Neuroimaging in Traumatic Spinal Cord Injury: An Evidence-based Review for Clinical Practice and Research

Abstract

Objective: To perform an evidence-based review of the literature on neuroimaging techniques utilized in spinal cord injury clinical practice and research.Methods: A search of the medical literature for articles on specific neuroimaging techniques used in SCI resulted in 2,302 published reports. Review at the abstract and full report level yielded 99 clinical and preclinical articles that were evaluated in detail. Sixty nine were clinical research studies subjected to quality of evidence grading. Twenty-three articles were drawn from the pre-clinical animal model literature and used for supportive evidence. Seven review articles were included to add an element of previous syntheses of current thinking on neuroimaging topics to the committee process (the review articles were not graded for quality of evidence). A list of clinical and research questions that might be answered on a variety of neuroimaging topics was created for use in article review. Recommendations on the use of neuroimaging in spinal cord injury treatment and research were made based on the quality of evidence.Results: Of the 69 original clinical research articles covering a range of neuroimaging questions, only one was judged to provide Class I evidence, 22 provided Class II evidence, 17 Class III evidence, and 29 Class IV evidence.Recommendations: MRI should be used as the imaging modality of choice for evaluation of the spinal cord after injury. CT and plain radiography should be used to assess the bony anatomy of the spine in patients with SCI. MRI may be used to identify the location of spinal cord injury. MRI may be used to demonstrate the degree of spinal cord compression after SCI. MRI findings of parenchymal hemorrhage/ contusion, edema, and spinal cord disruption in acute and subacute SCI may contribute to the understanding of severity of injury and prognosis for neurological improvement. MRI-Diffusion Weighted Imaging may be useful in quantifying the extent of axonal loss after spinal cord injury. Functional MRI may be useful in measuring the anatomic functional/metabolic correlates of sensory-motor activities in persons with SCI. MR Spectroscopy may be used to measure the biochemical characteristics of the brain and spinal cord following SCI. Intraoperative Spinal Sonography may be used to identify spinal and spinal cord anatomy and gross pathology during surgical procedures. Further research in these areas is warranted to improve the strength of evidence supporting the use of neuroimaging modalities. Positron Emission Tomography may be used to assess metabolic activity of CNS tissue (brain and spinal cord) in patients with SCI.

MRI in acute and subacute post-traumatic spinal cord injury: pictorial review

“…This is challenging to perform in the cord compared with brain imaging, but on more modern systems it can provide useful results. 7 It may be particularly useful in the clinical context of abnormal neurology and normal standard MR sequences when it may demonstrate diffusion restriction as a marker of previously occult cord injury. [8][9][10] In the subacute period, many patients will have spinal fixation and the clinical question is more commonly related to post-operative infection, post-operative bleeding and cause for ascending neurology or pain.…”

“…There is good evidence from many studies that the presence of haemorrhage within the cord is associated with a poor neurological status on presentation, with patients more likely to have a complete SCI and worse baseline American Spinal Injury Association motor scores. 2,7,19,21 In addition, the presence of cord haemorrhage is an independent poor prognostic indicator for neurological recovery even when patients are standardized for baseline scores. 2 Cord ischaemia Diffusion-weighted imaging is well-established in brain imaging but is more difficult to use in the cord due to the small volume of tissue, the CSF flow artefact and the inherent anisotropy of the cord tissue.…”

Structural biomarkers in the cerebrospinal fluid within 24 h after a traumatic spinal cord injury: a descriptive analysis of 16 subjects

“…4,5 Following a traumatic SCI, the initial severity of neurologic impairment is the best predictor of long-term neurologic outcome. 6 The assessment of neurologic impairment in accordance with the ISNCSCI (International Standards for Neurological Classification of Spinal Cord Injury) is considered to be most reliable and prognostic when conducted 72 h after the initial trauma. 7 Before the 72 h post-injury mark, several factors such as spinal shock, medical instability or concomitant injuries affect the reliability of the neurological examination.…”

Biomarkers in spinal cord injury

“…4 Although several MRI findings such as parenchymal hemorrhage, transection and longer lesion length correlate with less favorable neurological outcomes, the findings on neurological examinations are most predictive of outcomes. 5 Prediction of functional outcome by means of the American Spinal Injury Association (ASIA) motor scores is considered to be reliable and prognostic in patients with motor complete SCI when tested 72 h after the initial trauma. 6,7 Combining the results of MRI and initial neurological examination results in an even better prediction of the recovery of motor scores.…”

“…As the degree and localization of injured and spared white matter primarily determine functioning after SCI, MRI has limited success as a prognostic tool. 5 MRI is largely a qualitative measure and quantitative standards, in relation to functional SCI outcomes, will need to be developed and validated. 3 A new approach for evaluating the primary cord damage in the acute phase may be the assessment of biomarker concentrations in the cerebrospinal fluid (CSF).…”