Defining Minor Intracerebral Hemorrhage.

BACKGROUND AND PURPOSE The minor stroke concept has not been analyzed in intracerebral hemorrhage (ICH) patients. Our purpose was to determine the optimal cut point on the NIH Stroke Scale (NIHSS) for defining a minor ICH (mICH) in patients with primary ICH. METHODS An ICH was considered minor if associated with a favorable 3-month outcome (modified Rankin Scale score ≤2). For supratentorial ICH, the discovery cohort consisted of 478 patients prospectively admitted at University Hospital del Mar. Association between NIHSS at admission and 3-month outcome was evaluated with area under the curve-receiver operating characteristics (AUC-ROC) and Youden's index to identify the optimal NIHSS cutoff point to define mICH. External validation was performed in a cohort of 242 supratentorial ICH patients from University Hospital Sant Pau. For infratentorial location, patients from both hospitals (n = 85) were analyzed together. RESULTS The best -NIHSS cutoff point defining supratentorial-mICH was 6 (AUC-ROC = 0.815 [0.774-0.857] in the discovery cohort and AUC-ROC = 0.819 [0.756-0.882] in the external validation cohort). For infratentorial ICH, the best cutoff point was 4 (AUC-ROC = 0.771 [0.664-0.877]). Using these cutoff points, 40.5% of all primary ICH cases were mICH. Of these, 70.2% were living independently at 3-month follow-up (72% for supratentorial ICH and 56.1% for infratentorial ICH) and 6.5% had died (5.3% for supratentorial ICH, and 14.6% for infratentorial ICH). For patients identified as non-mICH, good 3-month outcome was observed in 11.3% of cases; mortality was 51%. CONCLUSIONS The definition of mICH using the NIHSS cutoff point of 6 for supratentorial ICH and 4 for infratentorial ICH is useful to identify good outcome in ICH patients.