Clinicoradiologic Study on Benign and Non-benign Pontine Hemorrhage

ABSTRACT

BACKGROUND: Since prognosis of pontine hemorrhage (PH) is dependent on the initial consciousness level, prediction of outcome is not difficult in patients presenting deeply comatose mentality or mild neurologic deficits without altered consciousness. The outcome of PH accompanied by some degree of altered mentality is, however, so various and cannot be easily predicted. The aim of this study was to analyze the radiologic factors determining the prognosis in this subgroup of PH. We also tried to describe the common clinical and radiologic features in patients with benign clinical course, which have rarely been studied systematically. METHODS: Chiefly based on the initial level of consciousness, 42 patients were classified into benign (BH, n=14), non-benign (NBH, n=19), and fatal (FH, n=9) PH. We retrospectively reviewed their medical records and radiologic data. The modified Rankin score was used for evaluating long-term prognosis. In NBH group, transverse and vertical extension index of hematoma, hemorrhage volume, and presence of extrapontine extension were investigated on CT images. RESULTS: Hemiparesis with or without ocular disturbance was the most common manifestation in BH group (64%) and two patients showed neurologic signs identical to lacunar syndrome. The most common location of hemorrhage was unilateral tegmentum (64%). In NBH group, transverse extension index was significantly greater in the patients with worse prognosis, though vertical extension index and extrapontine extension did not seem to be important in predicting the prognosis. CONCLUSIONS: The clinical features simulating lacunar syndrome are frequently found in BH. The degree of transverse extension in the pons is important in predicting the prognosis of NBH subgroup.