Sources of Phoneme Errors in Repetition: Perseverative, Neologistic, and Lesion Patterns in Jargon Aphasia

An online survey of clinical practice and confidence in diagnosing acquired apraxia of speech in Cantonese speakers

PURPOSE

The assessment and diagnosis of apraxia of speech (AOS) have been well studied in the English context, yet there is limited understanding of the clinical practice in speakers of other languages, like Cantonese. This study aimed to obtain information about the clinical practice of assessment methods and diagnostic criteria used, and confidence in diagnosing, AOS in Cantonese speakers.

METHOD

An online survey constructed with Google Forms was completed by 27 speech-language pathologists (SLPs) in Hong Kong. The questionnaire comprised 12 questions covering (a) demographic information, (b) experience working with speakers with AOS, (c) confidence in making AOS diagnosis in Cantonese speakers, (d) assessment tasks or methods used for assessing AOS in Cantonese speakers, (e) clinical features used for diagnostic purposes, and (f) assessment tasks used to determine the presence of clinical features for diagnostic purposes.

RESULT

All respondents (100%) made AOS diagnoses based on the observed clinical features, while no respondents made diagnoses using only standardised tests or quantitative measures. Six clinical features were commonly used by most of the respondents: articulatory groping (100%), inconsistent articulatory errors (100%), length effects (85.2%), difficulty initiating speech (81.5%), automaticity effects (81.5%), and sound distortions (77.8%). More than half of the respondents collected connected speech samples (64%), and conducted diadochokinesis (64%) and repetition tasks (64%). The average confidence level of the respondents for making AOS diagnoses was fair (3.63/5).

CONCLUSION

The SLPs in Hong Kong make AOS diagnoses based on the observed clinical features that have been reported in the English literature. Although some of the clinical features have been updated as non-discriminatory for AOS, they are still being used for AOS diagnosis in Cantonese speakers. Tendencies were observed with respect to the assessment tasks selected. The fair diagnostic confidence level suggests a need for future investigations of AOS in Cantonese speakers and the development of assessment tools.

Jargonaphasia in logopenic variant primary progressive aphasia

BACKGROUND

Logopenic variant primary progressive aphasia (lvPPA), which is most commonly an early onset variant of Alzheimer's disease (AD), is a progressive impairment in word retrieval and language expression. Clinicians often misdiagnose these patients when they present with severely unintelligible speech consistent with jargonaphasia.

METHODS

We reviewed all patients presenting to a behavioral neurology program over a 23-year period who met criteria for lvPPA after completion of an evaluation extending to positron emission tomography (PET) of the brain. Among these lvPPA patients, we additionally identified and characterized those whose presentation involved incomprehensible yet fluent verbal output.

RESULTS

Out of 95 patients with lvPPA, 9 (9.47%) had jargonaphasia on presentation. These patients differed from the remaining 86 patients in lacking awareness or concern for their impaired communication, having worse mental status scale scores, greater auditory comprehension difficulty, and more bilateral temporo-parietal hypometabolism. In addition, 44.4% of those with jargonaphasia, compared to 14% of those without, were bi/multilingual.

CONCLUSION

Nearly 1 in 10 patients with lvPPA present with severely unintelligible speech. These patients have disease extending to bilateral temporoparietal areas affecting language comprehension and disease awareness. Jargonaphasia can be a confusing presentation of AD and must be differentiated from other progressive aphasias, Wernicke's aphasia, and the word salad of "schizoaphasia".

Assessment and Diagnostic Standards of Apraxia of Speech in Chinese-Speaking Adults and Children: A Scoping Review

PURPOSE

Apraxia of speech (AOS) and childhood apraxia of speech (CAS) are motor-based speech disorders that have been well studied in Indo-European languages. There is limited understanding of these disorders in speakers of Sino-Tibetan languages, such as Chinese. The purpose of this study is to review methods used in research studies for the assessment and diagnosis of AOS and CAS in Chinese speakers.

METHOD

This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines. Articles with a focus on AOS or CAS in Chinese speakers were systematically searched in seven English and six Chinese databases. Three reviewers performed independent screening, data extraction, and quality assessment after obtaining 100% agreement on the prescreening exercise. A qualitative analysis was conducted to rate the quality of diagnoses, ranging from high (Level I) to low (Level III), with Level IV assigned to studies for which the appropriate rating was unclear due to insufficient evidence.

RESULTS

Twenty-eight AOS articles and five CAS articles were identified. A variety of assessment and diagnostic methods were reported. No study of Chinese speakers with AOS or CAS received a rating of Level I. The highest level achieved was Level IIIa for both AOS and CAS studies.

CONCLUSIONS

There is no reliable and valid test or method for the diagnosis of AOS or CAS in Chinese speakers. The current gold standard of diagnosis is based upon expert perceptual judgment. Further single-language and cross-linguistic investigations of AOS and CAS and the future development of assessment and diagnostic methods are recommended.

Specific disruption of the ventral anterior temporo-frontal network reveals key implications for language comprehension and cognition

Recent investigations have raised the question of the role of the anterior lateral temporal cortex in language processing (ventral language network). Here we present the language and overall cognitive performance of a rare male patient with chronic middle cerebral artery cerebrovascular accident with a well-documented lesion restricted to the anterior temporal cortex and its connections via the extreme capsule with the pars triangularis of the inferior frontal gyrus (i.e. Broca’s region). The performance of this unique patient is compared with that of two chronic middle cerebral artery cerebrovascular accident male patients with damage to the classic dorsal posterior temporo-parietal language system. Diffusion tensor imaging is used to reconstruct the relevant white matter tracts of the three patients, which are also compared with those of 10 healthy individuals. The patient with the anterior temporo-frontal lesion presents with flawless and fluent speech, but selective impairment in accessing lexico-semantic information, in sharp contrast to the impairments in speech, sentence comprehension and repetition observed after lesions to the classic dorsal language system. The present results underline the contribution of the ventral language stream in lexico-semantic processing and higher cognitive functions, such as active selective controlled retrieval.

Neuropsychological profiling and clinical DTI of three stroke patients highlight the importance of the ventral language system in normal language comprehension and cognition.

Dissociable language and executive control deficits and recovery in post-stroke aphasia: An exploratory observational and case series study

A growing body of evidence indicates many, but not all, individuals with post-stroke aphasia experience executive dysfunction. Relationships between language and executive function skills are often reported in the literature, but the degree of interdependence between these abilities remains largely unanswered. Therefore, in this study, we investigated the extent to which language and executive control deficits dissociated in 1) acute stroke and 2) longitudinal aphasia recovery. Twenty-three individuals admitted to Johns Hopkins Hospital with a new left hemisphere stroke completed the Western Aphasia Battery-Revised (WAB-R), several additional language measures (of naming, semantics, spontaneous speech, and oral reading), and three non-linguistic cognitive tasks from the NIH Toolbox (i.e., Pattern Comparison Processing Speed Test, Flanker Inhibitory Control and Attention Test, and Dimensional Change Card Sort Test). Two participants with aphasia (PWA) with temporoparietal lesions, one of whom (PWA1) had greater temporal but less frontal and superior parietal damage than the other (PWA2), also completed testing at subacute (three months post-onset) and early chronic (six months post-onset) time points. In aim 1, principal component analysis on the acute test data (excluding the WAB-R) revealed language and non-linguistic executive control tasks largely loaded onto separate components. Both components were significant predictors of acute aphasia severity per the WAB-R Aphasia Quotient (AQ). Crucially, executive dysfunction explained an additional 17% of the variance in AQ beyond the explanatory power of language impairments alone. In aim 2, both case patients exhibited language and executive control deficits at the acute post-stroke stage. A dissociation was observed in longitudinal recovery of these patients. By the early chronic time point, PWA1 exhibited improved (but persistent) deficits in several language domains and recovered executive control. In contrast, PWA2 demonstrated mostly recovered language but persistent executive dysfunction. Greater damage to language and attention networks in these respective patients may explain the observed behavioral patterns. These results demonstrate that language and executive control can dissociate (at least to a degree), but both contribute to early post-stroke presentation of aphasia and likely influence longitudinal aphasia recovery.

Utility of the Repeat and Point Test for Subtyping Patients With Primary Progressive Aphasia

BACKGROUND

Primary progressive aphasia (PPA) may present with three distinct clinical sybtypes: semantic variant PPA (svPPA), nonfluent/agrammatic variant PPA (nfvPPA), and logopenic variant PPA (lvPPA).

OBJECTIVE

The aim was to examine the utility of the German version of the Repeat and Point (R&P) Test for subtyping patients with PPA.

METHOD

During the R&P Test, the examiner reads out aloud a noun and the participants are asked to repeat the word and subsequently point to the corresponding picture. Data from 204 patients (68 svPPA, 85 nfvPPA, and 51 lvPPA) and 33 healthy controls were analyzed.

RESULTS

Controls completed both tasks with >90% accuracy. Patients with svPPA had high scores in repetition (mean=9.2±1.32) but low scores in pointing (mean=6±2.52). In contrast, patients with nfvPPA and lvPPA performed comparably in both tasks with lower scores in repetition (mean=7.4±2.7 for nfvPPA and 8.2±2.34 for lvPPA) but higher scores in pointing (mean=8.9±1.41 for nfvPPA and 8.6±1.62 for lvPPA). The R&P Test had high accuracy discriminating svPPA from nfvPPA (83% accuracy) and lvPPA (79% accuracy). However, there was low accuracy discriminating nfvPPA from lvPPA (<60%).

CONCLUSION

The R&P Test helps to differentiate svPPA from 2 nonsemantic variants (nfvPPA and lvPPA). However, additional tests are required for the differentiation of nfvPPA and lvPPA.

Jargonaphasia as a disconnection syndrome: A study combining white matter electrical stimulation and disconnectome mapping

BACKGROUND

In jargonaphasia, speech is fluent but meaningless. While neuropsychological evaluation may distinguish a neologistic component characterised by non-word production and a semantic component where pronounced words are real but speech is senseless, how this relates to the underlying white matter anatomy is debated.

OBJECTIVE

To identify white matter pathways causally involved in jargonaphasia.

METHODS

We retrospectively screened the intraoperative brain mapping data of 571 awake oncological resections using direct cortico-subcortical electrostimulation. Jargonaphasia was induced in 17 patients (19 sites) during a naming task. Stimulation sites were normalized to the Montreal Neurological Institute template space and used to generate individual disconnectome maps. Non-parametric voxelwise one and two sample t-tests were performed to identify the underlying white matter anatomy.

RESULTS

Jargonaphasia was induced only during stimulation of the left hemisphere. No cortical stimulation generated jargonaphasia. Subcortical sites causally associated with jargonaphasia clustered in 3 regions: in the temporal lobe (middle to inferior temporal gyri; n = 12), in the parietal lobe (supramarginal gyrus; n = 3) and in the temporal stem (n = 4). Disconnectome analysis indicated the inferior-fronto-occipital fasciculus (IFOF) was damaged in both neologistic and semantic jargonaphasia, while the involvement of the arcuate fasciculus was specific to neologistic jargonaphasia.

CONCLUSION

For the first time, we show that jargonaphasia is induced by white matter stimulation, hinting at disconnection. As IFOF disconnection unites both variants, these may represent a continuum of disorders distinguished by semantic impairment. Conversely, damage to the arcuate fasciculus in addition to the IFOF is specific to neologistic jargonaphasia, thus suggesting a dual-disconnection syndrome.

Neurocognitive signatures of phonemic sequencing in expert backward speakers

Despite its prolific growth, neurolinguistic research on phonemic sequencing has largely neglected the study of individuals with highly developed skills in this domain. To bridge this gap, we report multidimensional signatures of two experts in backward speech, that is, the capacity to produce utterances by reversing the order of phonemes while retaining their identity. Our approach included behavioral assessments of backward and forward speech alongside neuroimaging measures of voxel-based morphometry, diffusion tensor imaging, and resting-state functional connectivity. Relative to controls, both backward speakers exhibited behavioral advantages for reversing words and sentences of varying complexity, irrespective of working memory skills. These patterns were accompanied by increased grey matter volume, higher mean diffusivity, and enhanced functional connectivity along dorsal and ventral stream regions mediating phonological and other linguistic operations, with complementary support of areas subserving associative-visual and domain-general processes. Still, the specific loci of these neural patterns differed between both subjects, suggesting individual variability in the correlates of expert backward speech. Taken together, our results offer new vistas on the domain of phonemic sequencing, while illuminating neuroplastic patterns underlying extraordinary language abilities.

Auditory, Phonological, and Semantic Factors in the Recovery From Wernicke's Aphasia Poststroke: Predictive Value and Implications for Rehabilitation

Background. Understanding the factors that influence language recovery in aphasia is important for improving prognosis and treatment. Chronic comprehension impairments in Wernicke's aphasia (WA) are associated with impairments in auditory and phonological processing, compounded by semantic and executive difficulties. This study investigated whether the recovery of auditory, phonological, semantic, or executive factors underpins the recovery from WA comprehension impairments by charting changes in the neuropsychological profile from the subacute to the chronic phase. Method. This study used a prospective, longitudinal observational design. Twelve WA participants with superior temporal lobe lesions were recruited 2 months post-stroke onset (2 MPO). Language comprehension was measured alongside a neuropsychological profile of auditory, phonological, and semantic processing and phonological short-term memory and nonverbal reasoning at 3 poststroke time points: 2.5, 5, and 9 MPO. Results. Language comprehension displayed a strong and consistent recovery between 2.5 and 9 MPO. Improvements were also seen for slow auditory temporal processing, phonological short-term memory, and semantic processing but not for rapid auditory temporal, spectrotemporal, and phonological processing. Despite their lack of improvement, rapid auditory temporal processing at 2.5 MPO and phonological processing at 5 MPO predicated comprehension outcomes at 9 MPO. Conclusions. These results indicate that recovery of language comprehension in WA can be predicted from fixed auditory processing in the subacute stage. This suggests that speech comprehension recovery in WA results from reorganization of the remaining language comprehension network to enable the residual speech signal to be processed more efficiently, rather than partial recovery of underlying auditory, phonological, or semantic processing abilities.

Selection of neuropsychological tasks from a language test battery that optimally related to the function of each cortical area: Toward making a cognitive cortical map

We developed a cortical language map from performance data on a language test battery in patients with brain lesions. The research problem was how to select the subtest that was most related to the function of each cortical area from the battery. When studied by voxel-based lesion-symptom mapping (VLSM), patients were divided into two groups: those with and without a lesion at each particular region. We considered the task that optimally discriminated between the two groups to be the task most related to the function of a given region. One hundred and fifty left-lesioned patients were examined using the Japanese Standard Language Test of Aphasia (SLTA), which is composed of 26 subtests. Using logistic discriminant analysis, we selected the subtest that optimally discriminated the lesioned and non-lesioned groups for each cortical region. Patients with left middle frontal gyrus (area 46) lesions were optimally discriminated from patients without lesions in that area by the speech sound–kana letter choice matching subtest. Patients with lesions in the inferior postcentral gyrus were optimally distinguished by the disturbance of word repetition. Patients with lesions in the anterior cingulate gyrus were characterized by impaired performance on the category fluency subtest. Voxel-based discriminant analysis can thus select the subtest that can be regarded as most related to the function of each cortical area.

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From a cognitive test battery, we selected the subtest most related to the function of each cortical area.

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We conducted voxel-based lesion-symptom mapping using t-test and logistic regression.

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The t-statistic and G-statistic can be used as indicators of differences in task performance.

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This method is useful for clarifying the primary function of each region of cortex.