Localization patterns of speech and language errors during awake brain surgery:a systematic review

Awake craniotomy with direct electrical stimulation (DES) is the standard treatment for patients with eloquent area gliomas. DES detects speech and language errors, which indicate functional boundaries that must be maintained to preserve quality of life. During DES, traditional object naming or other linguistic tasks such as tasks from the Dutch Linguistic Intraoperative Protocol (DuLIP) can be used. It is not fully clear which speech and language errors occur in which brain locations. To provide an overview and to update DuLIP, a systematic review was conducted in which 102 studies were included, reporting on speech and language errors and the corresponding brain locations during awake craniotomy with DES in adult glioma patients up until 6 July 2020. The current findings provide a crude overview on language localization. Even though subcortical areas are in general less often investigated intraoperatively, still 40% out of all errors was reported at the subcortical level and almost 60% at the cortical level. Rudimentary localization patterns for different error types were observed and compared to the dual-stream model of language processing and the DuLIP model. While most patterns were similar compared to the models, additional locations were identified for articulation/motor speech, phonology, reading, and writing. Based on these patterns, we propose an updated DuLIP model. This model can be applied for a more adequate “location-to-function” language task selection to assess different linguistic functions during awake craniotomy, to possibly improve intraoperative language monitoring. This could result in a better postoperative language outcome in the future. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10143-022-01943-9

Differential Effects of Awake Glioma Surgery in "Critical" Language Areas on Cognition:4 Case Studies

Awake surgery with electrocorticosubcortical stimulation is the golden standard treatment for gliomas in eloquent areas. Preoperatively, mostly mild cognitive disturbances are observed with postoperative deterioration. We describe pre- and postoperative profiles of 4 patients (P1–P4) with gliomas in “critical” language areas (“Broca,” “Wernicke,” and the arcuate fasciculus) undergoing awake surgery to get insight into the underlying mechanism of neuroplasticity. Neuropsychological examination was carried out preoperatively (at T1) and postoperatively (at T2, T3). At T1, cognition of P1 was intact and remained stable. P2 had impairments in all cognitive domains at T1 with further deterioration at T2 and T3. At T1, P3 had impairments in memory and executive functions followed by stable recovery. P4 was intact at T1, followed by a decline in a language test at T2 and recovery at T3. Intraoperatively, in all patients language positive sites were identified. Patients with gliomas in “critical” language areas do not necessarily present cognitive disturbances. Surgery can either improve or deteriorate (existing) cognitive impairments. Several factors may underlie the plastic potential of the brain, for example, corticosubcortical networks and tumor histopathology. Our findings illustrate the complexity of the underlying mechanism of neural plasticity and provide further support for a “hodotopical” viewpoint

Foreign accent syndrome as a psychogenic disorder: A review

© 2016 Keulen, Verhoeven, De Witte, De Page, Bastiaanse and Mariën. In the majority of cases published between 1907 and 2014, FAS is due to a neurogenic etiology. Only a few reports about FAS with an assumed psychogenic origin have been published. The present article discusses the findings of a careful database search on psychogenic FAS. This review may be particularly relevant as it is the first to analyze the salient features of psychogenic FAS cases to date. This article hopes to pave the way for the view that psychogenic FAS is a cognate of neurogenic FAS. It is felt that this variant of FAS may have been underreported, as most of the psychogenic cases have been published after the turn of the century. This review may improve the diagnosis of the syndrome in clinical practice and highlights the importance of recognizing psychogenic FAS as an independent taxonomic entity

Generation of Large-Scale Vorticity in a Homogeneous Turbulence with a Mean Velocity Shear

An effect of a mean velocity shear on a turbulence and on the effective force which is determined by the gradient of Reynolds stresses is studied. Generation of a mean vorticity in a homogeneous incompressible turbulent flow with an imposed mean velocity shear due to an excitation of a large-scale instability is found. The instability is caused by a combined effect of the large-scale shear motions (''skew-induced" deflection of equilibrium mean vorticity) and ''Reynolds stress-induced" generation of perturbations of mean vorticity. Spatial characteristics, such as the minimum size of the growing perturbations and the size of perturbations with the maximum growth rate, are determined. This instability and the dynamics of the mean vorticity are associated with the Prandtl's turbulent secondary flows. This instability is similar to the mean-field magnetic dynamo instability. Astrophysical applications of the obtained results are discussed.Comment: 8 pages, 3 figures, REVTEX4, submitted to Phys. Rev.

Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

Organic and Non-Organic Language Disorders after Awake Brain Surgery

INTRODUCTION: Awake surgery with Direct Electrical Stimulation (DES) is considered the ‘gold standard’ to resect brain tumours in the language dominant hemisphere (De Witte & Mariën, 2013). Although transient language impairments are common in the immediate postoperative phase, permanent postoperative language deficits seem to be rare (Duffau, 2007). Milian et al. (2014) stated that most patients tolerate the awake procedure well and would undergo a similar procedure again. However, postoperative psychological symptoms including recurrent distressing dreams and persistent avoidance of stimuli have been recorded following awake surgery (Goebel, Nabavi, Schubert, & Mehdorn, 2010; Milian et al., 2014). To the best of our knowledge, psychogenic language disturbances have never been described after awake surgery. In general, only a handful of non-organic, psychogenic language disorders have been reported in the literature (De Letter et al., 2012). We report three patients with left brain tumours (see table 1) who presented linguistic symptoms after awake surgery that were incompatible with the lesion location, suggesting a psychogenic origin. METHODS: Neurocognitive (language, memory, executive functions) investigations were carried out before, during and after awake surgery (6 weeks, 6 months postsurgery) on the basis of standardised tests. Pre- and postoperative (f)MRI images, DTI results and intraoperative DES findings were analysed. A selection of tasks was used to map language intraoperatively (De Witte et al., 2013). In the postoperative phase spontaneous speech and behavioural phenomena to errors were video-recorded. RESULTS: Preoperative language tests did not reveal any speech or language problems. Intraoperatively, eloquent sites were mapped and preserved enabling good language skills at the end of the awake procedure. However, assessments in the first weeks postsurgery disclosed language and behavioural symptoms that support the hypothesis of a non-organic origin: fluent and nonfluent language disorders unrelated to the documented lesions, strong variablilty in the error profile, marked fluctuations of symptoms over time and condition, atypical personal comments. All three patients had a prior history of psychiatric disease and one patient witnessed language problems in an aphasic relative. In the study of De Letter et al. (2012) similar findings were mentioned, but no comprehension problems were found. In all 3 cases the "psychogenic language problems" resolved after three to six weeks. DISCUSSION: As a possible explanation for the psychogenic linguistic manifestations the following hypotheses will be discussed: 1) psychogenic language problems as part of an acute stress disorder (the awake setting); 2) psychological decompensation as the result of the fact that the patient was clearly informed that the tumour was situated near language regions; 3) getting a lot of attention in the hospital and a feeling of anxiety to return home; 4) unintended imitation of a witnessed aphasic disorder. CONCLUSION: Careful evaluation and selection of the patients and good preoperative preparation seem to be fundamental for good tolerance during awake surgery. Moreover, in the postoperative phase, extensive assessments are necessary to differentially diagnose patients with organic and non-organic language disorders in order to develop appropriate treatment strategies

Cognitive outcome after awake surgery for left and right hemisphere tumours

INTRODUCTION: Awake surgery in eloquent brain regions is performed to preserve language and other cognitive functions. Although in general, no major permanent cognitive deficits are found after awake brain surgery, clinically relevant impairments are detected and cognitive recovery takes longer than generally assumed (3 months) (Santini et al., 2012; Satoer et al., 2014; Talacchi et al., 2012). However, as there is a lack of extensive cognitive follow-up data it is unknown when recovery takes place. In addition, the influence of critical language sites identified by direct electrical stimulation (DES) and tumour variables (e.g. left/right tumour location, tumour grade) on long-term cognitive findings remains unclear. METHODS: In this longitudinal study the short-term and long-term effects of awake surgery on cognition were investigated in 40 patients (29 patients with left and 11 with right hemisphere tumours). Language, memory, attentional, executive and visuospatial functions were assessed in the preoperative phase, at short-term follow-up (6 weeks postsurgery) and at long-term follow-up (6 months postsurgery) with a neuropsychological protocol. In addition, the effect of intraoperative critical language sites, left/right tumour location, hemispheric language dominance, extent of resection and adjuvant treatment on cognitive change was studied. RESULTS: Both pre- and postoperatively, the mean performance of the patients was worse (impairment = z-score below -2) than the performance of the normal population in the language domain, the memory domain, the attentional and executive domain (p .05). Awake surgery negatively affected language, attentional and executive functions but not memory and visuospatial functions. At 6 weeks postsurgery, performance on all language, attentional and executive tasks deteriorated (object/action naming, semantic/phonological fluency from DuLIP, Token test; Trail Making Test A & B, Stroop I, II, & III). At 6 months postsurgery, recovery to the normative or to the preoperative level was found for all but one language task (semantic fluency). By contrast, a 'long-term' decline was still found for most attentional and executive tasks (Trail Making Test A & B, Stroop I & II). The short-term and long-term decrease for the language tasks and the attention task Stroop I was only observed in the patients with brain tumours in critical language areas identified by DES. No influence of left/right tumour location, hemispheric dominance, tumour grade, extent of resection, or adjuvant treatment on cognitive change was found. CONCLUSION: A tumour located near or within a critical language area (identified by DES) was the only risk factor for short-term and long-term postoperative decline in the language and partly the attentional domain. Most language functions recover to normative or to preoperative levels between 6 weeks and 6 months postsurgery, whereas recovery of attentional and executive functions takes more time. Postoperative testing at 6 weeks and 6 months seem to be sensitive follow-up test-moments to detect cognitive change. Future studies should focus on intraoperative mapping of both language and attentional/ executive functions in order to avoid postoperative deficits and to preserve quality of life