This research represents the initial integration of MRI variables alongside peripheral inflammatory response biomarkers to evaluate the correlation between injury severity and 1-year prognosis among patients with cervical TSCI. Our study established a significant association between admission MRI variables, peripheral inflammatory response biomarkers, and injury severity in individuals with cervical TSCI. Furthermore, a robust correlation was highlighted between MRI variables, peripheral inflammatory response biomarkers, and poor prognosis. When conducting multiple logistic regression analysis encompassing all peripheral inflammatory response biomarkers and MRI variables to predict 1-year prognosis in patients with cervical TSCI, only CRP and the BASIC score emerged as statistically significant and were retained within the model. Ultimately, our findings underscored the enhanced predictive accuracy achieved by combining the BASIC score with CRP to predict prognostic outcomes more precisely
The AIS grade has long served as a prominent prognostic predictor of TSCI. Our study reaffirms the significance of TSCI injury severity at admission (AIS grade) as an independent and significant predictor in determining patient outcomes. However, employing the AIS grade in clinical practice poses certain limitations. First, uncertainty arises in patients with spinal shock, wherein spontaneous recovery within hours post-injury is acknowledged(24). Second, patients with TSCI, particularly those under sedation or with polytrauma, can impede accurate physician judgment(25). Hence, there is an imperative not only for further diagnostic and predictive modelling concerning acute TSCI but also for frameworks to identify valuable biomarkers enhancing assessment and prediction accuracy. Currently, various alternative injury biomarkers have made significant strides in clinical advancements, including admission blood tests, cerebrospinal fluid sampling, motor-evoked potential monitoring, and MRI(15, 16, 26–30). The routine nature of blood tests and imaging upon admission, their typically rapid turnaround, and minimal disruption to prompt intensive care and surgical interventions render peripheral inflammatory response biomarkers and MRI biomarkers particularly appealing
In recent years, post-traumatic inflammation has garnered escalating interest, with numerous studies indicating its pivotal role in the pathogenesis and progression of TSCI. Acute TSCI has been linked to a systemic immune response that involves circulating WBCs. Zhou et al. observed a significant increase in WBCs and neutrophils among patients with severe TSCI(9). These findings suggest that early changes in WBC counts among patients with TSCI might shed light on the potential relationship between concomitant injury factors and neurological prognosis. Moreover, their study highlighted a positive correlation between acute neutrophilia in patients with TSCI and TSCI severity scores, yet a negative correlation with neurological prognosis(31). Similarly, our univariate analysis revealed markedly higher WBCs and neutrophils among patients with severe TSCI. The early stages of TSCI disrupt the blood-spinal cord barrier (BSCB), leading to altered BSCB permeability and the subsequent release of inflammatory factors (such as interleukin [IL]-6, IL-1β, tumour necrosis factor-α, etc.) into the peripheral bloodstream via the BSCB(32, 33). These inflammatory factors prompt an increased expression of serum CRP(34). In this study, serum CRP emerged as a peripheral inflammatory response biomarker and the sole prognostic factor for patients with cervical TSCI.
In addition to peripheral inflammatory response biomarkers, there has been an increasing interest in certain variables in routine MRI studies, such as IMLL, MSCC, MCC, and the BASIC score. However, these MRI variables have yet to establish themselves as sufficiently accurate biomarkers for assessing injury severity and long-term neurological prognosis in TSCI. In previous studies, the predictive role of MSCC and MCC in neurological recovery remains inconclusive(21, 35–37). Our findings revealed that although MSCC and MCC displayed strong associations with admission injury severity and follow-up AIS grade, they did not emerge as potential predictors of TSCI prognosis in multivariate logistic regression analysis. Haefeli et al.(21) and Mabray et al.(38), using the non-linear principal component analysis method (NL-PCA), assessed various MRI metrics' validity in predicting early neurological impairment and similarly found MCC and MSCC to be ineffective predictors. Our findings align with this, suggesting that MSCC and MCC might not be pivotal MRI variables for predicting TSCI prognosis due to two primary reasons. First, MSCC and MCC primarily correlate with admission injury severity, and their impact was negligible when initial injury severity was considered the strongest predictor of neurological recovery. Second, MSCC and MCC illustrate structural changes in post-traumatic compression on MRI, potentially underestimating the actual spinal cord compression during the traumatic event, leading to irreversible spinal cord damage.
A strong correlation was observed between abnormal signalling variables within the spinal cord (BASIC score and IMLL) and admission AIS grade and follow-up AIS grade. Previous research highlights that quantitative T2 signalling measurements (IMLL or BASIC) are significantly superior predictors of neurological prognosis 1 year after cervical TSCI when compared to MCC and MSCC. Although both BASIC score and IMLL focus on T2 signalling alterations within the spinal cord, they differ significantly in many ways. The BASIC score, an axial imaging scale, primarily reflects the degree of white matter preservation, with the most severe degree involving haemorrhage combined with oedema. In contrast, IMLL serves as a longitudinal imaging scale but lacks detailed insights into the degree of white matter preservation Talbott et al.(11) introduced the BASIC score based on axial MRI findings in 2015, demonstrating its strong association with neurological symptoms upon hospitalisation and discharge. Concurrently, a series of clinical studies have underscored the superior efficacy of the BASIC score over other MRI variables in assessing severity and predicting TSCI prognosis(12, 19, 21). Our study similarly identified the BASIC score as the sole significant predictor among MRI variables in the multivariate logistic regression analysis.
TThe MRI variable BASIC score and the peripheral inflammation response biomarker CRP exhibit reliable predictive capacities for prognosis. Our analysis also revealed a larger AUC in the model combining the BASIC score with CRP, indicating its superior predictability. Nevertheless, several factors can influence the validity of AUC outcomes. Factors such as, the timing(39) and types(40) of decompression surgery might be affected by spinal cord signalling abnormalities and the degree of spinal cord compression, potentially affecting prognosis.
Limitations
This study has several limitations. First, its retrospective nature could have introduced selection bias and hindered control over confounding variables. Second, during the acute injury phase, MRI might not fully reveal the nature and extent of the lesion, including potential daily increases in IMLL. Third, the employed clinical assessment (AIS grade) was relatively crude and subjective, potentially constraining the correlation's robustness, as more detailed measures were not utilised. Additionally, our study focused solely on admission MRI variables and peripheral inflammatory response biomarkers as indicators, overlooking the dynamic changes in these indicators over time. Thus, prospective studies are imperative to further validate our findings.