Motor Impairment Is the Key Determinant of the 1-Year Modified Rankin Scale Score in Intracerebral Haemorrhage

Intracerebral haemorrhage (ICH) is associated with significant long-term disability. Precise ICH location is readily available from routine diagnostic imaging and may thus enhance prognostic models. We have previously shown that involvement of motor pathways in the haematoma is highly predictive of poor outcome. However, ICH patients suffer many other impairments, and this is largely governed by ICH location. To better understand the potential prognostic significance of ICH location and guide further research, our aim was to investigate the associations between specific domains of neurological impairment and 1-year functional outcome after ICH and how these association change over time.

Data were pooled from 2 ICH trials: CLEAR-III and MISTIE-III. National Institutes of Health Stroke Scale and Stroke Impact Scale-3 subscores from day 30, 180, and 365 were used to construct eight neurological domains: consciousness, language, motor, sensory, vision, ataxia, memory and thinking, and emotions. The primary outcome was 1-year mRS in ICH survivors, dichotomised into good (0-3) or poor (4-5) outcome. Multivariable logistic regression models were used to investigate the association between impairments at days 30, 180, and 365 and good 1-year mRS, adjusting for baseline confounders (age, premorbid mRS, ICH, and intraventricular volume on stability CT scans) and treatment group (intervention vs. control).

A total of 736 patients were included in the analysis. Motor (OR 0.937; 95% CI: 0.925-0.950) and vision (OR 0.991; 95% CI: 0.983-0.999) impairment at day 30 were associated with poor 1-year mRS. At day 180, motor (OR 0.891; 95% CI: 0.874-0.908) and memory and thinking (OR 0.987; 95% CI: 0.975-0.998) impairment were associated with poor 1-year mRS. At day 365, motor (OR 0.876; 95% CI: 0.856-0.897) impairment was significantly associated with poor 1-year mRS, along with memory and thinking (OR 0.982; 95% CI: 0.971-0.994) and language (OR 0.982; 95% CI: 0.966-0.999) impairment.

In our secondary analysis of this ICH cohort, motor impairment within the first year after ICH is consistently and strongly associated with the 1-year mRS at all timepoints. Although the associations are weaker, memory and thinking at days 180 and 365 was also associated with 1-year mRS. Among the other domains, only vision showed a weak association at a single time point (day 30). Our exploratory study suggests that lesion locations impacting on motor function and memory and thinking may worsen functional recovery in ICH patients.