The role of language-related functional brain regions and white matter tracts in network plasticity of post-stroke aphasia.

The neural mechanisms underlying language recovery after a stroke remain controversial. This review aimed to summarize the plasticity and reorganization mechanisms of the language network through neuroimaging studies. Initially, we discussed the involvement of right language homologues, perilesional tissue, and domain-general networks. Subsequently, we summarized the white matter functional mapping and remodeling mechanisms associated with language subskills. Finally, we explored how non-invasive brain stimulation (NIBS) promoted language recovery by inducing neural network plasticity. It was observed that the recruitment of right hemisphere language area homologues played a pivotal role in the early stages of frontal post-stroke aphasia (PSA), particularly in patients with larger lesions. Perilesional plasticity correlated with improved speech performance and prognosis. The domain-general networks could respond to increased "effort" in a task-dependent manner from the top-down when the downstream language network was impaired. Fluency, repetition, comprehension, naming, and reading skills exhibited overlapping and unique dual-pathway functional mapping models. In the acute phase, the structural remodeling of white matter tracts became challenging, with recovery predominantly dependent on cortical activation. Similar to the pattern of cortical activation, during the subacute and chronic phases, improvements in language functions depended, respectively, on the remodeling of right white matter tracts and the restoration of left-lateralized language structural network patterns. Moreover, the midline superior frontal gyrus/dorsal anterior cingulate cortex emerged as a promising target for NIBS. These findings offered theoretical insights for the early personalized treatment of aphasia after stroke.

Evolución de la afasia en adolescentes con secuela de ACV: serie de casos / Post-stroke aphasia in adolescents' progress: case series

La afasia como secuela de un accidente cerebrovascular es un trastorno del lenguaje poco estudiado en adolescentes, tanto en Latinoamérica como a nivel mundial. Independientemente del hecho de que un número significativo de afasias mejora espontáneamente, la necesidad del inicio oportuno del tratamiento es imprescindible. En esta serie de casos se describe la presentación clínica y evolución de la afasia en 3 adolescentes con secuelas de accidente cerebrovascular que ingresaron a un instituto de neurorehabilitación. Fueron dos mujeres y un varón, de entre 15 y 17 años, que recibieron rehabilitación integral intensiva desde las áreas de fisioterapia, terapia ocupacional, neuropsicología, psicopedagogía, musicoterapia y fonoaudiología. Fueron evaluados con la versión chilena de la herramienta Western Aphasia Battery (WAB). A los 3 meses todos mejoraron y evolucionaron a un tipo de afasia más leve. Este estudio expone la importancia del tratamiento precoz e intensivo en esta población de adolescentes en plena etapa de construcción social como personas, en donde la alteración del lenguaje impacta en sus vínculos, grupo de pertenencia, estado anímico y a nivel académico. Se considera fundamental la evaluación y seguimiento sistemático con el objetivo de identificar los cambios y avances alcanzados durante la rehabilitación.

Aphasia as a sequela of stroke is an understudied language disorder in adolescents, both in Latin America and worldwide. Although a significant number of aphasia cases improve spontaneously, it is necessary to initiate treatment as soon as possible. This cases series describes the clinical presentation and evolution of aphasia in 3 adolescents with stroke sequelae who were admitted to a neurorehabilitation facility. Two females and one male, aged between 15 and 17 years, received intensive comprehensive rehabilitation from the areas of physiotherapy, occupational therapy, neuropsychology, psychopedagogy, music therapy and speech therapy. They were evaluated with the Chilean version of the Western Aphasia Battery (WAB). After 3 months, all of them improved and evolved to a milder type of aphasia. This study shows the importance of early, intensive treatment in adolescents who are in the height of their social development, where language alteration impacts on their bonds, their groups of belonging, their mood and their academic process. Systematicassessment and follow-up are considered essential to identify the changes and progress achieved during rehabilitation.

Effects of Low-Frequency Repetitive Transcranial Magnetic Stimulation on Language Recovery in Poststroke Survivors With Aphasia: An Updated Meta-analysis.

The effects of low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) on treating poststroke aphasia (PSA) remain inconclusive. We aimed to evaluate the efficacy and safety of LF-rTMS on language function poststroke and determine potential factors that may affect treatment effects. Electronic databases, including MEDLINE, EMBASE, and Cochrane Library were searched to identify relevant randomized controlled trials (RCTs) concerning the effects of LF-rTMS on language performance poststroke. We adopted fixed- and random-effects models to estimate intervention effects, which were represented by the Hedges' g and 95% CIs. Subgroup analyses regarding several factors potentially influencing the effects of LF-rTMS on language recovery were also conducted. A total of 14 RCTs involving 374 participants were included in the meta-analysis. The pooled analysis showed the positive and significant effects of LF-rTMS on language function, both short-term (Hedges' g = 0.65; P < .05) and long-term (Hedges' g = 0.46; P < .05). Subgroup analyses demonstrated that LF-rTMS for 20 minutes per day over 10 days yielded the largest effect size (Hedges' g = 1.02; P < .05) and that LF-rTMS significantly improved language performance in the chronic stage after stroke (Hedges' g = 0.55; P < .05). Patients with different native languages might have diverse responses to LF-rTMS treatment efficacy. Additionally, there were significant improvements in language subtests, including naming, repetition, comprehension, and writing. Overall, this updated meta-analysis demonstrated that LF-rTMS has significant positive effects on PSA, with moderate treatment effects. It provides additional evidence to support LF-rTMS as a promising complementary therapy to promote language recovery in PSA.

Language networks in aphasia and health: A 1000 participant activation likelihood estimation meta-analysis.

Aphasia recovery post-stroke is classically and most commonly hypothesised to rely on regions that were not involved in language premorbidly, through 'neurocomputational invasion' or engagement of 'quiescent homologues'. Contemporary accounts have suggested, instead, that recovery might be supported by under-utilised areas of the premorbid language network, which are downregulated in health to save neural resources ('variable neurodisplacement'). Despite the importance of understanding the neural bases of language recovery clinically and theoretically, there is no consensus as to which specific regions are more likely to be activated in post-stroke aphasia (PSA) than healthy individuals. Accordingly, we performed an Activation Likelihood Estimation (ALE) meta-analysis of language functional neuroimaging studies in PSA. We obtained coordinate-based functional neuroimaging data for 481 individuals with aphasia following left-hemisphere stroke and 530 linked controls from 33 studies that met predefined inclusion criteria. ALE identified regions of consistent, above-chance spatial convergence of activation, as well as regions of significantly different activation likelihood, between participant groups and language tasks. Overall, these findings dispute the prevailing theory that aphasia recovery involves recruitment of novel right hemisphere territory into the language network post-stroke. Instead, multiple regions throughout both hemispheres were consistently activated during language tasks in both PSA and controls. Regions of the right anterior insula, frontal operculum and inferior frontal gyrus (IFG) pars opercularis were more likely to be activated across all language tasks in PSA than controls. Similar regions were more likely to be activated during higher than lower demand comprehension or production tasks, consistent with them representing enhanced utilisation of spare capacity within right hemisphere executive-control related regions. This provides novel evidence that 'variable neurodisplacement' underlies language network changes that occur post-stroke. Conversely, multiple undamaged regions were less likely to be activated across all language tasks in PSA than controls, including domain-general regions of medial superior frontal and paracingulate cortex, right IFG pars triangularis and temporal pole. These changes might represent functional diaschisis, and demonstrate that there is not global, undifferentiated upregulation of all domain-general neural resources during language in PSA. Such knowledge is essential if we are to design neurobiologically-informed therapeutic interventions to facilitate language recovery.

Diagnosis of Transient Ischemic Attack: Sex-Specific Differences From a Retrospective Cohort Study.

BACKGROUND AND PURPOSE: Research suggests that women and men may present with different transient ischemic attack (TIA) and stroke symptoms. We aimed to explore symptoms and features associated with a definite TIA/stroke diagnosis and whether those associations differed by sex. METHODS: We completed a retrospective cohort study of patients referred to The Ottawa Hospital Stroke Prevention Clinic in 2015. Exploratory multinomial logistic regression was used to evaluate candidate variables associated with diagnosis and patient sex. Backwards elimination of the interaction terms with a significance level for staying in the model of 0.25 was used to arrive at a more parsimonious model. RESULTS: Based on 1770 complete patient records, sex-specific differences were noted in TIA/stroke diagnosis based on features such as duration of event, suddenness of symptom onset, unilateral sensory loss, and pain. CONCLUSIONS: This preliminary work identified sex-specific differences in the final diagnosis of TIA/stroke based on common presenting symptoms/features. More research is needed to understand if there are biases or sex-based differences in TIA/stroke manifestations and diagnosis.

The Gugging Swallowing Screen in dysphagia screening for patients with stroke: A systematic review.

BACKGROUND: Dysphagia in patients with stroke can cause serious complications, such as aspiration and pneumonia, that often lead to increase in mortality and length of hospitalization. Several screening tests for dysphagia have been developed and are used in clinical practice to prevent dysphagia complications. The Gugging Swallowing Screen is 1 such screening test. It is suggested for use in the assessment of the ability of patients to swallow fluid and non-fluid foods separately. It also promotes effective communication between healthcare providers. OBJECTIVES: We aimed to investigate the validity and benefit of the Gugging Swallowing Screen. DESIGN: This was a systematic review. DATA SOURCE: We sourced data from electronic databases including Ovid MEDLINE, Ovid EMBASE, the Cochrane Library, KoreaMed, Research Information Sharing Service, and Korean studies Information Service System. REVIEW METHODS: We conducted a systematic review of electronic databases. We included studies published in English and Korean up to November 2018 that pertained to the Gugging Swallowing Screen. We designed strategies that included Medical Subject Headings and keywords, such as "dysphagia," "swallowing," "assessment," "screening," and "GUSS," used alone or in combination. RESULTS: Of the 297 studies that appeared in the search result, 219 articles were reviewed by 2 independent reviewers after duplicate studies were eliminated. Finally, 8 articles were included in this study. With regard to validity, the Gugging Swallowing Screen had a pooled sensitivity of 0.97 (95% confidence interval: 0.93-0.99), a pooled specificity of 0.67 (95% confidence interval: 0.59-0.74), and an area under the receiver operating characteristic curve of 0.9381. With regard to benefit, early systematic dysphagia screening using Gugging Swallowing Screen performed by nurses reduced both screening time and pneumonia rate compared to the control group (p = 0.004). The incidence of X-ray-verified pneumonia was significantly lower in the Gugging Swallowing Screen group than in the clinical screening group (p ˂ 0.01), but no significant difference was observed in the incidence of pneumonia compared to the value predicted using the 10 mL water swallowing test. CONCLUSIONS: The Gugging Swallowing Screen is a reliable and sensitive tool for screening dysphagia. Early and systematic assessment can prevent aspiration and pneumonia. However, further studies are needed to confirm the effectiveness of this tool.

Recovery of Severe Aphasia After Cranioplasty: Considerations on a Case Study.

Cranioplasty is the main surgical intervention for repairing cranial defects performed in about 80% of the patients following cancer surgery or decompressive craniectomy. Although some works have shown recovery of motor and cognitive function, including memory, attention, and executive functions, until today no studies have focused on language recovery after cranioplasty. A 68-year-old woman came to the Neurorehabilitation Unit of the IRCCS Neurolesi (Messina, Italy) because of a fluent aphasia due to a severe left nucleocapsular hemorrhage and greatly improved her motor and neuropsychological status after cranioplasty. Results confirmed that cranioplasty might significantly improve motor and neuropsychological function, besides aphasia. Healthcare professionals involved in rehabilitation should be aware of the potential role of cranioplasty in improving rehabilitative outcomes to better plan a more personalized rehabilitative program. Moreover, rehabilitation nurses can play a pivotal role within the rehabilitation process, as they are educated to interact and communicate with the patient suffering from aphasia.

A Metabolic Brain Pattern Associated With Anti-N-Methyl-D-Aspartate Receptor Encephalitis.

BACKGROUND: Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis causes substantial neurological disability. Autoantibodies causing encephalitis directed against the neuronal cell surface or synapse are of diagnostic importance giving the possibility of successful immunotherapy. OBJECTIVE: In this study, we aim to provide supporting evidence that brain 18F-FDG-PET may be helpful in identifying likely patterns of regional brain glucose metabolism. METHODS: Thirty-three patients (18 men and 15 women; age range of 17-55 y) with positive NMDA receptor antibody encephalitis that underwent an 18F-FDG-PET imaging examination were prospectively selected and compared with a reference group of 14 brain 18F-FDG-PET scans from healthy volunteers using voxel-based statistical analysis. Clusters of hyper- and hypo-metabolism were reported for the whole sample of patients (FWE-corrected P < 0.05), and uncorrected at P < 0.005 for a group of relapsed patients. RESULTS: Mixed metabolic patterns (focal/bilateral hypermetabolism in the temporal lobe, insula, and cerebellum; associated with severe bilateral hypometabolism in the occipital and parietal lobes) were found. CONCLUSIONS: Our findings suggest that 18F-FDG-PET should be included as an imaging tool when assessing affected patients in the clinical workup to rule out anti-NMDA encephalitis and help determine the most effective treatment.

Long-Term Survival After Decompressive Craniectomy for Malignant Brain Infarction: A 10-Year Nationwide Study.

BACKGROUND: Decompressive craniectomy (DC) has been shown to be an effective treatment for malignant cerebral infarction (MCI). There are limited nationwide studies evaluating outcome after craniectomy for MCI. OBJECTIVE: To describe the evolution in DC practices for MCI, long-term survival, and associated prognostic factors. METHODS: We searched the French medico-administrative national database to retrieve patients who underwent DC between 2008 and 2017. RESULTS: A total of 1841 cases of DC were performed over 10 years in 51 centers. Mean age at procedure was 50.9 years, 18% were above 60 years, and 64.4% were male. There was a significant increase in DC for MCI over the 10 years (p < 0.001), and the annual volume of procedures more than doubled (95/year vs. 243/year). Early survival at one week and one month was 86%, 95%CI (84.5, 87.6) and 79.7%, 95%CI (77.8, 81.5), respectively. Long-term survival at 1 and 5 years were 73.6%, 95%CI (71.6, 75.7) and 68.9%, 95%CI (66.5, 71.4), respectively. Patients below 60 years at the time of DC (HR = 0.5; 95%CI [0.4, 0.7], p < 0.001), DC being performed in a center with a high surgical activity (HR = 0.8; 95%CI [0.6, 0.9], p = 0.002), and the patients having unimpaired consciousness (HR = 0.6; 95%CI [0.5, 0.8], p < 0.001) were associated with increased survival in both univariate and adjusted Cox regressions. 18.7% of the survivors had a cranioplasty inserted within 3 months and 57.8% within 6 months. The probability of having a cranioplasty at one year was 75.6%, 95%CI (77.9, 73.1). CONCLUSION: Over the past 10 years in France, DC has been increasingly performed for MCI regardless of age. However, in-hospital mortality remains considerable, as about one quarter of patients died within the first weeks. For those who survive beyond 6 months, the risk of death significantly decreases. Early mortality is especially high for comatose patients above 60 years operated in inexperienced centers. Most of those who remain in good functional status tend to undergo a cranioplasty within the year following DC.

Increased Functional Connectivity Within Intrinsic Neural Networks in Chronic Stroke Following Treatment with Red/Near-Infrared Transcranial Photobiomodulation: Case Series with Improved Naming in Aphasia.

Objective: To examine effects of four different transcranial, red/near-infrared (NIR), light-emitting diode (tLED) protocols on naming ability in persons with aphasia (PWA) due to left hemisphere (LH) stroke. This is the first study to report beneficial effects from tLED therapy in chronic stroke, and parallel changes on functional magnetic resonance imaging (fMRI). Materials and methods: Six PWA, 2-18 years poststroke, in whom 18 tLED treatments were applied (3 × /week, 6 weeks) using LED cluster heads: 500 mW, red (633 nm) and NIR (870 nm), 22.48 cm2, 22.2 mW/cm2. Results: After Protocol A with bilateral LED placements, including midline, at scalp vertex over left and right supplementary motor areas (L and R SMAs), picture naming was not improved. P1 underwent pre-/postovert, picture-naming task-fMRI scans; P2 could not. After Protocol A, P1 showed increased activation in LH and right hemisphere, including L and R SMAs. After Protocol B with LEDs only on ipsilesional, LH side, naming ability significantly improved for P1 and P2; the fMRI scans for P1 then showed activation only on the ipsilesional LH side. After Protocol C with LED placements on ipsilesional LH side, plus one midline placement over mesial prefrontal cortex (mPFC) at front hairline, a cortical node of the default mode network (DMN), P3 and P4 had only moderate/poor response, and no increase in functional connectivity on resting-state functional-connectivity MRI. After Protocol D, however, with LED placements on ipsilesional LH side, plus over two midline nodes of DMN, mPFC, and precuneus (high parietal) simultaneously, P5 and P6 each had good response with significant increase in functional connectivity within DMN, p < 0.0005; salience network, p < 0.0005; and central executive network, p < 0.05. Conclusions: NIR photons can affect surface brain cortex areas subjacent to where LEDs are applied on the scalp. Improved naming ability was present with optimal Protocol D. Transcranial photobiomodulation may be an additional noninvasive therapy for stroke.

The white matter architecture underlying semantic processing: A systematic review.

From a holistic point of view, semantic processes are subserved by large-scale subcortico-cortical networks. The dynamic routing of information between grey matter structures depends on the integrity of subcortical white matter pathways. Nonetheless, controversy remains on which of these pathways support semantic processing. Therefore, a systematic review of the literature was performed with a focus on anatomo-functional correlations obtained from direct electrostimulation during awake tumor surgery, and conducted between diffusion tensor imaging metrics and behavioral semantic performance in healthy and aphasic individuals. The 43 included studies suggest that the left inferior fronto-occipital fasciculus contributes to the essential connectivity that allows semantic processing. However, it remains uncertain whether its contributive role is limited to the organization of semantic knowledge or extends to the level of semantic control. Moreover, the functionality of the left uncinate fasciculus, inferior longitudinal fasciculus and the posterior segment of the indirect arcuate fasciculus in semantic processing has to be confirmed by future research.

Resting-state functional connectivity predicts individual language impairment of patients with left hemispheric gliomas involving language network.

Language deficits following brain tumors should consider the dynamic interactions between different tumor growth kinetics and functional network reorganization. We measured the resting-state functional connectivity of 126 patients with left cerebral gliomas involving language network areas, including 77 patients with low-grade gliomas (LGG) and 49 patients with high-grade gliomas (HGG). Functional network mapping for language was performed by construction of a multivariate machine learning-based prediction model of individual aphasia quotient (AQ), a summary score that indicates overall severity of language impairment. We found that the AQ scores for HGG patients were significantly lower than those of LGG patients. The prediction accuracy of HGG patients (R2 = 0.27, permutation P = 0.007) was much higher than that of LGG patients (R2 = 0.09, permutation P = 0.032). The rsFC regions predictive of LGG's AQ involved the bilateral frontal, temporal, and parietal lobes, subcortical regions, and bilateral cerebro-cerebellar connections, mainly in regions belonging to the canonical language network. The functional network of language processing for HGG patients showed strong dependence on connections of the left cerebro-cerebellar connections, limbic system, and the temporal, occipital, and prefrontal lobes. Together, our findings suggested that individual language processing of glioma patients links large-scale, bilateral, cortico-subcortical, and cerebro-cerebellar functional networks with different network reorganizational mechanisms underlying the different levels of language impairments in LGG and HGG patients.

A 41-year-old female with progressive multifocal leukoencephalopathy after liver transplant.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease caused by JC virus reactivation. Its occurrence is very rare after solid organ transplantation, especially liver transplantation. We report a patient who received liver transplantation due to liver failure resulting from autoimmune hepatitis and advanced PML presenting with aphasia. A 41-year-old female with a history of liver transplantation who received a usual immunosuppression regimen was admitted with a stroke attack resulting in right hemiplegia 2 months after liver transplantation. Surprisingly, she gradually developed dysarthria and left central facial paresis. A brain MRI showed an abnormal multifocal area with a high T2/flair signal in the deep subcortical white matter of the left hemisphere as well as the splenium of the corpus callosum. PCR evaluation of CSF for JCV was positive while other PCR results were negative. A liver transplant recipient receiving immunosuppressive treatment for a long time could develop PML due to JCV reactivation. Only eight cases of JCV infection were reported after liver transplantation by the time of reporting this case. Unfortunately, there is no definite treatment for PML.

Aphasia outcome: the interactions between initial severity, lesion size and location.

OBJECTIVES: The outcome of aphasia at 3 months is variable in patients with moderate/severe stroke. The aim was to predict 3-month aphasia outcome using prediction models including initial severity in addition to the interaction between lesion size and location at the acute phase. METHODS: Patients with post-stroke aphasia (assessed by the Aphasia Rapid Test at day 7-ART D7) and MRI performed at day 1 were enrolled (n = 73). Good outcome at 3-months was defined by an Aphasia Handicap Score of 0-2. Each infarct lesion was overlapped with an area of interest in the left temporo-parietal region to compute an intersection index (proportion of the critical region damaged by the infarct). We tested ART D7, age, lesion volume, and intersection index as well as a combined variable lesion volume*intersection in a univariate analysis. Then, we performed a multivariate analysis to investigate which variables were independent predictors of good outcome. RESULTS: ART at D7, infarct volume, and the intersection index were univariate predictors of good outcome. In the multivariate analysis, ART D7 and "volume ≥ 50 ml or intersection index ≥ 20%" correctly classified 89% of the patients (p < 0.0001). When added to the model, the interaction between both variables was significant indicating that the impact of the size or site variable depends on the initial severity of aphasia. CONCLUSION: In patients with initially severe aphasia, large infarct size or critical damage in left temporoparietal junction is associated with poor language outcome at 3 months.

Abnormal Functional Connectivity Density in Post-Stroke Aphasia.

Post-stroke aphasia (PSA), which refers to the loss or impairment of language, is typically caused by left hemisphere lesions. Previous neuroimaging studies have indicated that the pathology of PSA may be related to abnormalities in functional integration. In this study, we used resting-state functional magnetic resonance imaging (rs-fMRI) to examine functional connectivity density (FCD) in PSA. We compared short- and long-range FCD between individuals with PSA (n = 17) and healthy controls (HC, n = 20). We then performed Pearson's correlation analysis on the FCD values from the affected brain regions and the speech scores in the PSA group. Compared with HCs, individuals with PSA showed increased short-range FCD in the contralesional temporal gyrus, the inferior frontal gyrus, the thalamus, the insula, and the mesial temporal gyrus [hippocampus/parahippocampus (HIP/ParaHIP)]. PSA demonstrated an increased long-range FCD in the contralesional mesial temporal gyrus (HIP/ParaHIP). PSA also displayed decreased short-range FCD in the ipsilesional part of the frontal gyrus, the caudate, the thalamus, the fusiform gyrus, and the mesial temporal gyrus (HIP/ParaHIP), and decreased long-range FCD in the ipsilesional superior temporal gyrus, the fusiform gyrus, and the mesial temporal gyrus (HIP/ParaHIP). The decreased long-range FCD in the left superior temporal gyrus in PSA subjects was positively correlated with the spontaneous speech score. The altered FCD observed due to disrupted functional connectivity after stroke may lead to language production, semantic processing, and cognitive impairments. Our findings expand previous functional studies on stroke and provide new evidence of the intraregional and interregional interactions at the voxel level in the pathophysiology of PSA.

Altered Structure and Intrinsic Functional Connectivity in Post-stroke Aphasia.

Previous studies have demonstrated that alterations of gray matter exist in post-stroke aphasia (PSA) patients. However, so far, few studies combined structural alterations of gray matter volume (GMV) and intrinsic functional connectivity (iFC) imbalances of resting-state functional MRI to investigate the mechanism underlying PSA. The present study investigated specific regions with GMV abnormality in patients with PSA (n = 17) and age- and sex- matched healthy controls (HCs, n = 20) using voxel-based morphometry. In addition, we examined whether there is a link between abnormal gray matter and altered iFC. Furthermore, we explored the correlations between abnormal iFC and clinical scores in aphasic patients. We found significantly increased GMV in the right superior temporal gyrus, right inferior parietal lobule (IPL)/supramarginal gyrus (SMG), and left middle occipital gyrus. Decreased GMV was found in the right caudate gyrus, bilateral thalami in PSA patients. Patients showed increased remote interregional FC between the right IPL/SMG and right precuneus, right angular gyrus, right superior occipital gyrus; while reduced FC in the right caudate gyrus and supplementary motor area, dorsolateral superior frontal gyrus. Moreover, iFC strength between the left middle occipital gyrus and the left orbital middle frontal gyrus was positively correlated with the performance quotient. We suggest that GMV abnormality contributes to interregional FC in PSA. These results may provide useful information to understand the pathogenesis of post-stroke aphasia.

The different patterns of seizure-induced aphasia in temporal lobe epilepsies.

OBJECTIVES: Ictal language disturbances may occur in dominant hemisphere temporal lobe epilepsy (TLE), but little is known about the precise anatomoelectroclinical correlations. This study investigated the different facets of ictal aphasia in intracerebrally recorded TLE. METHODS: Video-stereoelectroencephalography (SEEG) recordings of 37 seizures in 17 right-handed patients with drug-resistant TLE were analyzed; SEEG electroclinical correlations between language disturbance and involvement of temporal lobe structures were assessed. In the clinical analysis, we separated speech disturbance from loss of consciousness. RESULTS: According to the region involved, different patterns of ictal aphasia in TLE were identified. Impaired speech comprehension was associated with posterior lateral involvement, anomia and reduced verbal fluency with anterior mediobasal structures, and jargonaphasia with basal temporal involvement. The language production deficits, such as anomia and low fluency, cannot be simply explained by an involvement of Broca's area, since this region was not affected by seizure discharge. SIGNIFICANCE: Assessment of language function in the early ictal state can be successfully performed and provides valuable information on seizure localization within the temporal lobe as well as potentially useful information for guiding surgery.

Aphasia and cognitive impairment decrease the reliability of rnTMS language mapping.

BACKGROUND: Navigated transcranial magnetic stimulation (nTMS) is a non-invasive mapping tool to locate functional areas of the brain. While gaining importance in the preoperative planning process in motor eloquent regions, its usefulness for reliably identifying language areas is still being discussed. The aim of this study was to identify biometric factors which might influence and therefore bias the results of repetitive nTMS (rnTMS) over cortex areas relevant for language. METHOD: We included data of 101 patients with language eloquent brain lesions who underwent preoperative rnTMS examination bihemispherically. Prior to rnTMS mapping, all patients performed two to three baseline runs of a picture-naming paradigm without stimulation, and only promptly and correctly named objects were retained for TMS mapping. Nine biometric factors (age, gender, baseline dataset, cognitive performance score, aphasia score, histology of lesion, affected hemisphere, location of lesion on the hemisphere, pain caused by examination) were included in the statistical analysis measuring their correlation with the incidence of errors during baseline naming as well as during rnTMS mapping. RESULTS: The incidence of baseline errors correlated with aphasia (p < 0.0001) and cognitive impairment (p < 0.0001). No significant correlation was observed between most biometric factors and errors during rnTMS mapping. Factors significantly affecting the incidence of errors during rnTMS mapping were again aphasia (p < 0.023) and cognitive impairment (p < 0.038). Patients affected by those factors showed a significantly higher baseline error rate, starting at 28% error rate. CONCLUSIONS: Patients with pre-existing aphasia or severe cognitive impairment did still make significantly more mistakes during rnTMS mapping than non-aphasic patients despite baseline stratification, rendering the question of whether the procedure is reliable in those patient groups. Baseline testing revealed a cut-off point at 28% error rate. Interestingly, age or pain (caused by the examination) did not bias the results.

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