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

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.

scholarly journals Dissociated Crossed Speech Areas in a Tumour Patient

2017 ◽  
Vol 9 (2) ◽  
pp. 131-136 ◽  
Author(s):  
Jörg Mauler ◽  
Irene Neuner ◽  
Georg Neuloh ◽  
Bruno Fimm ◽  
Frank Boers ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Insular Cortex ◽  
Low Grade ◽  
Wada Test ◽  
Brain Hemispheres ◽  
Eloquent Areas ◽  
Tumour Removal ◽  
Frontal Operculum ◽  
The Right ◽  
Impaired Speech

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.

scholarly journals Prefrontal High Gamma in ECoG tags periodicity of musical rhythms in perception and imagination

2019 ◽  
Author(s):  
S. A. Herff ◽  
C. Herff ◽  
A. J. Milne ◽  
G. D. Johnson ◽  
J. J. Shih ◽  
...  
Keyword(s):  
Auditory Processing ◽  
Right Hemisphere ◽  
Brain Activity ◽  
Activity Patterns ◽  
Superior Temporal Gyrus ◽  
Gamma Activity ◽  
Rhythm Perception ◽  
High Gamma ◽  
The Right ◽  
Musical Rhythms

AbstractRhythmic auditory stimuli are known to elicit matching activity patterns in neural populations. Furthermore, recent research has established the particular importance of high-gamma brain activity in auditory processing by showing its involvement in auditory phrase segmentation and envelope-tracking. Here, we use electrocorticographic (ECoG) recordings from eight human listeners, to see whether periodicities in high-gamma activity track the periodicities in the envelope of musical rhythms during rhythm perception and imagination. Rhythm imagination was elicited by instructing participants to imagine the rhythm to continue during pauses of several repetitions. To identify electrodes whose periodicities in high-gamma activity track the periodicities in the musical rhythms, we compute the correlation between the autocorrelations (ACC) of both the musical rhythms and the neural signals. A condition in which participants listened to white noise was used to establish a baseline. High-gamma autocorrelations in auditory areas in the superior temporal gyrus and in frontal areas on both hemispheres significantly matched the autocorrelation of the musical rhythms. Overall, numerous significant electrodes are observed on the right hemisphere. Of particular interest is a large cluster of electrodes in the right prefrontal cortex that is active during both rhythm perception and imagination. This indicates conscious processing of the rhythms’ structure as opposed to mere auditory phenomena. The ACC approach clearly highlights that high-gamma activity measured from cortical electrodes tracks both attended and imagined rhythms.

Dominance of the Right Hemisphere and Role of Area 2 in Human Kinesthesia

2005 ◽  
Vol 93 (2) ◽  
pp. 1020-1034 ◽  
Author(s):  
Eiichi Naito ◽  
Per E. Roland ◽  
Christian Grefkes ◽  
H. J. Choi ◽  
Simon Eickhoff ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Anterior Part ◽  
Premotor Cortex ◽  
Superior Temporal Gyrus ◽  
Lateral Part ◽  
Left Hand ◽  
Hemisphere Dominance ◽  
The Right ◽  
Processus Styloideus ◽  
Motor Areas

We have previously shown that motor areas are engaged when subjects experience illusory limb movements elicited by tendon vibration. However, traditionally cytoarchitectonic area 2 is held responsible for kinesthesia. Here we use functional magnetic resonance imaging and cytoarchitectural mapping to examine whether area 2 is engaged in kinesthesia, whether it is engaged bilaterally because area 2 in non-human primates has strong callosal connections, which other areas are active members of the network for kinesthesia, and if there is a dominance for the right hemisphere in kinesthesia as has been suggested. Ten right-handed blindfolded healthy subjects participated. The tendon of the extensor carpi ulnaris muscles of the right or left hand was vibrated at 80 Hz, which elicited illusory palmar flexion in an immobile hand (illusion). As control we applied identical stimuli to the skin over the processus styloideus ulnae, which did not elicit any illusions (vibration). We found robust activations in cortical motor areas [areas 4a, 4p, 6; dorsal premotor cortex (PMD) and bilateral supplementary motor area (SMA)] and ipsilateral cerebellum during kinesthetic illusions (illusion-vibration). The illusions also activated contralateral area 2 and right area 2 was active in common irrespective of illusions of right or left hand. Right areas 44, 45, anterior part of intraparietal region (IP1) and caudo-lateral part of parietal opercular region (OP1), cortex rostral to PMD, anterior insula and superior temporal gyrus were also activated in common during illusions of right or left hand. These right-sided areas were significantly more activated than the corresponding areas in the left hemisphere. The present data, together with our previous results, suggest that human kinesthesia is associated with a network of active brain areas that consists of motor areas, cerebellum, and the right fronto-parietal areas including high-order somatosensory areas. Furthermore, our results provide evidence for a right hemisphere dominance for perception of limb movement.

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

2005 ◽  
Vol 102 (1) ◽  
pp. 169-173 ◽  
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.

scholarly journals Intraosseous schwannoma of inferior pubic ramus – A rare benign osseous neoplasm

2021 ◽  
Vol 0 ◽  
pp. 1-4
Author(s):  
Pundalik Umalappa Lamani ◽  
Ramakrishna Narayanan ◽  
U. N. Rakesh ◽  
Nageswara K. Rao
Keyword(s):  
Bone Neoplasms ◽  
Pubic Bone ◽  
Low Grade ◽  
Resonance Imaging ◽  
Tissue Component ◽  
Pubic Ramus ◽  
Intraosseous Schwannoma ◽  
Primary Bone ◽  
The Right ◽  
Short Tau Inversion Recovery

Intraosseous schwannomas are a very rare subgroup of schwannomas. They account for <1% of all primary bone neoplasms. The mandible is the most commonly involved bone followed by the sacrum. We herein report a case of intraosseous schwannoma involving the inferior ramus and body of the pubic bone in a 43-year-old male who presented with a swelling in the right groin. On radiographs and computed tomography, it appeared as a mildly expansile, lytic, multiloculated lesion in the right pubic bone with a narrow zone of transition, sclerotic margins with areas of cortical breach, and a significant intra and extrapelvic soft-tissue component which did not show any areas of calcification. On magnetic resonance imaging, it appeared isointense to skeletal muscle on T1-weighted images, mildly hyperintense on T2-weighted images, and markedly hyperintense on short-tau inversion recovery images. The differentials considered on imaging were chondroid neoplasms such as chondromyxoid fibroma or low-grade chondrosarcoma, giant cell tumor, and plasmacytoma. However, biopsy and histopathology revealed an intraosseous schwannoma. The patient was operated and the lesion was excised in toto. Intraoperatively, the origin of the lesion was identified as the right obturator nerve. Post-operative, the patient recovery was uneventful and he was discharged.

scholarly journals Language activation in monozygotic twins discordant for schizophrenia

2004 ◽  
Vol 184 (2) ◽  
pp. 128-135 ◽  
Author(s):  
Iris E. C. Sommer ◽  
Nick F. Ramsey ◽  
René C. W. Mandl ◽  
Clarine J. Van Oel ◽  
René S. Kahn
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Right Hemisphere ◽  
Monozygotic Twins ◽  
Monozygotic Twin ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Language Activation ◽  
The Right ◽  
Discordant Twin

BackgroundIn previous functional magnetic resonance imaging (fMRI) studies, participants with schizophrenia showed decreased language lateralisation, resulting from increased activation of the right hemisphere compared with controls.AimTo determine whether decreased lateralisation and increased right cerebral language activation constitute genetic predispositions for schizophrenia.MethodLanguage activation was measured using fMRI in 12 right-handed monozygotic twin pairs discordant for schizophrenia and 12 healthy right-handed monozygotic twin pairs who were matched for gender, age and education.ResultsLanguage lateralisation was decreased in discordant twin pairs compared with the healthy twin pairs. The groups did not differ in activation of the language-related areas of the left hemisphere, but language-related activation in the right hemisphere was significantly higher in the discordant twin pairs than in the healthy pairs. Within the discordant twin pairs, language lateralisation was not significantly different between patients with schizophrenia and their co-twins.ConclusionsDecreased language lateralisation may constitute a genetic predisposition for schizophrenia.

scholarly journals Navigated transcranial magnetic stimulation of the supplementary motor cortex disrupts fine motor skills in healthy adults

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Severin Schramm ◽  
Lucia Albers ◽  
Sebastian Ille ◽  
Axel Schröder ◽  
Bernhard Meyer ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Skills ◽  
Magnetic Stimulation ◽  
Right Hemisphere ◽  
Fine Motor ◽  
Fine Motor Skills ◽  
Navigated Transcranial Magnetic Stimulation ◽  
Supplementary Motor Cortex ◽  
The Right ◽  
Stimulation Of

AbstractNavigated transcranial magnetic stimulation (nTMS) over the supplementary motor area (SMA) may impact fine motor skills. This study evaluates different nTMS parameters in their capacity to affect fine motor performance on the way to develop an SMA mapping protocol. Twenty healthy volunteers performed a variety of fine motor tests during baseline and nTMS to the SMA using 5 Hz, 10 Hz, and theta-burst stimulation (TBS). Effects on performance were measured by test completion times (TCTs), standard deviation of inter-tap interval (SDIT), and visible coordination problems (VCPs). The predominant stimulation effect was slowing of TCTs, i.e. a slowdown of test performances during stimulation. Furthermore, participants exhibited VCPs like accidental use of contralateral limbs or inability to coordinate movements. More instances of significant differences between baseline and stimulation occurred during stimulation of the right hemisphere compared to left-hemispheric stimulation. In conclusion, nTMS to the SMA could enable new approaches in neuroscience and enable structured mapping approaches. Specifically, this study supports interhemispheric differences in motor control as right-hemispheric stimulation resulted in clearer impairments. The application of our nTMS-based setup to assess the function of the SMA should be applied in patients with changed anatomo-functional representations as the next step, e.g. among patients with eloquent brain tumors.

scholarly journals The role of reading experience in atypical cortical tracking of speech and speech-in-noise in dyslexia

2021 ◽  
Author(s):  
Florian Destoky ◽  
Julie Bertels ◽  
Maxime Niesen ◽  
Vincent Wens ◽  
Marc Vander Ghinst ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Acoustic Noise ◽  
Brain Activity ◽  
Superior Temporal Gyrus ◽  
Reading Level ◽  
School Age Children ◽  
Reading Experience ◽  
Speech In Noise ◽  
The Right

Dyslexia is a frequent developmental disorder in which reading acquisition is delayed and that is usually associated with difficulties understanding speech in noise. At the neuronal level, children with dyslexia were reported to display abnormal cortical tracking of speech (CTS) at phrasal rate. Here, we aimed to determine if abnormal tracking is a cause or a consequence of dyslexia and if it is modulated by the severity of dyslexia or the presence of acoustic noise. We included 26 school-age children with dyslexia, 26 age-matched controls and 26 reading-level matched controls. All were native French speakers. Children's brain activity was recorded with magnetoencephalography while they listened to continuous speech in noiseless and multiple noise conditions. CTS values were compared between groups, conditions and hemispheres, and also within groups, between children with best and worse reading performance. Syllabic CTS was significantly reduced in the right superior temporal gyrus in children with dyslexia compared with controls matched for age but not for reading level. Among children with dyslexia, phrasal CTS tended to lateralize to the left hemisphere in severe dyslexia and lateralized to the right hemisphere in children with mild dyslexia and in all control groups. Finally, phrasal CTS was lower in children with dyslexia compared with age-matched controls, but only in informational noise conditions. No such effect was seen in comparison with reading-level matched controls. Overall, our results confirmed the finding of altered neuronal basis of speech perception in noiseless and babble noise conditions in dyslexia compared with age-matched peers. However, the absence of alteration in comparison with reading-level matched controls suggests that such alterations are a consequence of reduced reading experience rather than a cause of dyslexia.

Navigated transcranial magnetic stimulation for preoperative language mapping in a patient with a left frontoopercular glioblastoma

2013 ◽  
Vol 118 (1) ◽  
pp. 175-179 ◽  
Author(s):  
Nico Sollmann ◽  
Thomas Picht ◽  
Jyrki P. Mäkelä ◽  
Bernhard Meyer ◽  
Florian Ringel ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Right Hemisphere ◽  
Inferior Frontal Gyrus ◽  
Awake Surgery ◽  
Navigated Transcranial Magnetic Stimulation ◽  
Clear Speech ◽  
Language Mapping ◽  
Motor Mapping ◽  
The Right

Up to now, navigated transcranial magnetic stimulation (nTMS) has been used for motor mapping in the vicinity of rolandic brain lesions. Recently, nTMS has also been suggested to be useful in mapping human language areas. The authors describe the case of a left-handed patient with a left-side glioblastoma within the opercular inferior frontal gyrus who presented with severe motor aphasia. Preoperative functional MRI (fMRI) indicated speech dominance of the right hemisphere and did not show any language-related activation in the vicinity of the tumor. Navigated TMS, however, showed a significantly higher rate of induced speech arrests for the left than for the right. Left-side direct cortical stimulation induced clear speech arrests during awake surgery. This case suggests that nTMS may be useful for preoperative speech mapping in tumors affecting the anatomy, vasculature, and brain oxygen levels and therefore impairing fMRI reliability.

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