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1.
J Clin Neurosci ; 90: 363-369, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34275577

RESUMO

OBJECTIVE: To investigate the effects of paired associated stimulation (PAS) with different stimulation position on motor cortex excitability and upper limb motor function in patients with cerebral infarction. METHOD: A total of 120 volunteers with cerebral infarction were randomly divided into four groups. Based on conventional rehabilitation treatment, the PAS stimulation group was given the corresponding position of PAS treatment once a day for 28 consecutive days. The MEP amplitude and RMT of both hemispheres were assessed before and after treatment, and a simple upper limb Function Examination Scale (STEF) score, simplified upper limb Fugl-Meyer score (FMA), and improved Barthel Index (MBI) were used to assess upper limb motor function in the four groups. RESULTS: Following PAS, the MEP amplitude decreased, and the RMT of abductor pollicis brevis (APB) increased on the contralesional side, while the MEP amplitude increased and the RMT of APB decreased on the ipsilesional side. After 28 consecutive days the scores of STEF, FMA, and MBI in the bilateral stimulation group were significantly better than those in the ipsilesional stimulation group and the contralesional stimulation group, but there was no significant difference in the scores of STEF, FMA, and MBI between the ipsilesional stimulation group and the contralesional stimulation group. CONCLUSION: The excitability of the motor cortex can be changed when the contralesional side or the ipsilesional side was given the corresponding PAS stimulation, while the bilateral PAS stimulation can more easily cause a change of excitability of the motor cortex, resulting in better recovery of the upper limb function.


Assuntos
Infarto Cerebral/fisiopatologia , Infarto Cerebral/reabilitação , Terapia por Estimulação Elétrica , Córtex Motor/fisiopatologia , Extremidade Superior/fisiopatologia , Adulto , Potencial Evocado Motor , Feminino , Lateralidade Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Reabilitação do Acidente Vascular Cerebral/métodos , Estimulação Magnética Transcraniana
2.
Epilepsy Behav ; 121(Pt A): 108041, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34082317

RESUMO

Identification of the language dominant hemisphere is an essential part of the evaluation of potential pediatric epilepsy surgery patients. Historically, language dominance has been determined using the intracarotid amobarbitol procedure (IAP), but use of functional Magnetic Resonance Imaging (fMRI) scanning is becoming more common. Few studies examine the correspondence between fMRI and IAP in pediatric samples. The current study examined the agreement of hemispheric lateralization as determined by fMRI and IAP in a consecutive sample of 10 pediatric patients with epilepsy evaluated for epilepsy surgery. Data showed a strong correlation between IAP and fMRI lateralilty indices (r=.91) and 70% agreement in determination of hemispheric dominance, despite increased demonstration of bilateral or atypical language representation in this pediatric sample. Clinical implications and interpretation challenges are discussed.


Assuntos
Epilepsia , Idioma , Amobarbital , Mapeamento Encefálico , Córtex Cerebral , Criança , Tomada de Decisão Clínica , Dominância Cerebral , Epilepsia/diagnóstico por imagem , Lateralidade Funcional , Humanos , Imageamento por Ressonância Magnética
3.
J Clin Neurosci ; 89: 139-143, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34119257

RESUMO

Functional movement disorder (FMD) presents as disabling motor symptoms that cannot be explained by organic processes. Despite the lack of lesion or known central nervous system dysfunction, distortion in sensorimotor processing in movement generation and execution is often observed. A person's capacity to judge laterality of a body part requires processing of sensorimotor information. This prospective observational study compared reaction time (RT) and accuracy (ACC) of hand laterality recognition between 30 people diagnosed with FMD and 30 age-matched healthy control participants. The association of RT and ACC with severity of FMD as measured by the Simplified Functional Movement Disorders Rating Scale (SFMDRS) was also explored. RT was on average 0.6 s slower (95% CI 0.4 - 0.8 s, p < 0.001) in patients with FMD (mean 2.2 s, standard deviation (SD) 0.5) than controls (mean 1.7 s, SD 0.3). ACC was on average 8.9% lower (95% CI -15.7 - -2.2, p = 0.01) in patients with FMD (mean 79.6%, SD 16.6) than controls (mean 88.5%, SD 8.1). When adjusted for SFMDRS using robust regression, RT was 0.3 s slower (95% CI 0.01 - 0.5, p = 0.04) in cases than in controls, but ACC was no longer different between groups. There was a moderate negative correlation between RT and ACC in FMD patients (ρ -0.58, p < 0.001 but not in controls (ρ -0.26, p = 0.17). People with FMD had significantly slower RT and lower ACC compared to the control group. These results provide new insights into underlying sensorimotor processing deficits in those with FMD.


Assuntos
Lateralidade Funcional/fisiologia , Mãos/fisiologia , Imaginação/fisiologia , Transtornos dos Movimentos/fisiopatologia , Movimento/fisiologia , Reconhecimento Psicológico/fisiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos dos Movimentos/diagnóstico , Transtornos dos Movimentos/psicologia , Estudos Prospectivos , Tempo de Reação/fisiologia
5.
Adv Exp Med Biol ; 1269: 223-227, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33966221

RESUMO

Autonomic disorders such as orthostatic hypotension often become a problem during the early mobilization of poststroke patients. We reported that the prefrontal cortex (PFC) oxyhemoglobin changes at rest are often on the right, and a positive correlation was observed between the left and right activity balance and the change in oxy-Hb. In this study, we focused on the asymmetrical changes associated with the standing load from rest. We assessed the left-right asymmetry of the PFC oxyhemoglobin changes at rest and standing load by calculating the Laterality Index at Rest (LIR) and laterality index during activity (LIA); positive values indicate the right-dominant activity, while negative values indicate left-dominant activity. As for left-right asymmetry LIA, the active dominant PFC was reversed in five patients. It should be noted that in almost all of the 13 cases, the active PFC and the lesion side matched. The detailed mechanism of overactivity up to the prefrontal cortex on the lesion side is unknown, but it may be a recovery mechanism that elicits plasticity in the brain network.


Assuntos
Espectroscopia de Luz Próxima ao Infravermelho , Acidente Vascular Cerebral , Lateralidade Funcional , Humanos , Oxiemoglobinas , Córtex Pré-Frontal/diagnóstico por imagem , Acidente Vascular Cerebral/diagnóstico por imagem
6.
Neuroscience ; 466: 36-46, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33971265

RESUMO

Few studies have identified the intrahemispheric functional connectivity between the ipsilateral dorsal premotor cortex (PMd) and the primary motor hand area (M1hand) due to technical limitations. In this proof-of-concept study, a novel neuronavigated dsTMS set-up was employed, combining stimulation over left PMd and left M1hand using the edge of a butterfly coil and a small cooled-coil. This arrangement was warranted because coil (over)heating and inter coil distance are limiting factors when investigating connectivity between stimulation targets in close proximity and over a longer duration. The proposed set-up was designed to deal with these limitations. Specifically, the effect of four dual-site transcranial magnetic stimulation (dsTMS) protocols on twenty-eight right-handed participants (12 males) was evaluated. These protocols differed in stimulus order, interstimulus interval and current direction induced in PMd. A structural scan with electric (E-)field modeling was obtained from seven participants prior to dsTMS, demonstrating that PMd and M1hand were effectively stimulated. Results indicate that one protocol, in which a latero-medial current was induced in PMd 2.8 ms prior to stimulation over M1hand, induced a sex-mediated effect. In males, significant inhibition of motor-evoked potentials was identified, whereas females demonstrated a facilitatory effect that did not survive correction for multiple comparisons. E-field simulations revealed that the E-field induced by the coil targeting PMd was maximal in PMd, with weaker E-field strengths extending to regions beyond PMd. Summarizing, the current dsTMS set-up enabled stimulating at an inter-target distance of 35 mm without any indications of coil-overheating.


Assuntos
Córtex Motor , Potencial Evocado Motor , Feminino , Lateralidade Funcional , Mãos , Humanos , Masculino , Estudo de Prova de Conceito , Estimulação Magnética Transcraniana
7.
Brain Topogr ; 34(4): 489-503, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33948754

RESUMO

Idiomatic expressions (IE) are groups of words whose meaning is different from the sum of its components. Neural mechanisms underlying their processing are still debated, especially regarding lateralization, main structures involved, and whether this neural network is independent from the spoken language. To investigate the neural correlates of IE processing in healthy Spanish speakers.Twenty one native speakers of Spanish were asked to select one of 4 possible meanings for IE or literal sentences. fMRI scans were performed in a 3.0T scanner and processed by SPM 12 comparing IE vs. literal sentences. Laterality indices were calculated at the group level. IE activated a bilateral, slightly right-sided network comprising the pars triangularis and areas 9 and 10. In the left hemisphere (LH): the pars orbitalis, superior frontal, angular and fusiform gyrus. In the right hemisphere (RH): anterior insula, middle frontal, and superior temporal gyrus. This network reveals the importance of the RH, besides traditional LH areas, to comprehend IE. This agrees with the semantic coding model: the LH activates narrow semantic fields choosing one single meaning and ignoring others, and the RH detects distant semantic relationships, activating diffuse semantic fields. It is also in line with the configuration hypothesis: both meanings, literal and figurative, are executed simultaneously, until the literal meaning is definitively rejected and the figurative one is accepted. Processing IE requires the activation of fronto-temporal networks in both hemispheres. The results concur with previous studies in other languages, so these networks are independent from the spoken language. Understanding these mechanisms sheds light on IE processing difficulties in different clinical populations and must be considered when planning resective surgery.


Assuntos
Mapeamento Encefálico , Compreensão , Encéfalo/diagnóstico por imagem , Lateralidade Funcional , Humanos , Idioma , Imageamento por Ressonância Magnética , Semântica
8.
Cortex ; 140: 110-127, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33975084

RESUMO

While Liepmann was one of the first researchers to consider a relationship between skilled manual actions (praxis) and language for tasks performed "freely from memory", his primary focus was on the relations between the organization of praxis and left-hemisphere dominance. Subsequent attempts to apply his apraxia model to all cases he studied - including his first patient, a "non-pure right-hander" treated as an exception - left the praxis-handedness issue unresolved. Modern neuropsychological and recent neuroimaging evidence either showed closer associations of praxis and language, than between handedness and any of these two functions, or focused on their dissociations. Yet, present-day developments in neuroimaging and statistics allow us to overcome the limitations of the earlier work on praxis-language-handedness links, and to better quantify their interrelationships. Using functional magnetic resonance imaging (fMRI), we studied tool use pantomimes and subvocal word generation in 125 participants, including righthanders (NRH = 52), ambidextrous individuals (mixedhanders; NMH = 31), and lefthanders (NLH = 42). Laterality indices were calculated both in two critical cytoarchitectonic maps, and 180 multi-modal parcellations of the human cerebral cortex, using voxel count and signal intensity, and the most relevant regions of interest and their networks were further analyzed. We found that atypical organization of praxis was present in all handedness groups (RH = 25.0%, MH = 22.6%; LH = 45.2%), and was about two and a half times as common as atypical organization of language (RH = 3.8%; MH = 6.5%; LH = 26.2%), contingent on ROI selection/LI-calculation method. Despite strong associations of praxis and language, regardless of handedness and typicality, dissociations of atypically represented praxis from typical left-lateralized language were common (~20% of cases), whereas the inverse dissociations of atypically represented language from typical left-lateralized praxis were very rare (in ~2.5% of all cases). The consequences of the existence of such different phenotypes for theoretical accounts of manual praxis, and its links to language and handedness are modeled and discussed.


Assuntos
Lateralidade Funcional , Idioma , Mapeamento Encefálico , Córtex Cerebral , Humanos , Imageamento por Ressonância Magnética
9.
Cortex ; 140: 210-221, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34000477

RESUMO

Anxiety disorders are the most common mental disorders impacting people worldwide. Using an auditory Stop Signal Task (SST), we have developed an anxiety disorder biomarker (goal-conflict specific rhythmicity/GCSR) that occurs at the right frontal site F8 in right-handed participants. Here, we compare its laterality in left-handers (n = 26) versus demographically-matched right-handers (n = 26) between the ages of 18-30. We assessed the effects on GCSR power of the handedness of the participants (left or right), blocks of the SST, left-right variation across frontal channels (F7, F3, Fz, F4, F8), and EEG frequency (4-12 Hz). Left-handers differed from right-handers most at the channels furthest from the midline. This difference was largely a mirroring of right hander responses by left handers. With frontal channels coded in reverse order for left handers the original significant differences disappeared. Some differences remained between the groups in the frequency variation across blocks of testing. These and other data suggest that the circuitry engaged by conflict in the SST is different from that directly controlling stopping behaviour. Our results also suggest that where GCSR is used as an anxiety process or disorder biomarker in groups that combine both left and right-handed people, data only from the channel ipsilateral to the dominant hand should be used (F7, or F8, respectively).


Assuntos
Transtornos de Ansiedade , Lateralidade Funcional , Adolescente , Adulto , Biomarcadores , Eletroencefalografia , Mãos , Humanos , Adulto Jovem
10.
ACS Nano ; 15(6): 10328-10341, 2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34047551

RESUMO

Helical supramolecular architectures play important structural and functional roles in biological systems. Although their occurrence is widely perceived to correlate to fundamental chiral units including l-amino acids and d-sugars, the detailed relationship between molecular and supramolecular handedness is still unclear. At the same time, although achiral units are practically always in close proximity to chiral ones by covalent linkage along a polymeric chain, their effect on supramolecular handedness has received relatively less attention. Here, we designed a set of short amphiphilic peptides, in which an achiral glycine residue was incorporated at the interface between the hydrophobic and hydrophilic segments. We observed that glycine incorporation caused dramatic variations in suprastructural handedness in self-assembled peptide nanofibrils, and the effect of the hydrophilic charged residue at the C-terminus on supramolecular handedness was demolished, leading to chiral truncation. Furthermore, molecular dynamics simulations and quantum chemistry calculations revealed that the unanticipated role of the glycine residue in regulating supramolecular handedness originated from its effect on the conformational preference of single ß-strands. Importantly, reduced density gradient analyses on single ß-strands indicated that, due to the lack of a side chain in glycine, intricate noncovalent interactions were produced among the neighboring amino acid side chains of the incorporated glycine and its local backbone, resulting in diverse ß-strand conformations.


Assuntos
Lateralidade Funcional , Glicina , Aminoácidos , Simulação de Dinâmica Molecular , Peptídeos
11.
Biol Psychol ; 162: 108111, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33961931

RESUMO

Anxious apprehension and anxious arousal are central transdiagnostic anxiety dimensions and have been linked to divergent patterns of frontal and parietal alpha asymmetry. The present study examined the relationship between alpha asymmetry and anxiety dimensions in 130 individuals whose electroencephalogram (EEG) was recorded at rest. We applied a 2 (anxious apprehension: low vs. high) × 2 (anxious arousal, low vs. high) design to contrast brain lateralization in four groups. Results revealed that anxious apprehension was associated with more left-than-right frontal brain activity in the lower alpha band, an effect driven by decreased right frontal activity. Exploratory analyses showed more left-than-right brain activity at central sites associated with anxious apprehension. Parietal activity was not lateralized as a function of anxiety dimensions. Taken together, the current results support that anxious apprehension is associated with more left-than-right frontal and central activity, and suggest a broader distribution of alpha asymmetries associated with anxious apprehension than previously thought.


Assuntos
Ansiedade , Eletroencefalografia , Transtornos de Ansiedade , Nível de Alerta , Córtex Cerebral , Lateralidade Funcional , Humanos
12.
Neuropsychology ; 35(3): 310-322, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33970664

RESUMO

Objective: Right brain-damaged patients may show omissions and/or additional marks in target cancellation. The latter is classified as perseverative behavior and has been attributed to defective response inhibition or attentional disengagement deficit. This study aimed at (a) verifying that consecutive (immediate) and return (temporally distant) motor perseverations could be due to different mechanisms; (b) investigating the relationships among different types of perseveration (e.g., consecutive, return, scribble), spatial neglect and the impairment in specific components of executive functioning. Method: Seventeen right brain-damaged patients underwent letter, star, bell, and apple cancellation tasks. A global index for each type of perseveration found and Mean Position of Hits, as a neglect index, were calculated. The following components of executive functioning were evaluated: motor programming (Frontal Assessment Battery [FAB] subtest), inhibitory control FAB, interference sensitivity (FAB and Stroop color-word interference test), set-shifting (Weigl sorting test, Phonemic/semantic alternate fluencies), and working memory (Backward Digit span). Results: Ten patients out of 17 showed some degree of perseveration. Regularized linear regression analyses demonstrated that interference sensitivity and Stroop test performances were related to return perseverations and backward digit to scribble ones. No significant relationships were found for consecutive perseverations and between neglect and any type of perseverations. Conclusions: The present study showed that return perseverations might have a distinct etiology from consecutive ones, being related to an inability to update and shift between action programs according to the visual stimuli. A finer classification of perseverations could help in unveiling the neuropsychological mechanisms underlying each type of behavior. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Lesões Encefálicas/fisiopatologia , Lateralidade Funcional , Transtornos da Percepção/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Lesões Encefálicas/psicologia , Isquemia Encefálica/fisiopatologia , Isquemia Encefálica/psicologia , Neoplasias Encefálicas/fisiopatologia , Neoplasias Encefálicas/psicologia , Córtex Cerebral , Função Executiva , Feminino , Humanos , Hemorragias Intracranianas/fisiopatologia , Hemorragias Intracranianas/psicologia , Masculino , Memória de Curto Prazo , Pessoa de Meia-Idade , Testes Neuropsicológicos , Transtornos da Percepção/psicologia , Estudos Prospectivos , Desempenho Psicomotor/fisiologia , Teste de Stroop
13.
Neuropsychologia ; 158: 107894, 2021 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-34022186

RESUMO

Background; The goal of this review is 1) to summarize the studies assessing PFP by casual observers, patients themselves and the cosmetic appreciation of the PFP and 2) to summarize the studies assessing whether there is a difference in emotional recognition/processing of facial emotions and/or cognitive tasks in patients with a PFP. Materials and Methods; A multi-database systematic literature search was performed using the following databases: Pubmed, Embase, Medline, and The Cochrane Library from the earliest date of each database up to December 2019. Population of interest consisted of patients with a PFP and studies that investigated cosmetic appreciation and/or emotional recognition and/or emotional processing in these patients. Two authors rated the methodological quality of the included studies independently using the 'Newcastle - Ottawa Quality Assessment Scale' for nonrandomised studies' (NOS). Two authors extracted the outcome data regarding cosmetic appreciation and/or emotional recognition/processing from the included studies. Results; Twelve hundred and thirty-two studies were found of which eleven studies met the inclusion criteria. Most studies were assessed to be of 'fair' to 'good' methodological quality. The Cohen's kappa (between author RL and SP) was 0.68. Two studies investigated emotional processing and/or emotional recognition. Nine studies investigated cosmetic appreciation in both patients and casual observers. Important findings of this systematic review are that there is a correlation between the perceived severity of the PFP of the patients and the ratings by casual observers. Secondly there seems to be a laterality difference in cosmetic appreciation and thirdly there might to be a decreased emotional recognition and processing in patients with a PFP. Conclusion; Emotional recognition and cosmetic appreciation in patients with a PFP is an under investigated area, in which further studies are needed to substantiate the findings in current literature.


Assuntos
Paralisia Facial , Emoções , Face , Lateralidade Funcional , Humanos , Reconhecimento Psicológico
14.
Epilepsy Behav ; 121(Pt A): 107995, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34004523

RESUMO

OBJECTIVE: Following hemispherectomy surgery, children's educational outcomes are of great importance but are understudied. The study goal was to investigate reading, language, and nonverbal cognitive skills in children obligatorily relying on a left versus right hemisphere using a cross-sectional design. METHODS: Participants (ages 6-18) who had undergone left hemispherectomy (LH; n = 10) or right hemispherectomy (RH; n = 14) completed standardized measures of reading, language, and nonverbal cognition. RESULTS: LH and RH groups were balanced for socioeconomic status, sex, and age. Both groups scored below the population mean across standardized measures (RH: -0.79 to -1.95 SDs; LH: -0.97 to -2.32 SDs). Compared to the LH group, the group retaining a functional left hemisphere (RH group) learned to read sooner (p = .011) despite no significant differences for surgery age, and scored higher on untimed real word and pseudoword reading measures (p < .05). Effect sizes were medium (r = 0.34-0.46) for the LH and RH comparison on measures of phonological awareness and both untimed and timed word and pseudoword reading. In examining the association between clinical variables and reading-related outcomes, younger age of post-hemispherectomy reading acquisition and shorter duration between seizure onset and hemispherectomy surgery were associated with higher standardized reading and language test scores (p < .05). SIGNIFICANCE: Investigations of psychoeducational skills in reading, language, and nonverbal cognition among children who have undergone hemispherectomy can offer important insights into compensatory potential for left and right hemispheres as well as inform educational programming for children following medical stabilization.


Assuntos
Hemisferectomia , Adolescente , Criança , Estudos Transversais , Lateralidade Funcional , Humanos , Alfabetização , Leitura
15.
Zoolog Sci ; 38(3): 231-237, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34057347

RESUMO

A Japanese piscivorous chub, "hasu" (Opsariichthys uncirostris), and its main prey, "ayu" (Plecoglossus altivelis), both have laterally asymmetric bodies, similar to other fishes; each population consists of righty morphs and lefty morphs. This antisymmetric dimorphism has a genetic basis. Temporal changes in the ratios of laterality (i.e., frequency of righty morphs in a population) of these predator and prey fish species were investigated for a 20-year period at a pelagic site in the southwestern area of Lake Biwa, Japan. The dimorphism of each species was maintained dynamically throughout the period, and the ratio of laterality was found to change periodically in a semi-synchronized manner. Direct inspection of the relationship between the ratios of laterality of the two species indicated that the ratio of ayu followed that of hasu, suggesting that the predator-prey interaction was responsible for the semi-synchronized change. Stomach contents analysis of each hasu revealed that cross-predation, in which righty predators catch lefty prey and lefty predators catch righty prey, occurred more frequently than the reverse combination (parallel-predation). This differential predation is presumed to cause frequency-dependent selection on the two morphs of the predator and prey, and to drive semi-synchronized changes in the laterality of the two species. Some discussion pertaining to the atypical form of the semi-synchronized change in laterality found in this study is presented from the viewpoint of predator-prey interaction in fishes.


Assuntos
Peixes/fisiologia , Lateralidade Funcional , Comportamento Predatório/fisiologia , Animais , Lagos , Especificidade da Espécie , Fatores de Tempo
16.
Laterality ; 26(3): 348-357, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34047243

RESUMO

In our recent opinion paper "Laterality 2020: entering the next decade", we highlighted trends that we thought are likely to shape laterality research in the 2020s. Our opinion paper inspired 11 commentaries by experts from several disciplines which discussed a wide range of topics complementing the 10 trends we identified in the opinion paper. In this reply, we summarize and discuss the 11 commentaries by clustering them into 3 different main topics. The topic that was covered by the largest number of commentaries was the role of comparative and evolutionary approaches in laterality research. Moreover, several comments focused on the ontogenesis of hemispheric asymmetries and the importance of reliability and validity in laterality research. Embracing the technical advances, research trends and controversies laid out in the commentaries will significantly improve our understanding of several of the core questions of laterality research.


Assuntos
Evolução Biológica , Lateralidade Funcional , Reprodutibilidade dos Testes
17.
Nat Commun ; 12(1): 2514, 2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33947840

RESUMO

Primates use their arms in complex ways that frequently require coordination between the two arms. Yet the planning of bimanual movements has not been well-studied. We recorded spikes and local field potentials (LFP) from the parietal reach region (PRR) in both hemispheres simultaneously while monkeys planned and executed unimanual and bimanual reaches. From analyses of interhemispheric LFP-LFP and spike-LFP coherence, we found that task-specific information is shared across hemispheres in a frequency-specific manner. This shared information could arise from common input or from direct communication. The population average unit activity in PRR, representing PRR output, encodes only planned contralateral arm movements while beta-band LFP power, a putative PRR input, reflects the pattern of planned bimanual movement. A parsimonious interpretation of these data is that PRR integrates information about the movement of the left and right limbs, perhaps in service of bimanual coordination.


Assuntos
Potenciais de Ação/fisiologia , Movimento/fisiologia , Lobo Parietal/fisiologia , Desempenho Psicomotor/fisiologia , Animais , Escala de Avaliação Comportamental , Eletrofisiologia , Lateralidade Funcional/fisiologia , Macaca mulatta , Masculino , Córtex Motor/fisiologia , Neurônios/fisiologia , Movimentos Sacádicos/fisiologia , Transdução de Sinais/fisiologia
18.
J Stroke Cerebrovasc Dis ; 30(7): 105777, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33957604

RESUMO

BACKGROUND: The occurrence of unilateral spatial neglect (USN) in non-hemiplegic right-hemisphere damaged patients is rare. Earlier studies of such patients revealed a significant advantage when typical neglect tests were performed by the patient's left hand as compared to the dominant right hand. The mechanism underlying this "output-mode effect" remains elusive. METHODS: We analyzed the temporal dynamics of this effect using line-bisection task in 9 non-hemiplegic stroke patients with left-USN. RESULTS: In 4 patients tested shortly after stroke onset (≤ 6 weeks), the impact of hand laterality was variable (left-hand advantage in one patient; right-hand advantage in 2 patients; similar performance in both hands in one patient). Only later (> 6 weeks) a clear advantage of the left hand emerged in the majority of patients, similar to the earlier reports which were all based on late testing. CONCLUSIONS: We found variable dynamics in the expression of the output-mode effect in the first weeks following stroke onset, which may reflect changes of inter-hemispheric balance, related to recovery processes. We propose that therapeutic interventions aiming to manipulate the inter-hemispheric balance (e.g., by non-invasive brain stimulation) take into account the existence of such dynamics and their highly variate nature.


Assuntos
Cérebro/fisiopatologia , Lateralidade Funcional , Mãos/inervação , Atividade Motora , Acidente Vascular Cerebral/fisiopatologia , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/psicologia , Acidente Vascular Cerebral/terapia , Reabilitação do Acidente Vascular Cerebral , Fatores de Tempo
19.
Artigo em Inglês | MEDLINE | ID: mdl-33805348

RESUMO

The goal of the study was to investigate some of the factors suspected to be related to children's handedness: presentation during the last weeks of gestation and at birth (cephalic or breech), side of presentation (right or left), number of weeks of gestation, season of birth, parents' handedness and sex. We analyzed the relationships between these factors and the child's handedness at five years. Children (n = 1897) from the EDEN cohort participated in the study, among which 1129 were tested for handedness at five. The father's handedness, but not the mother's, was significantly related to the child's hand preference. The percentage of left-handed children was significantly larger when the father was non-right-handed compared to right-handed, and tended to be larger among children in non-left-cephalic presentation compared to left-cephalic presentation. Girls, but not boys, were significantly less lateralized when they were born before 37 weeks of pregnancy than after. Finally, children born in winter or spring were slightly but significantly less lateralized than children born in summer or autumn. All six children who were not lateralized at 5 presented one or several of these factors. These results are discussed in light of the mixed model of handedness.


Assuntos
Lateralidade Funcional , Mãos , Criança , Estudos de Coortes , Feminino , Humanos , Motivação , Parto , Gravidez
20.
Medicine (Baltimore) ; 100(15): e25461, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33847653

RESUMO

RATIONALE: Deep brain stimulation (DBS) of the ventralis intermedius nucleus (Vim) provides a safe and effective therapy for medically refractory essential tremor (ET). However, DBS may be risky in elderly patients and those with ischemic brain lesions. Gamma Knife radiosurgery (GKS) is a minimally invasive procedure, but bilateral thalamotomy is dangerous. PATIENT CONCERNS: We report a case of ventralis oralis anterior nucleus (Voa) DBS for dominant hand tremor plus Voa GKS for nondominant hand tremor in a very elderly patient with medically intractable ET. DIAGNOSIS: An 83-year-old right-handed woman visited our hospital with a medically intractable ET. Because of the ischemic lesion in the right basal ganglia, we decided to perform left unilateral DBS instead of bilateral DBS. INTERVENTION: We chose Voa as the target for DBS because, clinically, her tremor was mainly confined to her hands, and Voa had better intraoperative microelectrode recording results than Vim. OUTCOMES: After 2 years, her right-hand tremor remained in an improved state, but she still had severe tremor in her left hand. Therefore, we performed GKS targeting the right Voa. One year after surgery, the patient's hand tremor successfully improved without any complications. LESSONS: Salvage Voa GKS after unilateral Voa DBS is a valuable option for very elderly patients and patients with ischemic brain lesions. We suggest that Voa GKS thalamotomy is as useful and safe a surgical technique as Vim GKS for dystonic hand tremor. To the best of our knowledge, this is the first case report using salvage Voa as the only target for ET.


Assuntos
Estimulação Encefálica Profunda/métodos , Tremor Essencial/cirurgia , Psicocirurgia/métodos , Radiocirurgia/métodos , Tálamo/cirurgia , Idoso de 80 Anos ou mais , Tremor Essencial/fisiopatologia , Feminino , Lateralidade Funcional , Mãos/fisiopatologia , Humanos , Ilustração Médica , Resultado do Tratamento , Núcleos Ventrais do Tálamo
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