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P176. Methods for the Evaluation of the Recovery of the Posttraumatic Spinal Cord Injuries Using Functional Magnetic Resonance Imaging
Proceedings of the NASS 22nd Annual Meeting / The Spine Journal 7 (2007) 1S–163S PURPOSE: To prove that there is a significant difference between the midline rectus (MR) and the paramedian lateral rectus (PLR) approaches with regard to implant position for lumbar disc arthroplasty. A less than optimal implant position may influence clinical outcome. STUDY DESIGN/SETTING: Retrospective image and clinical outcome analysis. PATIENT SAMPLE: 57 Patients that undergone Total Disc Replacement between 2002 and 2006. OUTCOME MEASURES: Computerized radiographical measurements combined with Oswestry Disability Index (ODI) and VAS score. METHODS: Patients for this study were obtained from one center participating in the prospective randomized FDA study for the evaluation of the Lumbar Prodisc-LTM. We compared results obtained from two different surgical access techniques; the midline Rectus (MR) approach and left paramedian lateral Rectus (PLR) approach. Post-operative x-rays were measured from 57 patients undergoing one-level Prodisc arthroplasty at either the L4/L5 or L5/S1 levels. Post-operative x-rays were measured by two independent evaluators in order to calculate the displacement from the midline in the coronal and sagittal planes for each of the surgical techniques. Pre- and post-operative clinical outcomes were evaluated to determine if one of these surgical access techniques was associated with better outcomes and if there was a clinical correlation with technical accuracy.
RESULTS: The PLR approach was associated with greater malalignment of the prosthesis in both the coronal and sagittal planes compared to the MR approach. However, the difference was significant only in the sagittal plane (p50.021). There was no significant difference in clinical outcome ´ 5 mm prosthetic displacefor either approach (p50.34). Patients with ¡Y ment from the mid-vertebral point had significantly worse ODI scores than patients with !3 mm malalignment in both the coronal and sagittal planes regardless of the surgical approach employed. CONCLUSIONS: This investigation demonstrates that significant clinical and radiographic differences do exist between the use of the PLR and MR approaches. Specifically, the finding of a statistically significant, more anteriorly displaced position in the sagittal plane of the TDA using the PLR approach may indicate a need to change to the MR approach. This study mm prosthetic deviation from also demonstrates that patients with ¡Y5
163S
midline in either the coronal or sagittal planes had diminished clinical outcomes regardless of the approach used. FDA DEVICE/DRUG STATUS: Prodisc-L: Approved for this indication. doi: 10.1016/j.spinee.2007.07.385 P176. Methods for the Evaluation of the Recovery of the Posttraumatic Spinal Cord Injuries Using Functional Magnetic Resonance Imaging Saı¨d Boujraf, PhD1, Mohammed Benzagmout2, Paul Summers3, Spyros Kollias4; 1Department of Biophysics and Clinical MRI Methods, Fez, Morocco; 2Department of Neurosurgery, University Hospital of Fez, Fez, Morocco; 3King’s College London, London, United Kingdom; 4 Zu¨rich, Switzerland BACKGROUND CONTEXT: MRI is getting more efficient and reliable in the evaluation of the degenerative diseases and the recovery processes. Nowadays, the evaluation process of the recovery of the spinal cord after trauma such as injury is one of the most critical issues in legal medicine. PURPOSE: Assessment of the structural and functional integrity of the human spinal cord in vivo, Evaluation of extend and progression of spinal cord injury, Monitoring of a possible therapy-induced regeneration and functional recovery. STUDY DESIGN/SETTING: The goal is to determine: a) Whether spinal cord fMRI is feasible on a 1.5 Tesla clinical system. b) Whether the fMRI signal can be spatially localized to particular neuroanatomic locations specific to focal upper extremity motor tasks and sensory stimulations. METHODS: Spinal fMRI studies were carried out in two 1.5-T clinical MRI systems. Imaging was performed in the transverse plane with subjects lying supine and it was centred at the lower cervical spinal cord, containing vertebrae C4-T1 (C5-C8). Various acquisition algorithms have been used. Imaging parameters have been tested for optimising the functional signal. The in-plane spatial resolution was adjusted to 1 mm or below and the slice thickness to 7.5 mm. Image-processing algorithms were applied in the fMRI data sets to extract the areas of activation. Experimental activation conditions were designed to activate specific neuroanatomical areas of the cervical spinal cord and consisted of motor tasks, sensory stimulations using a thermal stimulus, and electrical stimulation. RESULTS: After long experimentation with the various fMRI methodologies outlined above, we eventually started observing, during repeated exercise, consisting of opening and closing of the dominant hand, consistent focal regional activation within the spinal cord. The areas of activation were predominantly on the same side of the spinal cord as the hand performing the exercise, between the levels of the C6-C8 spinal cord segments. Similar intensity changes have been observed in subsequent experiments with sensory and electrical stimuli corresponding with the expected areas of neuronal involvement. The physiologically identified consensus region of fMRI signal during motor tasks occupied the ipsilateral intermediate zone of the spinal cord grey matter (interneurons in Rexed’s lamina VII) with an extension in the ventrolateral direction (motor neurons in Rexed’s lamina IX). Hand and wrist movements elicited activation more caudally at the C6-C8 spinal cord segments, whereas elbow movements elicited the most prominent responses at the C5-C6 levels. In almost all motor experiments, less consistently activated areas in the dorsal horn and in the contralateral gray matter were also found, most probably representing closely related sensory and motor areas, which are essential for the regulation of motor control. Activation was detected in the ipsilateral dorsal horn spanning through Rexed’s laminae I to V, corresponding to sensory input. CONCLUSIONS: The Consistent high-quality fMRI images of the cervical spinal cord can be obtained at 1.5 Tesla scanner. The visualization of internal functional anatomic features such as the gray matter demonstrates that 1.5 Tesla imaging of the cervical spinal cord is a promising technique, this may make fMRI the future method of choice for the evaluation of spinal cord functional disorders. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2007.07.386
RESULTS: The PLR approach was associated with greater malalignment of the prosthesis in both the coronal and sagittal planes compared to the MR approach. However, the difference was significant only in the sagittal plane (p50.021). There was no significant difference in clinical outcome ´ 5 mm prosthetic displacefor either approach (p50.34). Patients with ¡Y ment from the mid-vertebral point had significantly worse ODI scores than patients with !3 mm malalignment in both the coronal and sagittal planes regardless of the surgical approach employed. CONCLUSIONS: This investigation demonstrates that significant clinical and radiographic differences do exist between the use of the PLR and MR approaches. Specifically, the finding of a statistically significant, more anteriorly displaced position in the sagittal plane of the TDA using the PLR approach may indicate a need to change to the MR approach. This study mm prosthetic deviation from also demonstrates that patients with ¡Y5
163S
midline in either the coronal or sagittal planes had diminished clinical outcomes regardless of the approach used. FDA DEVICE/DRUG STATUS: Prodisc-L: Approved for this indication. doi: 10.1016/j.spinee.2007.07.385 P176. Methods for the Evaluation of the Recovery of the Posttraumatic Spinal Cord Injuries Using Functional Magnetic Resonance Imaging Saı¨d Boujraf, PhD1, Mohammed Benzagmout2, Paul Summers3, Spyros Kollias4; 1Department of Biophysics and Clinical MRI Methods, Fez, Morocco; 2Department of Neurosurgery, University Hospital of Fez, Fez, Morocco; 3King’s College London, London, United Kingdom; 4 Zu¨rich, Switzerland BACKGROUND CONTEXT: MRI is getting more efficient and reliable in the evaluation of the degenerative diseases and the recovery processes. Nowadays, the evaluation process of the recovery of the spinal cord after trauma such as injury is one of the most critical issues in legal medicine. PURPOSE: Assessment of the structural and functional integrity of the human spinal cord in vivo, Evaluation of extend and progression of spinal cord injury, Monitoring of a possible therapy-induced regeneration and functional recovery. STUDY DESIGN/SETTING: The goal is to determine: a) Whether spinal cord fMRI is feasible on a 1.5 Tesla clinical system. b) Whether the fMRI signal can be spatially localized to particular neuroanatomic locations specific to focal upper extremity motor tasks and sensory stimulations. METHODS: Spinal fMRI studies were carried out in two 1.5-T clinical MRI systems. Imaging was performed in the transverse plane with subjects lying supine and it was centred at the lower cervical spinal cord, containing vertebrae C4-T1 (C5-C8). Various acquisition algorithms have been used. Imaging parameters have been tested for optimising the functional signal. The in-plane spatial resolution was adjusted to 1 mm or below and the slice thickness to 7.5 mm. Image-processing algorithms were applied in the fMRI data sets to extract the areas of activation. Experimental activation conditions were designed to activate specific neuroanatomical areas of the cervical spinal cord and consisted of motor tasks, sensory stimulations using a thermal stimulus, and electrical stimulation. RESULTS: After long experimentation with the various fMRI methodologies outlined above, we eventually started observing, during repeated exercise, consisting of opening and closing of the dominant hand, consistent focal regional activation within the spinal cord. The areas of activation were predominantly on the same side of the spinal cord as the hand performing the exercise, between the levels of the C6-C8 spinal cord segments. Similar intensity changes have been observed in subsequent experiments with sensory and electrical stimuli corresponding with the expected areas of neuronal involvement. The physiologically identified consensus region of fMRI signal during motor tasks occupied the ipsilateral intermediate zone of the spinal cord grey matter (interneurons in Rexed’s lamina VII) with an extension in the ventrolateral direction (motor neurons in Rexed’s lamina IX). Hand and wrist movements elicited activation more caudally at the C6-C8 spinal cord segments, whereas elbow movements elicited the most prominent responses at the C5-C6 levels. In almost all motor experiments, less consistently activated areas in the dorsal horn and in the contralateral gray matter were also found, most probably representing closely related sensory and motor areas, which are essential for the regulation of motor control. Activation was detected in the ipsilateral dorsal horn spanning through Rexed’s laminae I to V, corresponding to sensory input. CONCLUSIONS: The Consistent high-quality fMRI images of the cervical spinal cord can be obtained at 1.5 Tesla scanner. The visualization of internal functional anatomic features such as the gray matter demonstrates that 1.5 Tesla imaging of the cervical spinal cord is a promising technique, this may make fMRI the future method of choice for the evaluation of spinal cord functional disorders. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs. doi: 10.1016/j.spinee.2007.07.386