Primary Motor Cortex in Stroke: A Functional MRI-Guided Proton MR Spectroscopic Study

 If anything here helps survivors recover it is impossible to tell. I'd have the mentors and senior researchers on this fired for incompetency! Not even attempting to solve stroke or map this research to how survivors can get recovered!

Primary Motor Cortex in Stroke: A Functional MRI-Guided Proton MR Spectroscopic Study

Carmen M. Cirstea, MD, PhD; William M. Brooks, PhD; Sorin C. Craciunas, MD; Elena A. Popescu, PhD; In-Young Choi, PhD; Phil Lee, PhD; Ali Bani-Ahmed, BSc; Hung-Wen Yeh, PhD; Cary R. Savage, PhD; Leonardo G. Cohen, MD; Randolph J. Nudo, PhD  

 

Background and Purpose—

 

Our goal was to investigate whether certain metabolites, specific to neurons, glial cells, or the neuronal– glial neurotransmission system, in primary motor cortices (M1), are altered and correlated with clinical motor severity in chronic stroke.  

 

Methods—

 

Fourteen survivors of a single ischemic stroke located outside the M1 and 14 age-matched healthy control subjects were included. At>6 months after stroke, N-acetylaspartate, myo-inositol, and glutamate/glutamine were measured using proton magnetic resonance spectroscopic imaging (in-plane resolution=5x5 mm 2 ) in radiologically normal-appearing gray matter of the hand representation area, identified by functional MRI, in each M1. Metabolite concentrations and analyses of metabolite correlations within M1 were determined. Relationships between metabolite concentrations and arm motor impairment were also evaluated. 

 

Results—

 

The stroke survivors showed lower N-acetylaspartate and higher myo-inositol across ipsilesional and contralesional M1 compared with control subjects. Significant correlations between N-acetylaspartate and glutamate/glutamine were found in either M1. Ipsilesional N-acetylaspartate and glutamate/glutamine were positively correlated with arm motor impairment and contralesional N-acetylaspartate with time after stroke. 

 

Conclusions—

 

Our preliminary data demonstrated significant alterations of neuronal– glial interactions in spared M1 with the ipsilesional alterations related to stroke severity and contralesional alterations to stroke duration. Thus, MR spectroscopy might be a sensitive method to quantify relevant metabolite changes after stroke and consequently increase our knowledge of the factors leading from these changes in spared motor cortex to motor impairment after stroke. (Stroke. 2011;42:1004-1009.)

 

More at link.

Metabolic profile of motor cortex in stroke

Ask your competent? doctor and hospital if this test became standard procedure to document damage from the stroke and point DIRECTLY TO REHAB PROTOCOLS THAT DELIVER 100% RECOVERY! 

If they did nothing in the last decade; RUN AWAY!

Metabolic profile of motor cortex in stroke

Sorin C. Craciunas, MD, PhD 1 , William M. Brooks, PhD 1 , Randolph J. Nudo, PhD 1 , Elena A. Popescu, PhD 1 , In-Young Choi, PhD 1 , Phil Lee, PhD 1 , Hung-Wen Yeh, PhD 1 , Cary R. Savage, PhD 1 , and Carmen M. Cirstea, MD, PhD 1  

OnlineFirst Version of Record - Jan 9, 2013

Abstract  

Background. 

 

Although functional imaging and neurophysiological approaches reveal alterations in motor and premotor areas after stroke, insights into neurobiological events underlying these alterations are limited in human studies. 

 

Objective. 

 

We tested whether cerebral metabolites related to neuronal and glial compartments are altered in the hand representation in bilateral motor and premotor areas and correlated with distal and proximal arm motor impairment in hemiparetic persons. 

 

Methods. 

 

In 20 participants at >6 months postonset of a subcortical ischemic stroke and 16 age- and sex-matched healthy controls, the concentrations of N-acetylaspartate and myo-inositol were quantified by proton magnetic resonance spectroscopy. Regions of interest identified by functional magnetic resonance imaging included primary (M1), dorsal premotor (PMd), and supplementary (SMA) motor areas. Relationships between metabolite concentrations and distal (hand) and proximal (shoulder/elbow) motor impairment using Fugl-Meyer Upper Extremity (FMUE) subscores were explored. Results. N-Acetylaspartate was lower in M1 (P = .04) and SMA (P = .004) and myo-inositol was higher in M1 (P = .003) and PMd (P = .03) in the injured (ipsilesional) hemisphere after stroke compared with the left hemisphere in controls. N-Acetylaspartate in ipsilesional M1 was positively correlated with hand FMUE subscores (P = .04). Significant positive correlations were also found between N-acetylaspartate in ipsilesional M1, PMd, and SMA and in contralesional M1 and shoulder/elbow FMUE subscores (P = .02, .01, .02, and .02, respectively).  

 

Conclusions. 

 

Our preliminary results demonstrated that proton magnetic resonance spectroscopy is a sensitive method to quantify relevant neuronal changes in spared motor cortex after stroke and consequently increase our knowledge of the factors leading from these changes to arm motor impairment.

Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairment

'Measurements' DO ABSOLUTELY NOTHING FOR RECOVERY!

 Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairment

 Sorin C. Craciunas, MD, PhD 1, 

William M. Brooks, PhD 1, 

Randolph J. Nudo, PhD 1, 

Elena A. Popescu, PhD 1, 

In-Young Choi, PhD 1, 

Phil Lee, PhD 1, 

Hung-Wen Yeh, PhD 1, 

Cary R. Savage, PhD 1, and 

Carmen M. Cirstea, MD, PhD 1

Abstract

Background  

 

Although functional imaging and neurophysiological approaches reveal alterations in motor and premotor areas after stroke, insights into neurobiological events underlying these alterations are limited in human studies.
Objective 

 

We tested whether cerebral metabolites related to neuronal and glial compartments are altered in the hand representation in bilateral motor and premotor areas and correlated with distal and proximal arm motor impairment in hemiparetic persons.
 Methods 

 

In 20 participants at >6 months post onset of a subcortical ischemic stroke and 16 age- and sex-matched healthy controls, the concentrations of N-acetylaspartate and myo-inositol were quantified by proton magnetic resonance spectroscopy. Regions of interest identified by functional magnetic resonance imaging included primary (M1), dorsal premotor (PMd), and supplementary (SMA) motor areas. Relationships between metabolite concentrations and distal (hand) and proximal (shoulder/elbow) motor impairment using Fugl-Meyer Upper Extremity (FMUE) subscores were explored.
Results 

 

N-Acetylaspartate was lower in M1 (P = .04) and SMA (P = .004) and myo-inositol was higher in M1 (P
 = .003) and PMd (P = .03) in the injured (ipsilesional) hemisphere after stroke compared with the left hemisphere in controls.
N-Acetylaspartate in ipsilesional M1 was positively correlated with hand FMUE subscores (P = .04). Significant positive correlations were also found between N-acetylaspartate in ipsilesional M1, PMd, and SMA and in contralesional M1 and shoulder/elbow FMUE subscores (P = .02, .01, .02, and .02, respectively).
Conclusions 

 

Our preliminary results demonstrated that proton magnetic resonance spectroscopy is a sensitive method to quantify relevant neuronal changes in spared motor cortex after stroke and consequently increase our knowledge of the factors leading from these changes to arm motor impairment.

Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairment

Absolutely useless. Nothing here is going to get survivors recovered!

 Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairment

 Sorin C. Craciunas, MD, PhD
1
, William M. Brooks, PhD
1
, Randolph J. Nudo, PhD
1
, Elena A. Popescu, PhD
1
, In-Young Choi, PhD
1
, Phil Lee, PhD
1
, Hung-Wen Yeh, PhD
1
, Cary R. Savage, PhD
1
, and Carmen M. Cirstea, MD, PhD
1

Abstract

Background  

Although functional imaging and neurophysiological approaches reveal alterations in motor and premotor areas after stroke, insights into neurobiological events underlying these alterations are limited in human studies.
Objective 

We tested whether cerebral metabolites related to neuronal and glial compartments are altered in the hand representation in bilateral motor and premotor areas and correlated with distal and proximal arm motor impairment in hemiparetic persons.
 Methods
. In 20 participants at >6 months postonset of a subcortical ischemic stroke and 16 age- and sex-matched healthy controls, the concentrations of N-acetylaspartate and myoinositol were quantified by proton magnetic resonance spectroscopy. Regions of interest identified by functional magnetic resonance imaging included primary (M1), dorsal premotor (PMd), and supplementary (SMA) motor areas. Relationships between metabolite concentrations and distal (hand) and proximal (shoulder/elbow) motor impairment using Fugl-Meyer Upper Extremity (FMUE) subscores were explored.
Results. 

 N-Acetylaspartate was lower in M1 (P = .04) and SMA (P = .004) and myoinositol was higher in M1 (P = .003) and PMd (P = .03) in the injured (ipsilesional) hemisphere after stroke compared with the left hemisphere in controls.
N-Acetylaspartate in ipsilesional M1 was positively correlated with hand FMUE subscores (P = .04). Significant positive correlations were also found between N-acetylaspartate in ipsilesional M1, PMd, and SMA and in contralesional M1 and shoulder/elbow FMUE subscores (P = .02, .01, .02, and .02, respectively).
Conclusions 

Our preliminary results demonstrated that proton magnetic resonance spectroscopy is a sensitive method to quantify relevant neuronal changes in spared motor cortex after stroke and consequently increase our knowledge of the factors leading from these changes to arm motor impairment.

Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairment

I see absolutely nothing here that will get survivors recovered.  I'd fire all of you.

After you measured this what protocols are needed to cure the impairment? THAT IS WHAT SURVIVORS NEED. GET THERE!

Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairment

  Sorin C. Craciunas, MD, PhD
1
, William M. Brooks, PhD
1
, Randolph J. Nudo, PhD
1
, Elena A. Popescu, PhD
1
, In-Young Choi, PhD
1
, Phil Lee, PhD
1
, Hung-Wen Yeh, PhD
1
, Cary R. Savage, PhD
1
, and Carmen M. Cirstea, MD, PhD
1

Abstract

Background
. Although functional imaging and neurophysiological approaches reveal alterations in motor and premotor areas after stroke, insights into neurobiological events underlying these alterations are limited in human studies.
Objective
. We tested whether cerebral metabolites related to neuronal and glial compartments are altered in the hand representation in bilateral motor and premotor areas and correlated with distal and proximal arm motor impairment in hemiparetic persons.
 Methods
. In 20 participants at >6 months postonset of a subcortical ischemic stroke and 16 age- and sex-matched healthy controls, the concentrations of N-acetylaspartate and myo-inositol were quantified by proton magnetic resonance spectroscopy. Regions of interest identified by functional magnetic resonance imaging included primary (M1), dorsal premotor (PMd), and supplementary (SMA) motor areas. Relationships between metabolite concentrations and distal (hand) and proximal (shoulder/elbow) motor impairment using Fugl-Meyer Upper Extremity (FMUE) subscores were explored.
Results.  

N-Acetylaspartate was lower in M1 (P = .04) and SMA (P = .004) and myo-inositol was higher in M1 (P  .003) and PMd (P = .03) in the injured (ipsilesional) hemisphere after stroke compared with the left hemisphere in controls.
N-Acetylaspartate in ipsilesional M1 was positively correlated with hand FMUE subscores (P = .04). Significant positive correlations were also found between N-acetylaspartate in ipsilesional M1, PMd, and SMA and in contralesional M1 and shoulder/elbow FMUE subscores (P = .02, .01, .02, and .02, respectively).
Conclusions
. Our preliminary results demonstrated that proton magnetic resonance spectroscopy is a sensitive method to quantify relevant neuronal changes in spared motor cortex after stroke and consequently increase our knowledge of the factors leading from these changes to arm motor impairment.

Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairment

If this says anything useful, I can't tell.

Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairment

Sorin C. Craciunas, MD, PhD, William M. Brooks, PhD, […], and Carmen M. Cirstea, MD, PhD+6View all authors and affiliations

Volume 27, Issue 5

https://doi.org/10.1177/1545968312469835

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Handgrip-Related Activation in the Primary Motor Cortex Relates to Underlying Neuronal Metabolism After Stroke

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Evolution of Brain Activation with Good and Poor Motor Recovery after Stroke

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Abstract

Background. 

Although functional imaging and neurophysiological approaches reveal alterations in motor and premotor areas after stroke, insights into neurobiological events underlying these alterations are limited in human studies. 

 

Objective. 

 

We tested whether cerebral metabolites related to neuronal and glial compartments are altered in the hand representation in bilateral motor and premotor areas and correlated with distal and proximal arm motor impairment in hemiparetic persons.  

 

Methods. 

 

In 20 participants at >6 months postonset of a subcortical ischemic stroke and 16 age- and sex-matched healthy controls, the concentrations of N-acetylaspartate and myo-inositol were quantified by proton magnetic resonance spectroscopy. Regions of interest identified by functional magnetic resonance imaging included primary (M1), dorsal premotor (PMd), and supplementary (SMA) motor areas. Relationships between metabolite concentrations and distal (hand) and proximal (shoulder/elbow) motor impairment using Fugl-Meyer Upper Extremity (FMUE) subscores were explored. 

 

Results. 

 

N-Acetylaspartate was lower in M1 (P = .04) and SMA (P = .004) and myo-inositol was higher in M1 (P = .003) and PMd (P = .03) in the injured (ipsilesional) hemisphere after stroke compared with the left hemisphere in controls. N-Acetylaspartate in ipsilesional M1 was positively correlated with hand FMUE subscores (P = .04). Significant positive correlations were also found between N-acetylaspartate in ipsilesional M1, PMd, and SMA and in contralesional M1 and shoulder/elbow FMUE subscores (P = .02, .01, .02, and .02, respectively).  

 

Conclusions. 

 

Our preliminary results demonstrated that proton magnetic resonance spectroscopy is a sensitive method to quantify relevant neuronal changes in spared motor cortex after stroke and consequently increase our knowledge of the factors leading from these changes to arm motor impairment.

Introduction

Human imaging studies have revealed that early after subcortical stroke, restoration of paretic arm function is associated with a greater involvement of radiologically normal-appearing (or spared) motor (primary motor cortex or M1) and premotor (dorsal premotor cortex or PMd, supplementary motor area or SMA) areas in both injured (ipsilesional) and uninjured (contralesional) hemispheres.^1-3 Later, successful recovery occurs in stroke survivors who exhibit relatively normal patterns of ipsilesional activation and less contralesional motor activation, whereas patients, who often show bilateral cortical activation, typically have less complete recovery.^4-6 These results should be viewed in the context of the anatomic structures and pathways of these areas. Although M1 motor pathways are critical, the premotor areas also contribute to motor control and might be recruited during motor recovery after stroke. The parallel nature of the direct (corticospinal) pathways from premotor areas and M1 emphasizes that PMd and SMA are, in some respects, at a similar level of hierarchical organization as M1,⁷ although these projections to spinal cord motor neurons are less numerous and less efficient than those from M1.^8-10 Another possibility is the indirect (corticoreticulospinal) projections to cervical propriospinal premotoneurons, which have divergent projections to muscle groups operating at multiple joints.^11,12 Finally, corticocortical connections between these areas might also play an important role in poststroke recovery.^7,13-15 Thus, understanding the neural events associated with the functional changes in these areas could provide critical insight into successful treatments of patient’s impairment.

Proton magnetic resonance spectroscopy (¹H-MRS) provides a noninvasive means to measure concentrations of certain metabolites associated with a specific cell type¹⁶ after stroke.¹⁷ Most clinical stroke studies report lower levels of N-acetylaspartate (NAA, putative marker of neuronal integrity) in spared ipsilesional M1 and PMd.^18-21 In some instances, the NAA levels were related to clinical severity. In a series of studies of stroke survivors, we also found higher myo-inositol (mI, putative marker of glial cells) in ipsilesional and contralesional M1.²¹ However, none of these studies addressed the changes in key metabolites related to neuronal and glial compartments, that is, NAA and mI, in motor and premotor areas in stroke.

The first aim of the current study was to quantify NAA and mI concentrations in ipsilesional and contralesional motor and premotor areas in chronic subcortical stroke. Since neuronal integrity might be compromised in these remote areas,^21,22 we expected NAA to be lower, especially in the ipsilesional areas. Given the role of glia in plastic brain changes,^23-25 we also expected mI to be higher. The second aim was to explore correlations between metabolite concentrations and arm motor impairment. Since the premotor projections are significantly stronger on the proximal muscles than distal muscles compared with M1^8,9, we predicted that metabolite measures in ipsilesional PMd and SMA would be correlated with proximal (shoulder/elbow) motor impairment whereas those in M1 would be correlated with both proximal and distal (hand) impairments. Since both direct and indirect pathways from the contralesional M1 project to axial and proximal muscles rather than hand muscles,^26,27 relationships between contralesional M1 metabolites and proximal impairment were also expected.

Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairment

So you described something but put nothing together that will help survivors recover. I'd fire everybody involved in this. 

Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairment

Sorin C. Craciunas, MD, PhD, William M. Brooks, PhD, […], Randolph J. Nudo, PhD, Elena A. Popescu, PhD, In-Young Choi, PhD, Phil Lee, PhD, Hung-Wen Yeh, PhD, Cary R. Savage, PhD, and Carmen M. Cirstea, MD, PhD, +6 -6View all authors and affiliations

Volume 27, Issue 5

https://doi.org/10.1177/1545968312469835

• PDF / ePub
• • Cite article
  • Share options
  • Information, rights and permissions
  • Metrics and citations
  • Figures and tables

• Related content

Abstract

Background. 

 

Although functional imaging and neurophysiological approaches reveal alterations in motor and premotor areas after stroke, insights into neurobiological events underlying these alterations are limited in human studies. 

Objective. 

 

We tested whether cerebral metabolites related to neuronal and glial compartments are altered in the hand representation in bilateral motor and premotor areas and correlated with distal and proximal arm motor impairment in hemiparetic persons.  

 

Methods. 

 

In 20 participants at >6 months postonset of a subcortical ischemic stroke and 16 age- and sex-matched healthy controls, the concentrations of N-acetylaspartate and myo-inositol were quantified by proton magnetic resonance spectroscopy. Regions of interest identified by functional magnetic resonance imaging included primary (M1), dorsal premotor (PMd), and supplementary (SMA) motor areas. Relationships between metabolite concentrations and distal (hand) and proximal (shoulder/elbow) motor impairment using Fugl-Meyer Upper Extremity (FMUE) subscores were explored. Results. N-Acetylaspartate was lower in M1 (P = .04) and SMA (P = .004) and myo-inositol was higher in M1 (P = .003) and PMd (P = .03) in the injured (ipsilesional) hemisphere after stroke compared with the left hemisphere in controls. N-Acetylaspartate in ipsilesional M1 was positively correlated with hand FMUE subscores (P = .04). Significant positive correlations were also found between N-acetylaspartate in ipsilesional M1, PMd, and SMA and in contralesional M1 and shoulder/elbow FMUE subscores (P = .02, .01, .02, and .02, respectively).  

 

Conclusions. 

 

Our preliminary results demonstrated that proton magnetic resonance spectroscopy is a sensitive method to quantify relevant neuronal changes in spared motor cortex after stroke and consequently increase our knowledge of the factors leading from these changes to arm motor impairment.

Introduction

Human imaging studies have revealed that early after subcortical stroke, restoration of paretic arm function is associated with a greater involvement of radiologically normal-appearing (or spared) motor (primary motor cortex or M1) and premotor (dorsal premotor cortex or PMd, supplementary motor area or SMA) areas in both injured (ipsilesional) and uninjured (contralesional) hemispheres.^1-3 Later, successful recovery occurs in stroke survivors who exhibit relatively normal patterns of ipsilesional activation and less contralesional motor activation, whereas patients, who often show bilateral cortical activation, typically have less complete recovery.^4-6 These results should be viewed in the context of the anatomic structures and pathways of these areas. Although M1 motor pathways are critical, the premotor areas also contribute to motor control and might be recruited during motor recovery after stroke. The parallel nature of the direct (corticospinal) pathways from premotor areas and M1 emphasizes that PMd and SMA are, in some respects, at a similar level of hierarchical organization as M1,⁷ although these projections to spinal cord motor neurons are less numerous and less efficient than those from M1.^8-10 Another possibility is the indirect (corticoreticulospinal) projections to cervical propriospinal premotoneurons, which have divergent projections to muscle groups operating at multiple joints.^11,12 Finally, corticocortical connections between these areas might also play an important role in poststroke recovery.^7,13-15 Thus, understanding the neural events associated with the functional changes in these areas could provide critical insight into successful treatments of patient’s impairment.

Proton magnetic resonance spectroscopy (¹H-MRS) provides a noninvasive means to measure concentrations of certain metabolites associated with a specific cell type¹⁶ after stroke.¹⁷ Most clinical stroke studies report lower levels of N-acetylaspartate (NAA, putative marker of neuronal integrity) in spared ipsilesional M1 and PMd.^18-21 In some instances, the NAA levels were related to clinical severity. In a series of studies of stroke survivors, we also found higher myo-inositol (mI, putative marker of glial cells) in ipsilesional and contralesional M1.²¹ However, none of these studies addressed the changes in key metabolites related to neuronal and glial compartments, that is, NAA and mI, in motor and premotor areas in stroke.

The first aim of the current study was to quantify NAA and mI concentrations in ipsilesional and contralesional motor and premotor areas in chronic subcortical stroke. Since neuronal integrity might be compromised in these remote areas,^21,22 we expected NAA to be lower, especially in the ipsilesional areas. Given the role of glia in plastic brain changes,^23-25 we also expected mI to be higher. The second aim was to explore correlations between metabolite concentrations and arm motor impairment. Since the premotor projections are significantly stronger on the proximal muscles than distal muscles compared with M1^8,9, we predicted that metabolite measures in ipsilesional PMd and SMA would be correlated with proximal (shoulder/elbow) motor impairment whereas those in M1 would be correlated with both proximal and distal (hand) impairments. Since both direct and indirect pathways from the contralesional M1 project to axial and proximal muscles rather than hand muscles,^26,27 relationships between contralesional M1 metabolites and proximal impairment were also expected.

More at link.

Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairm

Survivors don't care about quantifying their impairment, they want it cured. This was almost totally fucking useless. After you measured this what protocols are needed to cure the impairment? THAT IS WHAT SURVIVORS NEED. GET THERE!

 

Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairment

Show all authors

Sorin C. Craciunas, MD, PhD, William M. Brooks, PhD, Randolph J. Nudo, PhD, ...

First Published January 8, 2013 Research Article Find in PubMed

https://doi.org/10.1177/1545968312469835

Article information

Abstract

Background. 

Although functional imaging and neurophysiological approaches reveal alterations in motor and premotor areas after stroke, insights into neurobiological events underlying these alterations are limited in human studies.  

Objective. 

We tested whether cerebral metabolites related to neuronal and glial compartments are altered in the hand representation in bilateral motor and premotor areas and correlated with distal and proximal arm motor impairment in hemiparetic persons.  

Methods. 

 In 20 participants at >6 months postonset of a subcortical ischemic stroke and 16 age- and sex-matched healthy controls, the concentrations of N-acetylaspartate and myo-inositol were quantified by proton magnetic resonance spectroscopy. Regions of interest identified by functional magnetic resonance imaging included primary (M1), dorsal premotor (PMd), and supplementary (SMA) motor areas. Relationships between metabolite concentrations and distal (hand) and proximal (shoulder/elbow) motor impairment using Fugl-Meyer Upper Extremity (FMUE) subscores were explored.  

Results. 

N-Acetylaspartate was lower in M1 (P = .04) and SMA (P = .004) and myo-inositol was higher in M1 (P = .003) and PMd (P = .03) in the injured (ipsilesional) hemisphere after stroke compared with the left hemisphere in controls. N-Acetylaspartate in ipsilesional M1 was positively correlated with hand FMUE subscores (P = .04). Significant positive correlations were also found between N-acetylaspartate in ipsilesional M1, PMd, and SMA and in contralesional M1 and shoulder/elbow FMUE subscores (P = .02, .01, .02, and .02, respectively). 

Conclusions. 

Our preliminary results demonstrated that proton magnetic resonance spectroscopy is a sensitive method to quantify relevant neuronal changes in spared motor cortex after stroke and consequently increase our knowledge of the factors leading from these changes to arm motor impairment.

Keywords

subcortical stroke, motor and premotor cortices, proton magnetic resonance spectroscopy, distal and proximal arm motor impairment

Introduction

Human imaging studies have revealed that early after subcortical stroke, restoration of paretic arm function is associated with a greater involvement of radiologically normal-appearing (or spared) motor (primary motor cortex or M1) and premotor (dorsal premotor cortex or PMd, supplementary motor area or SMA) areas in both injured (ipsilesional) and uninjured (contralesional) hemispheres.^1-3 Later, successful recovery occurs in stroke survivors who exhibit relatively normal patterns of ipsilesional activation and less contralesional motor activation, whereas patients, who often show bilateral cortical activation, typically have less complete recovery.^4-6 These results should be viewed in the context of the anatomic structures and pathways of these areas. Although M1 motor pathways are critical, the premotor areas also contribute to motor control and might be recruited during motor recovery after stroke. The parallel nature of the direct (corticospinal) pathways from premotor areas and M1 emphasizes that PMd and SMA are, in some respects, at a similar level of hierarchical organization as M1,⁷ although these projections to spinal cord motor neurons are less numerous and less efficient than those from M1.^8-10 Another possibility is the indirect (corticoreticulospinal) projections to cervical propriospinal premotoneurons, which have divergent projections to muscle groups operating at multiple joints.^11,12 Finally, corticocortical connections between these areas might also play an important role in poststroke recovery.^7,13-15 Thus, understanding the neural events associated with the functional changes in these areas could provide critical insight into successful treatments of patient’s impairment.

Proton magnetic resonance spectroscopy (¹H-MRS) provides a noninvasive means to measure concentrations of certain metabolites associated with a specific cell type¹⁶ after stroke.¹⁷ Most clinical stroke studies report lower levels of N-acetylaspartate (NAA, putative marker of neuronal integrity) in spared ipsilesional M1 and PMd.^18-21 In some instances, the NAA levels were related to clinical severity. In a series of studies of stroke survivors, we also found higher myo-inositol (mI, putative marker of glial cells) in ipsilesional and contralesional M1.²¹ However, none of these studies addressed the changes in key metabolites related to neuronal and glial compartments, that is, NAA and mI, in motor and premotor areas in stroke.

The first aim of the current study was to quantify NAA and mI concentrations in ipsilesional and contralesional motor and premotor areas in chronic subcortical stroke. Since neuronal integrity might be compromised in these remote areas,^21,22 we expected NAA to be lower, especially in the ipsilesional areas. Given the role of glia in plastic brain changes,^23-25 we also expected mI to be higher. The second aim was to explore correlations between metabolite concentrations and arm motor impairment. Since the premotor projections are significantly stronger on the proximal muscles than distal muscles compared with M1^8,9, we predicted that metabolite measures in ipsilesional PMd and SMA would be correlated with proximal (shoulder/elbow) motor impairment whereas those in M1 would be correlated with both proximal and distal (hand) impairments. Since both direct and indirect pathways from the contralesional M1 project to axial and proximal muscles rather than hand muscles,^26,27 relationships between contralesional M1 metabolites and proximal impairment were also expected.

More at link.

 

 

 

Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairment

Something might be important in here but with all the big words I got nothing out of it.

Motor and Premotor Cortices in Subcortical Stroke: Proton Magnetic Resonance Spectroscopy Measures and Arm Motor Impairment 

Show all authors

Sorin C. Craciunas, MD, PhD, William M. Brooks, PhD, Randolph J. Nudo, PhD,

First Published January 8, 2013 Research Article Find in PubMed 

https://doi.org/10.1177/1545968312469835

Article information

Abstract

Background. 

Although functional imaging and neurophysiological approaches reveal alterations in motor and premotor areas after stroke, insights into neurobiological events underlying these alterations are limited in human studies.  

Objective. 

We tested whether cerebral metabolites related to neuronal and glial compartments are altered in the hand representation in bilateral motor and premotor areas and correlated with distal and proximal arm motor impairment in hemiparetic persons.  

Methods. 

In 20 participants at >6 months postonset of a subcortical ischemic stroke and 16 age- and sex-matched healthy controls, the concentrations of N-acetylaspartate and myo-inositol were quantified by proton magnetic resonance spectroscopy. Regions of interest identified by functional magnetic resonance imaging included primary (M1), dorsal premotor (PMd), and supplementary (SMA) motor areas. Relationships between metabolite concentrations and distal (hand) and proximal (shoulder/elbow) motor impairment using Fugl-Meyer Upper Extremity (FMUE) subscores were explored.  

Results. 

N-Acetylaspartate was lower in M1 (P = .04) and SMA (P = .004) and myo-inositol was higher in M1 (P = .003) and PMd (P = .03) in the injured (ipsilesional) hemisphere after stroke compared with the left hemisphere in controls. N-Acetylaspartate in ipsilesional M1 was positively correlated with hand FMUE subscores (P = .04). Significant positive correlations were also found between N-acetylaspartate in ipsilesional M1, PMd, and SMA and in contralesional M1 and shoulder/elbow FMUE subscores (P = .02, .01, .02, and .02, respectively).  

Conclusions. 

 Our preliminary results demonstrated that proton magnetic resonance spectroscopy is a sensitive method to quantify relevant neuronal changes in spared motor cortex after stroke and consequently increase our knowledge of the factors leading from these changes to arm motor impairment.

Keywords subcortical stroke, motor and premotor cortices, proton magnetic resonance spectroscopy, distal and proximal arm motor impairment

Introduction

Human imaging studies have revealed that early after subcortical stroke, restoration of paretic arm function is associated with a greater involvement of radiologically normal-appearing (or spared) motor (primary motor cortex or M1) and premotor (dorsal premotor cortex or PMd, supplementary motor area or SMA) areas in both injured (ipsilesional) and uninjured (contralesional) hemispheres.^1-3 Later, successful recovery occurs in stroke survivors who exhibit relatively normal patterns of ipsilesional activation and less contralesional motor activation, whereas patients, who often show bilateral cortical activation, typically have less complete recovery.^4-6 These results should be viewed in the context of the anatomic structures and pathways of these areas. Although M1 motor pathways are critical, the premotor areas also contribute to motor control and might be recruited during motor recovery after stroke. The parallel nature of the direct (corticospinal) pathways from premotor areas and M1 emphasizes that PMd and SMA are, in some respects, at a similar level of hierarchical organization as M1,⁷ although these projections to spinal cord motor neurons are less numerous and less efficient than those from M1.^8-10 Another possibility is the indirect (corticoreticulospinal) projections to cervical propriospinal premotoneurons, which have divergent projections to muscle groups operating at multiple joints.^11,12 Finally, corticocortical connections between these areas might also play an important role in poststroke recovery.^7,13-15 Thus, understanding the neural events associated with the functional changes in these areas could provide critical insight into successful treatments of patient’s impairment.

Proton magnetic resonance spectroscopy (¹H-MRS) provides a noninvasive means to measure concentrations of certain metabolites associated with a specific cell type¹⁶ after stroke.¹⁷ Most clinical stroke studies report lower levels of N-acetylaspartate (NAA, putative marker of neuronal integrity) in spared ipsilesional M1 and PMd.^18-21 In some instances, the NAA levels were related to clinical severity. In a series of studies of stroke survivors, we also found higher myo-inositol (mI, putative marker of glial cells) in ipsilesional and contralesional M1.²¹ However, none of these studies addressed the changes in key metabolites related to neuronal and glial compartments, that is, NAA and mI, in motor and premotor areas in stroke.

The first aim of the current study was to quantify NAA and mI concentrations in ipsilesional and contralesional motor and premotor areas in chronic subcortical stroke. Since neuronal integrity might be compromised in these remote areas,^21,22 we expected NAA to be lower, especially in the ipsilesional areas. Given the role of glia in plastic brain changes,^23-25 we also expected mI to be higher. The second aim was to explore correlations between metabolite concentrations and arm motor impairment. Since the premotor projections are significantly stronger on the proximal muscles than distal muscles compared with M1^8,9, we predicted that metabolite measures in ipsilesional PMd and SMA would be correlated with proximal (shoulder/elbow) motor impairment whereas those in M1 would be correlated with both proximal and distal (hand) impairments. Since both direct and indirect pathways from the contralesional M1 project to axial and proximal muscles rather than hand muscles,^26,27 relationships between contralesional M1 metabolites and proximal impairment were also expected.

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