Stephanie M. Lyden, MD
The authors of this study investigated the prognostic significance of small spontaneous intracerebral hemorrhage (ICH) (<30 mL) with associated obstructive intraventricular hemorrhage (IVH), which has not been done before. They performed a prospective observational cohort study using subjects from the CLEAR (Clot Lysis: Evaluating Accelerated Resolution of Intraventricular Hemorrhage) III trial. The CLEAR III trial assessed the use of intraventricular alteplase vs saline in patients with non-traumatic, obstructive IVH. It found that there was no difference in good functional outcome between the two interventions, but that patients who received the alteplase had a lower risk of death and was not associated with increased adverse events.
These investigators analyzed computed tomography (CT) scans from 467/500 CLEAR III subjects and measured the specific anatomic locations affected by the intracerebral hemorrhage using lesion topography with a structured atlas based approach. They assessed stroke outcomes by looking at mortality, modified Rankin Scale score of 4 to 6, National Institutes of Health Stroke Scale score of >4, stroke impact scale score of <60, Barthel Index <86, and EuroQol visual analogue scale score of <50 and <70 at days 30 and 180, respectively, using logistic regression models.
Study results revealed involvement of the following anatomic locations: thalamus (332 lesions, 71.1% of subjects), caudate (219, 46.9% of subjects), posterior limb internal capsule (188, 40.3% of subjects), globus pallidus/putamen (127, 27.2% of subjects), anterior limb of the internal capsule (108, 23.1% of subjects), and lobar (29, 6.2% of subjects) location. On adjusted analysis, the researchers found that thalamic location was independently associated with mortality (days 30 and 180) and with poor outcomes on most stroke scales at day 180. Increased odds of worse disability at days 30 and 180 was associated with posterior limb of the internal capsule and globus pallidus/putamen involvement. Anterior limb of the internal capsule and caudate locations were associated with decreased mortality on days 30 and 180. Anterior limb of the internal capsule lesions were associated with decreased long-term morbidity. Patients who received alteplase were noted to have lower 180-day mortality after adjustment for all ICH locations.
Strengths of this study include the fact that it was a large prospective cohort study that used multiple stroke outcome scales at early and late time points. Because inclusion in the study was limited to patients with small ICH and severe IVH, there are limitations in generalizability. There are inherent limitations in the way outcome is assessed as many of the outcome scales are heavily biased by motor functionality and less cognitive evaluation. Additionally, the percentage of involvement within each anatomic structure was not listed, which is a limitation. For example, a small volume ICH in the internal capsule vs the cortex is likely to cause more functional disability. Another limiting factor was the use of CT scans for anatomic localization as this modality compared to magnetic resonance imaging is felt to have reduced accuracy.
Overall, this study found that lesion topography in patients with small ICH and obstructive IVH can provide important insights into prediction of mortality and functional status.
