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.

Object The goal of this study was to compare cortical sensorimotor adaptations associated with neurological deterioration and then recovery following surgical decompression for cervical spondylotic myelopathy (CSM). Methods Eight patients with CSM underwent functional MR (fMR) imaging during wrist extension and the 3-finger pinch task, along with behavioral assessments before and 3 and 6 months after surgery. Six healthy control volunteers were scanned twice. Results Cervical spine MR imaging demonstrated successful cord decompression. The patients improved after surgery on the modified Japanese Orthopaedic Association score for the upper extremity, which correlated with the changes in task-associated activation in specific sensorimotor regions of interest. Pinch-related activation in sensorimotor cortex contralateral to the movement paradigm was reduced before surgery then increased toward the extent of healthy controls after surgery. Before surgery, patients showed broader activation in ipsilateral sensorimotor cortex during wrist extension than during pinch, but activations became similar to those of healthy controls after surgery. Pinch-related activation volume in the ipsilateral sensorimotor cortex and the magnitude of activation in the contralateral dorsal premotor cortex evolved linearly across time after surgery, along with wrist extension–related activation magnitude in the contralateral supplementary motor area. Conclusions Serial fMR imaging studies in CSM can capture the adaptations in specific sensorimotor cortices that accompany clinical deterioration and postsurgical improvement in sensorimotor function associated with damage and partial recovery of conduction in corticospinal pathways. These adaptive regions can be monitored by serial fMR imaging to detect a critical loss of supraspinal reserve in compensatory plasticity, which might augment clinical information about the need for surgical decompression.

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 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.

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.

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.Address reprint requests to: Langston T. Holly, M.D., Division of Neurosurgery, David Geffen School of Medicine, University of California at Los Angeles, 10833 Leconte Avenue, Los Angeles, California 90095. lholly@mednet.ucla.edu. Cervical spondylotic myelopathy is the most common form of acquired myelopathy; it commonly presents with hand dysfunction and gait difficulty 9,31 . The signs and symptoms of CSM are primarily caused by damage to nerve fibers within the cervical spinal cord, in particular those in the lateral corticospinal tract. Not surprisingly, the overwhelming majority of clinical and laboratory investigations into the pathogenesis of CSM have focused on spinal column or cord abnormalities 9,10,12,14,17,[26][27][28][29] . In contrast, the function of the cerebral cortex within the affected motor network has been largely understudied and represents a potential area of novel investigation. NIH Public AccessOne of the most studied adaptive mechanisms ...