Use of transcranial magnetic stimulation in the treatment of nonfluent primary progressive aphasia: a case report.

Primary progressive aphasia comprises a group of neurodegenerative diseases characterized by progressive speech and language dysfunction. Neuroimaging (structural and functional), biomarkers, and neuropsychological assessments allow for early diagnosis. However, there is no pharmacological treatment for the disease. Speech and language therapy is the main rehabilitation strategy. In this case report, we describe a female patient diagnosed with nonfluent primary progressive aphasia who underwent sessions of high-frequency transcranial magnetic stimulation in the left dorsolateral prefrontal cortex and showed improvement in depression scores, naming tasks in oral and written speech, and comprehension tasks in oral and written discourse.

As afasias progressivas primárias (APP) representam um grupo de doenças neurodegenerativas caracterizadas por disfunção progressiva da fala e da linguagem. A neuroimagem (estrutural e funcional), os biomarcadores e as avaliações neuropsicológicas permitem o diagnóstico precoce. No entanto, não há tratamento farmacológico para a doença. A terapia fonoaudiológica é a principal estratégia de reabilitação. Neste relato de caso, descrevemos uma paciente com diagnóstico de APP não fluente que foi submetida a sessões de estimulação magnética transcraniana de alta frequência no córtex pré-frontal dorsolateral esquerdo e apresentou melhora nos escores de depressão, nas tarefas de nomeação da fala oral e escrita e nas tarefas de compreensão da fala oral e escrita.

Frontotemporal Dementia, Where Do We Stand? A Narrative Review.

Frontotemporal dementia (FTD) is a neurodegenerative disease of growing interest, since it accounts for up to 10% of middle-age-onset dementias and entails a social, economic, and emotional burden for the patients and caregivers. It is characterised by a (at least initially) selective degeneration of the frontal and/or temporal lobe, generally leading to behavioural alterations, speech disorders, and psychiatric symptoms. Despite the recent advances, given its extreme heterogeneity, an overview that can bring together all the data currently available is still lacking. Here, we aim to provide a state of the art on the pathogenesis of this disease, starting with established findings and integrating them with more recent ones. In particular, advances in the genetics field will be examined, assessing them in relation to both the clinical manifestations and histopathological findings, as well as considering the link with other diseases, such as amyotrophic lateral sclerosis (ALS). Furthermore, the current diagnostic criteria will be explored, including neuroimaging methods, nuclear medicine investigations, and biomarkers on biological fluids. Of note, the promising information provided by neurophysiological investigations, i.e., electroencephalography and non-invasive brain stimulation techniques, concerning the alterations in brain networks and neurotransmitter systems will be reviewed. Finally, current and experimental therapies will be considered.

Brain structural and functional correlates of the heterogenous progression of mixed transcortical aphasia.

Mixed transcortical aphasia (MTCA) is characterized by non-fluent speech and comprehension deficits coexisting with preserved repetition. MTCA may evolve to less severe variants of aphasias or even to full language recovery. Mechanistically, MCTA has traditionally been attributed to a disconnection between the spared left perisylvian language network (PSLN) responsible for preserved verbal repetition, and damaged left extrasylvian networks, which are responsible for language production and comprehension impairments. However, despite significant advances in in vivo neuroimaging, the structural and functional status of the PSLN network in MTCA and its evolution has not been investigated. Thus, the aim of the present study is to examine the status of the PSLN, both in terms of its functional activity and structural integrity, in four cases who developed acute post-stroke MTCA and progressed to different types of aphasia. For it, we conducted a neuroimaging-behavioral study performed in the chronic stage of four patients. The behavioral profile of MTCA persisted in one patient, whereas the other three patients progressed to less severe types of aphasias. Neuroimaging findings suggest that preserved verbal repetition in MTCA does not always depend on the optimal status of the PSLN and its dorsal connections. Instead, the right hemisphere or the left ventral pathway may also play a role in supporting verbal repetition. The variability in the clinical evolution of MTCA may be explained by the varying degree of PSLN alteration and individual premorbid neuroanatomical language substrates. This study offers a fresh perspective of MTCA through the lens of modern neuroscience and unveils novel insights into the neural underpinnings of repetition.

Use of transcranial magnetic stimulation in the treatment of nonfluent primary progressive aphasia: a case report / Uso da estimulação magnética transcraniana no tratamento da afasia progressiva primária não fluente: um relato de caso

ABSTRACT Primary progressive aphasia comprises a group of neurodegenerative diseases characterized by progressive speech and language dysfunction. Neuroimaging (structural and functional), biomarkers, and neuropsychological assessments allow for early diagnosis. However, there is no pharmacological treatment for the disease. Speech and language therapy is the main rehabilitation strategy. In this case report, we describe a female patient diagnosed with nonfluent primary progressive aphasia who underwent sessions of high-frequency transcranial magnetic stimulation in the left dorsolateral prefrontal cortex and showed improvement in depression scores, naming tasks in oral and written speech, and comprehension tasks in oral and written discourse.

RESUMO As afasias progressivas primárias (APP) representam um grupo de doenças neurodegenerativas caracterizadas por disfunção progressiva da fala e da linguagem. A neuroimagem (estrutural e funcional), os biomarcadores e as avaliações neuropsicológicas permitem o diagnóstico precoce. No entanto, não há tratamento farmacológico para a doença. A terapia fonoaudiológica é a principal estratégia de reabilitação. Neste relato de caso, descrevemos uma paciente com diagnóstico de APP não fluente que foi submetida a sessões de estimulação magnética transcraniana de alta frequência no córtex pré-frontal dorsolateral esquerdo e apresentou melhora nos escores de depressão, nas tarefas de nomeação da fala oral e escrita e nas tarefas de compreensão da fala oral e escrita.

Structural, Microstructural, and Metabolic Alterations in Primary Progressive Aphasia Variants.

Neuroimaging studies have described the brain alterations in primary progressive aphasia (PPA) variants (semantic, logopenic, nonfluent/agrammatic). However, few studies combined T1, FDG-PET, and diffusion MRI techniques to study atrophy, hypometabolism, and tract alterations across the three PPA main variants. We therefore explored a large early-stage cohort of semantic, logopenic and nonfluent/agrammatic variants (N = 86) and of 23 matched healthy controls with anatomical MRI (cortical thickness), FDG PET (metabolism) and diffusion MRI (white matter tracts analyses), aiming at identifying cortical and sub-cortical brain alterations, and confronting these alterations across imaging modalities and aphasia variants. In the semantic variant, there was cortical thinning and hypometabolism in anterior temporal cortices, with left-hemisphere predominance, extending toward posterior temporal regions, and affecting tracts projecting to the anterior temporal lobes (inferior longitudinal fasciculus, uncinate fasciculus) and tracts projecting to or running nearby posterior temporal cortices: (superior longitudinal fasciculus, inferior frontal-occipital fasciculus). In the logopenic variant metabolic alterations were more extensive than atrophy affecting mainly the left temporal-parietal junction and extending toward more anterior temporal cortices. Metabolic and tract data were coherent given the alterations of the left superior and inferior longitudinal fasciculus and the left inferior frontal-occipital fasciculus. In the nonfluent/agrammatic variant cortical thinning and hypometabolism were located in the left frontal cortex but Broca's area was only affected on metabolic measures. Metabolic and tract alterations were coherent as reflected by damage to the left uncinate fasciculus connecting with Broca's area. Our findings provide a full-blown statistically robust picture of brain alterations in early-stage variants of primary progressive aphasia which has implications for diagnosis, classification and future therapeutic strategies. They demonstrate that in logopenic and semantic variants patterns of brain damage display a non-negligible overlap in temporal regions whereas they are substantially distinct in the nonfluent/agrammatic variant (frontal regions). These results also indicate that frontal networks (combinatorial syntax/phonology) and temporal networks (lexical/semantic representations) constitute distinct anatomo-functional entities with differential vulnerability to degenerative processes in aphasia variants. Finally, the identification of the specific damage patterns could open an avenue for trans-cranial stimulation approaches by indicating the appropriate target-entry into the damaged language system.

Neuroradiologic correlation with aphasias. Cortico-subcortical map of language. / Correlación neurorradiológica de las afasias. Mapa cortico-subcortical del lenguaje.

Aphasia is an acquired language disorder due to a cerebral lesion; it is characterized by errors in production, denomination, or comprehension of language. Although most aphasias are mixed, from a practical point of view they are classified into different types according to their main clinical features: Broca's aphasia, Wernicke's aphasia, conduction aphasia, transcortical aphasia, and alexia with or without agraphia. We present the clinical findings for the main subtypes of aphasia, illustrating them with imaging cases, and we provide an up-to-date review of the language network with images from functional magnetic resonance imaging and tractography.

Dyslexic Characteristics of Chinese-Speaking Semantic Variant of Primary Progressive Aphasia.

Reading disorder is a recognized feature in primary progressive aphasia (PPA). Surface dyslexia, characterized by regularization errors, is typically seen in the English-speaking semantic variant of PPA (svPPA). However, dyslexic characteristics of other languages, particularly logographical languages such as Chinese, remain sparse in the literature. This study aims to characterize and describe the dyslexic pattern in this group of patients by comparing an English-speaking svPPA group with a Chinese-speaking svPPA group. The authors hypothesized that Chinese-speaking individuals with svPPA would likely commit fewer surface dyslexic errors. By accessing the database of Singapore's National Neuroscience Institute and the National Alzheimer's Coordinating Center of the United States, the authors identified three Chinese-speaking and 18 English-speaking patients with svPPA, respectively, for comparison. The results suggest that, instead of surface dyslexia, svPPA in Chinese-speaking individuals is characterized by a profound deep dyslexic error. Based on current evidence suggesting the role of the temporal pole as a semantic convergence center, the authors conclude that this region also mediates and converges lexical-semantic significance in logographical languages.

Características neuropsicológicas y neurofisiológicas de los distintos tipos de afasias / Neuropsychological and neurophysiological characteristics of the different types of aphasias

Las afasias se entienden como una pérdida de destrezas en el lenguaje, tanto hablado como escrito, y en la comprensión de contenidos. La afasia comúnmente es consecuencia de accidentes cerebrovasculares. A pesar de que los diversos tipos de afasias se correlacionan con áreas encefálicas especializadas para la comunicación, muchas poblaciones con lesiones cerebrales demuestran tener patologías del habla y del lenguaje no especificadas. Considerando las peculiaridades neuropsicológicas y neurofisiológicas que poseen las afasias, el presente estudio busca profundizar en las diferencias encontradas entre cada cuadro clínico de afasia, revisándose de este modo, los principales aportes contemporáneos para explicar las alteraciones lecto-escritoras producidas por la afasia.

Aphasias are understood like a loss of language skills, both spoken and written, and in the understanding of contents. Aphasia is commonly a consequence of stroke. Although various types of aphasia correlate with specialized brain areas for communication, many populations with traumatic brain injury shows unspecified speech and language pathologies. Considering the neuropsychological and neurophysiological peculiarities of aphasias, this research seeks to deepen the differences found between each clinical symptoms of aphasia, revising in this pathway, the main contemporary contributions to explain the reading-writing alterations produced by aphasia

Lexical-semantic processing in the semantic priming paradigm in aphasic patients / Processamento léxico-semântico no paradigma de priming semântico em pacientes afásicos

There is evidence that the explicit lexical-semantic processing deficits which characterize aphasia may be observed in the absence of implicit semantic impairment. The aim of this article was to critically review the international literature on lexical-semantic processing in aphasia, as tested through the semantic priming paradigm. Specifically, this review focused on aphasia and lexical-semantic processing, the methodological strengths and weaknesses of the semantic paradigms used, and recent evidence from neuroimaging studies on lexical-semantic processing. Furthermore, evidence on dissociations between implicit and explicit lexical-semantic processing reported in the literature will be discussed and interpreted by referring to functional neuroimaging evidence from healthy populations. There is evidence that semantic priming effects can be found both in fluent and in non-fluent aphasias, and that these effects are related to an extensive network which includes the temporal lobe, the pre-frontal cortex, the left frontal gyrus, the left temporal gyrus and the cingulated cortex.

Há evidências de que os déficits de processamento léxico-semântico explícitos que caracterizam a afasia podem ser observados na ausência de déficits semânticos implícitos. O objetivo deste artigo foi analisar criticamente a literatura internacional sobre processamento léxico-semântico na afasia, avaliado por meio do paradigma de priming semântico. Especificamente, esta revisão teve seu foco na afasia e processamento léxico-semântico, pontos fortes e fracos da metodologia dos paradigmas léxico-semânticos usados, e evidências recentes de estudos de neuroimagem sobre o processamento léxico-semântico. Além disso, evidências de dissociações entre processamento léxico-semântico implícito e explícito relatadas na literatura serão discutidas e interpretadas, relacionando-se aos dados de neuroimagem funcional de amostras saudáveis. Há indícios de que os efeitos de priming semântico podem ser encontrados tanto em afasias fluentes como em não fluentes, e que esses efeitos são relacionados a uma extensa rede que inclui o lobo temporal, o córtex pré-frontal, o giro frontal esquerdo, o giro temporal esquerdo e o córtex cingulado.