Journal of neurosurgery. Spine
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Comparative Study
Hybrid dynamic stabilization: a biomechanical assessment of adjacent and supraadjacent levels of the lumbar spine.
The object of this study was to evaluate the effect of hybrid dynamic stabilization on adjacent levels of the lumbar spine. ⋯ The dynamic stabilization system displayed stability characteristics similar to a solid, all-metal construct. Its addition of the supraadjacent level (L3-4) to the fusion (L4-5) did protect the adjacent level from excessive motion. However, it essentially transformed a 1-level lumbar fusion into a 2-level lumbar fusion, with exponential transfer of motion to the fewer remaining discs.
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Although the anatomy of the thoracic pedicle in adolescent idiopathic scoliosis is well known, that of the lumbar pedicle in degenerative lumbar scoliosis is not. The morphometric differences between the pedicles on the concave and convex sides can result in an increased risk of malpositioned pedicle screws. The purpose of this study was to analyze the lumbar pedicle morphology in degenerative lumbar scoliosis using multiplanar reconstructed CT. ⋯ This study demonstrated lumbar pedicle asymmetry in degenerative lumbar scoliosis. The authors speculate that these asymmetrical changes were attributed to the remodeling caused by axial load imbalance and the limited space available for pedicles on the concave side. On the concave side, because of the narrower pedicle diameter and larger axial angle, surgeons should carefully determine screw size and direction when inserting pedicle screws to prevent possible pedicle wall breakage and neural damage.
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Primary outcome measures for the upper limb in trials concerning human spinal cord injury (SCI) need to distinguish between functional and neurological changes and require satisfying psychometric properties for clinical application. ⋯ The GRASSP was found to demonstrate reliability, construct validity, and concurrent validity for use as a standardized upper-limb impairment measure for individuals with complete or incomplete tetraplegia. Responsiveness (follow-up from onset to 1 year postinjury) is currently being tested in international studies (in North America and Europe). The GRASSP can be administered early after injury, thus making it a tool that can be administered in acute care (in the ICU), rehabilitation, and outpatient clinics.
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Multicenter Study
Pharmacology of riluzole in acute spinal cord injury.
The aim of this paper was to characterize individual and population pharmacokinetics of enterally administered riluzole in a Phase 1 clinical trial of riluzole as a neuroprotective agent in adults 18-70 years old with acute spinal cord injury (SCI). ⋯ This is the first report of clinical pharmacokinetics of riluzole in patients with SCI. The C(max) and AUC(0-12) achieved in SCI patients were lower than those in ALS patients on the same dose basis, due to a higher clearance and larger volume of distribution in SCI patients. The finding in SCI patients of an increase in the clearance and distribution of riluzole between the 3rd and 14th days after SCI, with a lower plasma concentration of riluzole on the 14th day, stresses the importance of monitoring changes in drug metabolism after SCI in interpreting the safety and efficacy of therapeutic drugs that are used in clinical trials in SCI. Clinical trial registration no.: NCT00876889.
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The North American Clinical Trials Network (NACTN) for the Treatment of Spinal Cord Injury is a consortium of 10 neurosurgery departments, a data management center, and a pharmacological center. The NACTN was established with the goal of bringing recent molecular and cell-based discoveries in neuroprotection and regeneration from the laboratory into clinical trials that optimize meaningful data outcomes and maximum safety to patients. The requirements of planning and executing clinical trials in spinal cord injury (SCI) and the steps that the NACTN has taken to address these requirements are discussed and illustrated in articles in this issue of the Journal of Neurosurgery: Spine. The progress that the NACTN has made in meeting these goals can be summarized as organizing a network of hospitals capable of enrolling a sufficient number of patients for conducting Phase I and II trials; creating a Data Management Center and a database of the natural history of recovery after SCI (at the time of this writing 485 patients were enrolled in the database); creating a database of the incidence and severity of complications that occur during acute and subacute treatment after SCI; developing a Pharmacological Center capable of performing pharmacokinetic and pharmacodynamic studies of therapeutic drugs; completing enrollment of 36 patients in NACTN's first clinical trial, a Phase I study of riluzole, a neuroprotective drug; and performing pharmacokinetic and pharmacodynamic studies of riluzole in acute SCI.