Third Ventricle Obstruction by Thalamic Intracerebral Hemorrhage Predicts Poor Functional Outcome Among Patients Treated with Alteplase in the CLEAR III Trial

Introduction The Clot Lysis: Evaluating Accelerated Resolution of IVH trial examined whether irrigating the ventricular system with alteplase improved functional outcomes in patients with small intracerebral hemorrhage (ICH) and large intraventricular hemorrhage (IVH). Thalamic ICH location was common and was associated with poor outcome. One possible explanation is thalamic ICH-associated mass effect obstructing the third ventricle. We hypothesized that patients with thalamic ICH obstructing the third ventricle would have worse functional outcomes compared to patients without obstructing lesions. Methods ICH obstruction of third ventricle was defined as third ventricle compression on 1 or more axial computed tomography slices visually impeding cerebral spinal fluid flow. If the third ventricle was casted with IVH, it was scored as such. Multivariable logistic regression analyses were used to determine whether obstruction of the third ventricle predicts poor functional outcomes defined as modified Rankin score (mRS) 4–6, higher mRS, and mortality at 180 days. Models were adjusted for thalamic ICH location, ICH volume, IVH volume, age, hydrocephalus, baseline Glasgow coma scale, and percentage of low cerebral perfusion pressures during treatment. Results Among saline-treated patients, obstruction of the third ventricle by IVH was a significant predictor of higher mRS at 180 days (OR 1.87, CI 1.01–3.47) and mortality at 180 days (OR 2.73, CI 1.27–5.87) while obstruction by ICH was not. In contrast, among alteplase-treated patients, obstruction by ICH was a significant predictor of mRS 4–6 (OR 3.20, CI 1.30–7.88) and higher mRS at 180 days (OR 2.33, CI 1.24–4.35), while obstruction by IVH was not. Conclusions Poor outcomes were associated with mass-related obstruction of the third ventricle from thalamic ICH in alteplase-treated patients and from IVH in saline-treated patients. Once the ventricular system is cleared with alteplase, obstruction of cerebral spinal fluid flow from thalamic ICH might become important in functional recovery.