Left Perisylvian Regions Research Articles

Subtitled speech: the neural mechanisms of ticker-tape synaesthesia.

The acquisition of reading modifies areas of the brain associated with vision and with language, in addition to their connections. These changes enable reciprocal translation between orthography and the sounds and meaning of words. Individual variability in the pre-existing cerebral substrate contributes to the range of eventual reading abilities, extending to atypical developmental patterns, including dyslexia and reading-related synaesthesias. The present study is devoted to the little-studied but highly informative ticker-tape synaesthesia, in which speech perception triggers the vivid and irrepressible perception of words in their written form in the mind's eye. We scanned a group of 17 synaesthetes and 17 matched controls with functional MRI, while they listened to spoken sentences, words, numbers or pseudowords (Experiment 1), viewed images and written words (Experiment 2) or were at rest (Experiment 3). First, we found direct correlates of the ticker-tape synaesthesia phenomenon: during speech perception, as ticker-tape synaesthesia was active, synaesthetes showed over-activation of left perisylvian regions supporting phonology and of the occipitotemporal visual word form area, where orthography is represented. Second, we provided support to the hypothesis that ticker-tape synaesthesia results from atypical relationships between spoken and written language processing: the ticker-tape synaesthesia-related regions overlap closely with cortices activated during reading, and the overlap of speech-related and reading-related areas is larger in synaesthetes than in controls. Furthermore, the regions over-activated in ticker-tape synaesthesia overlap with regions under-activated in dyslexia. Third, during the resting state (i.e. in the absence of current ticker-tape synaesthesia), synaesthetes showed increased functional connectivity between left prefrontal and bilateral occipital regions. This pattern might reflect a lowered threshold for conscious access to visual mental contents and might imply a non-specific predisposition to all synaesthesias with a visual content. These data provide a rich and coherent account of ticker-tape synaesthesia as a non-detrimental developmental condition created by the interaction of reading acquisition with an atypical cerebral substrate.

Disruptions in modular structure and network integration of language-related network predict language performance in temporal lobe epilepsy: Evidence from graph-based analysis

ObjectiveTemporal lobe epilepsy (TLE) is a network disorder that alters the total organization of the language-related network. Task-based functional magnetic resonance imaging (fMRI) aimed at functional connectivity is a direct method to investigate how the network is reorganized. However, such studies are scarce and represented mostly by the resting-state analysis of the individual connections between regions. To fill this gap, we used a graph-based analysis, which allows us to cover the total language-related network changes, such as disruptions in an integration/segregation balance, during a language task in TLE. MethodsWe collected task-based fMRI data with sentence completion from 19 healthy controls and 28 people with left TLE. Using graph-based analysis, we estimated how the language-related network segregated into modules and tested whether they differed between groups. We evaluated the total network integration and the integration within modules. To assess intermodular integration, we considered the number and location of connector hubs—regions with high connectivity. ResultsThe language-related network was differently segregated during language processing in the groups. While healthy controls showed a module consisting of left perisylvian regions, people with TLE exhibited a bilateral module formed by the anterior language-related areas and a module in the left temporal lobe, reflecting hyperconnectivity within the epileptic focus. As a consequence of this reorganization, there was a statistical tendency that the dominance of the intramodular integration over the total network integration was greater in TLE, which predicted language performance. The increase in the number of connector hubs in the right hemisphere, in turn, was compensatory in TLE. SignificanceOur study provides insights into the reorganization of the language-related network in TLE, revealing specific network changes in segregation and integration. It confirms reduced global connectivity and compensation across the healthy hemisphere, commonly observed in epilepsy. These findings advance the understanding of the network-based reorganizational processes underlying language processing in TLE.

Atypical mixed logopenic and semantic progressive primary aphasia (PPA) in Arabic with white matter abnormalities

AbstractBackgroundThe concept of primary progressive aphasia (PPA) or Mesulam syndrome (Mesulam, 2014) is an isolated and progressive deterioration of language, usually due to progressive focal atrophy of the left perisylvian regions (of the dominant hemisphere). Four types of PPA have been already identified: Non‐fluent variant or Nfv‐PPA; Logopenic variant or Lv‐PPA; Semantic variant or Sv‐PPA and Mixed variant M‐PPA (Gorno‐Tempini et al., 2011; Mesulam et al., 2014).MethodWe report MH who displayed a Mixed‐variant of PPA (M‐PPA) in Arabic. Her daily activities were preserved. Neuroimaging using MRI coronal cut (FLAIR) showed a bi‐hippocampal atrophy, an increase in the sylvian valley and ventricular dilation; signs of cortical and subcortical vascular leukoencephalopathy. While the axial T2 cut showed a peri‐ventricular leukoencephalopathy. In FDG‐PET, there was a hypometabolism in the left anterior and the upper temporal gyrus. A neuropsychological battery was administered to the patient as well as a neurolinguistic assessment using an adapted and validated version of Moroccan Mini‐Linguistic State Examination (MLSE). It has been developed in English and Italian (Catricalà et al, 2017; Patel et al, 2020).ResultThe clinical profile of MH clearly showed an atypical overlap of neuropsychological, neurolinguistic and neuroradiological features which objectified a mixed variant of PPA predominantly logopenic and semantic with a slight syntactic impairment. These linguistic disturbances included some elements of Lv‐PPA (impaired sentence repetition and dysnomia) and some features of Sv‐PPA (dysnomia, impaired word comprehension, semantic association and sentence comprehension).ConclusionThe findings of this case study were mainly based on clinical and semiological criterias which are consistent with Mesulam’s descriptions (2014). It is possible that the presence of multi‐domain linguistic deficits may be linked eventually to a mixed underlying neuropathology which might be both neurodegenerative and vascular. This study is a call for a cross‐cultural neuropsychological, neuro‐anatomical and neurolinguistic characterization of PPA and Mixed‐PPA in non‐European languages

Language impairment in the genetic forms of behavioural variant frontotemporal dementia

BackgroundBehavioural variant fronto-temporal dementia (bvFTD) is characterised by a progressive change in personality in association with atrophy of the frontal and temporal lobes. Whilst language impairment has been described in people with bvFTD, little is currently known about the extent or type of linguistic difficulties that occur, particularly in the genetic forms.MethodsParticipants with genetic bvFTD along with healthy controls were recruited from the international multicentre Genetic FTD Initiative (GENFI). Linguistic symptoms were assessed using items from the Progressive Aphasia Severity Scale (PASS). Additionally, participants undertook the Boston Naming Test (BNT), modified Camel and Cactus Test (mCCT) and a category fluency test. Participants underwent a 3T volumetric T1-weighted MRI, with language network regional brain volumes measured and compared between the genetic groups and controls.Results76% of the genetic bvFTD cohort had impairment in at least one language symptom: 83% C9orf72, 80% MAPT and 56% GRN mutation carriers. All three genetic groups had significantly impaired functional communication, decreased fluency, and impaired sentence comprehension. C9orf72 mutation carriers also had significantly impaired articulation and word retrieval as well as dysgraphia whilst the MAPT mutation group also had impaired word retrieval and single word comprehension. All three groups had difficulties with naming, semantic knowledge and verbal fluency. Atrophy in key left perisylvian language regions differed between the groups, with generalised involvement in the C9orf72 group and more focal temporal and insula involvement in the other groups. Correlates of language symptoms and test scores also differed between the groups.ConclusionsLanguage deficits exist in a substantial proportion of people with familial bvFTD across all three genetic groups. Significant atrophy is seen in the dominant perisylvian language areas and correlates with language impairments within each of the genetic groups. Improved understanding of the language phenotype in the main genetic bvFTD subtypes will be helpful in future studies, particularly in clinical trials where accurate stratification and monitoring of disease progression is required.

Common predictors of spoken and written language performance in aphasia, alexia, and agraphia.

Language performance requires support from central cognitive/linguistic abilities as well as the more peripheral sensorimotor skills to plan and implement spoken and written communication. Both output modalities are vulnerable to impairment following damage to the language-dominant hemisphere, but much of the research to date has focused exclusively on spoken language. In this study we aimed to examine an integrated model of language processing that includes the common cognitive processes that support spoken and written language, as well as modality-specific skills. To do so, we evaluated spoken and written language performance from 87 individuals with acquired language impairment resulting from damage to left perisylvian cortical regions that collectively constitute the dorsal language pathway. Comprehensive behavioral assessment served to characterize the status of central and peripheral components of language processing in relation to neurotypical controls (n = 38). Performance data entered into principal components analyses (with or without control scores) consistently yielded a strong five-factor solution. In line with a primary systems framework, three central cognitive factors emerged: semantics, phonology, and orthography that were distinguished from peripheral processes supporting speech production and allographic skill for handwriting. The central phonology construct reflected performance on phonological awareness and manipulation tasks and showed the greatest deficit of all the derived factors. Importantly, this phonological construct was orthogonal to the speech production factor that reflected repetition of words/non-words. When entered into regression analyses, semantics and phonological skill were common predictors of language performance across spoken and written modalities. The speech production factor was also a strong, distinct predictor of spoken naming and oral reading, in contrast to allographic skills which only predicted written output. As expected, visual orthographic processing contributed more to written than spoken language tasks and reading/spelling performance was strongly reliant on phonological and semantic abilities. Despite the heterogeneity of this cohort regarding aphasia type and severity, the marked impairment of phonological skill was a unifying feature. These findings prompt greater attention to clinical assessment and potential treatment of underlying phonological skill in individuals with left perisylvian damage.

64-Year-Old Woman With Aphasia and Troponin Elevation

64-Year-Old Woman With Aphasia and Troponin Elevation

Speech sound categorization: The contribution of non-auditory and auditory cortical regions

Which processes in the human brain lead to the categorical perception of speech sounds? Investigation of this question is hampered by the fact that categorical speech perception is normally confounded by acoustic differences in the stimulus. By using ambiguous sounds, however, it is possible to dissociate acoustic from perceptual stimulus representations. Twenty-seven normally hearing individuals took part in an fMRI study in which they were presented with an ambiguous syllable (intermediate between /da/ and /ga/) in one ear and with disambiguating acoustic feature (third formant, F3) in the other ear. Multi-voxel pattern searchlight analysis was used to identify brain areas that consistently differentiated between response patterns associated with different syllable reports. By comparing responses to different stimuli with identical syllable reports and identical stimuli with different syllable reports, we disambiguated whether these regions primarily differentiated the acoustics of the stimuli or the syllable report. We found that BOLD activity patterns in left perisylvian regions (STG, SMG), left inferior frontal regions (vMC, IFG, AI), left supplementary motor cortex (SMA/pre-SMA), and right motor and somatosensory regions (M1/S1) represent listeners’ syllable report irrespective of stimulus acoustics. Most of these regions are outside of what is traditionally regarded as auditory or phonological processing areas. Our results indicate that the process of speech sound categorization implicates decision-making mechanisms and auditory-motor transformations.

A CASE OF INFECTIVE ENDOCARDITIS COMPLICATED BY ACUTE ISCHEMIC STROKE

Infective endocarditis is an infectious and inammatory process involving endothelial lining of heart structures and valves. Cerebrovascular complications (CVCs) frequently occur in patients who are in the active stage of infective endocarditis (IE), and result from cerebral septic embolization of an endocardial vegetation. Acute stroke due to septic emboli is a particularly dreaded complication , with a frequency of 25-35%. Here we present a case of 32 year old male patient, who comes to the ER with high grade fever and palpitations since 9 days. On examination we found hyperdynamic impulse with decrescendo type systolic murmur at mitral area and we decided to do a blood workup and also requested a 2D ECHO. Blood culture and 2D ECHO showed different species of streptococci and mitral regurgitation respectively. Based on the investigations we started the patient on antibiotics, However, on the day 7 of treatment, patient developed slurring of speech and hemiparesis followed by motor aphasia. We sent the patient for brain MRI that showed acute infarct in left central semioval, left corona radiata and left perisylvian region. Acute ischemic stroke is the complication of the infective endocarditis and we started tpAalong with intravenous antibiotics after which he experienced signicant clinical improvement in few days.

Intraoperative Corticocortical Evoked Potentials for Language Monitoring in Epilepsy Surgery

To evaluate the applicability of corticocortical evoked potentials (CCEP) for intraoperative monitoring of the language network in epilepsy surgery under general anesthesia. To investigate the clinical relevance on language functions of intraoperative changes of CCEP recorded under these conditions. CCEP monitoring was performed in 14 epileptic patients (6 females, 4 children) during resections in the left perisylvian region under general anesthesia. Electrode strips were placed on the anterior language area (AL) and posterior language area (PL), identified by structural and functional magnetic resonance imaging. Single-pulse electric stimulations were delivered to pairs of adjacent contacts in a bipolar fashion. During resection, we monitored the integrity of the dorsal language pathway by stimulating either AL by recording CCEP from PL or vice versa, depending on stability and reproducibility of CCEP. We evaluated the first negative (N1) component of CCEP before, during, and after resection. All procedures were successfully completed without adverse events. The best response was obtained from AL during stimulation of PL in 8 patients and from PL during stimulation of AL in 6 patients. None of 12 patients with a postresection N1 amplitude decrease of 0%-15% from baseline presented postoperative language impairment. Decreases of 28% and 24%, respectively, of the N1 amplitude were observed in 2 patients who developed transient postoperative speech disturbances. The application of CCEP monitoring is possible and safe in epilepsy surgery under general anesthesia. Putative AL and PL can be identified using noninvasive presurgical neuroimaging. Decrease of N1 amplitude >15% from baseline may predict postoperative language deficits.

Impaired Perception and Neural Processing of Rules in Developmental Dyslexia

Rules and regularities of language are typically processed in an implicit and effortless way in the human brain. Individuals with developmental dyslexia have problems in implicit learning of regularities in sequential stimuli, but the neural basis of this deficit has not been studied. This study investigated extraction and utilization of a complex auditory rule at neural and perceptual levels in 18 adults with dyslexia and 20 typical readers. Mismatch negativity (MMN) and P3a responses to rule violations in speech stimuli, reflecting change detection and attention switch, respectively, were recorded with electroencephalogram. Both groups reported no or little explicit awareness of the rule, suggesting implicit processing. People with dyslexia showed deficient extraction of the rule evidenced by diminished MMNs estimated to originate particularly from the left perisylvian region. The group difference persisted in the attentive condition after the participants were told about the rule, and behavioral detection of the rule violations was poor in people with dyslexia, possibly suggesting difficulties also in utilizing explicit information of the rule. Based on these results, the speech processing difficulties in dyslexia extend beyond phoneme discrimination and basic auditory feature extraction. Challenges in implicit extraction and effortless adoption of complex auditory rules may be central to language learning difficulties in dyslexia.

Longitudinal naming and repetition relates to AD pathology and burden in autopsy-confirmed primary progressive aphasia.

IntroductionIn primary progressive aphasia (PPA) patients with autopsy‐confirmed Alzheimer's disease (AD) or frontotemporal lobar degeneration (FLTD), we tested how the core clinical features of logopenic PPA—naming and repetition—change over time and relate to pathologic burden.MethodsIn PPA with AD (n = 13) or FTLD (n = 16) pathology, Boston Naming Test and Forward Digit Span measured longitudinal naming and repetition; as reference, Mini‐Mental State Examination (MMSE) measured global cognition. Pathologic burden in left peri‐Sylvian regions was related to longitudinal cognitive decline.ResultsPPA with AD showed greater decline in naming (P = 0.021) and repetition (P = 0.020), compared to FTLD; there was no difference in MMSE decline (P = 0.99). Across all PPA, declining naming (P = 0.0084) and repetition (P = 0.011) were associated with angular, superior‐middle temporal (naming P = 0.014; repetition P = 0.011) and middle frontal (naming P = 0.041; repetition P = 0.030) pathologic burden.DiscussionUnique longitudinal profiles of naming and repetition performance in PPA with AD are related to left peri‐Sylvian pathology.

NEUROLINGUISTIC AND ACOUSTIC STUDY OF LOGOPENIC PRIMARY PROGRESSIVE APHASIA IN ARABIC

The primary progressive aphasia (PPA) or Mesulam syndrome is an isolated and progressive deterioration of language, usually due to progressive focal atrophy of the left peri sylvian regions. Given that very little data on PPA is available in non-Western languages in the literature, we describe the first case of logopenic PPA in Arabic. Neuropsychological, neuroimaging and linguistic protocol have been administered to the patient. The Neurolinguistic assessment was carried out with the Moroccan version of the Montreal-Toulouse linguistic exploration protocol, the apraxia of speech protocol, the Moroccan version of MLSE (Mini-Linguistic Status Examination); some subtests of the BDAE (Boston Diagnostic Aphasia Examination) while the computerized acoustic analysis was performed with Vocalab4 ™. The acoustic analysis showed mainly instability in pitch and amplitude. However articulatory disruptions are very mild in our case. There is a parallelism between spoken language which is marked by phonological paraphasias with a „pseudostuttering „and written language disorder which displays a phonological alexia, a severe acalculia and an agraphia. Our pa tient presents L-PPA subtype 1 on the logopenic spectrum. These results are consistent with the neuropsychological hypothesis of a dysfunction in phonological buffer reflecting the features of logopenic PPA. Furthermore, our case displayed atypical neurolinguistic patterns in comparison with other cases described in the European languages due to the Arabic specific linguistic structure.

Presurgical resting-state functional MRI language mapping with seed selection guided by regional homogeneity.

Resting-state functional MRI (rs-FMRI) has shown potential for presurgical mapping of eloquent cortex when a patient's performance on task-based FMRI is compromised. The seed-based analysis is a practical approach for detecting rs-FMRI functional networks; however, seed localization remains challenging for presurgical language mapping. Therefore, we proposed a data-driven approach to guide seed localization for presurgical rs-FMRI language mapping. Twenty-six patients with brain tumors located in left perisylvian regions had undergone task-based FMRI and rs-FMRI before tumor resection. For the seed-based rs-FMRI language mapping, a seeding approach that integrates regional homogeneity and meta-analysis maps (RH+MA) was proposed to guide the seed localization. Canonical and task-based seeding approaches were used for comparison. The performance of the 3 seeding approaches was evaluated by calculating the Dice coefficients between each rs-FMRI language mapping result and the result from task-based FMRI. With the RH+MA approach, selecting among the top 6 seed candidates resulted in the highest Dice coefficient for 81% of patients (21 of 26) and the top 9 seed candidates for 92% of patients (24 of 26). The RH+MA approach yielded rs-FMRI language mapping results that were in greater agreement with the results of task-based FMRI, with significantly higher Dice coefficients (P < .05) than that of canonical and task-based approaches within putative language regions. The proposed RH+MA approach outperformed the canonical and task-based seed localization for rs-FMRI language mapping. The results suggest that RH+MA is a robust and feasible method for seed-based functional connectivity mapping in clinical practice.

Degenerative and Vascular Fluent Aphasia: Looking for Differences.

To investigate whether the characteristics of language disorders of degenerative and vascular aphasias depend on the underlying neuropathology. Logopenic variant/mixed primary progressive aphasics (lvmPPA; n=18) and poststroke fluent aphasics (PSA; n=11) underwent a neuropsychological examination and an assessment of the macro- and microlinguistic aspects of language. A principal component analysis and a cluster analysis applying a two-group solution were performed on the scores obtained from the neuropsychological and language examination. Global cognition, lexical-semantic, and morphosyntactic components, and two components loading macrolinguistic variables, were extracted by the principal component analysis. A first cluster of 18 participants (14 lvmPPA and 4 PSA) and a second cluster of 11 participants (4 lvmPPA and 7 PSA) were identified. Participants in the first cluster were significantly more impaired than those in the second cluster in global cognition, lexical-semantic, and morphosyntactic components. Macrolinguistic components did not differentiate the two clusters. lvmPPA in the first cluster showed bilateral cortical thinning (greater on the left), whereas lvmPPA in the second cluster showed atrophy only in the left. Participants with PSA in both clusters showed vascular lesions encompassing the posterior left perisylvian regions. Underestimation of the severity of the leukoencephalopathy and damage of the interhemispheric connectivity might be responsible for the inclusion of PSA individuals in the first cluster, despite a unilateral lesion. Lesion localization is the main factor that determines the characteristics of aphasic deficits. Etiology indirectly acts through a different sensitivity of the brain regions to various pathologies.

Rethinking the Neural Basis of Prosody and Non-literal Language: Spared Pragmatics and Cognitive Compensation in a Bilingual With Extensive Right-Hemisphere Damage.

Above and beyond the critical contributions of left perisylvian regions to language, the neural networks supporting pragmatic aspects of verbal communication in native and non-native languages (L1s and L2, respectively) have often been ascribed to the right hemisphere (RH). However, several reports have shown that left-hemisphere activity associated with pragmatic domains (e.g., prosody, indirect speech, figurative language) is comparable to or even greater than that observed in the RH, challenging the proposed putative role of the latter for relevant domains. Against this background, we report on an adult bilingual patient showing preservation of pragmatic verbal skills in both languages (L1: Spanish, L2: English) despite bilateral damage mainly focused on the RH. After two strokes, the patient sustained lesions in several regions previously implicated in pragmatic functions (vast portions of the right fronto-insulo-temporal cortices, the bilateral amygdalae and insular cortices, and the left putamen). Yet, comparison of linguistic and pragmatic skills with matched controls revealed spared performance on multiple relevant tasks in both her L1 and L2. Despite mild difficulties in some aspects of L2 prosody, she showed no deficits in comprehending metaphors and idioms, or understanding indirect speech acts in either language. Basic verbal skills were also preserved in both languages, including verbal auditory discrimination, repetition of words and pseudo-words, cognate processing, grammaticality judgments, equivalent recognition, and word and sentence translation. Taken together, the evidence shows that multiple functions of verbal communication can be widely spared despite extensive damage to the RH, and that claims for a putative relation between pragmatics and the RH may have been overemphasized in the monolingual and bilingual literature. We further discuss the case in light of previous reports of pragmatic and linguistic deficits following brain lesions and address its relation to cognitive compensation in bilingual patients.

Decreased Cerebellar-Orbitofrontal Connectivity Correlates with Stuttering Severity: Whole-Brain Functional and Structural Connectivity Associations with Persistent Developmental Stuttering.

Persistent developmental stuttering is characterized by speech production disfluency and affects 1% of adults. The degree of impairment varies widely across individuals and the neural mechanisms underlying the disorder and this variability remain poorly understood. Here we elucidate compensatory mechanisms related to this variability in impairment using whole-brain functional and white matter connectivity analyses in persistent developmental stuttering. We found that people who stutter had stronger functional connectivity between cerebellum and thalamus than people with fluent speech, while stutterers with the least severe symptoms had greater functional connectivity between left cerebellum and left orbitofrontal cortex (OFC). Additionally, people who stutter had decreased functional and white matter connectivity among the perisylvian auditory, motor, and speech planning regions compared to typical speakers, but greater functional connectivity between the right basal ganglia and bilateral temporal auditory regions. Structurally, disfluency ratings were negatively correlated with white matter connections to left perisylvian regions and to the brain stem. Overall, we found increased connectivity among subcortical and reward network structures in people who stutter compared to controls. These connections were negatively correlated with stuttering severity, suggesting the involvement of cerebellum and OFC may underlie successful compensatory mechanisms by more fluent stutterers.

A Mutation in the Tubulin-Encoding TUBB3 Gene Causes Complex Cortical Malformations and Unilateral Hypohidrosis

Recent studies have emphasized the association between tubulin gene mutations and developmental abnormalities of the cortex. In this study, the authors identified a mutation in the tubulin-encoding class III β-tubulin (TUBB3) gene in a 4-year-old boy presenting with brain abnormalities and unilateral hypohidrosis. The patient showed a left internal strabismus, moderate developmental delay, and congenital hypohidrosis of the right side of the body. Magnetic resonance imaging disclosed gyral disorganization mainly in the left perisylvian region, dysmorphic and hypertrophic basal ganglia with fusion between the putamen and caudate nucleus without affecting the anterior limb of the internal capsule, and moderate hypoplasia of the right brain stem and cerebellum. Diffusion tensor imaging studies revealed disorganization of the pyramidal fibers. The amplitude of the sympathetic skin response was low in the right arm, which led to a diagnosis of focal autonomic neuropathy. Sequencing the TUBB3 gene revealed a de novo missense mutation, c.862G>A (p.E288K).

RARE-11INTRACRANIAL ATYPICAL RHABDOID MENINGIOMA LACKING MALIGNANT FEATURES: CASE REPORT AND LITERATURE REVIEW

RARE-11. INTRACRANIAL ATYPICAL RHABDOID MENINGIOMA LACKING MALIGNANT FEATURES: CASE REPORT AND LITERATURE REVIEW Mansour Mathkour1,2, Juanita Garces2, Joshua Hanna1, and Marcus Ware1; Ochsner Clinic Foundatino, Jefferson, LA, USA; Tulane Medical Center, New Orleans, LA, USA INTRODUCTION: Meningiomas are the most common benign intracranial tumors. They present with a number of cytological variants, most of which have no prognostic or clinical significance. One exceedingly rare variant is a meningioma with rhabdoid features, accounting for 2-3% of all meningiomas. This variant is also derived from meningoepithelial cells, however it is classified as WHO grade III owing to rapid growth, invasion of brain tissue and frequent recurrence. We describe a meningioma with rhabdoid features classified as WHO grade II as a result of uncharacteristically reduced malignant potential on cytology. To our knowledge there are three prior reported cases, two of which are intracranial of WHO Grade II meningioma with rhabdoid features. CASE: A 56-year-old male presented with abulia and slowed speech for several days. Physical exam of the patient was normal. Magnetic resonance imaging (MRI) of the brain revealed a focal heterogeneously enhancing extra-axial lesion within the left perisylvian region with mass effect on the left lateral ventricle. The patientunderwent craniotomy for tumor resection.The histological examination revealed meningioma with extensive rhabdoid features (greater than 50%). Cytology showed eccentric nuclei with abundant globoid eosinophilic cytoplasm consistent with rhabdoid features, however mitotic activity was relatively low with only 4 mitoses per 10 HPF. The patient is presently 4-months post-operation with resolution of his presenting symptoms and without evidence of recurrence. CONCLUSION: Meningiomas with rhabdoid features are known to be highly malignant with high recurrence rates, yet the tumor described by these authors exhibits reduced mitotic activity uncharacteristic of this tumor type. Based on our follow-up, there is currently no recurrence. We present a case of a rhabdoid meningioma with less aggressive features consistent with WHO II. As such, low-grade rhabdoid meningiomas should be considered as an exceedingly rare etiology, with unknown diagnostic and prognostic significance. Neuro-Oncology 17:v201–v206, 2015. doi:10.1093/neuonc/nov232.11 Published by Oxford University Press on behalf of the Society for Neuro-Oncology 2015.

Development of a selective left-hemispheric fronto-temporal network for processing syntactic complexity in language comprehension

The development of language comprehension abilities in childhood is closely related to the maturation of the brain, especially the ability to process syntactically complex sentences. Recent studies proposed that the fronto-temporal connection within left perisylvian regions, supporting the processing of syntactically complex sentences, is still immature at preschool age. In the current study, resting state functional magnetic resonance imaging data were acquired from typically developing 5-year-old children and adults to shed further light on the brain functional development. Children additionally performed a behavioral syntactic comprehension test outside the scanner. The amplitude of low-frequency fluctuations was analyzed in order to identify the functional correlation networks of language-relevant brain regions. Results showed an intrahemispheric correlation between left inferior frontal gyrus (IFG) and left posterior superior temporal sulcus (pSTS) in adults, whereas an interhemispheric correlation between left IFG and its right-hemispheric homolog was predominant in children. Correlation analysis between resting-state functional connectivity and sentence processing performance in 5-year-olds revealed that local connectivity within the left IFG is associated with competence of processing syntactically simple canonical sentences, while long-range connectivity between IFG and pSTS in left hemisphere is associated with competence of processing syntactically relatively more complex non-canonical sentences. The present developmental data suggest that a selective left fronto-temporal connectivity network for processing complex syntax is already in functional connection at the age of 5 years when measured in a non-task situation. The correlational findings provide new insight into the relationship between intrinsic functional connectivity and syntactic language abilities in preschool children.

Anterior opercular syndrome induced by Epstein–Barr virus encephalitis

We report a 19-year-old female presenting with fever, drooling, anarthria, and voluntary facial movement disruption, characteristic of anterior opercular syndrome (AOS). Serological examination revealed Epstein–Barr virus (EBV) infection following acute encephalitis with severe ataxia. A single-photon emission computerized tomography (SPECT) examination indicated hypoperfusion in the left perisylvian region, bilateral thalamus, occipital lobe, and cerebellum. This is the first report of AOS related to EBV encephalitis. SPECT was a useful method for detecting the damaged region of the operculum. In addition, AOS is a clinically distinct entity that may help us understand the mechanisms of language circuits within the operculum.