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Gwin JT, Gramann K, Makeig S, Ferris DP. Electrocortical activity is coupled to gait cycle phase during treadmill walking. Neuroimage 2010; 54:1289-96. [PMID: 20832484 DOI: 10.1016/j.neuroimage.2010.08.066] [Citation(s) in RCA: 301] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 08/23/2010] [Accepted: 08/29/2010] [Indexed: 10/19/2022] Open
Abstract
Recent findings suggest that human cortex is more active during steady-speed unperturbed locomotion than previously thought. However, techniques that have been used to image the brain during locomotion lack the temporal resolution necessary to assess intra-stride cortical dynamics. Our aim was to determine if electrocortical activity is coupled to gait cycle phase during steady-speed human walking. We used electroencephalography (EEG), motion capture, and a force-measuring treadmill to record brain and body dynamics while eight healthy young adult subjects walked on a treadmill. Infomax independent component analysis (ICA) parsed EEG signals into maximally independent component (IC) processes representing electrocortical sources, muscle sources, and artifacts. We calculated a spatially fixed equivalent current dipole for each IC using an inverse modeling approach, and clustered electrocortical sources across subjects by similarities in dipole locations and power spectra. We then computed spectrograms for each electrocortical source that were time-locked to the gait cycle. Electrocortical sources in the anterior cingulate, posterior parietal, and sensorimotor cortex exhibited significant (p<0.05) intra-stride changes in spectral power. During the end of stance, as the leading foot was contacting the ground and the trailing foot was pushing off, alpha- and beta-band spectral power increased in or near the left/right sensorimotor and dorsal anterior cingulate cortex. Power increases in the left/right sensorimotor cortex were more pronounced for contralateral limb push-off (ipsilateral heel-strike) than for ipsilateral limb push-off (contralateral heel-strike). Intra-stride high-gamma spectral power changes were evident in anterior cingulate, posterior parietal, and sensorimotor cortex. These data confirm cortical involvement in steady-speed human locomotion. Future applications of these techniques could provide critical insight into the neural mechanisms of movement disorders and gait rehabilitation.
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Affiliation(s)
- Joseph T Gwin
- Human Neuromechanics Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, MI 48109-2214, USA.
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152
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Trinastic JP, Kautz SA, McGregor K, Gregory C, Bowden M, Benjamin MB, Kurtzman M, Chang YL, Conway T, Crosson B. An fMRI study of the differences in brain activity during active ankle dorsiflexion and plantarflexion. Brain Imaging Behav 2010; 4:121-31. [PMID: 20502995 DOI: 10.1007/s11682-010-9091-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Little is known regarding the differences in active cortical and subcortical systems during opposing movements of an agonist-antagonist muscle group. The objective of this study was to characterize the differences in cortical activation during active ankle dorsiflexion and plantarflexion using functional MRI (fMRI). Eight right-handed healthy adults performed auditorily cued right ankle dorsiflexions and plantarflexions during fMRI. Differences in activity patterns between dorsiflexion and plantarflexion during fMRI were assessed using between- and within-subject voxel-wise t-tests. Results indicated that ankle dorsiflexion recruited significantly more regions in left M1, the supplementary motor area (SMA) bilaterally, and right cerebellum. Both movements activated similar left hemisphere regions in the putamen and thalamus. Dorsiflexion activated additional areas in the right putamen. Results suggest that ankle dorsiflexion and plantarflexion may be controlled by both shared and independent neural circuitry. This has important implications for functional investigations of gait pathology and how rehabilitation may differentially affect each movement.
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Affiliation(s)
- Jonathan P Trinastic
- Department of Veteran Affairs Rehabilitation Research and Development Brain Rehabilitation Research Center at the Malcom Randall VA Medical Center, Gainesville, Florida, USA.
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153
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Petzinger GM, Fisher BE, Van Leeuwen JE, Vukovic M, Akopian G, Meshul CK, Holschneider DP, Nacca A, Walsh JP, Jakowec MW. Enhancing neuroplasticity in the basal ganglia: the role of exercise in Parkinson's disease. Mov Disord 2010; 25 Suppl 1:S141-5. [PMID: 20187247 DOI: 10.1002/mds.22782] [Citation(s) in RCA: 145] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Epidemiological and clinical trials have suggested that exercise is beneficial for patients with Parkinson's disease (PD). However, the underlying mechanisms and potential for disease modification are currently unknown. This review presents current findings from our laboratories in patients with PD and animal models. The data indicate that alterations in both dopaminergic and glutamatergic neurotransmission, induced by activity-dependent (exercise) processes, may mitigate the cortically driven hyper-excitability in the basal ganglia normally observed in the parkinsonian state. These insights have potential to identify novel therapeutic treatments capable of reversing or delaying disease progression in PD.
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Affiliation(s)
- Giselle M Petzinger
- The George and MaryLou Boone Center for Parkinson's Disease Research, Department of Neurology, University of Southern California, Los Angeles, California 90033, USA.
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154
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Temporal and spatial patterns of cortical activation during assisted lower limb movement. Exp Brain Res 2010; 203:181-91. [PMID: 20364340 DOI: 10.1007/s00221-010-2223-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Accepted: 03/08/2010] [Indexed: 10/19/2022]
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155
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Constraint-Induced Therapy Versus Control Intervention in Patients with Stroke. Am J Phys Med Rehabil 2010; 89:177-85. [DOI: 10.1097/phm.0b013e3181cf1c78] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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156
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Gait parameters associated with responsiveness to treadmill training with body-weight support after stroke: an exploratory study. Phys Ther 2010; 90:209-23. [PMID: 20022996 DOI: 10.2522/ptj.20090141] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
BACKGROUND Task-specific training programs after stroke improve walking function, but it is not clear which biomechanical parameters of gait are most associated with improved walking speed. OBJECTIVE The purpose of this study was to identify gait parameters associated with improved walking speed after a locomotor training program that included body-weight-supported treadmill training (BWSTT). DESIGN A prospective, between-subjects design was used. METHODS Fifteen people, ranging from approximately 9 months to 5 years after stroke, completed 1 of 3 different 6-week training regimens. These regimens consisted of 12 sessions of BWSTT alternated with 12 sessions of: lower-extremity resistive cycling; lower-extremity progressive, resistive strengthening; or a sham condition of arm ergometry. Gait analysis was conducted before and after the 6-week intervention program. Kinematics, kinetics, and electromyographic (EMG) activity were recorded from the hemiparetic lower extremity while participants walked at a self-selected pace. Changes in gait parameters were compared in participants who showed an increase in self-selected walking speed of greater than 0.08 m/s (high-response group) and in those with less improvement (low-response group). RESULTS Compared with participants in the low-response group, those in the high-response group displayed greater increases in terminal stance hip extension angle and hip flexion power (product of net joint moment and angular velocity) after the intervention. The intensity of soleus muscle EMG activity during walking also was significantly higher in participants in the high-response group after the intervention. LIMITATIONS Only sagittal-plane parameters were assessed, and the sample size was small. CONCLUSIONS Task-specific locomotor training alternated with strength training resulted in kinematic, kinetic, and muscle activation adaptations that were strongly associated with improved walking speed. Changes in both hip and ankle biomechanics during late stance were associated with greater increases in gait speed.
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157
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Tang PF, Ko YH, Luo ZA, Yeh FC, Chen SHA, Tseng WYI. Tract-specific and region of interest analysis of corticospinal tract integrity in subcortical ischemic stroke: reliability and correlation with motor function of affected lower extremity. AJNR Am J Neuroradiol 2010; 31:1023-30. [PMID: 20110374 DOI: 10.3174/ajnr.a1981] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND PURPOSE TS analysis has been suggested as a useful method to evaluate the fiber integrity of white matter tracts. This study investigated the intrarater and interrater reliability and validity of a TS analysis for the CST and compared the results with those of a ROI-based analysis. MATERIALS AND METHODS Diffusion spectrum imaging was performed on 7 patients with subcortical ischemic stroke on a 3T MR imaging system. For the TS analysis, seed regions were placed at the cerebral peduncle and the medial portion of the primary motor cortex to reconstruct the tracts of the CST for motor control of the lower extremity. The mean GFA was measured at the PLIC by calculating the weighted sum of the GFAs sampled by the CST tracts at this segment. For the ROI-based analysis, the posterior two-thirds of the PLIC were enclosed on the GFA maps, and the mean GFA in this ROI was calculated. RESULTS The results showed good-to-excellent intrarater and interrater reliability on the seed region/ROI placement (mean kappa values >0.80) and mean GFA values (ICCs >0.90) for both the TS and ROI-based analyses. Both the GFA(PLIC-TS) and GFA(PLIC-ROI) values were highly correlated with the motor function of the affected lower extremity (r = 0.76 and 0.80, respectively; P < .05). CONCLUSIONS We demonstrated good reliability and validity of the TS and ROI-based analyses of the CST corresponding to lower extremity motor control in patients with subcortical ischemic stroke.
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Affiliation(s)
- P-F Tang
- School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, No. 1 Jen-Ai Road, Taipei, Taiwan, Republic of China
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158
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Crosson B, Ford A, McGregor KM, Meinzer M, Cheshkov S, Li X, Walker-Batson D, Briggs RW. Functional imaging and related techniques: an introduction for rehabilitation researchers. JOURNAL OF REHABILITATION RESEARCH AND DEVELOPMENT 2010; 47:vii-xxxiv. [PMID: 20593321 PMCID: PMC3225087 DOI: 10.1682/jrrd.2010.02.0017] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Functional neuroimaging and related neuroimaging techniques are becoming important tools for rehabilitation research. Functional neuroimaging techniques can be used to determine the effects of brain injury or disease on brain systems related to cognition and behavior and to determine how rehabilitation changes brain systems. These techniques include: functional magnetic resonance imaging (fMRI), positron emission tomography (PET), electroencephalography (EEG), magnetoencephalography (MEG), near infrared spectroscopy (NIRS), and transcranial magnetic stimulation (TMS). Related diffusion weighted magnetic resonance imaging techniques (DWI), including diffusion tensor imaging (DTI) and high angular resolution diffusion imaging (HARDI), can quantify white matter integrity. With the proliferation of these imaging techniques in rehabilitation research, it is critical that rehabilitation researchers, as well as consumers of rehabilitation research, become familiar with neuroimaging techniques, what they can offer, and their strengths and weaknesses The purpose to this review is to provide such an introduction to these neuroimaging techniques.
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Affiliation(s)
- Bruce Crosson
- VA RR&D Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, Gainesville, Florida
- Department of Clinical & Health Psychology, University of Florida, Gainesville, Florida
| | - Anastasia Ford
- Department of Psychology, University of Florida, Gainesville, Florida
| | - Keith M. McGregor
- VA RR&D Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, Gainesville, Florida
- Department of Psychology, University of Florida, Gainesville, Florida
| | - Marcus Meinzer
- Department of Clinical & Health Psychology, University of Florida, Gainesville, Florida
| | - Sergey Cheshkov
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Xiufeng Li
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | | | - Richard W. Briggs
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas
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159
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Abstract
Emotions have powerful effects on pain perception. However, the brain mechanisms underlying these effects remain largely unknown. In this study, we combined functional cerebral imaging with psychophysiological methods to explore the neural mechanisms involved in the emotional modulation of spinal nociceptive responses (RIII-reflex) and pain perception in healthy participants. Emotions induced by pleasant or unpleasant pictures modulated the responses to painful electrical stimulations in the right insula, paracentral lobule, parahippocampal gyrus, thalamus, and amygdala. Right insula activation covaried with the modulation of pain perception, consistent with a key role of this structure in the integration of pain signals with the ongoing emotion. In contrast, activity in the thalamus, amygdala, and several prefrontal areas was associated with the modulation of spinal reflex responses. Last, connectivity analyses suggested an involvement of prefrontal, parahippocampal, and brainstem structures in the cerebral and cerebrospinal modulation of pain by emotions. This multiplicity of mechanisms underlying the emotional modulation of pain is reflective of the strong interrelations between pain and emotions, and emphasizes the powerful effects that emotions can have on pain.
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160
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Treadmill-based locomotor training with leg weights to enhance functional ambulation in people with chronic stroke: a pilot study. J Neurol Phys Ther 2009; 33:129-35. [PMID: 19809391 DOI: 10.1097/npt.0b013e3181b57de5] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND PURPOSE Novel locomotor training strategies for individuals with disorders of the central nervous system have been associated with improved locomotor function. The purpose of this study was to investigate the effects of treadmill-based locomotor training combined with leg weights on functional ambulation in individuals with chronic stroke. We assessed functional ambulation and muscle activity in ambulatory individuals with chronic stroke. METHODS We used a pre/posttest design. Six individuals with chronic stroke who were community ambulators were recruited. Participants underwent a 30-minute treadmill-based locomotor training sessions three times per week for four to 12 weeks. The training program involved treadmill walking for 30 minutes with partial body weight support as needed. Leg weights, equivalent to 5% of body weight, were affixed around the paretic leg. Outcome measures consisted of the 10-m walk test, the modified Emory Functional Ambulation Profile, and temporal gait parameters. RESULTS Improvements were observed in functional ambulation measures, particularly the stairs subscore of the modified Emory Functional Ambulation Profile. Participants also exhibited an increase in the proportion of time the paretic leg spent in swing. No significant improvements were observed in the 10-m walk test. CONCLUSIONS This pilot study demonstrates that the combination of leg weights and treadmill training is a feasible approach, that is well tolerated by participants. This approach may have the potential to improve some aspects of functional ambulation and the performance of activities requiring hip and knee flexion.
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161
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Crosson B, Moore AB, McGregor KM, Chang YL, Benjamin M, Gopinath K, Sherod ME, Wierenga CE, Peck KK, Briggs RW, Rothi LJG, White KD. Regional changes in word-production laterality after a naming treatment designed to produce a rightward shift in frontal activity. BRAIN AND LANGUAGE 2009; 111:73-85. [PMID: 19811814 PMCID: PMC3239407 DOI: 10.1016/j.bandl.2009.08.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 07/29/2009] [Accepted: 08/03/2009] [Indexed: 05/04/2023]
Abstract
Five nonfluent aphasia patients participated in a picture-naming treatment that used an intention manipulation (opening a box and pressing a button on a device in the box with the left hand) to initiate naming trials and was designed to re-lateralize word production mechanisms from the left to the right frontal lobe. To test the underlying assumption regarding re-lateralization, patients participated in fMRI of category-member generation before and after treatment. Generally, the four patients who improved during treatment showed reduced frontal activity from pre- to post-treatment fMRI with increasing concentration of activity in the right posterior frontal lobe (motor/premotor cortex, pars opercularis), demonstrating a significant shift in lateraliity toward the right lateral frontal lobe, as predicted. Three of these four patients showed no left frontal activity by completion of treatment, indicating that right posterior lateral frontal activity supported category-member generation. Patients who improved in treatment showed no difference in lateralization of lateral frontal activity from normal controls pre-treatment, but post-treatment, their lateral frontal activity during category-member generation was significantly more right lateralized than that of controls. Patterns of activity pre- and post-treatment suggested increasing efficiency of cortical processing as a result of treatment in the four patients who improved. The one patient who did not improve during treatment showed a leftward shift in lateral frontal lateralization that was significantly different from the four patients who did improve. Neither medial frontal nor posterior perisylvian re-lateralization from immediately pre- to immediately post-treatment images was a necessary condition for significant treatment gains or shift in lateral frontal lateralization. Of the three patients who improved and in whom posterior perisylvian activity could be measured at post-treatment fMRI, all maintained equal or greater amounts of left-hemisphere perisylvian activity as compared to right. This finding is consistent with reviews suggesting both hemispheres are involved in recovery of language in aphasia patients.
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Affiliation(s)
- Bruce Crosson
- VA RR&D Brain Rehabilitation Research Center, Gainesville, FL, USA.
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162
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Katiuscia S, Franco C, Federico D, Davide M, Sergio D, Giuliano G. Reorganization and enhanced functional connectivity of motor areas in repetitive ankle movements after training in locomotor attention. Brain Res 2009; 1297:124-34. [DOI: 10.1016/j.brainres.2009.08.049] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Revised: 08/13/2009] [Accepted: 08/14/2009] [Indexed: 11/26/2022]
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163
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Bowden MG, Clark DJ, Kautz SA. Evaluation of abnormal synergy patterns poststroke: relationship of the Fugl-Meyer Assessment to hemiparetic locomotion. Neurorehabil Neural Repair 2009; 24:328-37. [PMID: 19794132 DOI: 10.1177/1545968309343215] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Assessment of poststroke motor impairment has historically focused on the ability to move within and outside of abnormal synergistic motor patterns and is typically quantified by the Fugl-Meyer Assessment (FMA). However, it is unclear if the voluntary, isolated movement tasks of the FMA are appropriate for evaluating walking task-specific motor control requirements because walking is cyclical and involves considerable sensorimotor integration. OBJECTIVE The purpose of this study is to test whether the motor impairment measured by the FMA is indicative of motor dysfunction during walking in poststroke adults. METHODS Thirty-four individuals with chronic poststroke hemiparesis and 17 healthy controls walked for 60 seconds on an instrumented treadmill while recording electromyographic activity (EMG) from 8 lower extremity muscles. EMG recordings were also obtained during the FMA for those with hemiparesis to examine muscle activation patterns. Each participant was examined with a battery of walking-specific clinical and biomechanical assessment tools and stratified based on the FMA synergy (FMS) score. To further quantify muscle activation patterns during walking, a nonnegative matrix factorization (NNMF) determined the number of independent modules required to describe 90% of the total variance in the EMG patterns. RESULTS Stratification poorly differentiated motor activation across FMA tasks as well as EMG patterns during walking. While FMS correlated with 2 of 6 walking assessments, the number of EMG modules significantly correlated with all 6 walking performance measures. CONCLUSIONS Voluntary, discrete activities as performed in the FMA may be inadequate to capture the complex motor behavior in walking. Conversely, walking-specific evaluations such as NNMF appear more appropriate.
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Affiliation(s)
- Mark G Bowden
- Brain Rehabilitation Research Center, NF/SG Veterans Affairs Health System, Gainesville, Florida 32608, USA.
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164
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Attentional requirements of walking according to the gait phase and onset of auditory stimuli. Gait Posture 2009; 30:227-32. [PMID: 19540124 DOI: 10.1016/j.gaitpost.2009.05.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 04/30/2009] [Accepted: 05/08/2009] [Indexed: 02/02/2023]
Abstract
A dual-task paradigm was used to examine the influence of an attention demanding cognitive task on each phase of gait. Twenty-three participants (aged 18-27) walked on a treadmill at a 20% increase of their self-selected speed, either alone or while performing a cognitive task. Muscle activity was measured with electromyography (iEMG) for eight muscles of the dominant leg. The cognitive task consisted of subtracting one (EASY) or seven (HARD) from orally presented numbers. Reaction time (RT) and accuracy were recorded. iEMG events were selected according to stimulus onset (0-150 ms, 150-300 ms and 300-450 ms) prior to phases of gait (double-leg stance, single-leg stance and swing). There was a decrease in iEMG amplitude of fibularis longus (p=.013) and a trend in the same direction for vastus lateralis (p=.065) while walking and performing the cognitive task. When stimulus onset was considered, iEMG of medial gastrocnemius (p=.021) and lateral gastrocnemius (p=.004) were reduced during single-leg stance, when stimuli occurred between 300 and 450 ms prior to this phase. Cognitive performance was affected by task difficulty (RT, accuracy) and by dual-task load (RT). Dual-task costs were observed in both the motor and the cognitive tasks, suggesting that walking requires attention. There was a specific moment (300 ms after stimulus onset) during single-leg stance when dual-task costs were most pronounced, corroborating supraspinal involvement in the control of normal walking. Time-based approaches should be considered when analyzing attentional demands of a dynamic task such as gait.
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165
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Shinoura N, Suzuki Y, Yamada R, Tabei Y, Saito K, Yagi K. Marked and rapid recovery of motor strength in premotor area compared with primary motor area in surgery for brain tumors. Br J Neurosurg 2009; 23:309-14. [DOI: 10.1080/02688690802638166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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166
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Enzinger C, Dawes H, Johansen-Berg H, Wade D, Bogdanovic M, Collett J, Guy C, Kischka U, Ropele S, Fazekas F, Matthews PM. Brain activity changes associated with treadmill training after stroke. Stroke 2009; 40:2460-7. [PMID: 19461018 PMCID: PMC7610851 DOI: 10.1161/strokeaha.109.550053] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE The mechanisms underlying motor recovery after stroke are not fully understood. Several studies used functional MRI longitudinally to relate brain activity changes with performance gains of the upper limb after therapy, but research into training-induced recovery of lower limb function has been relatively neglected thus far. METHODS We investigated functional reorganization after 4 weeks of treadmill training with partial body weight support in 18 chronic patients (mean age, 59.9+/-13.5 years) with mild to moderate paresis (Motricity Index affected leg: 77.7+/-10.5; range, 9 to 99) and gait impairment (Functional Ambulation Category: 4.4+/-0.6; range, 3 to 5) due to a single subcortical ischemic stroke using repeated 3.0-T functional MRI and an ankle-dorsiflexion paradigm. RESULTS Walking endurance improved after training (2-minute timed walking distance: 121.5+/-39.0 versus pre: 105.1+/-38.1 m; P=0.0001). For active movement of the paretic foot versus rest, greater walking endurance correlated with increased brain activity in the bilateral primary sensorimotor cortices, the cingulate motor areas, and the caudate nuclei bilaterally and in the thalamus of the affected hemisphere. CONCLUSIONS Despite the strong subcortical contributions to gait control, rehabilitation-associated walking improvements are associated with cortical activation changes. This is similar to findings in upper limb rehabilitation with some differences in the involved cortical areas. We observed bihemispheric activation increases with greater recovery both in cortical and subcortical regions with movement of the paretic foot. However, although the dorsal premotor cortex appears to play an important role in recovery of hand movements, evidence for the involvement of this region in lower extremity recovery was not found.
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167
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Dobkin BH. Progressive Staging of Pilot Studies to Improve Phase III Trials for Motor Interventions. Neurorehabil Neural Repair 2009; 23:197-206. [PMID: 19240197 DOI: 10.1177/1545968309331863] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Based on the suboptimal research pathways that finally led to multicenter randomized clinical trials (MRCTs) of treadmill training with partial body weight support and of robotic assistive devices, strategically planned successive stages are proposed for pilot studies of novel rehabilitation interventions. Stage 1, consideration-of-concept studies, drawn from animal experiments, theories, and observations, delineate the experimental intervention in a small convenience sample of participants, so the results must be interpreted with caution. Stage 2, development-of-concept pilots, should optimize the components of the intervention, settle on most appropriate outcome measures, and examine dose-response effects. A well-designed study that reveals no efficacy should be published to counterweight the confirmation bias of positive trials. Stage 3, demonstration-of-concept pilots, can build out from what has been learned to test at least 15 participants in each arm, using random assignment and blinded outcome measures. A control group should receive an active practice intervention aimed at the same primary outcome. A third arm could receive a substantially larger dose of the experimental therapy or a combinational intervention. If only 1 site performed this trial, a different investigative group should aim to reproduce positive outcomes based on the optimal dose of motor training. Stage 3 studies ought to suggest an effect size of 0.4 or higher, so that approximately 50 participants in each arm will be the number required to test for efficacy in a stage 4, proof-of-concept MRCT. By developing a consensus around acceptable and necessary practices for each stage, similar to CONSORT recommendations for the publication of phase III clinical trials, better quality pilot studies may move quickly into better designed and more successful MRCTs of experimental interventions.
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Affiliation(s)
- Bruce H Dobkin
- Department of Neurology, Geffen School of Medicine, University of California Los Angeles, USA.
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168
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Mehta JP, Verber MD, Wieser JA, Schmit BD, Schindler-Ivens SM. A novel technique for examining human brain activity associated with pedaling using fMRI. J Neurosci Methods 2009; 179:230-9. [DOI: 10.1016/j.jneumeth.2009.01.029] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 01/27/2009] [Accepted: 01/30/2009] [Indexed: 10/21/2022]
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169
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Blickenstorfer A, Kleiser R, Keller T, Keisker B, Meyer M, Riener R, Kollias S. Cortical and subcortical correlates of functional electrical stimulation of wrist extensor and flexor muscles revealed by fMRI. Hum Brain Mapp 2009; 30:963-75. [PMID: 18344193 DOI: 10.1002/hbm.20559] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The main scope of this study was to test the feasibility and reliability of FES in a MR-environment. Functional Electrical Stimulation (FES) is used in the rehabilitation therapy of patients after stroke or spinal cord injury to improve their motor abilities. Its principle lies in applying repeated electrical stimulation to the relevant nerves or muscles for eliciting either isometric or concentric contractions of the treated muscles. In this study we report cerebral activation patterns in healthy subjects undergoing fMRI during FES stimulation. We stimulated the wrist extensor and flexor muscles in an alternating pattern while BOLD-fMRI was recorded. We used both block and event-related designs to demonstrate their feasibility for recording FES activation in the same cortical and subcortical areas. Six out of fifteen subjects repeated the experiment three times within the same session to control intraindividual variance. In both block and event-related design, the analysis revealed an activation pattern comprising the contralateral primary motor cortex, primary somatosensory cortex and premotor cortex; the ipsilateral cerebellum; bilateral secondary somatosensory cortex, the supplementary motor area and anterior cingulate cortex. Within the same subjects we observed a consistent replication of the activation pattern shown in overlapping regions centered on the peak of activation. Similar time course within these regions were demonstrated in the event-related design. Thus, both techniques demonstrate reliable activation of the sensorimotor network and eventually can be used for assessing plastic changes associated with FES rehabilitation treatment.
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170
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Alexander LD, Black SE, Patterson KK, Gao F, Danells CJ, McIlroy WE. Association between gait asymmetry and brain lesion location in stroke patients. Stroke 2008; 40:537-44. [PMID: 19109546 DOI: 10.1161/strokeaha.108.527374] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Associations between the site of brain injury and poststroke gait impairment are poorly understood. Temporal gait asymmetry after stroke is a salient index of gait dysfunction that has important functional consequences. The current study investigated whether subtraction lesion analysis could distinguish brain regions associated with persisting temporal gait asymmetry in chronic stroke patients. METHODS Analysis was conducted on 37 chronic ambulatory stroke patients (17 symmetrical gait, 20 asymmetrical gait). Spatiotemporal gait parameters were recorded using an instrumented walking surface. Lesions were traced from 3D T1-MRI, and region of interest images were generated. The lesion overlay of patients with symmetrical gait was subtracted from patients with asymmetrical gait to highlight voxels more frequently lesioned in asymmetrical patients and relatively spared in symmetrical patients. RESULTS Demographic data were comparable between the 2 groups. Asymmetrical patients exhibited significantly higher National Institute of Health Stroke Scale neglect scores and more severe motor impairment. Gait asymmetry was significantly correlated to Chedoke-McMaster Stroke Scale leg (r=-0.767, P<0.001) and foot (r=-0.759, P<0.001) scores, whereas gait speed correlated less strongly. After subtraction analysis, injury to the posterolateral putamen was evident 60% to 80% more frequently in the asymmetrical group compared to the symmetrical group. CONCLUSIONS In this sample of ambulatory chronic stroke patients, damage to the posterolateral putamen was associated with temporal gait asymmetry. Further advances in our understanding of the neural correlates of gait asymmetry may provide prognostic markers for future persistent gait dysfunction and lead to early targeted rehabilitation when key regions are damaged.
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Affiliation(s)
- Lisa D Alexander
- Heart and Stroke Foundation Centre for Stroke Recovery, Toronto, Ontario, Canada
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171
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Bartels AL, Leenders KL. Brain imaging in patients with freezing of gait. Mov Disord 2008; 23 Suppl 2:S461-7. [PMID: 18668627 DOI: 10.1002/mds.21912] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Freezing of gait (FOG) is a disabling gait disturbance with unknown cerebral pathophysiology. In this review, we discuss the functional brain imaging studies that address gait physiology and pathophysiology of FOG. Radiotracer metabolic studies show basal ganglia-cortical circuitry involvement in different aspects of gait control. FOG patients showed orbitofrontal and posterior parietal deficits and possibly predominant involvement of right-sided circuitry. We suggest that FOG results from neuronal circuitry dysfunction in right-sided parietal-lateral premotor circuits. These circuits incorporate sensory information into the control of gait. Furthermore, abnormal function of frontostriatal loops, which probably sheer cognitive and attentional activities is also a main factor in FOG. Gait-induced brain circuitry activation can not adequately be achieved when investigated subjects are in a supine rest position, as is the case in most present day imaging studies. Some radiotracer activation studies were performed after walking. Imagination of gait has been used in some radiotracer activation studies with positron emission tomography (PET) and in studies with functional magnetic resonance imaging (fMRI), showing cortical activation patterns involved in several aspects of gait control. For future investigation of FOG, it is suggested to design PET and fMRI studies which concentrate on activation of neuropsychological and sensory integration circuits.
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Affiliation(s)
- Anna L Bartels
- Department of Neurology, University Medical Center Groningen (UMCG), University of Groningen, Groningen, The Netherlands.
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172
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Freivogel S, Mehrholz J, Husak-Sotomayor T, Schmalohr D. Gait training with the newly developed 'LokoHelp'-system is feasible for non-ambulatory patients after stroke, spinal cord and brain injury. A feasibility study. Brain Inj 2008; 22:625-32. [PMID: 18568717 DOI: 10.1080/02699050801941771] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
PRIMARY OBJECTIVE To evaluate the feasibility of using a newly developed electromechanical gait device (LokoHelp) for locomotion training in neurological patients with impaired walking ability with respect to training effects and patients' and therapists' efforts and discomfort. METHODS AND PROCEDURES design: Case series. setting: A neurological rehabilitation centre for children, adolescents and young adults. subjects: Six patients with impaired walking function: two after stroke, two after spinal cord injury and two after brain injury. INTERVENTION Twenty additional training sessions on a treadmill fitted with a newly developed electromechanical gait device and body weight support (BWS), performed over a study-period of 6 weeks. MAIN OUTCOMES AND RESULTS Patients' progress was assessed with the following instruments: the Functional Ambulation Category FAC (walking ability), the 10-metre walk test (gait velocity), the Motricity Index (lower limb strength), the Berg Balance Scale (postural capacity), the modified Ashworth Scale (spasticity) and the Rivermead Mobility Index (activity). After each therapy session, therapists completed a form, thereby indicating whether manual assistance was necessary and, if so, how much physical effort was expended and how much discomfort was experienced during the therapy session. The therapists also indicated on the form information about the patient's effort and discomfort. No severe adverse events were observed during the locomotion training with the LokoHelp device. Patients improved with regard to Functional Ambulation Category (FAC) (from mean 0.7, SD = 1.6, to mean 2.5, SD = 2.1, p = 0.048), Motricity Index (from mean 94 points, SD = 50, to mean 111, SD = 52, p = 0.086), Berg Balance Scale (BBS) (from mean 20 points, SD = 23 to mean 25, SD = 23, p = 0.168) and Rivermead Mobility Index (RMI) (from mean 5 points, SD = 4, to mean 7, SD = 5, p = 0.033). Therapists required a low level of effort to carry out the training and seldom experienced discomfort. Patients described their effort during training as being low-to-exhausting. They rarely experienced discomfort, which was mostly related to difficulties with the BWS-System. Training intensity had to be adjusted in one patient who complained of knee pain. CONCLUSIONS Locomotion training with the newly developed 'LokoHelp'-system is feasible in severely affected patients after brain injury, stroke and spinal cord injury. In addition, our results indicate that the described alternative method of gait training may decrease the exertion needed by therapists to carry out the training.
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Affiliation(s)
- Susanna Freivogel
- Neurological Rehabilitation Hospital, Hegau Jugendwerk, Gailingen, Germany.
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173
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Johansen-Berg H. Functional imaging of stroke recovery: what have we learnt and where do we go from here? Int J Stroke 2008; 2:7-16. [PMID: 18705982 DOI: 10.1111/j.1747-4949.2007.00093.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Functional brain imaging techniques have been used to visualise patterns of activity following stroke and to characterise how these patterns change with recovery or rehabilitation. Some consensus is now emerging on patterns that are predictive of improved outcome, and therapeutic strategies are beginning to be guided by such findings. However, patient heterogeneity predicts that the same approach will not be appropriate for all. Future studies should aim to characterise the factors that influence this heterogeneity, and to individualise rehabilitation strategies based in part on early imaging findings. Functional imaging studies of stroke should also embrace recent methodological and conceptual advances that allow for fuller characterisation of the structural and functional properties of distributed brain networks.
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Affiliation(s)
- Heidi Johansen-Berg
- Centre for Functional Magnetic Resonance Imaging of the Brain, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK.
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174
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MacIntosh BJ, McIlroy WE, Mraz R, Staines WR, Black SE, Graham SJ. Electrodermal recording and fMRI to inform sensorimotor recovery in stroke patients. Neurorehabil Neural Repair 2008; 22:728-36. [PMID: 18784267 DOI: 10.1177/1545968308316386] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Functional magnetic resonance imaging (fMRI) appears to be useful for investigating motor recovery after stroke. Some of the potential confounders of brain activation studies, however, could be mitigated through complementary physiological monitoring. OBJECTIVE To investigate a sensorimotor fMRI battery that included simultaneous measurement of electrodermal activity in subjects with hemiparetic stroke to provide a measure related to the sense of effort during motor performance. METHODS Bilateral hand and ankle tasks were performed by 6 patients with stroke (2 subacute, 4 chronic) during imaging with blood oxygen level-dependent (BOLD) fMRI using an event-related design. BOLD percent changes, peak activation, and laterality index values were calculated in the sensorimotor cortex. Electrodermal recordings were made concurrently and used as a regressor. RESULTS Sensorimotor BOLD time series and percent change values provided evidence of an intact motor network in each of these well-recovered patients. During tasks involving the hemiparetic limb, electrodermal activity changes were variable in amplitude, and electrodermal activity time-series data showed significant correlations with fMRI in 3 of 6 patients. No such correlations were observed for control tasks involving the unaffected lower limb. CONCLUSIONS Electrodermal activity activation maps implicated the contralesional over the ipsilesional hemisphere, supporting the notion that stroke patients may require higher order motor processing to perform simple tasks. Electrodermal activity recordings may be useful as a physiological marker of differences in effort required during movements of a subject's hemiparetic compared with the unaffected limb during fMRI studies.
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175
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Luft AR, Macko RF, Forrester LW, Villagra F, Ivey F, Sorkin JD, Whitall J, McCombe-Waller S, Katzel L, Goldberg AP, Hanley DF. Treadmill exercise activates subcortical neural networks and improves walking after stroke: a randomized controlled trial. Stroke 2008; 39:3341-50. [PMID: 18757284 DOI: 10.1161/strokeaha.108.527531] [Citation(s) in RCA: 180] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Stroke often impairs gait thereby reducing mobility and fitness and promoting chronic disability. Gait is a complex sensorimotor function controlled by integrated cortical, subcortical, and spinal networks. The mechanisms of gait recovery after stroke are not well understood. This study examines the hypothesis that progressive task-repetitive treadmill exercise (T-EX) improves fitness and gait function in subjects with chronic hemiparetic stroke by inducing adaptations in the brain (plasticity). METHODS A randomized controlled trial determined the effects of 6-month T-EX (n=37) versus comparable duration stretching (CON, n=34) on walking, aerobic fitness and in a subset (n=15/17) on brain activation measured by functional MRI. RESULTS T-EX significantly improved treadmill-walking velocity by 51% and cardiovascular fitness by 18% (11% and -3% for CON, respectively; P<0.05). T-EX but not CON affected brain activation during paretic, but not during nonparetic limb movement, showing 72% increased activation in posterior cerebellar lobe and 18% in midbrain (P<0.005). Exercise-mediated improvements in walking velocity correlated with increased activation in cerebellum and midbrain. CONCLUSIONS T-EX improves walking, fitness and recruits cerebellum-midbrain circuits, likely reflecting neural network plasticity. This neural recruitment is associated with better walking. These findings demonstrate the effectiveness of T-EX rehabilitation in promoting gait recovery of stroke survivors with long-term mobility impairment and provide evidence of neuroplastic mechanisms that could lead to further refinements in these paradigms to improve functional outcomes.
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Affiliation(s)
- Andreas R Luft
- Department of General Neurology, University of Maryland, School of Medicine, Baltimore, MD, USA.
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176
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Newton JM, Dong Y, Hidler J, Plummer-D'Amato P, Marehbian J, Albistegui-Dubois RM, Woods RP, Dobkin BH. Reliable assessment of lower limb motor representations with fMRI: use of a novel MR compatible device for real-time monitoring of ankle, knee and hip torques. Neuroimage 2008; 43:136-46. [PMID: 18675363 DOI: 10.1016/j.neuroimage.2008.07.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Revised: 06/25/2008] [Accepted: 07/01/2008] [Indexed: 11/17/2022] Open
Abstract
This study describes the use of a novel magnetic resonance imaging (MRI) compatible system capable of measuring isometric ankle, knee and hip joint torques in real-time during functional MRI (fMRI) testing in healthy volunteers. The motor representations of three isometric torques--ankle dorsiflexion, ankle plantarflexion and knee extension--were studied at two time points. The reliability of motor performance and fMRI-derived measures of brain activity across sessions was examined. Reproducible motor performance was observed for each of the tasks; torques of the requested amplitude, assisted by visual feedback, were generated at the relevant joint with good accuracy, both within and across the two sessions. Significant blood oxygen level dependent (BOLD) signal increases were observed in the left primary sensorimotor cortex (SM1) in the paracentral lobule and in secondary motor areas for all tasks. Within these areas there was substantial overlap of the motor representations though differential activation was observed in SM1, with greater activation of inferior paracentral lobule during knee extension than for either ankle task. Also, BOLD signal decreases were observed bilaterally within SM1 in the hand knob region for all tasks. No major session-related effects were identified at the group level. High intraclass correlation coefficients were observed for t-values of voxels in cortical motor areas for each contraction type for individuals, suggesting that fMRI-derived activity across time points was reliable. These findings support the use of this apparatus in serial studies of lower limb function.
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Affiliation(s)
- Jennifer M Newton
- Department of Neurology, University of California, Los Angeles, CA 90095-1769, USA.
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177
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Cortical control of gait in healthy humans: an fMRI study. J Neural Transm (Vienna) 2008; 115:1149-58. [PMID: 18506392 DOI: 10.1007/s00702-008-0058-z] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2007] [Accepted: 04/26/2008] [Indexed: 10/22/2022]
Abstract
This study examined the cortical control of gait in healthy humans using functional magnetic resonance imaging (fMRI). Two block-designed fMRI sessions were conducted during motor imagery of a locomotor-related task. Subjects watched a video clip that showed an actor standing and walking in an egocentric perspective. In a control session, additional fMRI images were collected when participants observed a video clip of the clutch movement of a right hand. In keeping with previous studies using SPECT and NIRS, we detected activation in many motor-related areas including supplementary motor area, bilateral precentral gyrus, left dorsal premotor cortex, and cingulate motor area. Smaller additional activations were observed in the bilateral precuneus, left thalamus, and part of right putamen. Based on these findings, we propose a novel paradigm to study the cortical control of gait in healthy humans using fMRI. Specifically, the task used in this study--involving both mirror neurons and mental imagery--provides a new feasible model to be used in functional neuroimaging studies in this area of research.
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178
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Enzinger C, Johansen-Berg H, Dawes H, Bogdanovic M, Collett J, Guy C, Ropele S, Kischka U, Wade D, Fazekas F, Matthews PM. Functional MRI correlates of lower limb function in stroke victims with gait impairment. Stroke 2008; 39:1507-13. [PMID: 18340092 PMCID: PMC7610857 DOI: 10.1161/strokeaha.107.501999] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Although knowledge concerning cortical reorganization related to upper limb function after ischemic stroke is growing, similar data for lower limb movements are limited. Previous studies with hand movement suggested increasing recruitment of motor areas in the unlesioned hemisphere with increasing disability. We used ankle movement as a lower limb analog to test for similarities and differences in recovery patterns. METHODS Eighteen subjects were selected with chronic residual gait impairment due to a single subcortical ischemic stroke. Functional MRI scans were obtained at 3.0 T during active and passive ankle dorsiflexion in the patients (8 females, 10 males; mean age, 59.9+/-13.5 years; range, 32 to 74 years) and 18 age-matched healthy control subjects. RESULTS We observed substantial neocortical activity associated with foot movement both in the patients with stroke and in the healthy control subjects. Our primary finding was increased cortical activation with increasing functional impairment. The extent of activation (particularly in the primary sensorimotor cortex and the supplementary motor area of the unlesioned hemisphere) increased with disability. The changes were most prominent with the active movement task. CONCLUSIONS Using ankle movement, we observed increased activation in the unlesioned hemisphere associated with worse function of the paretic leg, consistent with studies on movement of paretic upper limbs. We interpret this finding as potentially adaptive recruitment of undamaged ipsilateral motor control pathways from the supplementary motor area and (possibly maladaptive) disinhibition of the ipsilateral sensorimotor cortex.
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Affiliation(s)
- Christian Enzinger
- Department of Neurology, Medical University of Graz, Auenbruggerplatz 22, A-8036 Graz, Austria.
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179
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180
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Training and exercise to drive poststroke recovery. ACTA ACUST UNITED AC 2008; 4:76-85. [PMID: 18256679 DOI: 10.1038/ncpneuro0709] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2007] [Accepted: 11/01/2007] [Indexed: 01/19/2023]
Abstract
To make practical recommendations regarding therapeutic strategies for the rehabilitation of patients with hemiparetic stroke, it is important to have a general understanding of the fundamental mechanisms underlying the neuroplasticity that is induced by skills training and by exercise programs designed to increase muscle strength and cardiovascular fitness. Recent clinical trials have provided insights into methods that promote adaptations within the nervous system that correlate with improved walking and upper extremity function, and that can be instigated at any time after stroke onset. Data obtained to date indicate that patients who have mild to moderate levels of impairment and disability can benefit from interventions that depend on repetitive task-oriented practice at the intensity and duration necessary to reach a plateau in a reacquired skill. Studies are underway to lessen the consequences of more-severe motor deficits by drawing on medications that augment plasticity, biological interventions that promote neural repair, and strategies that employ electrical stimulation and robotics.
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181
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Ankle dexterity is less impaired than muscle strength in incomplete spinal cord lesion. J Neurol 2008; 255:273-9. [DOI: 10.1007/s00415-008-0724-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2007] [Revised: 07/21/2007] [Accepted: 08/21/2007] [Indexed: 10/22/2022]
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182
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Preservation of motor programs in paraplegics as demonstrated by attempted and imagined foot movements. Neuroimage 2008; 39:383-94. [DOI: 10.1016/j.neuroimage.2007.07.065] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2007] [Revised: 07/26/2007] [Accepted: 07/29/2007] [Indexed: 11/19/2022] Open
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183
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Abstract
The matrix of stroke rehabilitation is evolving as we look outside the box of traditional therapy type, timing, and intensity of rehabilitation techniques. For inpatient wards, the goal of medical stability and prompt resolution of complications to maximize participation in therapy remains paramount. In the current medical model, we focus on teaching compensatory strategies and rarely on restorative approaches because of time and financial limitations. Researchers aim to identify new technologic and molecular approaches to improve functional outcomes and more accurately predict disability. This article examines different concepts surrounding the comprehensive rehabilitation paradigm of stroke survivors.
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Affiliation(s)
- Brian M Kelly
- Department of Physical Medicine and Rehabilitation, University of Michigan Health System, 325 Eisenhower, Suite 200, Ann Arbor, MI 48108, USA.
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184
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Walking performance and its recovery in chronic stroke in relation to extent of lesion overlap with the descending motor tract. Exp Brain Res 2007; 186:325-33. [PMID: 18157670 DOI: 10.1007/s00221-007-1237-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Accepted: 11/28/2007] [Indexed: 10/22/2022]
Abstract
We investigated the association between the degree of lesion overlap with the corticospinal tract and walking performance before and after 4-weeks of partial body weight support (PBWS) treadmill training in 18 individuals (ten male, eight female) with a mean age 59 +/- 13 years (mean +/- SD), range 32-74 years, who were ambulant and 6 months from a subcortical ischaemic stroke. Lesion volumes were manually defined on high resolution T1-weighted 3T-MRI scans and a probabilistic map of the corticospinal tract created using diffusion tensor imaging data collected previously in healthy subjects. The percentage overlap between the lesion and the corticospinal tract was calculated for each patient. Walking performance was determined by measures of 10 m speed, spatiotemporal parameters, percentage recovery of centre of mass (CoM), walking symmetry and 2-min endurance walk prior to and following 4 weeks of treadmill training with PBWS that emphasised normal fast walking. Lesion overlap measures weakly correlated with walking performance measures. Spatiotemporal and performance measures changed in response to training, but spatial symmetry and mechanical energy recovery did not. Walking speed at entry to the study predicted change in response to training of 10 m walk time and swing time asymmetry. Age and lesion overlap did not add to prediction of outcome models. The extent of lesion overlap with the corticospinal tract was not strongly associated with either walking performance or response to gait retraining, despite the correlation of these parameters with upper limb recovery.
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185
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Lord S, McPherson KM, McNaughton HK, Rochester L, Weatherall M. How feasible is the attainment of community ambulation after stroke? A pilot randomized controlled trial to evaluate community-based physiotherapy in subacute stroke. Clin Rehabil 2007; 22:215-25. [DOI: 10.1177/0269215507081922] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Objective: This pilot randomized controlled trial evaluated an assistant-led, community-based intervention to improve community mobility and participation after stroke, and examined the potential for independent community ambulation in people with subacute stroke who present with moderate gait deficit. Design: A multicentre, pilot randomized controlled trial. Setting: Three hospitals and three community settings in New Zealand. Subjects: Thirty post-acute, home-dwelling stroke survivors were randomly allocated to receive intervention in the community (n = 14) or as hospital outpatients (n = 16) twice a week for seven weeks. Interventions: The community intervention involved practice of functional gait activities in community environments relevant to each participant. Hospital-based physiotherapy was based upon a Motor Relearning approach. Main measures: The primary outcome measure was gait speed (m/min). Secondary outcomes included endurance (six-minute walk time), Activities-specific Confidence Balance Scale, and the Subjective Index of Physical and Social Outcomes measured at baseline, post intervention and six months. Results: Large gains in gait speed were obtained for participants in both groups: community group mean (SD) 16 (16.1) m/min; physiotherapy group mean (SD) 15.9 (16.1) m/min, maintained at six months. There were no significant differences between groups for primary and secondary outcomes after treatment (P = 0.86 ANOVA) or at six months (P = 0.83 ANOVA). Only 11 participants reported independent community ambulation. Levels of social integration were low to moderate. Conclusions: A community-based gait recovery programme appears a practicable alternative to routine physiotherapy, however independent community ambulation is a challenging rehabilitation goal.
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Affiliation(s)
- Susan Lord
- Department of Medicine (Rehabilitation), Wellington School of Medicine and Health Sciences, University of Otago,
| | - Kathryn M McPherson
- Division of Rehabilitation and Occupation Studies, Auckland University of Technology
| | | | - Lynn Rochester
- Gerontology Research Programme, HealthQWest, Glasgow, UK
| | - Mark Weatherall
- Department of Medicine (Rehabilitation), Wellington School of Medicine and Health Sciences, University of Otago, New Zealand
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186
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Ng SSM, Hui-Chan CWY. Transcutaneous Electrical Nerve Stimulation Combined With Task-Related Training Improves Lower Limb Functions in Subjects With Chronic Stroke. Stroke 2007; 38:2953-9. [PMID: 17901383 DOI: 10.1161/strokeaha.107.490318] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
Previous studies have shown that repeated sensory inputs could enhance brain plasticity and cortical motor output. The purpose of this study was to investigate whether combining electrically induced sensory inputs through transcutaneous electrical nerve stimulation (TENS) with task-related training (TRT) in a home-based program would augment voluntary motor output in chronic stroke survivors better than either treatment alone or no treatment.
Methods—
Eighty-eight patients with stroke were assigned randomly to receive a home-based program of (1) TENS, (2) TENS+TRT, (3) placebo TENS+TRT, or (4) no treatment (control) 5 days a week for 4 weeks. Outcome measurements included Composite Spasticity Scale, peak torques generated during maximum isometric voluntary contraction of ankle dorsiflexors and plantarflexors, and gait velocity recorded at baseline, after 2 and 4 weeks of treatment, and 4 weeks after treatment ended.
Results—
When compared with TENS, the combined TENS+TRT group showed significantly greater improvement in ankle dorsiflexion torque at follow-up and in ankle plantarflexion torque at week 2 and follow-up (
P
<0.01). When compared with placebo+TRT, the TENS+TRT group produced earlier and greater reduction of plantarflexor spasticity and improvement in ankle dorsiflexion torque at week 2 (
P
<0.01). When compared with all 3 groups, the TENS+TRT group showed significantly greater improvement in gait velocity (
P
<0.01).
Conclusions—
In patients with chronic stroke, 20 sessions of a combined TENS+TRT home-based program decreased plantarflexor spasticity, improved dorsiflexor and plantarflexor strength, and increased gait velocity significantly more than TENS alone, placebo+TRT, or no treatment. Such improvements can even be maintained 4 weeks after treatment ended.
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Affiliation(s)
- Shamay S M Ng
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
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187
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Tsekos NV, Khanicheh A, Christoforou E, Mavroidis C. Magnetic resonance-compatible robotic and mechatronics systems for image-guided interventions and rehabilitation: a review study. Annu Rev Biomed Eng 2007; 9:351-87. [PMID: 17439358 DOI: 10.1146/annurev.bioeng.9.121806.160642] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The continuous technological progress of magnetic resonance imaging (MRI), as well as its widespread clinical use as a highly sensitive tool in diagnostics and advanced brain research, has brought a high demand for the development of magnetic resonance (MR)-compatible robotic/mechatronic systems. Revolutionary robots guided by real-time three-dimensional (3-D)-MRI allow reliable and precise minimally invasive interventions with relatively short recovery times. Dedicated robotic interfaces used in conjunction with fMRI allow neuroscientists to investigate the brain mechanisms of manipulation and motor learning, as well as to improve rehabilitation therapies. This paper gives an overview of the motivation, advantages, technical challenges, and existing prototypes for MR-compatible robotic/mechatronic devices.
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Affiliation(s)
- Nikolaos V Tsekos
- Cardiovascular Imaging Laboratory, Mallinckrodt Institute of Radiology, Washington University, St. Louis, Missouri 63110, USA.
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188
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Dobkin BH. Curiosity and cure: translational research strategies for neural repair-mediated rehabilitation. Dev Neurobiol 2007; 67:1133-47. [PMID: 17514711 PMCID: PMC4099053 DOI: 10.1002/dneu.20514] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Clinicians who seek interventions for neural repair in patients with paralysis and other impairments may extrapolate the results of cell culture and rodent experiments into the framework of a preclinical study. These experiments, however, must be interpreted within the context of the model and the highly constrained hypothesis and manipulation being tested. Rodent models of repair for stroke and spinal cord injury offer examples of potential pitfalls in the interpretation of results from developmental gene activation, transgenic mice, endogeneous neurogenesis, cellular transplantation, axon regeneration and remyelination, dendritic proliferation, activity-dependent adaptations, skills learning, and behavioral testing. Preclinical experiments that inform the design of human trials ideally include a lesion of etiology, volume and location that reflects the human disease; examine changes induced by injury and by repair procedures both near and remote from the lesion; distinguish between reactive molecular and histologic changes versus changes critical to repair cascades; employ explicit training paradigms for the reacquisition of testable skills; correlate morphologic and physiologic measures of repair with behavioral measures of task reacquisition; reproduce key results in more than one laboratory, in different strains or species of rodent, and in a larger mammal; and generalize the results across several disease models, such as axonal regeneration in a stroke and spinal cord injury platform. Collaborations between basic and clinical scientists in the development of translational animal models of injury and repair can propel experiments for ethical bench-to-bedside therapies to augment the rehabilitation of disabled patients.
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Affiliation(s)
- Bruce H Dobkin
- Department of Neurology, Reed Neurologic Research Center, University of California Los Angeles, Los Angeles, California 90095, USA.
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189
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Silva JG, Knackfuss IG, Portella CE, Machado S, Velasques B, Bastos VHDV, Queiroz RDA, Neves MAO, Pacheco M, Vorkapic CF, Cagy M, Piedade R, Ribeiro P. Changes in cortical relative power in patients submitted to a tendon transfer: a pre and post surgery study. ARQUIVOS DE NEURO-PSIQUIATRIA 2007; 65:628-32. [PMID: 17876404 DOI: 10.1590/s0004-282x2007000400016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2007] [Accepted: 03/21/2007] [Indexed: 11/21/2022]
Abstract
The aim of this study is analyze possible modifications in the cerebral cortex, through quantitative electroencephalography (qEEG) in patients submitted to a tendon transfer procedure (posterior tibialis) by the Srinivasan's technique. Four subjects (2 men and 2 women), 49.25 age average (SD +/ 21.4) were studied. All subjects have been through surgical procedure due to leprosy and had, at least, two years of drop foot condition. The qEEG measured the electrocortical activity (relative power) between 8 and 25 Hz frequencies pre and post surgery. A paired t test analyzed all data (p< or =0,05). The results show significant alterations in the alpha relative power, electrodes F7 (p=0.01) and F8 (p=0.021). Altogether, based on findings of the current literature, we can conclude that the tendon transfer procedure suggests electrocortical alterations sensitive to specific qEEG bands.
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Affiliation(s)
- Julio Guilherme Silva
- Laboratory of Brain Mapping and Sensory-Motor Integration, Institute of Psychiatry, Federal University of Rio de Janeiro, Rua Filgueiras Lima 68, 20950-050 Rio de Janeiro, RJ, Brazil.
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190
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Holly LT, Dong Y, Albistegui-DuBois R, Marehbian J, Dobkin B. Cortical reorganization in patients with cervical spondylotic myelopathy. J Neurosurg Spine 2007; 6:544-51. [PMID: 17561743 PMCID: PMC4160311 DOI: 10.3171/spi.2007.6.6.5] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Recent investigations have demonstrated that the cerebral cortex can reorganize as a result of spinal cord injury and may play a role in preserving neurological function. Reorganization of cortical representational maps in patients with cervical spondylotic myelopathy (CSM) has not been previously described. The authors sought to determine the feasibility of using functional magnetic resonance (fMR) imaging in patients with CSM to investigate changes in the cortical representation of the wrist and ankle before and after surgical intervention. METHODS Four patients with clinical and imaging evidence of CSM were prospectively enrolled in this study. The patients underwent preoperative neurological examination, functional assessment, cervical imaging, and brain fMR imaging. The fMR imaging activation task undertaken was either wrist extension or ankle dorsiflexion, depending on whether the patient's primary impairment was hand dysfunction or gait difficulty. The cohort then underwent further evaluations at 6 weeks and 3 and 6 months postoperatively. In addition, five healthy volunteers underwent fMR imaging at two different time points and served as controls. In the healthy volunteers fMR imaging demonstrated areas of focal cortical activation limited to the contralateral primary motor area for the assigned motor tasks; the activation patterns were stable throughout repeated imaging. In comparison, in patients with CSM fMR imaging demonstrated expansion of the cortical representation of the affected extremity. Surgical decompression resulted in improvements in neurological function and reorganization of the representational map. CONCLUSIONS The findings of this preliminary study demonstrate the potential of fMR imaging to assess changes in cortical representation before and after surgical intervention in patients with CSM. A future study involving a larger cohort of patients as well as the stratification of patients with CSM, based on the aforementioned factors that influence cortical adaptation, will allow a more detailed quantitative analysis.
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Affiliation(s)
- Langston T Holly
- Division of Neurosurgery, David Geffen School of Medicine, University of California at Los Angeles, California 90095, USA.
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191
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Sütbeyaz S, Yavuzer G, Sezer N, Koseoglu BF. Mirror therapy enhances lower-extremity motor recovery and motor functioning after stroke: a randomized controlled trial. Arch Phys Med Rehabil 2007; 88:555-9. [PMID: 17466722 DOI: 10.1016/j.apmr.2007.02.034] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To evaluate the effects of mirror therapy, using motor imagery training, on lower-extremity motor recovery and motor functioning of patients with subacute stroke. DESIGN Randomized, controlled, assessor-blinded, 4-week trial, with follow-up at 6 months. SETTING Rehabilitation education and research hospital. PARTICIPANTS A total of 40 inpatients with stroke (mean age, 63.5 y), all within 12 months poststroke and without volitional ankle dorsiflexion. INTERVENTIONS Thirty minutes per day of the mirror therapy program, consisting of nonparetic ankle dorsiflexion movements or sham therapy, in addition to a conventional stroke rehabilitation program, 5 days a week, 2 to 5 hours a day, for 4 weeks. MAIN OUTCOME MEASURES The Brunnstrom stages of motor recovery, spasticity assessed by the Modified Ashworth Scale (MAS), walking ability (Functional Ambulation Categories [FAC]), and motor functioning (motor items of the FIM instrument). RESULTS The mean change score and 95% confidence interval (CI) of the Brunnstrom stages (mean, 1.7; 95% CI, 1.2-2.1; vs mean, 0.8; 95% CI, 0.5-1.2; P=.002), as well as the FIM motor score (mean, 21.4; 95% CI, 18.2-24.7; vs mean, 12.5; 95% CI, 9.6-14.8; P=.001) showed significantly more improvement at follow-up in the mirror group compared with the control group. Neither MAS (mean, 0.8; 95% CI, 0.4-1.2; vs mean, 0.3; 95% CI, 0.1-0.7; P=.102) nor FAC (mean, 1.7; 95% CI, 1.2-2.1; vs mean, 1.5; 95% CI, 1.1-1.9; P=.610) showed a significant difference between the groups. CONCLUSIONS Mirror therapy combined with a conventional stroke rehabilitation program enhances lower-extremity motor recovery and motor functioning in subacute stroke patients.
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Affiliation(s)
- Serap Sütbeyaz
- IVth Physical Medicine and Rehabilitation Clinic, Ankara Physical Medicine and Rehabilitation Education and Research Hospital, Ankara, Turkey
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192
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Yavuzer G, Oken O, Atay MB, Stam HJ. Effect of Sensory-Amplitude Electric Stimulation on Motor Recovery and Gait Kinematics After Stroke: A Randomized Controlled Study. Arch Phys Med Rehabil 2007; 88:710-4. [PMID: 17532891 DOI: 10.1016/j.apmr.2007.02.030] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the effects of sensory-amplitude electric stimulation (SES) of the paretic leg on motor recovery and gait kinematics of patients with stroke. DESIGN Randomized, controlled, double-blind study. SETTING Rehabilitation ward and gait laboratory of a university hospital. PARTICIPANTS A total of 30 consecutive inpatients with stroke (mean age, 63.2 y), all within 6 months poststroke and without volitional ankle dorsiflexion were studied. INTERVENTION Both the SES group (n=15) and the placebo group (n=15) participated in a conventional stroke rehabilitation program 5 days a week for 4 weeks. The SES group also received 30 minutes of SES to the paretic leg without muscle contraction 5 days a week for 4 weeks. MAIN OUTCOME MEASURES Brunnstrom stages of motor recovery and time-distance and kinematic characteristics of gait. RESULTS Brunnstrom stages improved significantly in both groups (P<.05). In total, 58% of the SES group and 56% of the placebo group gained voluntary ankle dorsiflexion. The between-group difference of percentage change was not significant (P>.05). Gait kinematics was improved in both groups, but the between-group difference was not significant. CONCLUSIONS In our patients with stroke, SES of the paretic leg was not superior to placebo in terms of lower-extremity motor recovery and gait kinematics.
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Affiliation(s)
- Gunes Yavuzer
- Department of Physical Medicine & Rehabilitation, Ankara University Faculty of Medicine, Ankara, Turkey.
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193
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Yen CL, Wang RY, Liao KK, Huang CC, Yang YR. Gait training induced change in corticomotor excitability in patients with chronic stroke. Neurorehabil Neural Repair 2007; 22:22-30. [PMID: 17507641 DOI: 10.1177/1545968307301875] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Numerous studies have reported the effects of gait training on motor performance after stroke. However, there is limited information on treatment-induced changes in corticomotor excitability. OBJECTIVES The purpose of the study was to investigate the effects of additional gait training on motor performance and corticomotor excitability and to demonstrate the relationship between motor improvement and corticomotor excitability change in patients with chronic stroke. METHODS Fourteen patients were randomly assigned to the experimental or control group. Participants in both groups participated in general physical therapy. Those in the experimental group received additional body weight- supported treadmill training for 4 weeks. All participants received baseline and posttreatment assessments. The outcome measures included assessment of the Berg Balance Scale (BBS) and gait parameters. Focal transcranial magnetic stimulation was used to measure the motor threshold, map size, and location of the amplitude-weighted center of gravity of the motor map for the tibialis anterior (TA) and abductor hallucis (AH) muscles. RESULTS After general physical therapy, we noted that the patients showed an improvement only in walking speed and cadence, and there were no significant changes in corticomotor excitability. After additional gait training, participants improved significantly on BBS score, walking speed, and step length. Moreover, the motor threshold for TA decreased significantly in the unaffected hemisphere. The map size for TA was increased in both hemispheres, whereas that for AH was increased only in the affected hemisphere. There were significant differences between the change scores of the groups in terms of walking speed, step length, and motor threshold for TA in the unaffected hemisphere and map size for AH in the affected hemisphere. Additionally, the changes in corticomotor excitability correlated with functional improvement. CONCLUSIONS Additional gait training may improve balance and gait performance and may induce changes in corticomotor excitability.
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Affiliation(s)
- Chu-Ling Yen
- Institute and Faculty of Physical Therapy, National Yang-Ming University, Taipei, Taiwan
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194
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Silva JG, Knackfuss IG, Portella CE, Bastos VHDV, Machado DDCD, Basile L, Piedade R, Ribeiro P. [EEG spectral coherence at patients submitted to tendon transfer surgery: study pre- and post-surgery]. ARQUIVOS DE NEURO-PSIQUIATRIA 2007; 64:473-7. [PMID: 16917622 DOI: 10.1590/s0004-282x2006000300023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2005] [Accepted: 02/06/2006] [Indexed: 11/22/2022]
Abstract
Tendon transfer of the tibiliais posterior muscle is a surgical intervention widely employed in orthopedics for the correction of drop foot caused by leprosy. However, few models have proposed a thorough investigation of the brain plasticity phenomenon during tendon transfer. Thus, the present study aimed at analyzing EEG spectral coherence (SC) in patients submitted to tendon transfer of the tibiliais posterior muscle by Srinivasan's technique and quantitative EEG (EEGq). The sample consisted of four subjects with drop foot caused by leprosy. The SC parameter was evaluated in two experimental moments: pre and post-surgery. Results demonstrated a main moment effect for the C3-CZ electrode pair. Specifically, a significant increase in coherence values was observed. However, the ANOVA did not indicate a significant band/moment interaction. It can be assumed that coherence augmentation indicates that functional rehabilitation promoted by this specific surgery yields cortical alterations.
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Affiliation(s)
- Julio Guilherme Silva
- Laboratório de Mapeamento Cerebral e Integração Sensório-motor, IPUB, Universidade Federal do Rio de Janeiro, Rua Filgueiras Lima 68/104, 20950-050 Rio de Janeiro RJ, Brazil.
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195
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Dong Y, Winstein CJ, Albistegui-DuBois R, Dobkin BH. Evolution of FMRI activation in the perilesional primary motor cortex and cerebellum with rehabilitation training-related motor gains after stroke: a pilot study. Neurorehabil Neural Repair 2007; 21:412-28. [PMID: 17369516 PMCID: PMC4067098 DOI: 10.1177/1545968306298598] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Previous studies report that motor recovery after partial destruction of the primary motor cortex (M1) may be associated with adaptive functional reorganization within spared M1. OBJECTIVE To test feasible methodologies for evaluating relationships between behavioral gains facilitated by rehabilitative training and functional adaptations in perilesional M1 and the cerebellum. METHODS Four patients with hemiparesis for more than 3 months after a cortical lesion partially within M1 and 12 healthy volunteers participated. Functional magnetic resonance imaging (fMRI) using a finger-tapping task and concurrent behavioral assessments, including the Fugl-Meyer Motor Assessment of the upper extremity and the Wolf Motor Function Test, were conducted before and after 2 weeks of arm-focused training; 2 patients were further examined 6 and 12 months later to evaluate long-term persistence of brain-behavior adaptations. RESULTS All patients showed higher activation magnitude in perilesional M1 than healthy controls before and after therapy. Further long-term functional gains paralleled the decrease of activation magnitude in perilesional M1 in the 2 more impaired cases. CONCLUSION The evolution of suggestive correlations between serial scans of fMRI adaptive activity within the primary motor cortex and the cerebellum in relation to relevant behavioral changes over the course of 2 weeks of task-specific therapy and then no formal therapy suggests that repeated assessments may be best for monitoring therapy-induced neuroplasticity. This approach may help develop optimal rehabilitation strategies to maximize poststroke motor recovery as well as improve the search for brain-behavior correlations in functional neuroimaging research.
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Affiliation(s)
- Yun Dong
- Department of Neurology, University of California at Los Angeles, Los Angeles, CA 90095-1769, USA
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196
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de Bode S, Mathern GW, Bookheimer S, Dobkin B. Locomotor training remodels fMRI sensorimotor cortical activations in children after cerebral hemispherectomy. Neurorehabil Neural Repair 2007; 21:497-508. [PMID: 17369509 PMCID: PMC4080925 DOI: 10.1177/1545968307299523] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE This study examined whether locomotor training, which included body weight-supported treadmill therapy, improved walking and induced cortical representational adaptations using functional magnetic resonance imaging in the remaining sensorimotor network after cerebral hemispherectomy. METHODS Hemispherectomy patients (n = 12) underwent 2 weeks of gait training for at least 30 hours each. They were tested pre- and posttraining with the Fugl-Meyer Motor Assessment, unassisted single-limb stance time, and usual and fastest walking speeds. Three patients performed voluntary ankle movements as the functional magnetic resonance imaging activation task pre- and posttraining. Control subjects included 5 healthy children tested 2 weeks apart, 2 of whom trained on the treadmill, and 2 hemispherectomy patients who received upper extremity rehabilitation and no gait therapy. RESULTS Although patients reported improvements with gait training, behavioral outcomes did not significantly change. Training was associated with increased volume and intensity of cortical activation in the primary sensorimotor (S1M1), supplementary motor, motor cingulate, and secondary somatosensory cortex for the paretic foot, along with greater overlap in the representation for each moving foot in S1M1 and the supplementary motor area of the remaining hemisphere. Control subjects showed a decrease in activation in these cortical regions after training. CONCLUSIONS Locomotor training of hemispherectomy patients improved mobility subjectively in association with functional magnetic resonance imaging evidence of cortical remodeling with ankle dorsiflexion. These findings support the notion that hemispherectomy patients may respond to rehabilitation interventions through mechanisms of activity-dependent cortical plasticity. The authors hypothesize that developmentally persistent descending ipsilateral and contralateral corticospinal tracts may allow the remaining hemisphere to maintain bilateral lower extremity motor control after surgery.
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Affiliation(s)
- Stella de Bode
- Department of Communication Sciences and Disorders, Arnold School of Public Health, University of South Carolina, USA
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197
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Dobkin BH. Confounders in rehabilitation trials of task-oriented training: lessons from the designs of the EXCITE and SCILT multicenter trials. Neurorehabil Neural Repair 2007; 21:3-13. [PMID: 17172549 PMCID: PMC4106697 DOI: 10.1177/1545968306297329] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Two multicenter randomized clinical trials (MRCT), the Extremity Constraint Induced Therapy Evaluation (EXCITE) to improve upper extremity function after stroke and the Spinal Cord Injury Locomotor Trial (SCILT) to enable functional walking after incomplete spinal cord injury, demonstrate that complex, task-oriented physical therapies can be studied using a scientific methodology during inpatient or outpatient rehabilitation. In the past, a new therapy's benefit may have been overestimated by comparing it to no treatment or to a conventional treatment at a low intensity of practice. Sample sizes were often too small and may have failed to detect the efficacy of a new intervention. In addition, whereas statistical significance in outcomes has been critical to understanding whether one treatment is better than another, the clinical significance of outcomes must also impact the interpretation of the results of a trial. MRCT designs will continue to improve through attention to the limitations of preclinical animal models that offer a conceptual basis for the treatment, [corrected] from enrichment strategies at every phase of trial development, [corrected] from more vigorous dose-response studies using adaptive methods, [corrected] by capturing interim measures of behavior and functional neurophysiologic adaptations during the treatment phase, [corrected] by aiming for a clinically meaningful control intervention, [corrected] and by including ratio or interval outcome measures when feasible that capture a target of the intervention in relation to gains in daily functioning and quality of life.
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Affiliation(s)
- Bruce H Dobkin
- Department of Neurology, University of California Los Angeles, Los Angeles, California 90095, USA.
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198
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Dobkin BH. Behavioral, Temporal, and Spatial Targets for Cellular Transplants as Adjuncts to Rehabilitation for Stroke. Stroke 2007; 38:832-9. [PMID: 17261748 DOI: 10.1161/01.str.0000248408.49398.9c] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Stem cell and more differentiated neural cell transplantation strategies are an intriguing approach for neural repair to augment rehabilitation interventions after stroke. In the cortex, exogenous cells could create, augment, or extend in time endogenous peri-infarct and remote molecular signals, such as those for neurogenesis, cell differentiation, axonal and dendritic sprouting, network connectivity, and long-term potentiation, as well as deliver engineered genes and provide replacement cells in a network. If demyelinated axons exist in the periphery of an infarct, they could be targets for remyelination to reestablish conductivity. Much is unknown, however, about the mechanisms by which pluripotent embryonic and multipotent neural stem cells serve as agents of therapeutic plasticity. The robustness of their effects on neuromodulation, reorganization, regeneration, and behavioral recovery is a work in progress. Invasive interventions may have adverse effects not appreciated in preclinical testing. These should initially be offered only to patients with specific profound impairments after it is clinically certain that major disabilities will not improve. If a cellular strategy is very safe, it may be offered to subjects with moderate impairments when they are no longer likely to make further functional gains. Clinical trial designs are suggested that take into account the optimal timing after stroke and specific targets for cellular therapies to foster repair, remapping, and modulation of neural circuits. Cell-mediated rehabilitation would then use task-specific therapies in an optimal dose to maximize training-induced reorganization and learning and, most important, reduce unwanted disability.
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Affiliation(s)
- Bruce H Dobkin
- Reed Neurologic Research Center, Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA 90095, USA.
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199
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Kapreli E, Athanasopoulos S, Papathanasiou M, Van Hecke P, Keleki D, Peeters R, Strimpakos N, Sunaert S. Lower Limb Sensorimotor Network: Issues of Somatotopy and Overlap. Cortex 2007; 43:219-32. [PMID: 17405668 DOI: 10.1016/s0010-9452(08)70477-5] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Functional magnetic resonance imaging (fMRI) was used (1) to describe the pattern of whole brain activity during motion of isolated joints of the lower limb, (2) to examine the somatotopic organization of lower limb joint representations in the primary sensorimotor cortex and the anterior lobe of the cerebellum and 3) to quantify the degree of overlap between these lower limb joint activations. Eighteen healthy, right leg dominant volunteers participated in a motor block-design study, performing repetitive knee, ankle and toes flexion/extension movements. In order to relate lower limb joints activation to the well-described patterns of finger movement, serial finger-to-thumb opposition was also assessed. All movements were auditory paced at 72 beats/min (1.2 Hz). Isolated lower limb joints movement activated a distributed sensorimotor network, including primary and non-primary sensorimotor areas. Although a large overlap was evident in primary sensorimotor cortex (SM1) and cerebellum representations of the three lower limb joints, a somatotopic arrangement was recognizable with reference to center of mass coordinates of each individual joint in the above areas. Detection of active brain regions during movement of the lower limb joints is feasible with fMRI although a carefully optimized methodology protocol is required.
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Affiliation(s)
- Eleni Kapreli
- Department of Sports Medicine and Biology of Exercise, National and Kapodistrian University of Athens, Athens, Greece.
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200
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Breier JI, Maher LM, Novak B, Papanicolaou AC. Functional imaging before and after constraint-induced language therapy for aphasia using magnetoencephalography. Neurocase 2006; 12:322-31. [PMID: 17182395 DOI: 10.1080/13554790601126054] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Five patients with chronic aphasia underwent functional imaging using magnetoencephalography (MEG) before and after constraint-induced language therapy (CILT). Patients who responded well to CILT exhibited a greater degree of late MEG activation in posterior language areas of the left hemisphere and homotopic areas of the right hemisphere prior to therapy than those who did not respond well. Response to CILT, however, was positively correlated with the degree of pre-therapy MEG activity within posterior areas of the right hemisphere only on an individual basis.
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Affiliation(s)
- Joshua I Breier
- Division of Clinical Neurosciences in the Department of Neurosurgery, University of Texas - Houston Health Science Center, Houston, Texas 77030, USA.
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