scholarly journals Is Lateropulsion Really Related with a Specific Lesion of the Brain?

2021 ◽  
Vol 11 (3) ◽  
pp. 354
Author(s):  
Kyoung Lee ◽  
Sang Yoo ◽  
Eun Ji ◽  
Woo Hwang ◽  
Yeun Yoo ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Parietal Lobe ◽  
Inferior Frontal Gyrus ◽  
Brain Lesions ◽  
Vertical Posture ◽  
Lesion Volume ◽  
Precentral Gyrus ◽  
Stroke Patients ◽  
The Right ◽  
Right Hemisphere Stroke

Lateropulsion (pusher syndrome) is an important barrier to standing and gait after stroke. Although several studies have attempted to elucidate the relationship between brain lesions and lateropulsion, the effects of specific brain lesions on the development of lateropulsion remain unclear. Thus, the present study investigated the effects of stroke lesion location and size on lateropulsion in right hemisphere stroke patients. The present retrospective cross-sectional observational study assessed 50 right hemisphere stroke patients. Lateropulsion was diagnosed and evaluated using the Scale for Contraversive Pushing (SCP). Voxel-based lesion symptom mapping (VLSM) analysis with 3T-MRI was used to identify the culprit lesion for SCP. We also performed VLSM controlling for lesion volume as a nuisance covariate, in a multivariate model that also controlled for other factors contributing to pusher behavior. VLSM, combined with statistical non-parametric mapping (SnPM), identified the specific region with SCP. Lesion size was associated with lateropulsion. The precentral gyrus, postcentral gyrus, inferior frontal gyrus, insula and subgyral parietal lobe of the right hemisphere seemed to be associated with the lateropulsion; however, after adjusting for lesion volume as a nuisance covariate, no lesion areas were associated with the SCP scores. The size of the right hemisphere lesion was the only factor most strongly associated with lateropulsion in patients with stroke. These results may be useful for planning rehabilitation strategies of restoring vertical posture and understanding the pathophysiology of lateropulsion in stroke patients.

scholarly journals Impaired Recognition of Emotional Faces after Stroke Involving Right Amygdala or Insula

2018 ◽  
Vol 39 (01) ◽  
pp. 087-100 ◽  
Author(s):  
Brittany Godin ◽  
Kumiko Oishi ◽  
Kenichi Oishi ◽  
Cameron Davis ◽  
Yessenia Gomez ◽  
...  
Keyword(s):  
Facial Expressions ◽  
Right Hemisphere ◽  
Anterior Insula ◽  
Human Anatomy ◽  
Lesion Volume ◽  
Stroke Patients ◽  
Emotional Faces ◽  
The Right ◽  
Right Hemisphere Stroke

AbstractDespite its basic and translational importance, the neural circuitry supporting the perception of emotional faces remains incompletely understood. Functional imaging studies and chronic lesion studies indicate distinct roles of the amygdala and insula in recognition of fear and disgust in facial expressions, whereas intracranial encephalography studies, which are not encumbered by variations in human anatomy, indicate a somewhat different role of these structures. In this article, we leveraged lesion-mapping techniques in individuals with acute right hemisphere stroke to investigate lesions associated with impaired recognition of prototypic emotional faces before significant neural reorganization can occur during recovery from stroke. Right hemisphere stroke patients were significantly less accurate than controls on a test of emotional facial recognition for both positive and negative emotions. Patients with right amygdala or anterior insula lesions had significantly lower scores than other right hemisphere stroke patients on recognition of angry and happy faces. Lesion volume within several regions, including the right amygdala and anterior insula, each independently contributed to the error rate in recognition of individual emotions. Results provide additional support for a necessary role of the right amygdala and anterior insula within a network of regions underlying recognition of facial expressions, particularly those that have biological importance or motivational relevance and have implications for clinical practice.

FV15 Revisiting the concept of apraxia in the right hemisphere: Evidence from 139 acute right hemisphere stroke patients

2020 ◽  
Vol 131 (4) ◽  
pp. e230-e231
Author(s):  
A. Dreßing ◽  
L.A. Beume ◽  
M. Martin ◽  
D.Kümmerer ◽  
H. Urbach ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Stroke Patients ◽  
The Right ◽  
Right Hemisphere Stroke

Abstract WP160: Delirium in Right Hemisphere Stroke

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Sara K Rostanski ◽  
Marykay A Pavol ◽  
Marissa Barbaro ◽  
Minji Kim ◽  
Randolph S Marshall ◽  
...  
Keyword(s):  
Right Hemisphere ◽  
Parietal Lobe ◽  
Cognitive Status ◽  
Screening Tools ◽  
Stroke Patients ◽  
Altered Level ◽  
Stroke Registry ◽  
Public Health Burden ◽  
Systematic Assessment ◽  
Right Hemisphere Stroke

Introduction: Delirium, a disorder of attention and arousal, poses a large public health burden. Inattention and fluctuating cognitive status, two primary delirium symptoms, also occur when specialized right brain systems are impaired. Although right hemisphere stroke may predispose to delirium, systematic assessment methods and management of these patients are not yet available. We sought to characterize the incidence of delirium in right hemisphere stroke patients and explore whether stroke localization was associated with delirium. Methods: We identified consecutive patients admitted to our stroke service with acute right hemisphere stroke over a 6-month period from our prospective stroke registry. We reviewed the medical record for core delirium symptoms: inattention, cognitive fluctuation, and either disorganized thinking, or altered level of consciousness. Delirium was assessed by systematically screening for trigger words. We compared baseline characteristics with Fisher’s exact and t-tests and assessed relation of stroke localization to delirium with logistic regression. Results: Of 105 patients with acute right hemisphere stroke, 27 (26%) had delirium. Delirium patients were older (mean age 78 vs. 68, p<0.01), more likely to have dementia (30% vs. 5%, p<0.01) and prior stroke (52% vs. 28%, p=0.03). Median length of stay was longer (5 vs. 3 days, p<0.01), and discharge home less likely (37% vs. 64%, p=0.01) in those with delirium. Delirium patients more often had strokes involving the parietal lobe (44% vs. 17%, p<0.01). In a multivariable model, parietal localization strongly predicted incident delirium (OR 3.6 95%CI 1.1-11.3, p=0.03) adjusting for age, baseline NIHSS, and premorbid dementia. Conclusion: The high delirium incidence we found supports routine delirium screening in acute stroke patients. Stroke localization may be one factor to incorporate into screening tools. Studies to prospectively identify and treat delirium in both right and left hemisphere stroke patients are warranted.

Dysfunction of the Human Mirror Neuron System in Ideomotor Apraxia: Evidence from Mu Suppression

2016 ◽  
Vol 28 (6) ◽  
pp. 775-791 ◽  
Author(s):  
Silvi Frenkel-Toledo ◽  
Dario G. Liebermann ◽  
Shlomo Bentin ◽  
Nachum Soroker
Keyword(s):  
Right Hemisphere ◽  
Mirror Neuron System ◽  
Inferior Frontal Gyrus ◽  
Mirror Neuron ◽  
Stroke Patients ◽  
Neuron System ◽  
Mu Suppression ◽  
Ideomotor Apraxia ◽  
Manual Movements ◽  
The Right

Stroke patients with ideomotor apraxia (IMA) have difficulties controlling voluntary motor actions, as clearly seen when asked to imitate simple gestures performed by the examiner. Despite extensive research, the neurophysiological mechanisms underlying failure to imitate gestures in IMA remain controversial. The aim of the current study was to explore the relationship between imitation failure in IMA and mirror neuron system (MNS) functioning. Mirror neurons were found to play a crucial role in movement imitation and in imitation-based motor learning. Their recruitment during movement observation and execution is signaled in EEG recordings by suppression of the lower (8–10 Hz) mu range. We examined the modulation of EEG in this range in stroke patients with left (n = 21) and right (n = 15) hemisphere damage during observation of video clips showing different manual movements. IMA severity was assessed by the DeRenzi standardized diagnostic test. Results showed that failure to imitate observed manual movements correlated with diminished mu suppression in patients with damage to the right inferior parietal lobule and in patients with damage to the right inferior frontal gyrus pars opercularis—areas where major components of the human MNS are assumed to reside. Voxel-based lesion symptom mapping revealed a significant impact on imitation capacity for the left inferior and superior parietal lobules and the left post central gyrus. Both left and right hemisphere damages were associated with imitation failure typical of IMA, yet a clear demonstration of relationship to the MNS was obtained only in the right hemisphere damage group. Suppression of the 8–10 Hz range was stronger in central compared with occipital sites, pointing to a dominant implication of mu rather than alpha rhythms. However, the suppression correlated with De Renzi's apraxia test scores not only in central but also in occipital sites, suggesting a multifactorial mechanism for IMA, with a possible impact for deranged visual attention (alpha suppression) beyond the effect of MNS damage (mu suppression).

scholarly journals Speech–Brain Frequency Entrainment of Dyslexia with and without Phonological Deficits

2020 ◽  
Vol 10 (12) ◽  
pp. 920
Author(s):  
Juliana Dushanova ◽  
Yordanka Lalova ◽  
Antoaneta Kalonkina ◽  
Stefan Tsokov
Keyword(s):  
Developmental Dyslexia ◽  
Verbal Memory ◽  
Right Hemisphere ◽  
Parietal Lobe ◽  
Inferior Frontal Gyrus ◽  
Posterior Part ◽  
Cortical Reorganization ◽  
Frequency Entrainment ◽  
Phonological Deficits ◽  
The Right

Developmental dyslexia is a cognitive disorder characterized by difficulties in linguistic processing. Our purpose is to distinguish subtypes of developmental dyslexia by the level of speech–EEG frequency entrainment (δ: 1–4; β: 12.5–22.5; γ1: 25–35; and γ2: 35–80 Hz) in word/pseudoword auditory discrimination. Depending on the type of disabilities, dyslexics can divide into two subtypes—with less pronounced phonological deficits (NoPhoDys—visual dyslexia) and with more pronounced ones (PhoDys—phonological dyslexia). For correctly recognized stimuli, the δ-entrainment is significantly worse in dyslexic children compared to controls at a level of speech prosody and syllabic analysis. Controls and NoPhoDys show a stronger δ-entrainment in the left-hemispheric auditory cortex (AC), anterior temporal lobe (ATL), frontal, and motor cortices than PhoDys. Dyslexic subgroups concerning normolexics have a deficit of δ-entrainment in the left ATL, inferior frontal gyrus (IFG), and the right AC. PhoDys has higher δ-entrainment in the posterior part of adjacent STS regions than NoPhoDys. Insufficient low-frequency β changes over the IFG, the inferior parietal lobe of PhoDys compared to NoPhoDys correspond to their worse phonological short-term memory. Left-dominant 30 Hz-entrainment for normolexics to phonemic frequencies characterizes the right AC, adjacent regions to superior temporal sulcus of dyslexics. The pronounced 40 Hz-entrainment in PhoDys than the other groups suggest a hearing “reassembly” and a poor phonological working memory. Shifting up to higher-frequency γ-entrainment in the AC of NoPhoDys can lead to verbal memory deficits. Different patterns of cortical reorganization based on the left or right hemisphere lead to differential dyslexic profiles.

scholarly journals Unilateral Stroke: Computer-based Assessment Uncovers Non-Lateralized and Contralesional Visuoattentive Deficits

2021 ◽  
pp. 1-11
Author(s):  
Sanna Villarreal ◽  
Matti Linnavuo ◽  
Raimo Sepponen ◽  
Outi Vuori ◽  
Mario Bonato ◽  
...  
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Stroke Patients ◽  
Cancellation Task ◽  
Computer Based ◽  
Left And Right ◽  
The Right ◽  
Visual Inattention ◽  
Left Hemisphere Stroke ◽  
Right Hemisphere Stroke

Abstract Objective: Patients with unilateral stroke commonly show hemispatial neglect or milder contralesional visuoattentive deficits, but spatially non-lateralized visuoattentive deficits have also been reported. The aim of the present study was to compare spatially lateralized (i.e., contralesional) and non-lateralized (i.e., general) visuoattentive deficits in left and right hemisphere stroke patients. Method: Participants included 40 patients with chronic unilateral stroke in either the left hemisphere (LH group, n = 20) or the right hemisphere (RH group, n = 20) and 20 healthy controls. To assess the contralesional deficits, we used a traditional paper-and-pencil cancellation task (the Bells Test) and a Lateralized Targets Computer Task. To assess the non-lateralized deficits, we developed a novel large-screen (173 × 277 cm) computer method, the Ball Rain task, with moving visual stimuli and fast-paced requirements for selective attention. Results: There were no contralesional visuoattentive deficits according to the cancellation task. However, in the Lateralized Targets Computer Task, RH patients missed significantly more left-sided than right-sided targets in bilateral trials. This omission distribution differed significantly from those of the controls and LH patients. In the assessment of non-lateralized attention, RH and LH patients missed significantly more Ball Rain targets than controls in both the left and right hemifields. Conclusions: Computer-based assessment sensitively reveals various aspects of visuoattentive deficits in unilateral stroke. Patients with either right or left hemisphere stroke demonstrate non-lateralized visual inattention. In right hemisphere stroke, these symptoms can be accompanied by subtle contralesional visuoattentive deficits that have remained unnoticed in cancellation task.

Assessing visual extinction in right-hemisphere stroke patients with and without neglect

2010 ◽  
Vol 41 (01) ◽  
Author(s):  
S Vossel ◽  
P Eschenbeck ◽  
P Weiss ◽  
G Fink
Keyword(s):  
Right Hemisphere ◽  
Stroke Patients ◽  
Visual Extinction ◽  
Right Hemisphere Stroke

scholarly journals Are visual working memory and episodic memory distinct processes? Insight from stroke patients by lesion-symptom mapping

2021 ◽  
Author(s):  
Selma Lugtmeijer ◽  
◽  
Linda Geerligs ◽  
Frank Erik de Leeuw ◽  
Edward H. F. de Haan ◽  
...  
Keyword(s):  
Working Memory ◽  
Episodic Memory ◽  
Visual Working Memory ◽  
Visual Memory ◽  
Right Hemisphere ◽  
Memory Task ◽  
Stroke Patients ◽  
Lesion Symptom Mapping ◽  
Criterion Setting ◽  
The Right

AbstractWorking memory and episodic memory are two different processes, although the nature of their interrelationship is debated. As these processes are predominantly studied in isolation, it is unclear whether they crucially rely on different neural substrates. To obtain more insight in this, 81 adults with sub-acute ischemic stroke and 29 elderly controls were assessed on a visual working memory task, followed by a surprise subsequent memory test for the same stimuli. Multivariate, atlas- and track-based lesion-symptom mapping (LSM) analyses were performed to identify anatomical correlates of visual memory. Behavioral results gave moderate evidence for independence between discriminability in working memory and subsequent memory, and strong evidence for a correlation in response bias on the two tasks in stroke patients. LSM analyses suggested there might be independent regions associated with working memory and episodic memory. Lesions in the right arcuate fasciculus were more strongly associated with discriminability in working memory than in subsequent memory, while lesions in the frontal operculum in the right hemisphere were more strongly associated with criterion setting in subsequent memory. These findings support the view that some processes involved in working memory and episodic memory rely on separate mechanisms, while acknowledging that there might also be shared processes.

The Role of the Right Prefrontal Cortex in Self-evaluation of the Face: A Functional Magnetic Resonance Imaging Study

2008 ◽  
Vol 20 (2) ◽  
pp. 342-355 ◽  
Author(s):  
Tomoyo Morita ◽  
Shoji Itakura ◽  
Daisuke N. Saito ◽  
Satoshi Nakashita ◽  
Tokiko Harada ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Face Recognition ◽  
Inferior Frontal Gyrus ◽  
Video Recording ◽  
Imaging Study ◽  
The Self ◽  
Anterior Cingulate ◽  
Precentral Gyrus ◽  
Self Evaluation ◽  
The Right

Individuals can experience negative emotions (e.g., embarrassment) accompanying self-evaluation immediately after recognizing their own facial image, especially if it deviates strongly from their mental representation of ideals or standards. The aim of this study was to identify the cortical regions involved in self-recognition and self-evaluation along with self-conscious emotions. To increase the range of emotions accompanying self-evaluation, we used facial feedback images chosen from a video recording, some of which deviated significantly from normal images. In total, 19 participants were asked to rate images of their own face (SELF) and those of others (OTHERS) according to how photogenic they appeared to be. After scanning the images, the participants rated how embarrassed they felt upon viewing each face. As the photogenic scores decreased, the embarrassment ratings dramatically increased for the participant's own face compared with those of others. The SELF versus OTHERS contrast significantly increased the activation of the right prefrontal cortex, bilateral insular cortex, anterior cingulate cortex, and bilateral occipital cortex. Within the right prefrontal cortex, activity in the right precentral gyrus reflected the trait of awareness of observable aspects of the self; this provided strong evidence that the right precentral gyrus is specifically involved in self-face recognition. By contrast, activity in the anterior region, which is located in the right middle inferior frontal gyrus, was modulated by the extent of embarrassment. This finding suggests that the right middle inferior frontal gyrus is engaged in self-evaluation preceded by self-face recognition based on the relevance to a standard self.

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