Dysgraphia in primary progressive aphasia: Characterisation of impairments and therapy options

This is an Accepted Manuscript of an article published by Taylor & Francis in Aphasiology on January 3, 2014, available online: http://www.tandfonline.com/10.1080/02687038.2013.869308.Background: Spelling impairment is common in primary progressive aphasia (PPA). Although behavioural interventions tend to focus on spoken language, remediation of written language may be desirable, either because an individual’s regular use of writing makes it a priority or because writing is needed for communication in cases where it is better preserved than spoken language. Aims: This paper has three aims: (1) to provide an up-to-date survey of spelling and handwriting impairments in each variant of PPA, (2) to provide guidance on characterisation of dysgraphia and identification of loci of impairment, and (3) to outline possible interventions. Because the number of studies which have specifically evaluated therapy for dysgraphia in PPA is small, this paper also reviews relevant studies of therapy in non-progressive dysgraphia. Main Contribution: Review of the literature indicated that the most common pattern of spelling impairment in the semantic variant of PPA is surface dysgraphia (impairment in lexical spelling). The profile is more variable in the non-fluent and logopenic variants of PPA, but most commonly there is impairment in lexical spelling and in phoneme-to-grapheme conversion. Review of the literature on therapy for dysgraphia indicated that four main types of therapy have been evaluated and shown to improve spelling performance: (1) training of spelling of specific target words (used to ameliorate lexical and graphemic buffer impairments), (2) training of sound-to-spelling correspondence rules (used to treat impairment in assembled spelling), (3) training in segmentation of stimulus words into smaller chunks (to make them manageable for a damaged graphemic buffer, or as a first stage in applying sound-to-spelling correspondence rules), and (4) learning to identify and self-correct errors (used in treatment of graphemic buffer disorder). Conclusions: It is likely that spelling impairment in PPA would be responsive to treatment, although this has only been demonstrated in the logopenic variant. Reported improvements following therapy for anomia demonstrate that relearning is possible in PPA, despite the progressive nature of the condition. This gives reason for optimism regarding a positive response to therapy for dysgraphia in all variants of PPA

Automated classification of primary progressive aphasia subtypes from narrative speech samples

The final version of this article from Elsevier can be found at http://dx.doi.org/10.1016/j.cortex.2012.12.006In the early stages of neurodegenerative disorders, individuals may exhibit a decline in language abilities that is difficult to quantify with standardized tests. Careful analysis of connected speech can provide valuable information about a patient's language capacities. To date, this type of analysis has been limited by its time-consuming nature. In this study, we present a method for evaluating and classifying connected speech in primary progressive aphasia using computational techniques. Syntactic and semantic features were automatically extracted from transcriptions of narrative speech for three groups: semantic dementia (SD), progressive nonfluent aphasia (PNFA), and healthy controls. Features that varied significantly between the groups were used to train machine learning classifiers, which were then tested on held-out data. We achieved accuracies well above baseline on the three binary classification tasks. An analysis of the influential features showed that in contrast with controls, both patient groups tended to use words which were higher in frequency (especially nouns for SD, and verbs for PNFA). The SD patients also tended to use words (especially nouns) that were higher in familiarity, and they produced fewer nouns, but more demonstratives and adverbs, than controls. The speech of the PNFA group tended to be slower and incorporate shorter words than controls. The patient groups were distinguished from each other by the SD patients' relatively increased use of words which are high in frequency and/or familiarity

Lack of Frank Agrammatism in the Nonfluent Agrammatic Variant of Primary Progressive Aphasia

Background/Aims: Frank agrammatism, defined as the omission and/or substitution of grammatical morphemes with associated grammatical errors, is variably reported in patients with nonfluent variant primary progressive aphasia (nfPPA). This study addressed whether frank agrammatism is typical in agrammatic nfPPA patients when this feature is not required for diagnosis. Method: We assessed grammatical production in 9 patients who satisfied current diagnostic criteria. Although the focus was agrammatism, motor speech skills were also evaluated to determine whether dysfluency arose primarily from apraxia of speech (AOS), instead of, or in addition to, agrammatism. Volumetric MRI analyses provided impartial imaging-supported diagnosis. Results: The majority of cases exhibited neither frank agrammatism nor AOS. Conclusion: There are nfPPA patients with imaging-supported diagnosis and preserved motor speech skills who do not exhibit frank agrammatism, and this may persist beyond the earliest stages of the illness. Because absence of frank agrammatism is a subsidiary diagnostic feature in the logopenic variant of PPA, this result has implications for differentiation of the nonfluent and logopenic variants, and indicates that PPA patients with nonfluent speech in the absence of frank agrammatism or AOS do not necessarily have the logopenic variant

Lack of Frank Agrammatism in the Nonfluent Agrammatic Variant of Primary Progressive Aphasia

The final, published version of this article is available at http://www.karger.com/?doi=10.1159/000456710Frank agrammatism, defined as the omission and/or substitution of grammatical morphemes with associated grammatical errors, is variably reported in patients with nonfluent variant primary progressive aphasia (nfPPA). This study addressed whether frank agrammatism is typical in agrammatic nfPPA patients when this feature is not required for diagnosis.This work was supported by the Canadian Institutes of Health Research (grant No. 82744)

White Matter Disruption and Connected Speech in Non-Fluent and Semantic Variants of Primary Progressive Aphasia

The final, published version of this article is available at http://www.karger.com/?doi=10.1159/000456710Differential patterns of white matter disruption have recently been reported in the non-fluent (nfvPPA) and semantic (svPPA) variants of primary progressive aphasia (PPA). No single measure is sufficient to distinguish between the PPA variants, but connected speech allows for the quantification of multiple measures. The aim of the present study was to further investigate the white matter correlates associated with connected speech features in PPA. We examined the relationship between white matter metrics and connected speech deficits using an automated analysis of transcriptions of connected speech and diffusion tensor imaging in language-related tracts. Syntactic, lexical, and semantic features were automatically extracted from transcriptions of topic-directed interviews conducted with groups of individuals with nfvPPA or svPPA as well as with a group of healthy controls. A principal component analysis was performed in order to reduce the number of language measures and yielded a five-factor solution. The results indicated that nfvPPA patients differed from healthy controls on a syntactic factor, and svPPA patients differed from controls on two semantic factors. However, the patient groups did not differ on any factor. Moreover, a correlational analysis revealed that the lexical richness factor was significantly correlated with radial diffusivity in the left inferior longitudinal fasciculus, which suggests that semantic deficits in connected speech reflect a disruption of this ventral pathway, and which is largely consistent with the results of previous studies. Using an automated approach for the analysis of connected speech combined with probabilistic tractography, the present findings demonstrate that nfvPPA patients are impaired relative to healthy controls on syntactic measures and have increased radial diffusivity in the left superior longitudinal fasciculus, whereas the svPPA group was impaired on lexico-semantic measures relative to controls and showed increased radial diffusivity in the uncinate and inferior longitudinal fasciculus bilaterally.This research was supported by grants from the Canadian Institutes of Health Research (CIHR 82744 and 130462) to E.R., S.E.B., C.L., N.L.G., K.M., D.T.W., and T.W.C.; from the Toronto Rehabilitation Institute (to K.M.); and from the Department of Medicine at the University of Toronto and Sunnybrook Health Sciences Center, the Brill Chair in Neurology, the L.C. Campbell Cognitive Neurology Research Unit, Hurvitz Brain Sciences Research Program, and Sunnybrook Research Institute (to S.E.B.)

Profiling Speech and Pausing in Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD).

OBJECTIVE:This study examines reading aloud in patients with amyotrophic lateral sclerosis (ALS) and those with frontotemporal dementia (FTD) in order to determine whether differences in patterns of speaking and pausing exist between patients with primary motor vs. primary cognitive-linguistic deficits, and in contrast to healthy controls. DESIGN:136 participants were included in the study: 33 controls, 85 patients with ALS, and 18 patients with either the behavioural variant of FTD (FTD-BV) or progressive nonfluent aphasia (FTD-PNFA). Participants with ALS were further divided into 4 non-overlapping subgroups--mild, respiratory, bulbar (with oral-motor deficit) and bulbar-respiratory--based on the presence and severity of motor bulbar or respiratory signs. All participants read a passage aloud. Custom-made software was used to perform speech and pause analyses, and this provided measures of speaking and articulatory rates, duration of speech, and number and duration of pauses. These measures were statistically compared in different subgroups of patients. RESULTS:The results revealed clear differences between patient groups and healthy controls on the passage reading task. A speech-based motor function measure (i.e., articulatory rate) was able to distinguish patients with bulbar ALS or FTD-PNFA from those with respiratory ALS or FTD-BV. Distinguishing the disordered groups proved challenging based on the pausing measures. CONCLUSIONS AND RELEVANCE:This study demonstrated the use of speech measures in the identification of those with an oral-motor deficit, and showed the usefulness of performing a relatively simple reading test to assess speech versus pause behaviors across the ALS-FTD disease continuum. The findings also suggest that motor speech assessment should be performed as part of the diagnostic workup for patients with FTD

Correlations between (a, left) ALSFRS-R bulbar subscore (/12) and articulatory rate (SPM); and (b, right) FVC (%) and Mean phrase durations (sec) with the coefficients of determination in patients with ALS.

<p>Correlations between (a, left) ALSFRS-R bulbar subscore (/12) and articulatory rate (SPM); and (b, right) FVC (%) and Mean phrase durations (sec) with the coefficients of determination in patients with ALS.</p