Time reference is often impaired in people with aphasia (PWA), but most research has focused on verb tense production in sentence-level tasks. Few studies have examined how PWA manage time reference in discourse, particularly in fluent aphasia. This study thus investigated how people with fluent and nonfluent aphasia produce verb tenses in discourse and how task type influences performance. Additionally, we explored linguistic patterns associated with time reference in PWA, namely, reduced verb diversity and increased use of temporal adverbs. We conducted a cross-sectional observational study with 21 PWA (11 nonfluent, 10 fluent) and 21 healthy controls. Participants completed two discourse tasks: a sequential picture description (past, present, and future frameworks) and a semistandardized interview (past and future frameworks). Verb tense production, verb diversity, and temporal adverbs were analyzed using generalized linear mixed models. Both aphasia groups produced a comparable number of inflected verbs to control when controlling for word count, aligning with the expected temporal framework. Task effects were observed across all participants, with more present tense verbs in the interview and more future tense verbs in the picture description task, irrespective of the temporal framework. Regarding the linguistic patterns associated with time reference, individuals with nonfluent aphasia exhibited a trade-off effect in the past framework of the picture description task: higher verb diversity was associated with lower past-tense verb production. Conversely, individuals with fluent aphasia relied more on temporal adverbs. The study demonstrates that both fluent and nonfluent aphasia impact discourse-level time reference, each with distinct associated linguistic patterns. It also highlights the need for task-specific assessments in clinical practice. https://doi.org/10.23641/asha.30329683.

Abstract Introduction/Objective Oligodendrogliomas are diffuse gliomas characterized by IDH mutation and 1p/19q codeletion, representing approximately 1–1.5% of all primary brain tumors and typically associated with an indolent clinical course and favorable prognosis. Extraneural metastasis of oligodendroglioma is exceedingly rare. We report here a case of oligodendroglioma, IDH-mutant and 1p/19q codeleted that was metastatic to the liver. This case aims to highlight the potential for metastasis of oligodendroglioma to the liver, as well as to emphasize the importance of comprehensive molecular and histologic analysis in accurately diagnosing such metastases. Methods/Case Report A 63-year-old male with a history of recurrent anaplastic oligodendroglioma in the left cerebral hemisphere, previously treated with three surgical resections and radiation therapy, presented with progressive neurological deficits including right upper extremity spastic hemiplegia, worsening motor strength in the right arm, and receptive aphasia. MRI revealed disease progression, and the patient subsequently underwent a left craniotomy for tumor resection. Histopathologic analysis confirmed recurrent oligodendroglioma (CNS WHO grade 3), with an IDH1 R132H mutation and 1p/19q codeletion. Postoperatively, the patient developed acute diarrhea, and further imaging revealed new hepatic and bone lesions as well as prominent mesenteric lymphadenopathy. Biopsy of one of the new liver lesions revealed metastatic oligodendroglioma. Molecular testing of both the liver and brain lesions revealed an IDH1 p.R132H mutation, TERT promoter mutation (c.-124C>T), PIK3CA alteration (p.E110del), and 1p/19q codeletion. These molecular findings were consistent with metastatic oligodendroglioma, IDH-mutant, 1p/19q-codeleted. Results NA Conclusion Liver metastasis from oligodendroglioma is exceedingly rare, but with the increasing survival of patients due to improved therapeutic approaches, metastatic patterns are becoming more evident. This case highlights the importance of considering extraneural metastasis in patients with the diagnosis of oligodendroglioma. Surgical procedures that disrupt the blood-brain barrier, such as repeated craniotomies, may provide a pathway for metastasis via vascular or lymphatic routes.

Tumefactive demyelination as the first presentation of MOG ab-associated disease.

ABSTRACT Background & Aims Theoretical models suggest that gestures play both compensatory and facilitative roles in verbal communication. This research aims to compare the treatment and generalization effects of word-level and sentence-level Gesture plus Verbal Treatment (GVT) in Cantonese-speaking people with aphasia (PWA). Methods & Procedures Four PWA, two of whom exhibited moderate to severe non-fluent aphasia, and two with mild to moderate fluent aphasia, were included in a single-participant, alternating treatment design. Each participant attended two phases of training, one on word-level and another on sentence-level GVT. Treatment effects on verbal naming and gesture production were measured using picture naming probes. Generalization effects to untrained items and discourse tasks were measured through verbal and gesture production in one narrative topic and one picture description task. Outcomes & Results No significant differences were observed in the results of verbal and gesture production tasks for word-level versus sentence-level GVT. Both levels of GVT led to significant improvements in verbal and gesture production for trained words in most participants. Although not statistically significant, some generalization effects were also observed. Conclusions This study supported the compensatory role gesture plays in verbal communication but did not support the facilitative roles. Moreover, this study showed that GVT is particularly effective for people with moderate non-fluent aphasia.

Since the era of Penfield, invasive neurophysiology has laid a lasting foundation for functional neuroscience by elucidating brain regions necessary for speech. However, whole-brain investigations have yet to distinguish the millisecond-scale dynamics and specific white matter pathways that support rapid naming in the auditory and visual domains. In this observational study, we constructed a whole-brain Dynamic Causal Tractography atlas using intracranial neurophysiological data from 125 neurosurgical patients. The resulting video atlas captured local cortical high-gamma activity and cortico-cortical coactivation via white matter tracts during rapid and delayed auditory and picture naming. Direct electrical stimulation was employed to assess the causal significance of the observed neural dynamics. The atlas revealed white matter coactivation intensity patterns at specific 5-millisecond time windows that best aligned with sensorimotor and language symptoms elicited by electrical stimulation (Spearman's ρ = 0.58-0.91; p = 4.8 × 10cc to 1.6 × 10c²c). Rapid auditory naming was associated with deactivation of the right rostral middle frontal gyrus and increased coactivation along the left arcuate fasciculus, linked to stimulation-induced receptive and expressive aphasia. In contrast, delayed auditory naming correlated with a late surge in bifrontal coactivation. Rapid picture naming involved early coactivation between cortices connected via the bilateral inferior longitudinal fasciculi-associated with stimulation-induced visual distortions-coinciding with transient co-inactivation of Broca's area. These findings delineate dissociable white matter-mediated mechanisms supporting rapid naming in the auditory and visual domains. Reduced inhibitory monitoring by the right dorsolateral prefrontal cortex may facilitate efficient lexical retrieval via left perisylvian pathways during auditory naming. In contrast, excessive bifrontal interaction may underlie delayed auditory naming. Rapid visual object recognition appears to rely on early occipitotemporal coactivation with minimal involvement of Broca's area. The resulting atlas-accompanied by a publicly available dataset (61.2 GB) and analysis code-serves as a valuable resource for students and trainees studying the network dynamics underlying speech, as well as for presurgical language mapping in patients undergoing cortical or subcortical intervention.

Dystonic hand postures are uncommon in patients with frontal lobe infarction. Here, we report the first case of a patient with frontal lobe infarction presenting with unique dystonic hand postures-specifically, a pointing gun posture and full-finger extension posture-in combination with frontal release signs. A 68-year-old man with a prior diagnosis of probable Parkinson disease acutely developed speech and communication impairment, along with reduced voluntary motor function in the right lower extremity. Neurological examination revealed apathy, motor and sensory aphasia, and flaccid paralysis of the right lower limb. Brain magnetic resonance imaging showed an ischemic stroke involving the left superior frontal gyrus, cingulate gyrus, and corpus callosum. Dopamine transporter single-photon emission computed tomography revealed reduced tracer accumulation in the left striatum. Ten days after stroke onset, the patient exhibited a pointing gun posture in the right hand. A repeat neurological examination revealed a grasp reflex. Removing grasped objects led to a transient index finger extension with flexion of the other fingers or a transient full extension of all fingers. The former resembled a pointing gun posture, while the latter, a newly described phenomenon, was termed the full-finger extension posture. In addition, groping movements with the pointing gun posture were observed. Atypical frontal release signs, including the pointing gun posture and full-finger extension posture, may reflect specific thalamocortical excitation resulting from a combination of contralateral striatal dopaminergic denervation and frontal lobe infarction involving the supplementary motor area.

Aphasia assessment plays a crucial role in rehabilitating people with aphasia (PWA), including classifying healthy individuals, identifying subtypes of aphasia, and assessing severity. This study explores unsupervised clustering methods in aphasic speech data, comparing five feature extraction approaches and four clustering algorithms. Hierarchical Density-Based Spatial Clustering of Applications with Noise (HDBSCAN), Agglomerative clustering, K-means, and Gaussian Mixture Models. The focus is on distinguishing between fluent and non-fluent aphasia and subtypes such as Broca's, Wernicke's, and anomic aphasia. The feature extraction methods include Mel-Frequency Cepstral Coefficients (MFCCs), OpenL3 embeddings, their combination, and a fusion of MFCC with chroma features, spectral contrast, zero-crossing rate, and a novel deep convolutional autoencoder-based (CAE) model. These methods are evaluated for their ability to capture key characteristics of aphasic speech, with the clustering results assessed using intrinsic evaluation metrics. Our findings highlight the effectiveness of different feature extraction methods, with CAE emerging as the most effective approach in distinguishing aphasic speech categories and improving clustering performance. This research highlights the potential of unsupervised learning in aphasia research and offers insight into automated diagnosis and speech therapy tools, contributing to enhanced aphasia assessment and rehabilitation.

ABSTRACT Background Semantically varied verb production in people with aphasia has been studied; however, the evidence of heavy and light verb dissociation remains inconsistent, potentially due to methodological differences. Earlier methods used the frequency rate of heavy and light verb production. However, this approach may inflate the number of verbs produced, as it counts repetitive and contextually unrelated verbs. To address this issue, the current study adopted the core-lexicon approach and aimed to compare the results acquired by the two different approaches to evaluate the heavy-light verb dissociation in people with fluent and nonfluent aphasia. Methods Cinderella storytelling language samples from 20 people with fluent aphasia and 23 people with nonfluent aphasia were obtained from the AphasiaBank database. The percentages of their productions of all heavy and light verbs and core heavy and light verbs were calculated in each aphasia group. In addition, the four heavy and light verb measures with the percentage of all verbs were evaluated for their correlations. Results Findings from the two approaches were inconsistent. Only the core verb approach, but not the frequency rate analysis, showed the group difference in heavy and light verb production. Further, the two core verb measures (%core heavy verbs and %core light verbs) were positively correlated, whereas the frequency measures (%all heavy verbs and %all light verbs) were negatively correlated in both groups of aphasia. Conclusions This suggests that the core-lexicon approach may be a more sensitive measure for identifying the limited lexicon of people with aphasia and their restricted ability to produce verbs from the constrained selections compared to frequency rate analysis. This inconsistency between these two measures also highlights the importance of using various methods to assess verb skills in people with aphasia, providing an in-depth understanding of their language skills.

BackgroundTumor treating fields (TTFields) treatment has been an important option for the treatment of glioblastoma. The introduction of novel treatment options may lead to distinct recurrence patterns compared to those observed with conventional therapies; however, the specific recurrence pattern during TTFields treatment has not been elucidated.Methods and resultsHere, we analyzed 39 cases of glioblastoma treated with TTFields. Although a usage rate of more than 75% is recommended, among 39 cases, 18 discontinued TTFields treatment owing to requests by patients with lower usage rates. In these discontinued cases, patients exhibiting sensory aphasia were more frequently included compared to those who continued TTFields (44.4%, p < 0.001). Among 21 cases involving patients who continued TTFields, tumor recurrence was observed in 15 of those cases. Five out of 15 cases (33.3%) exhibited recurrence in distant parenchyma from the primary lesion. A higher usage rate and relatively longer use of TTFields were observed in these five cases, along with more favorable progression-free survival than those in the other 10 cases (p = 0.019, p = 0.040, and p = 0.024, respectively). In one case, recurrent tumors with lower grade glioma histology but molecular markers characteristic for glioblastoma, IDH-wildtype were indentified. This tumor arose in an area that received a lower local minimum power density of TTFields compared to the primary lesion, following long-term TTFields therapy.ConclusionsLong-term use of TTFields might be correlated with a high frequency of distant parenchymal recurrence in cases with favorable response.

Large language models (LLMs) respond fluently but often inaccurately, which resembles aphasia in humans. Does this behavioral similarity indicate any resemblance in internal information processing between LLMs and aphasic humans? Here, we address this question by comparing the network dynamics between LLMs—ALBERT, GPT‐2, Llama‐3.1 and one Japanese variant of Llama—and various aphasic brains. Using energy landscape analysis, we quantify how frequently the network activity pattern is likely to move from one state to another (transition frequency) and how long it tends to dwell in each state (dwelling time). First, by investigating the frequency spectrums of these two indices for brain dynamics, we find that the degrees of the polarization of the transition frequency and dwelling time enable accurate classification of receptive aphasia, expressive aphasia and controls: receptive aphasia shows the bimodal distributions for both indices, whereas expressive aphasia exhibits the most uniform distributions. In parallel, we identify highly polarized distributions in both transition frequency and dwelling time in the network dynamics in the four LLMs. These findings indicate the similarity in internal information processing between LLMs and receptive aphasia, and the current approach can provide a novel diagnosis and classification tool for LLMs and help their performance improve.

Sensory aphasia is an area that has not yet been researched in the Uzbek language. This article analyzes the results of an experiment conducted on two participants with sensory aphasia whose native language is Uzbek. In accordance with A. Luria's classification, impairments in object naming and repetition skills were observed. Due to the absence of significant differences in acoustic-phonological differentiation, the necessity for conducting further experiments is highlighted.

Glioblastoma (GBM) is known for its significant intratumoral heterogeneity, making biopsies susceptible to underdiagnosis if samples are taken from less malignant regions. [18F]Fluciclovine, a novel PET tracer, has demonstrated high accumulation in glioma tissue, with minimal uptake in normal brain tissue. A 50-year-old woman presented with sensory aphasia. MRI revealed a FLAIR lesion extending from the left parietal to the medial temporal lobe. [18F]Fluciclovine PET/MRI identified two areas of increased uptake, both FLAIR negative. Stereotactic biopsy was used to obtain samples from PET-positive (PET+) and FLAIR-positive (FLAIR+) lesions. Pathological analysis of the PET+ lesion revealed densely proliferating tumor cells with irregularly enlarged nuclei, while the FLAIR+ lesion exhibited sparsely proliferating cells. Molecular analysis showed that both lesions were IDH wildtype with MGMT promoter hypomethylation. Sanger sequencing identified a telomerase reverse transcriptase promoter -124 C>T mutation in the PET+ lesion but not in the FLAIR+ lesion. The integrated diagnosis, based primarily on the PET+ lesion, was GBM, IDH wildtype. This case highlights the importance of [18F]fluciclovine PET/MRI in identifying high-cell-density regions, minimizing the risk of underdiagnosis in GBM. Further studies are necessary to evaluate its prognostic value in GBM management. https://thejns.org/doi/10.3171/CASE24677.

Background and Objective: Primary Progressive Aphasias (PPAs) are rare neurodegenerative disorders classified within frontotemporal lobar degeneration (FTLD) and typically manifest between 45 and 70 years of age. In Mexico-and many other countries-reliable epidemiological data are lacking; however, estimates suggest that PPA accounts for 0.5-2.5% of neurodegenerative disease cases in Memory Clinics, with an incidence of approximately 1 per 100,000 and an average survival of 8 years. This review aims to provide clinicians with an overview of PPA's epidemiology, clinical features, and classification, thereby enhancing understanding of its subtypes and distinguishing characteristics from other aphasic conditions, such as vascular aphasia. Methods: This narrative review was conducted through a literature search using databases such as PubMed and Scopus. Relevant studies addressing the epidemiology, clinical presentation, and classification of PPA were identified, selected, and synthesized to offer a broad, clinically oriented overview of the condition. This approach was chosen to inform clinical practice and highlight the need for further targeted investigations, such as future systematic reviews focusing on specific aspects like therapeutic strategies. Key Contents and Findings: (a) Epidemiology: PPA is estimated to affect 0.5-2.5% of patients with neurodegenerative diseases in Memory Clinics, with an incidence of roughly 1 per 100,000. Average survival time is around 8 years (ranging from 3 to 17 years), with a generally balanced gender ratio, though some studies indicate a predominance of men. A positive family history is observed in 20-40% of cases, with about 10% following an autosomal dominant inheritance pattern. (b) Clinical Characteristics and Classification: PPA is marked by a gradual decline in language abilities, differentiating it from vascular aphasias. Subtypes include non-fluent forms (non-fluent progressive aphasia [nfPPA] and logopenic progressive aphasia [lPPA]), fluent forms (progressive fluent aphasia [PFA] and semantic dementia [SD]), and mixed forms (progressive mixed aphasia [PMA]). The neurodegenerative process in PPA extends beyond vascular boundaries, often resulting in presentations that deviate from classical Broca's and Wernicke's aphasias. Common symptoms include difficulties in word finding and naming, sometimes mistaken for memory loss, and, in the case of semantic dementia, personality changes that may go unnoticed by the patient. Conclusions: PPA is a heterogeneous and complex group of neurodegenerative disorders with significant clinical variability and a profound impact on patients and their families. While current epidemiological data are limited, this review emphasizes the need for further research to better delineate disease progression and refine diagnostic and therapeutic approaches. Future systematic reviews will be essential to address specific aspects of PPA, such as treatment strategies, to further improve patient care.

Purpose: Discourse analysis is an important component of aphasia assessment because it can provide insight into functional communication abilities of the participants. Understanding the essence of discourse becomes pivotal, as it is the most rudimentary way of communication in individuals’ daily routine. Hence, the present study aimed to explore the superiority of different discourse elicitation tasks in persons with fluent aphasia (PwFA). Methods: A total of six PwFA were recruited for the study. These participants were assessed for their discourse abilities using three tasks: picture description, conversation, and narration. The participants' discourse samples were analysed using the discourse analysis scale. In all these tasks, the propositional and non-propositional aspects of communication were evaluated. After recording the responses, the scores of each task (picture description, conversation, and narration) were consolidated to compute the discourse quotient. Results: Quantitative analysis revealed significant differences across general conversation compared to narration and picture description tasks. Out of these three tasks, general conversation is outperformed the other two tasks. Further, the individual case-wise analysis showed similar pattern of results. Conclusion: The findings of this study hold significant implications for both clinical practice and research. Understanding the potency and setbacks of different discourse genres aids speech language pathologist to analyse the discourse elicited from different genres using different cutoff values. Despite the positive findings of the current study the findings of the study should be interpreted meticulously due to the small sample size and the limited ecological validity of the study.

ABSTRACT Purpose Formulaic language is an under-explored area of research in the field of acquired language disorders as compared to propositional language. The primary purpose of this study was to explore the utility of a proposed theoretical formulaic language model (Van Lancker Sidtis, 2022) for individuals with post-stroke aphasia to inform research and clinical practice. Method The dataset included previously described formulaic language extracted from Aphasiabank speech samples produced by 144 individuals with fluent and non-fluent aphasias. Formulaic language items were coded according to six psycholinguistic characteristics from the theoretical model. Between-group comparisons and regression analyses were run to determine whether particular psycholinguistic characteristics of produced formulaic items could predict speaker fluency. Results Findings revealed formulaic language differences between fluent and nonfluent aphasias based on the theoretical model. Importantly, psycholinguistic characteristics of frequency and syntactic completeness along with presence of apraxia of speech predicted fluency status with high accuracy (88.4% of individuals with fluent and 70.3% with nonfluent aphasia). Conclusions Findings in this study illustrate how theoretically-driven analyses of formulaic language production may enhance diagnostic and intervention practices in post-stroke aphasia.

Behavioral, neurodevelopmental profile, and epilepsy trajectory in two series of SLC6A1-NDD: A retrospective study with comprehensive assessment, and a participatory database study.

Individuals with “agrammatic” receptive aphasia have long been known to rely on semantic plausibility rather than syntactic cues when interpreting sentences. In contrast to early interpretations of this pattern as indicative of a deficit in syntactic knowledge, a recent proposal views agrammatic comprehension as a case of “noisy-channel” language processing with an increased expectation of noise in the input relative to healthy adults. Here, we investigate the nature of the noise model in aphasia and whether it is adapted to the statistics of the environment. We first replicate findings that a) healthy adults (N = 40) make inferences about the intended meaning of a sentence by weighing the prior probability of an intended sentence against the likelihood of a noise corruption and b) their estimate of the probability of noise increases when there are more errors in the input (manipulated via exposure sentences). We then extend prior findings that adults with chronic post-stroke aphasia (N = 28) and healthy age-matched adults (N = 19) similarly engage in noisy-channel inference during comprehension. We use a hierarchical latent mixture modeling approach to account for the fact that rates of guessing are likely to differ between healthy controls and individuals with aphasia and capture individual differences in the tendency to make inferences. We show that individuals with aphasia are more likely than healthy controls to draw noisy-channel inferences when interpreting semantically implausible sentences, even when group differences in the tendency to guess are accounted for. While healthy adults rapidly adapt their inference rates to an increase in noise in their input, whether individuals with aphasia do the same remains equivocal. Further investigation of comprehension through a noisy-channel lens holds promise for a parsimonious understanding of language processing in aphasia and may suggest potential avenues for treatment.

We herein report a rare case of progressive supranuclear palsy (PSP) that initially presented as progressive fluent aphasia and echolalia. A 75-year-old woman exhibited significant language impairments for 2 years before developing motor symptoms, including vertical gaze palsy and frequent falls. Neuroimaging revealed asymmetric frontal and midbrain atrophy, with reduced perfusion in the left frontal and parietal lobes. This case highlights the importance of recognizing atypical PSP presentations, particularly language-dominant variants that may mimic other neurodegenerative disorders. Early identification using detailed neuropsychological assessments and imaging may facilitate a timely diagnosis and intervention in non-classical PSP cases.

Background. The problem of the relationship between thinking and speech is fundamental for psychological science: it underlies the understanding of formation and functioning of human consciousness, marked by its speech form. The study of aphasia is one of the promising areas of research into the relationship between these functions, which also has important practical significance in the field of neuropsychological rehabilitation. Objective. The aim of the study was to compare the views of two researchers working within cultural-historical psychology on the subject of the relationship of thinking and speech, using the example of sensory aphasia. Methods. The principles underlying the supposed mechanism of aphasia were compared to the principles of the relationship between thinking and speech, as revealed in general psychology. From the side of aphasic disorders, the main emphasis was placed on the analysis of the works of A.R. Luria and the disciples of his school, while a more general analysis of the connection between thinking and speech is based on the classical works of L.S. Vygotsky and his student R.E. Levina. The history of the development of the view on the problem of thinking and speech in the works of representatives of structuralism, functionalism, gestalt theory, and other schools was also briefly considered. Results. As a result, a discrepancy in understanding the relationship between these two mental functions was revealed: according to L.S. Vygotsky’s view, thinking and speech are in unity and mediate each other, therefore different forms of aphasia are different variants of the impairment of this unity. While, based on the analysis of A.R. Luria’s works, it can be concluded that aphasia is a primary impairment of speech with or without slight secondary thinking disorder. Conclusion. The difference in the approaches of the two scientists to the problem of relationship between thinking and speech revealed in the work allows us to move on to the further application of L.S. Vygotsky’s ideas about the inextricable unity of speech thinking in the study of aphasia. Variants of aphasic disorder can be understood as various forms of disturbance of mental-speech unity, and not as a primary speech disorder.

We investigated semantic cognition in the logopenic variant of primary progressive aphasia, including (i) the status of verbal and non-verbal semantic performance; and (ii) whether the semantic deficit reflects impaired semantic control. Our a priori hypothesis that individuals with logopenic variant of primary progressive aphasia would exhibit semantic control impairments was motivated by the anatomical overlap between the temporoparietal atrophy typically associated with logopenic variant of primary progressive aphasia and lesions associated with post-stroke semantic aphasia and Wernicke's aphasia, which cause heteromodal semantic control impairments. We addressed the presence, type (semantic representation and semantic control; verbal and non-verbal), and progression of semantic deficits in logopenic variant of primary progressive aphasia. Since most people with logopenic variant of primary progressive aphasia have Alzheimer's disease pathology and are part of a broader multi-dimensional phenotype space encompassing Alzheimer's disease sub-types, we compared semantic performance in logopenic variant of primary progressive aphasia and typical amnestic Alzheimer's disease. Given the differences in lesion and atrophy patterns in semantic aphasia and Wernicke's aphasia versus semantic-dementia/semantic-variant primary progressive aphasia patients, our second aim was to examine atrophy patterns in people with logopenic variant of primary progressive aphasia and typical Alzheimer's disease compared to age-matched controls. Twenty-seven patients participated in the study. People were grouped into those meeting consensus criteria for logopenic variant of primary progressive aphasia (N = 10) and others who may have previously satisfied definitions of logopenic variant of primary progressive aphasia but had progressed with multi-domain cognitive impairments (herein referred to as 'logopenic variant of primary progressive aphasia+'; N = 8). People with typical amnestic Alzheimer's disease (N = 9) were relatively preserved across verbal and non-verbal semantic assessments. Logopenic variant of primary progressive aphasia patients were impaired on both verbal and non-verbal semantic tasks and their impairments showed the hallmark characteristics of a semantic control deficit. Logopenic variant of primary progressive aphasia and logopenic variant of primary progressive aphasia + patients showed effects of varying semantic control demands, positive cueing effects, and correlated performance between semantic and executive tasks. Whole-brain voxel-based morphometry, comparing each of the patient groups to age-matched controls, revealed significantly reduced grey and white matter in the bilateral hippocampi and lateral temporal regions in typical Alzheimer's disease patients. The logopenic variant of primary progressive aphasia group exhibited an asymmetric pattern of reduced grey and white matter intensity in the language-dominant left hemisphere, including a significant portion of the lateral and medial temporal lobe. Logopenic variant of primary progressive aphasia + patients demonstrated reduced grey and white matter in the left temporal lobe extending sub-cortically, anteriorly and posteriorly, as well as right temporal involvement. Our findings could aid diagnostic sub-typing of primary progressive aphasia by adopting semantic control features and offer improved clinical characterization of logopenic variant of primary progressive aphasia in the trajectory of semantic decline.