Dissociated Crossed Speech Areas in a Tumour Patient

In the past, the eloquent areas could be deliberately localised by the invasive Wada test. The very rare cases of dissociated crossed speech areas were accidentally found based on the clinical symptomatology. Today functional magnetic resonance imaging (fMRI)-based imaging can be employed to non-invasively localise the eloquent areas in brain tumour patients for therapy planning. A 41-year-old, left-handed man with a low-grade glioma in the left frontal operculum extending to the insular cortex, tension headaches, and anomic aphasia over 5 months underwent a pre-operative speech area localisation fMRI measurement, which revealed the evidence of the transhemispheric disposition, where the dominant Wernicke speech area is located on the left and the Broca’s area is strongly lateralised to the right hemisphere. The outcome of the Wada test and the intraoperative cortico-subcortical stimulation mapping were congruent with this finding. After tumour removal, language area function was fully preserved. Upon the occurrence of brain tumours with a risk of impaired speech function, the rare dissociate crossed speech areas disposition may gain a clinically relevant meaning by allowing for more extended tumour removal. Hence, for its identification, diagnostics which take into account both brain hemispheres, such as fMRI, are recommended.

Download Full-text

Provocation and prediction of visual peripersonal neglect-like symptoms in preoperative planning and during awake brain surgery

Acta Neurochirurgica ◽

10.1007/s00701-021-04822-2 ◽

2021 ◽

Author(s):

Viktória Tamás ◽

Gabriella Sebestyén ◽

Szilvia Anett Nagy ◽

Péter Zsolt Horváth ◽

Ákos Mérei ◽

...

Keyword(s):

Preoperative Planning ◽

Right Hemisphere ◽

Superior Temporal Gyrus ◽

Low Grade ◽

Navigated Transcranial Magnetic Stimulation ◽

Resonance Imaging ◽

Parietal Area ◽

Routine Magnetic Resonance Imaging ◽

Visuospatial Functions ◽

The Right

AbstractNeglect is a severe neuropsychological/neurological deficit that usually develops due to lesions of the posterior inferior parietal area of the right hemisphere and is characterized by a lack of attention to the left side. Our case is a proven right-handed, 30-year-old female patient with a low-grade glioma, which was located in the temporo-opercular region and also in the superior temporal gyrus of the right hemisphere. Upon presurgical planning, the motor, language, and visuospatial functions were mapped. In order to achieve this, the protocol for routine magnetic resonance imaging and navigated transcranial magnetic stimulation has been expanded, accordingly.

Download Full-text

Lateralization in monogamous pairs: wild geese prefer to keep their partner in the left hemifield except when disturbed

Current Zoology ◽

10.1093/cz/zoaa074 ◽

2020 ◽

Author(s):

Elmira Zaynagutdinova ◽

Karina Karenina ◽

Andrey Giljov

Keyword(s):

Social Interactions ◽

Right Hemisphere ◽

Natural Setting ◽

Intraspecific Interactions ◽

Brain Hemispheres ◽

Emergency Situations ◽

Anser Albifrons ◽

Significant Bias ◽

Visual Hemifield ◽

The Right

Abstract Behavioural lateralization, which reflects the functional specializations of the two brain hemispheres, is assumed to play an important role in cooperative intraspecific interactions. However, there are few studies focused on the lateralization in cooperative behaviours of individuals, especially in a natural setting. In the present study, we investigated lateralized spatial interactions between the partners in life-long monogamous pairs. The male-female pairs of two geese species (barnacle, Branta leucopsis, and white-fronted, Anser albifrons geese), were observed during different stages of the annual cycle in a variety of conditions. In geese flocks, we recorded which visual hemifield (left/right) the following partner used to monitor the leading partner relevant to the type of behaviour and the disturbance factors. In a significant majority of pairs, the following bird viewed the leading partner with the left eye during routine behaviours such as resting and feeding in undisturbed conditions. This behavioural lateralization, implicating the right hemisphere processing, was consistent across the different aggregation sites and years of the study. In contrast, no significant bias was found in a variety of geese behaviours associated with enhanced disturbance (when alert on water, flying or fleeing away when disturbed, feeding during the hunting period, in urban area feeding and during moulting). We hypothesize that the increased demands for right hemisphere processing to deal with stressful and emergency situations may interfere with the manifestation of lateralization in social interactions.

Download Full-text

Medial Cortical Structures Mediate Implicit Trustworthiness Judgments about Kin Faces, but Not Familiar Faces: A Brief Report

Psych ◽

10.3390/psych1010037 ◽

2019 ◽

Vol 1 (1) ◽

pp. 482-490 ◽

Cited By ~ 1

Author(s):

Steven M. Platek ◽

Judson C. Hendry

Keyword(s):

Right Hemisphere ◽

Kin Recognition ◽

Insular Cortex ◽

Neural Correlates ◽

The Self ◽

Anterior Cingulate ◽

Dorsal Anterior Cingulate Cortex ◽

Facial Stimuli ◽

The Right ◽

Processing Network

Human kin recognition activates substrates of the extended facial processing network, notably the right-hemisphere structures involved in self-face recognition and posterior medial cortical substrates. To understand the mechanisms underlying prosociality toward kin faces in comparison to other familiar faces, we investigated the neural correlates of implicit trustworthiness ratings to faces of actual kin and personal friends, controlling for activation to distracter faces. When controlling for activation associated with unknown faces, trustworthiness ratings of faces of kin, compared to friends, were associated with increased activation in the dorsal anterior cingulate cortex, posterior cingulate, and precuneous. On the other hand, trustworthiness ratings of friend faces, relative to kin faces, were associated with the lateral occipital gyrus and insular cortex. Trustworthiness ratings for unknown faces were only associated with activation in the fusiform gyrus. These findings suggest that we should employ medial cortical substrates known to be part of the self-other network when making implicit social judgements about kin, but not other classes of facial stimuli.

Download Full-text

Symmetry of the arcuate fasciculus and its impact on language performance of patients with brain tumors in the language-dominant hemisphere

Journal of Neurosurgery ◽

10.3171/2016.9.jns161281 ◽

2017 ◽

Vol 127 (6) ◽

pp. 1407-1416 ◽

Cited By ~ 3

Author(s):

Margit Jehna ◽

Juliane Becker ◽

Karla Zaar ◽

Gord von Campe ◽

Kariem Mahdy Ali ◽

...

Keyword(s):

Brain Tumor ◽

Fiber Tracking ◽

Low Grade ◽

High Grade ◽

Arcuate Fasciculus ◽

Language Performance ◽

Language Deficits ◽

Tumor Patients ◽

Eloquent Areas ◽

The Right

OBJECTIVECerebral damage in frontal, parietal, and temporal brain areas and, probably more importantly, their interconnections can lead to deficits in language. However, neural plasticity and repair allow the brain to partly compensate for neural injury, mediated by both functional and structural changes. In this study, the authors sought to systematically investigate the relationship between language performance in brain tumor patients and structural perisylvian pathways (i.e., the arcuate fasciculus [AF]) using probabilistic fiber tracking on diffusion tensor imaging. The authors used a previously proposed model in which the AF is divided into anterior, long, and posterior segments. The authors hypothesized that right-handed patients with gliomas in the language-dominant (left) hemisphere would benefit from a more symmetrical or right-lateralized language pathway in terms of better preservation of language abilities. Furthermore, they investigated to what extent specific tumor characteristics, including proximity to the AF, affect language outcome in such patients.METHODSTwenty-seven right-handed patients (12 males and 15 females; mean age 52 ± 16 years) with 11 low-grade and 16 high-grade gliomas of the left hemisphere underwent 3-T diffusion-weighted MRI (30 directions) and language assessment as part of presurgical planning. For a systematic quantitative evaluation of the AF, probabilistic fiber tracking with a 2 regions of interest approach was carried out. Volumes of the 3 segments of both hemispheric AFs were evaluated by quantifying normalized and thresholded pathways. Resulting values served to generate the laterality index of the AFs.RESULTSPatients without language deficits tended to have an AF that was symmetric or lateralized to the right, whereas patients with deficits in language significantly more often demonstrated a left-lateralized posterior segment of the AF. Patients with high-grade gliomas had more severe language deficits than those with low-grade gliomas. Backward logistic regression revealed the laterality index of the posterior AF segment and tumor grade as the only independent statistically significant predictors for language deficits in this cohort.CONCLUSIONSIn addition to the well-known fact that tumor entity influences behavioral outcome, the authors' findings suggest that the right homologs of structural language-associated pathways could be supportive for language function and facilitate compensation mechanisms after brain damage in functionally eloquent areas. This further indicates that knowledge about preoperative functional redistribution (identified by neurofunctional imaging) increases the chance for total or near-total resections of tumors in eloquent areas. In the future, longitudinal studies with larger groups are mandatory to overcome the methodological limitations of this cross-sectional study and to map neuroplastic changes associated with language performance and rehabilitation in brain tumor patients.

Download Full-text

Hemispheric Specialization and Cognitive Development: Implications for Mathematics Education

Journal for Research in Mathematics Education ◽

10.5951/jresematheduc.9.1.0020 ◽

1978 ◽

Vol 9 (1) ◽

pp. 20-32

Author(s):

Grayson H. Wheatley ◽

Robert Mitchell ◽

Robert L. Frankland ◽

Rosemarie Kraft

Keyword(s):

Left Hemisphere ◽

Hemispheric Asymmetry ◽

Right Hemisphere ◽

Mathematics Curriculum ◽

Hemispheric Specialization ◽

Brain Hemispheres ◽

Spatial Tasks ◽

Concrete Operational ◽

The Right ◽

Hemisphere Specialization

Evidence is presented for hemisphere specialization of the two brain hemispheres: the left hemisphere specialized for logico-analytic tasks and the right hemisphere, visuo-spatial tasks. A hypothesis is put forth for the emergence of the specialization that suggests a shift from predominant right hemisphere processing in infancy to predominant left hemisphere processing in adulthood. Results of the studies reviewed suggest the emergence of concrete-operational thought as the left hemisphere becomes capable of processing logical tasks. Electroencephalography seems particularly useful in determining specialization and mapping changes in hemispheric asymmetry. Implications for school mathematics curriculum are presented.

Download Full-text

Discrepant findings for Wada test and functional magnetic resonance imaging with regard to language function: use of electrocortical stimulation mapping to confirm results

Journal of Neurosurgery ◽

10.3171/jns.2005.102.1.0169 ◽

2005 ◽

Vol 102 (1) ◽

pp. 169-173 ◽

Cited By ~ 25

Author(s):

Kuan H. Kho ◽

Frans S. S. Leijten ◽

Geert-Jan Rutten ◽

Jan Vermeulen ◽

Peter van Rijen ◽

...

Keyword(s):

Magnetic Resonance ◽

Right Hemisphere ◽

Test Results ◽

Functional Magnetic Resonance ◽

Resonance Imaging ◽

Wada Test ◽

Content Type ◽

Language Functions ◽

Imaging Results ◽

The Right

✓ The Wada test is still considered the gold standard for determining the language-dominant hemisphere prior to brain surgery. The authors report on a 34-year-old right-handed woman whose Wada test results indicated that the right hemisphere was dominant for language. In contrast, functional magnetic resonance (fMR) imaging was indicative of bilaterally represented language functions. Activation in the left hemisphere demonstrated on fMR imaging was most pronounced in the Broca area. Importantly, fMR imaging results in this area were confirmed on electrocortical stimulation mapping. These contradictory findings indicated that a right hemispherre dominance for language according to the Wada test should be questioned and verified using electrocortical stimulation. Nonetheless, the question remains whether involvement of these areas in the left frontal hemisphere is critical for language, as these were spared during surgery.

Download Full-text

Transopercular Insular Approach, Overcoming the Training Curve Using a Cadaveric Simulation Model: 2-Dimensional Operative Video

Operative Neurosurgery ◽

10.1093/ons/opab342 ◽

2021 ◽

Author(s):

Carlos Santos ◽

Carlos Velasquez ◽

Jesus Esteban ◽

Leticia Fernandez ◽

Emmanuel Mandonnet ◽

...

Keyword(s):

White Matter ◽

Video Recording ◽

Insular Cortex ◽

Cost Effective ◽

Training Model ◽

Surgical Skills ◽

Low Grade ◽

Eloquent Areas ◽

Landmark Identification ◽

Neuronavigation System

Abstract Transopercular approach to the insula is indicated for resection of insular low-grade gliomas, particularly for Yasargil's 3B, 5A, and 5B types. Nevertheless, the infrequent location and its challenging approach make it difficult to master the surgery. Consequently, a realistic laboratory training model might help to acquire key surgical skills. In this video, we describe a cadaveric-based model simulating the resection of a temporo-insular low-grade glioma. Kingler's fixation technique was used to fix the cadaver head before injecting red and blue colorants for a realistic vascular appearance. Hemisphere was frozen for white matter tract dissection. Tractography and intraoperative eloquent areas were extrapolated from a glioma patient by using a neuronavigation system. Then, a fronto-temporal craniotomy was performed through a question mark incision, exposing from inferior temporal gyrus up to middle frontal gyrus. After cortical anatomic landmark identification, eloquent areas were extrapolated creating a simulated functional cortical map. Then, transopercular noneloquent frontal and temporal corticectomies were performed, followed by subpial resection. Detailed identification of Sylvian vessels and insular cortex was demonstrated. Anatomic resection limits were exposed, and implicated white matter bundles, uncinate and fronto-occipital fascicles, were identified running through the temporal isthmus. Finally, a temporo-mesial resection was performed. In summary, this model provides a simple, cost-effective, and very realistic simulation of a transopercular approach to the insula, allowing the development of surgical skills needed to treat insular tumors in a safe environment. Besides, the integration of simulated navigation has proven useful in better understanding the complex white matter anatomy involved. Cadaver donation, subject or relatives, includes full consent for publication of the images. For the purpose of this video, no ethics committee approval was needed. Images correspond to a cadaver head donation. Cadaver donation, subject or relatives, includes full consent for any scientific purposes involving the corpse. The consent includes image or video recording. Regarding the intraoperative surgical video and tractography, the patient gave written consent for scientific divulgation prior to surgery.

Download Full-text

Psychophysiological Analysis of the Influence of Vasopressin on Speech in Patients with Post-Stroke Aphasias

The Spanish Journal of Psychology ◽

10.1017/s1138741600006442 ◽

2007 ◽

Vol 10 (1) ◽

pp. 178-188 ◽

Cited By ~ 14

Author(s):

Sergei G. Tsikunov ◽

Svetlana G. Belokoskova

Keyword(s):

Intranasal Administration ◽

Right Hemisphere ◽

Positive Influence ◽

Speech Disorders ◽

Human Species ◽

Brain Hemispheres ◽

Neuroendocrine Mechanisms ◽

Left And Right ◽

The Right ◽

Positive Effect

Speech is an attribute of the human species. Central speech disorders following stroke are unique models for the investigation of the organization of speech. Achievements in neurobiology suggest that there are possible neuroendocrine mechanisms involved in the organization of speech. It is known that the neuropeptide vasotocin, analogous of vasopressin in mammals, modulates various components of vocalization in animals. Furthermore, the positive influence of vasopressin on memory, which plays an important role in the formation of speech, has been described. In this study, speech organization processes and their recovery with the administration of vasopressin (1-desamino-8-D-arginin-vasopressin) to 26 patients with chronic aphasias after stroke were investigated. Results showed that sub-endocrine doses of the neuropeptide with intranasal administration had positive influence primarily on simple forms of speech and secondarily on composite forms. There were no statistically significant differences between the sensory and integrative components of the organization of speech processes with vasopressin. In all cases, the positive effect of the neuropeptide was demonstrated. As a result of the effects, speech regulated by both brain hemispheres improved. It is suggested that the neuropeptide optimizes the activity both in the left and right hemispheres, with primary influence on the right hemisphere. The persistence of the acquired effects is explained by an induction of compensatory processes resulting in the reorganization of the intra-central connections by vasopressin.

Download Full-text

Wada Testing Reveals Frontal Lateralization for the Memorization of Words and Faces

Journal of Cognitive Neuroscience ◽

10.1162/089892902317205375 ◽

2002 ◽

Vol 14 (1) ◽

pp. 116-125 ◽

Cited By ~ 19

Author(s):

W. M. Kelley ◽

J. G. Ojemann ◽

R. D. Wetzel ◽

C. P. Derdeyn ◽

C. J. Moran ◽

...

Keyword(s):

Right Hemisphere ◽

Temporal Cortex ◽

Memory Formation ◽

Wada Test ◽

Memory Impairments ◽

Reversible Lesion ◽

The Right ◽

Open Question ◽

Normal Performance ◽

Better Than

Neuroimaging studies have suggested that specific regions of the frontal and medial temporal cortex are engaged during memory formation. Further, there is specialization across these regions such that verbal materials appear to preferentially engage the left regions while nonverbal materials primarily engage the right regions. An open question, however, has been to what extent frontal regions contribute to successful memory formation. The present study investigates this question using a reversible lesion technique known as the Wada test. Patients memorized words and unfamiliar faces while portions of their left and right hemispheres were temporarily anesthetized with sodium amytal. Subsequent memory tests revealed that faces were remembered better than words following left-hemisphere anesthesia, whereas words were remembered better than faces following right-hemisphere anesthesia. Importantly, inspection of the circulation affected by the amytal further suggests that these memory impairments did not result from direct anesthetization of the medial temporal regions. Taken in the context of the imaging findings, these results suggest that frontal regions may also contribute to memory formation in normal performance.

Download Full-text