ABSTRACT
OBJECTIVE: The objective of this study was to evaluate the existing Spetzler-Martin (SM), Spetzler-Ponce (SP), and Lawton-Young (LY) grading systems for cerebellar arteriovenous malformations (AVMs) and to propose a new grading system to estimate the risks associated with these lesions. METHODS: Data for patients with cerebellar AVMs treated microsurgically in two tertiary medical centers were retrospectively reviewed. Data from patients at institution 1 were collected from September 1999 to February 2013, and at institution 2 from October 2008 to October 2015. Patient outcomes were classified as favorable (modified Rankin Scale [mRS] score 0-2) or poor (mRS score 3-6) at the time of discharge. Using chi-square and logistic regression analysis, variables associated with poor outcomes were assigned risk points to design the proposed grading system. The proposed system included neurological status prior to treatment (poor, +2 points), emergency surgery (+1 point), age > 60 years (+1 point), and deep venous drainage (deep, +1 point). Risk point totals of 0-1 comprised grade 1, 2-3 grade 2, and 4-5 grade 3. RESULTS: A total of 125 cerebellar AVMs of 1328 brain AVMs were reviewed in 125 patients, 120 of which were treated microsurgically and included in the study. With our proposed grading system, we found poor outcomes differed significantly between each grade (p < 0.001), while with the SM, SP, and LY grading systems they did not (p = 0.22, p = 0.25, and p = 1, respectively). Logistic regression revealed grade 2 had 3.3 times the risk of experiencing a poor outcome (p = 0.008), while grade 3 had 9.9 times the risk (p < 0.001). The proposed grading system demonstrated a superior level of predictive accuracy (area under the receiver operating characteristic curve [AUROC] of 0.72) compared with the SM, SP, and LY grading systems (AUROC of 0.61, 0.57, and 0.51, respectively). CONCLUSIONS: The authors propose a novel grading system for cerebellar AVMs based on emergency surgery, venous drainage, preoperative neurological status, and age that provides a superior prognostication power than the formerly proposed SM, SP, and LY grading systems. This grading system is clinically predictive of patient outcomes and can be used to better guide vascular neurosurgeons in clinical decision-making.
ABSTRACT
Traumatic atlanto-occipital dislocation (AOD) is an ominous injury with high mortality and morbidity in trauma patients. Improved survival has been observed with advancements in pre-hospital and hospital care. Furthermore, high quality imaging studies are accessible at most trauma centers; these are crucial for prompt diagnosis of AOD. The objective of this study is to perform a comprehensive literature review of traumatic AOD, with specific emphasis on identifying prognostic factors for survival. A review of the literature was performed using the Medline database for all traumatic atlanto-occipital articles published between March 1959 and June 2015; 141 patients from 60 total studies met eligibility criteria for study inclusion. A binary logistic regression model was utilized to identify prognostic factors. The analysis assessed age, sex, spinal cord injury (SCI), traumatic brain injury (TBI), polytrauma injury (PI), and Traynelis AOD Classification. Only TBI was statistically significantly associated with death (OR 8.05 p<0.05); SCI did not reach statistical significance for predicting mortality in AOD patients (OR 1.25 p>0.05). Age, sex, PI, and Traynelis AOD Classification did not meet significance to predict mortality in AOD patients. We found that patients with TBI are eight times more likely to die than patients without TBI. A high degree of suspicion for AOD during pre-hospital care, as well as, prompt diagnosis and management in the trauma center play a key role in the treatment of this devastating injury. The relationship between survival and factors such as TBI and SCI should be further explored.
