Publications by authors named "B Aarabi"

168 Publications

Imaging and Electrophysiology for Degenerative Cervical Myelopathy [AO Spine RECODE DCM Research Priority Number 9].

Global Spine J 2021 Nov 19:21925682211057484. Epub 2021 Nov 19.

Department of Neurosurgery, 5506Medical College of Wisconsin, Wauwatosa, WI, USA.

Study Design: Narrative review.

Objective: The current review aimed to describe the role of existing techniques and emerging methods of imaging and electrophysiology for the management of degenerative cervical myelopathy (DCM), a common and often progressive condition that causes spinal cord dysfunction and significant morbidity globally.

Methods: A narrative review was conducted to summarize the existing literature and highlight future directions.

Results: Anatomical magnetic resonance imaging (MRI) is well established in the literature as the key imaging tool to identify spinal cord compression, disc herniation/bulging, and inbuckling of the ligamentum flavum, thus facilitating surgical planning, while radiographs and computed tomography (CT) provide complimentary information. Electrophysiology techniques are primarily used to rule out competing diagnoses. However, signal change and measures of cord compression on conventional MRI have limited utility to characterize the degree of tissue injury, which may be helpful for diagnosis, prognostication, and repeated assessments to identify deterioration. Early translational studies of quantitative imaging and electrophysiology techniques show potential of these methods to more accurately reflect changes in spinal cord microstructure and function.

Conclusion: Currently, clinical management of DCM relies heavily on anatomical MRI, with additional contributions from radiographs, CT, and electrophysiology. Novel quantitative assessments of microstructure, perfusion, and function have the potential to transform clinical practice, but require robust validation, automation, and standardization prior to uptake.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
November 2021

Spinal Cord Signal Change on Magnetic Resonance Imaging May Predict Worse Clinical In- and Outpatient Outcomes in Patients with Spinal Cord Injury: A Prospective Multicenter Study in 459 Patients.

J Clin Med 2021 Oct 18;10(20). Epub 2021 Oct 18.

Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON M5T 2S8, Canada.

Prognostic factors for clinical outcome after spinal cord (SC) injury (SCI) are limited but important in patient management and education. There is a lack of evidence regarding magnetic resonance imaging (MRI) and clinical outcomes in SCI patients. Therefore, we aimed to investigate whether baseline MRI features predicted the clinical course of the disease. This study is an ancillary to the prospective North American Clinical Trials Network (NACTN) registry. Patients were enrolled from 2005-2017. MRI within 72 h of injury and a minimum follow-up of one year were available for 459 patients. Patients with American Spinal Injury Association impairment scale (AIS) E were excluded. Patients were grouped into those with ( = 354) versus without ( = 105) SC signal change on MRI T2-weighted images. Logistic regression analysis adjusted for commonly known a priori confounders (age and baseline AIS). Main outcomes and measures: The primary outcome was any adverse event. Secondary outcomes were AIS at the baseline and final follow-up, length of hospital stay (LOS), and mortality. A regression model adjusted for age and baseline AIS. Patients with intrinsic SC signal change were younger (46.0 (interquartile range (IQR) 29.0 vs. 50.0 (IQR 20.5) years, = 0.039). There were no significant differences in the other baseline variables, gender, body mass index, comorbidities, and injury location. There were more adverse events in patients with SC signal change (230 (65.0%) vs. 47 (44.8%), < 0.001; odds ratio (OR) = 2.09 (95% confidence interval (CI) 1.31-3.35), = 0.002). The most common adverse event was cardiopulmonary (186 (40.5%)). Patients were less likely to be in the AIS D category with SC signal change at baseline (OR = 0.45 (95% CI 0.28-0.72), = 0.001) and in the AIS D or E category at the final follow-up (OR = 0.36 (95% CI 0.16-0.82), = 0.015). The length of stay was longer in patients with SC signal change (13.0 (IQR 17.0) vs. 11.0 (IQR 14.0), = 0.049). There was no difference between the groups in mortality (11 (3.2%) vs. 4 (3.9%)). MRI SC signal change may predict adverse events and overall LOS in the SCI population. If present, patients are more likely to have a worse baseline clinical presentation (i.e., AIS) and in- or outpatient clinical outcome after one year. Patients with SC signal change may benefit from earlier, more aggressive treatment strategies and need to be educated about an unfavorable prognosis.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
October 2021

The development of lived experience-centered word clouds to support research uncertainty gathering in degenerative cervical myelopathy: results from an engagement process and protocol for their evaluation, via a nested randomized controlled trial.

Trials 2021 Jun 25;22(1):415. Epub 2021 Jun 25.

Academic Neurosurgery Unit & Anne McLaren Laboratory of Regenerative Medicine, Department of Clinical Neurosurgery, University of Cambridge, Cambridge, UK.

Objectives: AO Spine REsearch objectives and Common Data Elements for Degenerative Cervical Myelopathy [RECODE-DCM] is a multi-stakeholder consensus process aiming to promote research efficiency in DCM. It aims to establish the top 10 research uncertainties, through a James Lind Alliance Priority Setting Partnership [PSP]. Through a consensus process, research questions are generated and ranked. The inclusion of people with cervical myelopathy [PwCM] is central to the process. We hypothesized that presenting PwCM experience through word cloud generation would stimulate other key stakeholders to generate research questions better aligned with PwCM needs. This protocol outlines our plans to evaluate this as a nested methodological study within our PSP.

Methods: An online poll asked PwCM to submit and vote on words associated with aspects of DCM. After review, a refined word list was re-polled for voting and word submission. Word clouds were generated and an implementation plan for AO Spine RECODE-DCM PSP surveys was subsequently developed.

Results: Seventy-nine terms were submitted after the first poll. Eighty-seven refined words were then re-polled (which added a further 39 words). Four word clouds were generated under the categories of diagnosis, management, long-term effects, and other. A 1:1 block randomization protocol to assess word cloud impact on the number and relevance of PSP research questions was generated.

Conclusions: We have shown it is feasible to work with PwCM to generate a tool for the AO Spine RECODE-DCM nested methodological study. Once the survey stage is completed, we will be able to evaluate the impact of the word clouds. Further research will be needed to assess the value of any impact in terms of stimulating a more creative research agenda.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
June 2021

Longitudinal Impact of Acute Spinal Cord Injury on Clinical Pharmacokinetics of Riluzole, a Potential Neuroprotective Agent.

J Clin Pharmacol 2021 09 9;61(9):1232-1242. Epub 2021 Jul 9.

Department of Neurosurgery, Houston Methodist Research Institute, Houston, Texas, USA.

Riluzole, a benzothiazole sodium channel blocker that received US Food and Drug Administration approval to attenuate neurodegeneration in amyotrophic lateral sclerosis in 1995, was found to be safe and potentially efficacious in a spinal cord injury (SCI) population, as evident in a phase I clinical trial. The acute and progressive nature of traumatic SCI and the complexity of secondary injury processes can alter the pharmacokinetics of therapeutics. A 1-compartment with first-order elimination population pharmacokinetic model for riluzole incorporating time-dependent clearance and volume of distribution was developed from combined data of the phase 1 and the ongoing phase 2/3 trials. This change in therapeutic exposure may lead to a biased estimate of the exposure-response relationship when evaluating therapeutic effects. With the developed model, a rational, optimal dosing scheme can be designed with time-dependent modification that preserves the required therapeutic exposure of riluzole.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
September 2021

Trajectory-Based Classification of Recovery in Sensorimotor Complete Traumatic Cervical Spinal Cord Injury.

Neurology 2021 Apr 13. Epub 2021 Apr 13.

Division of Neurosurgery and Spine Program, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada.

Objective: To test the hypothesis that sensorimotor complete traumatic cervical spinal cord injury is a heterogenous clinical entity comprising several subpopulations that follow fundamentally different trajectories of neurologic recovery.

Methods: We analyzed demographic and injury data from 655 patients who were pooled from 4 prospective longitudinal multicenter studies. Group based trajectory modeling was applied to model neurologic recovery trajectories over the initial 12-months postinjury and to identify predictors of recovery trajectories. Neurologic outcomes included: Upper Extremity Motor Score, Total Motor Scores and AIS grade improvement.

Results: The analysis identified 3 distinct trajectories of neurologic recovery. These clinical courses included: (1) Marginal recovery trajectory: characterized by minimal or no improvement in motor strength or change in AIS grade status (remained grade A); (2) Moderate recovery trajectory: characterized by low baseline motor scores that improved approximately 13 points; or AIS conversion of one grade point; (3) Good recovery trajectory: characterized by baseline motor scores in the upper quartile that improved to near maximum values within 3 months of injury. Patients following the moderate or good recovery trajectories were of younger age, had more caudally located injuries, a higher degree of preserved motor and sensory function at baseline examination and exhibited a greater extent of motor and sensory function in the zone of partial preservation.

Conclusion: Cervical complete SCI can be classified into one of 3 distinct subpopulations with fundamentally different trajectories of neurologic recovery. This study defines unique clinical phenotypes based on potential for recovery, rather than baseline severity of injury alone. This approach may prove beneficial in clinical prognostication and in the design and interpretation of clinical trials in SCI.
View Article and Find Full Text PDF

Download full-text PDF

Source Listing
April 2021