and written modalities. The speech production factor was also a strong, distinct predictor of spoken naming and oral reading, in contrast to allographic skills which only predicted written output. As expected, visual orthographic processing contributed more to written than spoken language tasks and reading/spelling performance was strongly reliant on phonological and semantic abilities. Despite the heterogeneity of this cohort regarding aphasia type and severity, the marked impairment of phonological skill was a unifying feature. These findings prompt greater attention to clinical assessment and potential treatment of underlying phonological skill in individuals with left perisylvian damage.

A Retrospective Study of Long-Term Improvement on the Boston Naming Test.

Purpose Lexical retrieval impairment is a universal characteristic of aphasia and a common treatment focus. Although naming improvement is well documented, there is limited information to shape expectations regarding long-term recovery. This was the motivation for a retrospective study of longitudinal data on the Boston Naming Test (BNT; Kaplan, Goodglass, & Weintraub, 1983, 2000). Method BNT scores were analyzed from a heterogeneous cohort of 42 individuals with anomia associated with a range of aphasia types. The data were collected over the course of 20 years from individuals who had participated in treatment and received at least 2 BNT administrations. A linear mixed model was implemented to evaluate effects of initial BNT score, time postonset, and demographic variables. For those over 55 years of age, BNT change was evaluated relative to data from the Mayo Clinic's Older Americans Normative Studies. Results There was a significant average improvement of +7.67 points on the BNT in individuals followed for an average of 2 years. Overall, the average rate of improvement was +5.84 points per year, in contrast to a decline of 0.23 points per year in a healthy adult cohort from the Mayo Clinic's Older Americans Normative Studies. Naming recovery was approximately linear, with significant main effects of initial BNT score (i.e., initial severity) and time postonset; the greatest changes were noted in those whose initial severity was moderate. Conclusions These findings indicate a positive prognosis for naming improvement over time regardless of demographic factors and provide estimates for clinical predictions for those who seek rehabilitation during the chronic phase.

Phonological dyslexia and dysgraphia: cognitive mechanisms and neural substrates.

To examine the validity of different theoretical assumptions about the neuropsychological mechanisms and lesion correlates of phonological dyslexia and dysgraphia, we studied written and spoken language performance in a large cohort of patients with focal damage to perisylvian cortical regions implicated in phonological processing. Despite considerable variation in accuracy for both words and non-words, the majority of participants demonstrated the increased lexicality effects in reading and spelling that are considered the hallmark features of phonological dyslexia and dysgraphia. Increased lexicality effects were also documented in spoken language tasks such as oral repetition, and patients performed poorly on a battery of phonological tests that did not involve an orthographic component. Furthermore, a composite measure of general phonological ability was strongly predictive of both reading and spelling accuracy, and we obtained evidence that the continuum of severity that characterized the written language disorder of our patients was attributable to an underlying continuum of phonological impairment. Although patients demonstrated qualitatively similar deficits across measures of written and spoken language processing, there were quantitative differences in levels of performance reflecting task difficulty effects. Spelling was more severely affected than reading by the reduction in phonological capacity and this differential vulnerability accounted for occasional disparities between patterns of impairment on the two written language tasks. Our findings suggest that phonological dyslexia and dysgraphia in patients with perisylvian lesions are manifestations of a central or modality-independent phonological deficit rather than the result of damage to cognitive components dedicated to reading or spelling. Our results also provide empirical support for shared-components models of written language processing, according to which the same central cognitive systems support both reading and spelling. Lesion-deficit correlations indicated that phonological dyslexia and dysgraphia may be produced by damage to a variety of perisylvian cortical regions, consistent with distributed network models of phonological processing.

Auditory-Perceptual Rating of Connected Speech in Aphasia.

Purpose Auditory-perceptual assessment, in which trained listeners rate a large number of perceptual features of speech samples, is the gold standard for the differential diagnosis of motor speech disorders. The goal of this study was to investigate the feasibility of applying a similar, formalized auditory-perceptual approach to the assessment of language deficits in connected speech samples from individuals with aphasia. Method Twenty-seven common features of connected speech in aphasia were defined, each of which was rated on a 5-point scale. Three experienced researchers evaluated 24 connected speech samples from the AphasiaBank database, and 12 student clinicians evaluated subsets of 8 speech samples each. We calculated interrater reliability for each group of raters and investigated the validity of the auditory-perceptual approach by comparing feature ratings to related quantitative measures derived from transcripts and clinical measures, and by examining patterns of feature co-occurrence. Results Most features were rated with good-to-excellent interrater reliability by researchers and student clinicians. Most features demonstrated strong concurrent validity with respect to quantitative connected speech measures computed from AphasiaBank transcripts and/or clinical aphasia battery subscores. Factor analysis showed that 4 underlying factors, which we labeled Paraphasia, Logopenia, Agrammatism, and Motor Speech, accounted for 79% of the variance in connected speech profiles. Examination of individual patients' factor scores revealed striking diversity among individuals classified with a given aphasia type. Conclusion Auditory-perceptual rating of connected speech in aphasia shows potential to be a comprehensive, efficient, reliable, and valid approach for characterizing connected speech in aphasia.

Neural substrates of sublexical processing for spelling.

We used fMRI to examine the neural substrates of sublexical phoneme-grapheme conversion during spelling in a group of healthy young adults. Participants performed a writing-to-dictation task involving irregular words (e.g., choir), plausible nonwords (e.g., kroid), and a control task of drawing familiar geometric shapes (e.g., squares). Written production of both irregular words and nonwords engaged a left-hemisphere perisylvian network associated with reading/spelling and phonological processing skills. Effects of lexicality, manifested by increased activation during nonword relative to irregular word spelling, were noted in anterior perisylvian regions (posterior inferior frontal gyrus/operculum/precentral gyrus/insula), and in left ventral occipito-temporal cortex. In addition to enhanced neural responses within domain-specific components of the language network, the increased cognitive demands associated with spelling nonwords engaged domain-general frontoparietal cortical networks involved in selective attention and executive control. These results elucidate the neural substrates of sublexical processing during written language production and complement lesion-deficit correlation studies of phonological agraphia.

Treatment for Alexia With Agraphia Following Left Ventral Occipito-Temporal Damage: Strengthening Orthographic Representations Common to Reading and Spelling.

PURPOSE: Damage to left ventral occipito-temporal cortex can give rise to written language impairment characterized by pure alexia/letter-by-letter (LBL) reading, as well as surface alexia and agraphia. The purpose of this study was to examine the therapeutic effects of a combined treatment approach to address concurrent LBL reading with surface alexia/agraphia. METHOD: Simultaneous treatment to address slow reading and errorful spelling was administered to 3 individuals with reading and spelling impairments after left ventral occipito-temporal damage due to posterior cerebral artery stroke. Single-word reading/spelling accuracy, reading latencies, and text reading were monitored as outcome measures for the combined effects of multiple oral re-reading treatment and interactive spelling treatment. RESULTS: After treatment, participants demonstrated faster and more accurate single-word reading and improved text-reading rates. Spelling accuracy also improved, particularly for untrained irregular words, demonstrating generalization of the trained interactive spelling strategy. CONCLUSION: This case series characterizes concomitant LBL with surface alexia/agraphia and demonstrates a successful treatment approach to address both the reading and spelling impairment.

Writing treatment for severe aphasia: who benefits?

Writing treatment that involved repeated copying and recall of target words was implemented with 8 individuals with severe aphasia in order to discern the best candidates for the treatment. Four of the 8 participants had strong positive responses to the copy and recall treatment (CART), relearning spellings for 15 targeted words during 10 to 12 weeks of treatment and up to 5 additional words during a month-long homework-based program. Of the 4 other participants, 3 learned the spellings of some target words but failed to reach criterion, and 1 had a poor treatment outcome. Insights regarding possible factors that limited success were gained by examination of individual responses to treatment as well as performance on the pretreatment assessments of semantic, phonological, and orthographic processes. Among the factors associated with success were (a) consistent, accurate completion of daily homework, (b) a relatively preserved semantic system, (c) the ability to discern words from nonwords, and (d) adequately preserved nonverbal visual problem-solving skills. Aphasia severity and minimal pretreatment spelling abilities did not necessarily limit the response to treatment. Participants with positive treatment outcomes demonstrated improved spelling of target words following repeated copying within a single treatment session, and accurately completed daily writing homework. Thus, pretreatment assessment and stimulability within initial treatment sessions provided indications of likely outcome.

Writing treatment for aphasia: a texting approach.

PURPOSE: Treatment studies have documented the therapeutic and functional value of lexical writing treatment for individuals with severe aphasia. The purpose of this study was to determine whether such retraining could be accomplished using the typing feature of a cellular telephone, with the ultimate goal of using text messaging for communication. METHOD: A 31-year-old man with persistent Broca's aphasia, severe apraxia of speech, global dysgraphia, and right hemiparesis participated in this study. Using a multiple baseline design, relearning and maintenance of single-word spellings (and oral naming) of targeted items were examined in response to traditional Copy and Recall Treatment (CART) for handwriting and a new paradigm using 1-handed typing on a cell phone keyboard (i.e., a texting version of CART referred to as T-CART). RESULTS: Marked improvements were documented in spelling and spoken naming trained in either modality, with stronger maintenance for handwriting than cell phone typing. Training resulted in functional use of texting that continued for 2 years after treatment. CONCLUSIONS: These results suggest that orthographic retraining using a cell phone keyboard has the potential to improve spelling knowledge and provide a means to improve functional communication skills. Combined training with both handwriting and cell phone typing should be considered in order to maximize the durability of treatment effects.

Syntactic processing depends on dorsal language tracts.

Frontal and temporal language areas involved in syntactic processing are connected by several dorsal and ventral tracts, but the functional roles of the different tracts are not well understood. To identify which white matter tract(s) are important for syntactic processing, we examined the relationship between white matter damage and syntactic deficits in patients with primary progressive aphasia, using multimodal neuroimaging and neurolinguistic assessment. Diffusion tensor imaging showed that microstructural damage to left hemisphere dorsal tracts--the superior longitudinal fasciculus including its arcuate component--was strongly associated with deficits in comprehension and production of syntax. Damage to these dorsal tracts predicted syntactic deficits after gray matter atrophy was taken into account, and fMRI confirmed that these tracts connect regions modulated by syntactic processing. In contrast, damage to ventral tracts--the extreme capsule fiber system or the uncinate fasciculus--was not associated with syntactic deficits. Our findings show that syntactic processing depends primarily on dorsal language tracts.

A treatment sequence for phonological alexia/agraphia.

PURPOSE: Damage to left perisylvian cortex often results in impaired phonological processing abilities with written language profiles consistent with phonological alexia and phonological agraphia. The purpose of this article was to examine a behavioral treatment sequence for such individuals intended to strengthen phonological processing and links between phonology and orthography, as well as train a means to maximize use of residual orthographic and phonological knowledge for spelling. METHOD: Two women with persistent impairments of written language and phonological processing following damage to left perisylvian cortical regions participated in this study. Both exhibited characteristic features of phonological alexia and agraphia in that reading and spelling performance for real words was better preserved than nonwords (lexicality effect). A 2-stage treatment protocol was administered to strengthen sublexical skills (phonological treatment) and to train interactive use of lexical and sublexical information to maximize spelling performance (interactive treatment). RESULTS: Both participants improved phonological processing abilities and reading/spelling via the sublexical route. They also improved spelling of real words and were able to detect and correct most residual errors using an electronic spelling aid. CONCLUSIONS: Behavioral treatment served to strengthen phonological skills supporting reading and spelling, and provided a functional compensatory strategy to overcome residual weaknesses.

A novel method for examining response to spelling treatment.

BACKGROUND: According to a dual-route model of written language processing, spelling of irregular words provides an index of the status of lexical spelling procedures, whereas nonword spelling provides information about non-lexical processing that relies on phoneme-grapheme conversion. Because regular words can be spelled using either route, accuracy for such words may reflect the combined function of the two routes, and may be mathematically predicted on the basis of spelling accuracy for irregular words and nonwords. AIMS: The purpose of the present study was to examine the application of a dual-route prediction equation, and a related multiple regression model, to evaluate pre-post treatment spelling performance of individuals with acquired alexia/agraphia. METHODS #ENTITYSTARTX00026; PROCEDURES: Eight individuals with language impairment due to left hemisphere damage received behavioral treatment to improve their written spelling. Their spelling performance was examined before and after treatment on untrained word lists with regular and irregular spellings, and pronounceable nonwords, and concurrence between predicted and observed spelling of regular words was evaluated. OUTCOMES #ENTITYSTARTX00026; RESULTS: The group demonstrated significantly improved spelling performance after treatment, and the prediction equation and multiple regression model both accurately predicted regular word performance on the basis of irregular word and nonword scores. In addition, the multiple regression model provided potentially useful information about the relative contribution of the lexical and non-lexical routes to spelling performace. CONCLUSIONS: The prediction equation and related multiple regression model used in this study can offer novel insight into the cognitive processes available to individuals with agraphia as well as provide a quantitative means to characterize response to treatment.