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Aberrant cerebral intrinsic activity and cerebro-cerebellar functional connectivity in right temporal lobe epilepsy: a resting-state functional MRI study. Neuroreport 2021; 32:1009-1016. [PMID: 34075003 DOI: 10.1097/wnr.0000000000001681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Numerous neuroimaging studies have demonstrated that functional brain aberrations are associated with cognitive impairments in temporal lobe epilepsy (TLE). Here, we aimed to investigate the neural substrates of attention deficits by combining assessment of regional intrinsic brain activities with large-scale functional connectivity in patients with right TLE (rTLE). METHODS Thirty-five patients with rTLE and 33 matched healthy controls were recruited. All participants completed the Attention Network Test (ANT) and resting-sate functional MRI (rs-fMRI) scans. The z-standardized fractional amplitude of the low-frequency fluctuation (zfALFF) approach was applied to evaluate the brain's intrinsic activity. The cerebral regions with significant zfALFF values were selected as seeds for subsequent functional connectivity analyses. A correlation analysis was performed between functional activity and clinical variables. RESULTS Compared with the healthy control group, the patients showed decreased zfALFF in the right inferior temporal gyrus and bilateral superior parietal gyrus, and the right inferior temporal gyrus exhibited increased functional connectivity with the bilateral cerebellum-6/vermis-6 and decreased functional connectivity with right superior frontal gyrus. The ANT indicated that the rTLE group exhibited attention deficits. Furthermore, a positive correlation was found between the zfALFF value of the left superior parietal gyrus and alerting performance, while a negative correlation between the zfALFF value of the right superior parietal gyrus and disease duration. CONCLUSION This study demonstrated aberrant intrinsic cerebral activity and functional connectivity in the whole brain network, which may act as responsible and compensatory factors in attention deficits, especially further profoundly illuminated the compensatory role of cerebellum in patients with rTLE.
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Gao M, Wong CHY, Huang H, Shao R, Huang R, Chan CCH, Lee TMC. Connectome-based models can predict processing speed in older adults. Neuroimage 2020; 223:117290. [PMID: 32871259 DOI: 10.1016/j.neuroimage.2020.117290] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/10/2020] [Accepted: 08/17/2020] [Indexed: 12/12/2022] Open
Abstract
Decrement in processing speed (PS) is a primary cognitive morbidity in clinical populations and could significantly influence other cognitive functions, such as attention and memory. Verifying the usefulness of connectome-based models for predicting neurocognitive abilities has significant translational implications on clinical and aging research. In this study, we verified that resting-state functional connectivity could be used to predict PS in 99 older adults by using connectome-based predictive modeling (CPM). We identified two distinct connectome patterns across the whole brain: the fast-PS and slow-PS networks. Relative to the slow-PS network, the fast-PS network showed more within-network connectivity in the motor and visual networks and less between-network connectivity in the motor-visual, motor-subcortical/cerebellum and motor-frontoparietal networks. We further verified that the connectivity patterns for prediction of PS were also useful for predicting attention and memory in the same sample. To test the generalizability and specificity of the connectome-based predictive models, we applied these two connectome models to an independent sample of three age groups (101 younger adults, 103 middle-aged adults and 91 older adults) and confirmed these models could specifically be generalized to predict PS of the older adults, but not the younger and middle-aged adults. Taking all the findings together, the identified connectome-based predictive models are strong for predicting PS in older adults. The application of CPM to predict neurocognitive abilities can complement conventional neurocognitive assessments, bring significant clinical benefits to patient management and aid the clinical diagnoses, prognoses and management of people undergoing the aging process.
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Affiliation(s)
- Mengxia Gao
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China; Laboratory of Neuropsychology, The University of Hong Kong, Hong Kong, China
| | - Clive H Y Wong
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China; Laboratory of Neuropsychology, The University of Hong Kong, Hong Kong, China
| | - Huiyuan Huang
- School of Psychology, Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, South China Normal University, Guangzhou 510631, China; Key Laboratory of Brain Cognition and Education Sciences (South China Normal University) Ministry of Education
| | - Robin Shao
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China; Laboratory of Neuropsychology, The University of Hong Kong, Hong Kong, China
| | - Ruiwang Huang
- School of Psychology, Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, South China Normal University, Guangzhou 510631, China; Key Laboratory of Brain Cognition and Education Sciences (South China Normal University) Ministry of Education.
| | - Chetwyn C H Chan
- Applied Cognitive Neuroscience Laboratory, Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hum Hom, Hong Kong.
| | - Tatia M C Lee
- The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China; Laboratory of Neuropsychology, The University of Hong Kong, Hong Kong, China; Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangzhou, China; Laboratory of Emotion and Cognition, The Affiliated Hospital of Guangzhou Medical University, China.
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Kopanitsa MV, Lehtimäki KK, Forsman M, Suhonen A, Koponen J, Piiponniemi TO, Kärkkäinen AM, Pavlidi P, Shatillo A, Sweeney PJ, Merenlender-Wagner A, Kaye J, Orbach A, Nurmi A. Cognitive disturbances in the cuprizone model of multiple sclerosis. GENES BRAIN AND BEHAVIOR 2020; 20:e12663. [PMID: 32372528 DOI: 10.1111/gbb.12663] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 04/29/2020] [Accepted: 04/29/2020] [Indexed: 12/19/2022]
Abstract
Cognitive problems frequently accompany neurological manifestations of multiple sclerosis (MS). However, during screening of preclinical candidates, assessments of behaviour in mouse models of MS typically focus on locomotor activity. In the present study, we analysed cognitive behaviour of 9 to 10-week-old female C57Bl/6J mice orally administered with the toxin cuprizone that induces demyelination, a characteristic feature of MS. Animals received 400 mg/kg cuprizone daily for 2 or 4 weeks, and their performance was compared with that of vehicle-treated mice. Cuprizone-treated animals showed multiple deficits in short touchscreen-based operant tasks: they responded more slowly to visual stimuli, rewards and made more errors in a simple rule-learning task. In contextual/cued fear conditioning experiments, cuprizone-treated mice showed significantly lower levels of contextual freezing than vehicle-treated mice. Diffusion tensor imaging showed treatment-dependent changes in fractional anisotropy as well as in axial and mean diffusivities in different white matter areas. Lower values of fractional anisotropy and axial diffusivity in cuprizone-treated mice indicated developing demyelination and/or axonal damage. Several diffusion tensor imaging measurements correlated with learning parameters. Our results show that translational touchscreen operant tests and fear conditioning paradigms can reliably detect cognitive consequences of cuprizone treatment. The suggested experimental approach enables screening novel MS drug candidates in longitudinal experiments for their ability to improve pathological changes in brain structure and reverse cognitive deficits.
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Affiliation(s)
- Maksym V Kopanitsa
- Charles River Discovery Services, Kuopio, Finland.,UK Dementia Research Institute, Department of Brain Sciences, Imperial College, London, UK
| | | | | | - Ari Suhonen
- Charles River Discovery Services, Kuopio, Finland
| | - Juho Koponen
- Charles River Discovery Services, Kuopio, Finland
| | | | | | - Pavlina Pavlidi
- MSc Programme in Translational Neuroscience, Imperial College, London, UK
| | | | | | | | - Joel Kaye
- Teva Pharmaceutical Industries Ltd, Netanya, Israel
| | - Aric Orbach
- Teva Pharmaceutical Industries Ltd, Netanya, Israel
| | - Antti Nurmi
- Charles River Discovery Services, Kuopio, Finland
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Tamè L, Carr A, Longo MR. Vision of the body improves inter-hemispheric integration of tactile-motor responses. Acta Psychol (Amst) 2017; 175:21-27. [PMID: 28259727 DOI: 10.1016/j.actpsy.2017.02.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 02/01/2017] [Accepted: 02/28/2017] [Indexed: 12/01/2022] Open
Abstract
Sensory input from and motor output to the two sides of the body needs to be continuously integrated between the two cerebral hemispheres. This integration can be measured through its cost in terms of processing speed. In simple detection tasks, reaction times (RTs) are faster when stimuli are presented to the side of the body ipsilateral to the body part used to respond. This advantage - the contralateral-ipsilateral difference (also known as the crossed-uncrossed difference: CUD) - is thought to reflect inter-hemispheric interactions needed for sensorimotor information to be integrated between the two hemispheres. Several studies have shown that non-informative vision of the body enhances performance in tactile tasks. However, it is unknown whether the CUD can be similarly affected by vision. Here, we investigated whether the CUD is modulated by vision of the body (i.e., the stimulated hand) by presenting tactile stimuli unpredictably on the middle fingers when one hand was visible (i.e., either the right or left hand). Participants detected the stimulus and responded as fast as possible using either their left or right foot. Consistent with previous results, a clear CUD (5.8ms) was apparent on the unseen hand. Critically, however, no such effect was found on the hand that was visible (-2.2ms). Thus, when touch is delivered to a seen hand, the usual cost in processing speed of responding with a contralateral effector is eliminated. This result suggests that vision of the body improves the interhemispheric integration of tactile-motor responses.
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Affiliation(s)
- Luigi Tamè
- Department of Psychological Sciences, Birkbeck, University of London, London, United Kingdom.
| | - Alex Carr
- Department of Psychological Sciences, Birkbeck, University of London, London, United Kingdom
| | - Matthew R Longo
- Department of Psychological Sciences, Birkbeck, University of London, London, United Kingdom
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Corbo V, Amick MA, Milberg WP, McGlinchey RE, Salat DH. Early life trauma is associated with altered white matter integrity and affective control. J Psychiatr Res 2016; 79:70-77. [PMID: 27214523 DOI: 10.1016/j.jpsychires.2016.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 04/15/2016] [Accepted: 05/03/2016] [Indexed: 02/08/2023]
Abstract
Early life trauma (ELT) has been shown to impair affective control and attention well into adulthood. Neuroimaging studies have further shown that ELT was associated with decreased white matter integrity in the prefrontal areas in children and adults. However, no study to date has looked at the relationship between white matter integrity and affective control in individuals with and without a history of ELT. To examine this, we tested 240 Veterans with (ELT N = 80) and without (NoELT N = 160) a history of childhood sexual abuse, physical abuse or family violence. Affective control was measured with the Affective Go/No-Go (AGN) and attention was indexed with the Test of Variable Attention (TOVA). White matter integrity was measured using fractional anisotropy (FA). Results showed greater number of errors on the AGN in ELT compared to NoELT. There was no difference on the TOVA. While there were no mean differences in FA, there was an interaction between FA and reaction time to positive stimuli on the AGN where the ELT group showed a positive relationship between FA and reaction time in right frontal and prefrontal areas, whereas the NoELT group showed a negative or no association between FA and reaction time. This suggests that ELT may be associated with a distinct brain-behavior relationship that could be related to other determinants of FA than those present in healthy adults.
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Affiliation(s)
- Vincent Corbo
- Translational Research Center for TBI and Stress Disorders/Geriatric Research Education and Clinical Centers (GRECC), VA Boston Healthcare System, Boston, MA, USA; Boston University School of Medicine, Boston, MA, USA.
| | - Melissa A Amick
- Translational Research Center for TBI and Stress Disorders/Geriatric Research Education and Clinical Centers (GRECC), VA Boston Healthcare System, Boston, MA, USA
| | - William P Milberg
- Translational Research Center for TBI and Stress Disorders/Geriatric Research Education and Clinical Centers (GRECC), VA Boston Healthcare System, Boston, MA, USA; Department of Psychiatry, Harvard Medical School, Cambridge, MA, USA
| | - Regina E McGlinchey
- Translational Research Center for TBI and Stress Disorders/Geriatric Research Education and Clinical Centers (GRECC), VA Boston Healthcare System, Boston, MA, USA; Department of Psychiatry, Harvard Medical School, Cambridge, MA, USA
| | - David H Salat
- Translational Research Center for TBI and Stress Disorders/Geriatric Research Education and Clinical Centers (GRECC), VA Boston Healthcare System, Boston, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
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Tamè L, Longo MR. Inter-hemispheric integration of tactile-motor responses across body parts. Front Hum Neurosci 2015; 9:345. [PMID: 26124718 PMCID: PMC4466437 DOI: 10.3389/fnhum.2015.00345] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Accepted: 05/29/2015] [Indexed: 12/14/2022] Open
Abstract
In simple detection tasks, reaction times (RTs) are faster when stimuli are presented to the visual field or side of the body ipsilateral to the body part used to respond. This advantage, the crossed-uncrossed difference (CUD), is thought to reflect inter-hemispheric interactions needed for sensorimotor information to be integrated between the two cerebral hemispheres. However, it is unknown whether the tactile CUD is invariant when different body parts are stimulated. The most likely structure mediating such processing is thought to be the corpus callosum (CC). Neurophysiological studies have shown that there are denser callosal connections between regions that represent proximal parts of the body near the body midline and more sparse connections for regions representing distal extremities. Therefore, if the information transfer between the two hemispheres is affected by the density of callosal connections, stimuli presented on more distal regions of the body should produce a greater CUD compared to stimuli presented on more proximal regions. This is because interhemispheric transfer of information from regions with sparse callosal connections will be less efficient, and hence slower. Here, we investigated whether the CUD is modulated as a function of the different body parts stimulated by presenting tactile stimuli unpredictably on body parts at different distances from the body midline (i.e., Middle Finger, Forearm, or Forehead of each side of the body). Participants detected the stimulus and responded as fast as possible using either their left or right foot. Results showed that the magnitude of the CUD was larger on the finger (~2.6 ms) and forearm (~1.8 ms) than on the forehead (≃0.9 ms). This result suggests that the interhemispheric transfer of tactile stimuli varies as a function of the strength of callosal connections of the body parts.
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Affiliation(s)
- Luigi Tamè
- Department of Psychological Sciences, Birkbeck, University of London London, UK
| | - Matthew R Longo
- Department of Psychological Sciences, Birkbeck, University of London London, UK
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Auditory and visual interhemispheric communication in musicians and non-musicians. PLoS One 2014; 8:e84446. [PMID: 24386382 PMCID: PMC3873989 DOI: 10.1371/journal.pone.0084446] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 11/16/2013] [Indexed: 11/19/2022] Open
Abstract
The corpus callosum (CC) is a brain structure composed of axon fibres linking the right and left hemispheres. Musical training is associated with larger midsagittal cross-sectional area of the CC, suggesting that interhemispheric communication may be faster in musicians. Here we compared interhemispheric transmission times (ITTs) for musicians and non-musicians. ITT was measured by comparing simple reaction times to stimuli presented to the same hemisphere that controlled a button-press response (uncrossed reaction time), or to the contralateral hemisphere (crossed reaction time). Both visual and auditory stimuli were tested. We predicted that the crossed-uncrossed difference (CUD) for musicians would be smaller than for non-musicians as a result of faster interhemispheric transfer times. We did not expect a difference in CUDs between the visual and auditory modalities for either musicians or non-musicians, as previous work indicates that interhemispheric transfer may happen through the genu of the CC, which contains motor fibres rather than sensory fibres. There were no significant differences in CUDs between musicians and non-musicians. However, auditory CUDs were significantly smaller than visual CUDs. Although this auditory-visual difference was larger in musicians than non-musicians, the interaction between modality and musical training was not significant. Therefore, although musical training does not significantly affect ITT, the crossing of auditory information between hemispheres appears to be faster than visual information, perhaps because subcortical pathways play a greater role for auditory interhemispheric transfer.
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Mayer KM, Vuong QC. TBSS and probabilistic tractography reveal white matter connections for attention to object features. Brain Struct Funct 2013; 219:2159-71. [DOI: 10.1007/s00429-013-0631-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 08/26/2013] [Indexed: 12/13/2022]
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Abstract
There are many reports of relations between age and cognitive variables and of relations between age and variables representing different aspects of brain structure and a few reports of relations between brain structure variables and cognitive variables. These findings have sometimes led to inferences that the age-related brain changes cause the age-related cognitive changes. Although this conclusion may well be true, it is widely recognized that simple correlations are not sufficient to warrant causal conclusions, and other types of correlational information, such as mediation and correlations between longitudinal brain changes and longitudinal cognitive changes, also have limitations with respect to causal inferences. These issues are discussed, and the existing results on relations of regional volume, white matter hyperintensities, and diffusion tensor imaging measures of white matter integrity to age and to measures of cognitive functioning are reviewed. It is concluded that at the current time the evidence that these aspects of brain structure are neuroanatomical substrates of age-related cognitive decline is weak. The final section contains several suggestions concerning measurement and methodology that may lead to stronger conclusions in the future.
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Affiliation(s)
- Timothy A Salthouse
- Department of Psychology, University of Virginia, Charlottesville, VA 22904-4400, USA.
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Mohades SG, Struys E, Van Schuerbeek P, Mondt K, Van De Craen P, Luypaert R. DTI reveals structural differences in white matter tracts between bilingual and monolingual children. Brain Res 2011; 1435:72-80. [PMID: 22197702 DOI: 10.1016/j.brainres.2011.12.005] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Revised: 11/03/2011] [Accepted: 12/02/2011] [Indexed: 11/24/2022]
Abstract
The impact of bilingualism on the microstructure of the white matter pathways related to language processing is assessed in elementary school children by magnetic resonance diffusion tensor imaging (MR-DTI). Forty children, 8-11 years old, subdivided into 3 different groups (15 simultaneous bilinguals, 15 sequential bilinguals and 10 monolinguals), were scanned. The hypothesis was that the starting age and the manner of second language acquisition would affect the characteristics of language circuitry. In each subject the mean fractional anisotropy (FA) was obtained for four major white matter pathways: 1 - the left arcuate fasciculus/superior longitudinal fasciculus (lAF/lSLF) that connects Broca's area in the opercular and triangular regions of the left inferior frontal gyrus to the posterior language zone, 2 - the left inferior occipitofrontal fasciculus (lIFOF), connecting anterior regions in the frontal lobe with posterior regions in the temporal occipital lobes, 3 - the bundle arising from the anterior part of the corpus callosum projecting to the orbital lobe (AC-OL) and 4 - the fibers emerging from the anterior midbody (AMB) of the corpus callosum that associate with the premotor and supplementary motor cortices (AMB-PMC). The three groups did not show significant differences in mean FA over the lAF/lSLF or AMB-PMC tracts. In simultaneous bilingual subjects the lIFOF tracts had higher mean FA value compared to monolinguals and also sequential bilinguals, whereas the comparison for the AC-OL fibers yielded a significantly lower mean FA value in simultaneous bilingual subjects compared to monolinguals. In both cases the FA value for sequential bilinguals was intermediate to that of the other two groups. To our knowledge, this study provides the first evidence of bilingualism related adaptation of white matter microstructure in the human brain.
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Madsen KS, Baaré WFC, Skimminge A, Vestergaard M, Siebner HR, Jernigan TL. Brain microstructural correlates of visuospatial choice reaction time in children. Neuroimage 2011; 58:1090-100. [PMID: 21791247 DOI: 10.1016/j.neuroimage.2011.07.032] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 06/26/2011] [Accepted: 07/09/2011] [Indexed: 11/28/2022] Open
Abstract
The corticospinal tracts and the basal ganglia continue to develop during childhood and adolescence, and indices of their maturation can be obtained using diffusion-weighted imaging. Here we show that a simple measure of visuomotor function is correlated with diffusion parameters in the corticospinal tracts and neostriatum. In a cohort of 75 typically-developing children aged 7 to 13years, mean 5-choice reaction times (RTs) were assessed. We hypothesised that children with faster choice RTs would show lower mean diffusivity (MD) in the corticospinal tracts and neostriatum and higher fractional anisotropy (FA) in the corticospinal tracts, after controlling for age, gender, and handedness. Mean MD and/or FA were extracted from the right and left corticospinal tracts, putamen, and caudate nuclei. As predicted, faster 5-choice RTs were associated with lower MD in the corticospinal tracts, putamen, and caudate. MD effects on RT were bilateral in the corticospinal tracts and putamen, whilst right caudate MD was more strongly related to performance than was left caudate MD. Our results suggest a link between motor performance variability in children and diffusivity in the motor system, which may be related to: individual differences in the phase of fibre tract and neostriatal maturation in children of similar age, individual differences in motor experience during childhood (i.e., use-dependent plasticity), and/or more stable individual differences in the architecture of the motor system.
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Affiliation(s)
- Kathrine Skak Madsen
- Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital, Hvidovre, Denmark.
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Eckert MA, Keren NI, Roberts DR, Calhoun VD, Harris KC. Age-related changes in processing speed: unique contributions of cerebellar and prefrontal cortex. Front Hum Neurosci 2010; 4:10. [PMID: 20300463 PMCID: PMC2839847 DOI: 10.3389/neuro.09.010.2010] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Accepted: 01/24/2010] [Indexed: 01/12/2023] Open
Abstract
Age-related declines in processing speed are hypothesized to underlie the widespread changes in cognition experienced by older adults. We used a structural covariance approach to identify putative neural networks that underlie age-related structural changes associated with processing speed for 42 adults ranging in age from 19 to 79 years. To characterize a potential mechanism by which age-related gray matter changes lead to slower processing speed, we examined the extent to which cerebral small vessel disease influenced the association between age-related gray matter changes and processing speed. A frontal pattern of gray matter and white matter variation that was related to cerebral small vessel disease, as well as a cerebellar pattern of gray matter and white matter variation were uniquely related to age-related declines in processing speed. These results demonstrate that at least two distinct factors affect age-related changes in processing speed, which might be slowed by mitigating cerebral small vessel disease and factors affecting declines in cerebellar morphology.
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Affiliation(s)
- Mark A Eckert
- Department of Otolaryngology - Head and Neck Surgery, Medical University of South Carolina Charleston, SC, USA
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Schaechter JD, Fricker ZP, Perdue KL, Helmer KG, Vangel MG, Greve DN, Makris N. Microstructural status of ipsilesional and contralesional corticospinal tract correlates with motor skill in chronic stroke patients. Hum Brain Mapp 2010; 30:3461-74. [PMID: 19370766 DOI: 10.1002/hbm.20770] [Citation(s) in RCA: 223] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Greater loss in structural integrity of the ipsilesional corticospinal tract (CST) is associated with poorer motor outcome in patients with hemiparetic stroke. Animal models of stroke have demonstrated that structural remodeling of white matter in the ipsilesional and contralesional hemispheres is associated with improved motor recovery. Accordingly, motor recovery in patients with stroke may relate to the relative strength of CST degeneration and remodeling. This study examined the relationship between microstructural status of brain white matter tracts, indexed by the fractional anisotropy (FA) metric derived from diffusion tensor imaging (DTI) data, and motor skill of the stroke-affected hand in patients with chronic stroke. Voxelwise analysis revealed that motor skill significantly and positively correlated with FA of the ipsilesional and contralesional CST in the patients. Additional voxelwise analyses showed that patients with poorer motor skill had reduced FA of bilateral CST compared to normal control subjects, whereas patients with better motor skill had elevated FA of bilateral CST compared to controls. These findings were confirmed using a DTI-tractography method applied to the CST in both hemispheres. The results of this study suggest that the level of motor skill recovery achieved in patients with hemiparetic stroke relates to microstructural status of the CST in both the ipsilesional and contralesional hemispheres, which may reflect the net effect of degeneration and remodeling of bilateral CST.
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Affiliation(s)
- Judith D Schaechter
- MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts 02129, USA.
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Han Y, Yang H, Lv YT, Zhu CZ, He Y, Tang HH, Gong QY, Luo YJ, Zang YF, Dong Q. Gray matter density and white matter integrity in pianists' brain: a combined structural and diffusion tensor MRI study. Neurosci Lett 2008; 459:3-6. [PMID: 18672026 DOI: 10.1016/j.neulet.2008.07.056] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Revised: 05/23/2008] [Accepted: 07/21/2008] [Indexed: 11/29/2022]
Abstract
The current study combined structural magnetic resonance imaging (sMRI) and diffusion tensor MRI (DT-MRI) to investigate both gray matter density (GMD) and white matter integrity (WMI) in 18 pianists and 21 age-matched non-musicians. The pianists began their piano training at a mean age of 12. Voxel-based morphometry of the sMRI data showed that the pianists had higher GMD in the left primary sensorimotor cortex and right cerebellum. Voxel-based analysis of the DT-MRI data showed that pianists had higher fractional anisotropy (FA) (indicating higher WMI) in the right posterior limb of the internal capsule. The sMRI and DT-MRI results indicate that both the GMD and WMI of pianists may exhibit movement-related increases during adolescence or even early adulthood compared with non-musicians.
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Affiliation(s)
- Ying Han
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, China
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