ZJUSAH Classification: A New Classification for Primary Brainstem Hemorrhage

Abstract

To analyze and improve ZJUSAH classification for primary brainstem hematoma, we retrospectively reviewed 211 patients with primary brainstem hemorrhage who were admitted to our institution between January 2014 and October 2020. The primary clinical outcomes were the 30-day survival rate and 90-day consciousness recovery rate, which were evaluated using the National Institutes of Health Stroke Scale score. Univariate logistic regression and multivariate Cox regression analyses were performed to evaluate the prognostic model. The overall 30-day survival rate of the 211 patients was 69.7%. The 30-day survival rate was 95% among Type 1 patients, 77.8% among Type 2 patients, and 63.2% among Type 3 patients. The 90-day consciousness recovery rate was 63.2% among Type 1 patients, 61.9% among Type 2 patients, and 30.2% among Type 3 patients. Our findings suggest that ZJUSAH classification can be optimized according to hematoma volume, with Type 3 patients with a hematoma larger than 12.4 mL tending to have a worse state of consciousness. Additionally, we discovered that ZJUSAH classification is valuable in predicting 30-day survival rates in conservative treatment patients. In conclusion, our study established and optimized a new CT-based hematoma classification system for primary brainstem hematoma, which facilitates treatment selection and prognostic prediction.

Keywords: multiple logistic regression; predictive factors; primary brainstem hemorrhage; state of consciousness.

Figure 1

(A) Schematic representations of ZJUSAH classifications showing horizontal cross-sections of the brainstem are shown in the figure, with the fourth ventricle at the bottom. The dashed lines divide the ventral–dorsal diameter into three equal parts. (B) An easy way to find left and right 1/4 borderlines: The green line represents the ventral–dorsal midline. The yellow lines represent the tangent lines of the ventrolateral edges. The red lines represent the left and right 1/4 borderlines, starting from the intersection of green lines and yellow lines, equally dividing the angles in half.

Figure 2

Representative cases of ZJUSAH classification. (A) The hematoma is within the cistern or the fourth ventricle, with the brainstem being compressed but not damaged (Type 0). (B) The hematoma remains on the right side of the brainstem without affecting the left side (Type 1). (C) The hematoma spans both the left and right sides of the midline, without involving the right or left 1/4 of the brainstem, localizing mainly within the ventral part of the brainstem (Type 2A). (D) The hematoma spans both sides, without involving the right or left 1/4 of the brainstem, localizing mainly within the dorsal part of the brainstem (Type 2B). (E) The hematoma spans both sides, without involving the right or left 1/4 of the brainstem, localizing mainly within the central part of the brainstem (Type 2C). (F) The hematoma spans both sides, involving 1/4 borderlines of both sides, localizing mainly within the ventral part of the brainstem (Type 3A). (G) The hematoma spans both sides, involving 1/4 borderlines of both sides, localizing mainly within the dorsal part of the brainstem (Type 3B). (H) The hematoma spans both sides, involving 1/4 borderlines of both sides, localizing mainly within the central part of the brainstem (Type 3C).

Figure 3

Distribution of the hematoma volumes of patients classified through ZJUSAH classification. Hematoma volumes in 210 Type 1, Type 2, and Type 3 patients. The error bar indicates the standard error of the mean (SEM).

Figure 4

The 30-day death HR for different ZJUSAH classifications and different treatments. ZJUSAH stands for ZJUSAH classification; surgery stands for stereotactic aspiration surgeries.

Figure 5

Kaplan–Meier Curve of different ZJUSAH classifications and different treatments. (A) Kaplan–Meier curve of 30-day survival stratified by ZJUSAH classification types. (B) Kaplan–Meier curve of 30-day survival stratified by treatments.

Figure 6

ROC curve: univariable logistic regression model of 30-day survival rate, ZJUSAH classification, and the predictive factors. Note that when Type 1 is set as the reference, Type 2B and 3B are unfavorable factors for 30-day survival outcomes, while the rest of the classifications show no significant correlation (p > 0.05).