Mirror movement asymmetries in congenita1 hemiparesis

Nass, Ruth

doi:10.1212/wnl.35.7.1059

Cited by 137 publications

(108 citation statements)

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“…Specifically in the motor system, negative BOLD was found in the ipsilateral hand area in M1 during unimanual hand movements (20,21), and it was also shown to be related to neural inhibition (22). It is thought to be specifically related to movement suppression of unwanted mirror movements of the contralateral hand (23)(24)(25). We, therefore, address the issues of somatotopic representation and coordinated activation and suppression of muscles during movement as indicated by positive and negative BOLD signals in M1 and the SMA.…”

Section: Somatotopy | Neural Inhibitionmentioning

confidence: 94%

Negative blood oxygenation level dependent homunculus and somatotopic information in primary motor cortex and supplementary motor area

Zeharia¹,

Hertz²,

Flash

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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A crucial attribute in movement encoding is an adequate balance between suppression of unwanted muscles and activation of required ones. We studied movement encoding across the primary motor cortex (M1) and supplementary motor area (SMA) by inspecting the positive and negative blood oxygenation level-dependent (BOLD) signals in these regions. Using periodic and eventrelated experiments incorporating the bilateral/axial movements of 20 body parts, we report detailed mototopic imaging maps in M1 and SMA. These maps were obtained using phase-locked analysis. In addition to the positive BOLD, significant negative BOLD was detected in M1 but not in the SMA. The negative BOLD spatial pattern was neither located at the ipsilateral somatotopic location nor randomly distributed. Rather, it was organized somatotopically across the entire homunculus and inversely to the positive BOLD, creating a negative BOLD homunculus. The neuronal source of negative BOLD is unclear. M1 provides a unique system to test whether the origin of negative BOLD is neuronal, because different arteries supply blood to different regions in the homunculus, ruling out blood-stealing explanations. Finally, multivoxel pattern analysis showed that positive BOLD in M1 and SMA and negative BOLD in M1 contain somatotopic information, enabling prediction of the moving body part from inside and outside its somatotopic location. We suggest that the neuronal processes underlying negative BOLD participate in somatotopic encoding in M1 but not in the SMA. This dissociation may emerge because of differences in the activity of these motor areas associated with movement suppression.O ne of the most important attributes encoded in motor homunculi is somatotopy. The work by Penfield and Boldrey (1) discovered the ventral-to-dorsal, face-to-leg somatotopic representation in the primary motor cortex (M1) in humans. Subsequent imaging studies have used up to 10 body parts to confirm this organization (2, 3). In the supplementary motor area (SMA), imaging techniques, electrophysiological measurements, and tumor resection have revealed a rostrocaudal, face-to-leg representation in humans (4-6), similar to the representation in primates (7). Studies in the SMA have only used a few body parts and thus, have been unable to show full-body somatotopy.Our first objective was to map the body representation in M1 and SMA in much greater detail using 20 body parts covering the entire body. Detailed maps on the single-subject level are important for medical purposes as well as assessment of intersubject variability and experience-related plastic changes. We used a continuous cyclic design, enabling us to apply phased-locked analysis approaches, which provide the optimal tools for mapping topographic gradients in the brain (8-11). Our study applies these methods to somatotopic mapping of the motor system. However, movement encoding does not depend solely on the correct activation of specific muscles but also on the suppression of unwanted ones. The importance of suppressing noninvo...

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Section: Somatotopy | Neural Inhibitionmentioning

confidence: 94%

Negative blood oxygenation level dependent homunculus and somatotopic information in primary motor cortex and supplementary motor area

Zeharia¹,

Hertz²,

Flash

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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“…Therefore, as age and myelination increase, the CC may commence effective mediation of interhemispheric transfer, either in terms of increase inhibition or reduced facilitation, thus dampening overflow. Conversely, in the elderly the process of naturally occurring callosal agenesis (including a decrease in size of the CC and demyelination of callosal fibers) is thought to lead to inefficient transcallosal functioning (Nass, 1985). Clarify the cortical origins of motor overflow in ADHD subjects could lead to a greater understanding of some brain abnormalities in these patients.…”

Section: Cortical Origin Of Motor Overflow In Adhdmentioning

confidence: 99%

“…Theories on overflow movements consistently implicate impairment in white matter (WM) tracts, including, in particular, the corpus callosum (CC) (Dennis, 1976). In any case, this tract is still undergoing considerable maturation prior to age 10 (Nass, 1985). A study on older children suggests that the directionality of diffusion in WM pathways continues to increase from childhood through adolescence (Barnea-Goraly et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Overflow movements and white matter abnormalities in ADHD

D’Agati

Casarelli

Pitzianti

et al. 2010

Progress in Neuro-Psychopharmacology and Biological Psychiatry

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Multiple motor abnormalities have been identified in some children with Attention Deficit/Hyperactivity Disorder (ADHD). These include persistence of overflow movements, impaired timing of motor responses and deficits in fine motor abilities. Motor overflow is defined as co-movement of body parts not specifically needed to efficiently complete a task. The presence of age-inappropriate overflow may reflect immaturity of the cortical systems involved in automatic motor inhibition. Theories on overflow movements consistently implicate impairments in white matter (WM) tracts, including the corpus callosum. WM connections might be altered selectively in brain networks and thus influence motor behaviours. We reviewed the scientific contributions on overflow movements and WM abnormalities in ADHD. They suggest that WM abnormalities in motor/premotor circuits, which are important for motor response inhibition, might be responsible for overflow movements in patients with ADHD.

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“…11 On the basis of neuroimaging and electrophysiologic studies, 2 main hypotheses were elaborated concerning the cause of MM: abnormal development of the primary motor system, involving the ipsilateral corticospinal tract; and lack of contralateral motor cortex inhibitory mechanisms, mainly through the corpus callosum. [12][13][14] Voxel-based morphometry (VBM) is a relatively recent method for morphometric evaluation, based on statistical analysis of pooled data, 15,16 which showed pathologic changes of gray matter in various neurologic and psychiatric conditions, including Alzheimer disease, schizophrenia, and medial temporal lobe epilepsy. [17][18][19][20][21] A previous study used conventional VBM to compare only the white matter attenuation of the brains of patients with the X-linked form of KS (exhibiting MM) and those of patients with autosomal inherited KS (no MM) and suggested a bilateral corticospinal tract hypertrophy involved in the MM etiology.…”

mentioning

confidence: 99%

Whole-Brain Voxel-Based Morphometry in Kallmann Syndrome Associated with Mirror Movements

Koenigkam-Santos¹,

Santos²,

Borduqui³

et al. 2008

AJNR Am J Neuroradiol

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BACKGROUND AND PURPOSE:There are 2 main hypotheses concerning the cause of mirror movements (MM) in Kallmann syndrome (KS): abnormal development of the primary motor system, involving the ipsilateral corticospinal tract; and lack of contralateral motor cortex inhibitory mechanisms, mainly through the corpus callosum. The purpose of our study was to determine white and gray matter volume changes in a KS population by using optimized voxel-based morphometry (VBM) and to investigate the relationship between the abnormalities and the presence of MM, addressing the 2 mentioned hypotheses.

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Mirror movement asymmetries in congenita1 hemiparesis

Cited by 137 publications

References 0 publications

Negative blood oxygenation level dependent homunculus and somatotopic information in primary motor cortex and supplementary motor area

Negative blood oxygenation level dependent homunculus and somatotopic information in primary motor cortex and supplementary motor area

Overflow movements and white matter abnormalities in ADHD

Whole-Brain Voxel-Based Morphometry in Kallmann Syndrome Associated with Mirror Movements

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