Novel Anatomic Classification of Spontaneous Thalamic Hemorrhage Classified by Vascular Territory of Thalamus

Spontaneous thalamic hemorrhage has increased in incidence in recent years. Analysis of the characteristics of thalamic hemorrhage was based on the vascular territories of the thalamus. Retrospective analysis included 303 consecutive patients with spontaneous thalamic hemorrhage. Thalamic hemorrhage was classified into 4 types: anterior type (supplied mainly by the tuberothalamic artery), medial (mainly paramedian thalamic-subthalamic artery), lateral (mainly thalamogeniculate artery), and posterior (mainly posterior choroidal artery). The baseline characteristics, complications, and functional outcomes were assessed. The anterior type was found in 10 patients (3.3%), the medial type in 47 (15.5%), the lateral type in 230 (75.9%), and the posterior type in 16 (5.3%). Intracerebral hemorrhage volume was smallest in the anterior type, and significantly smaller than in the medial (P = 0.002) and lateral types (P < 0.001). Intraventricular hemorrhage (IVH) or acute hydrocephalus was significantly associated with the medial type (P < 0.01 or P < 0.01, respectively). Non-IVH or non-acute hydrocephalus was significantly associated with the anterior (P < 0.05 or P < 0.05, respectively) and lateral (P < 0.05 or P < 0.05, respectively) types. Emergency surgery was correlated only with the medial type (P < 0.01). The independent predictors of poor outcome were age (odds ratio [OR], 1.07; P = 0.002), admission National Institutes of Health Stroke Scale score (OR, 1.32; P < 0.001), and type of thalamic hemorrhage (OR, 2.08; P = 0.038). The present study proposed a novel anatomic classification of thalamic hemorrhage according to the major thalamic vascular territories.