Defining Minor Intracerebral Hemorrhage.

Area of Science:

• Neurology
• Neurosurgery
• Stroke Medicine

Background:

• The concept of minor stroke has not been well-defined for intracerebral hemorrhage (ICH) patients.
• Establishing criteria for minor ICH is crucial for understanding patient prognoses.

Purpose of the Study:

• To determine the optimal cutoff point on the NIH Stroke Scale (NIHSS) for defining minor ICH (mICH) in patients with primary ICH.
• To identify specific NIHSS thresholds for supratentorial and infratentorial ICH.

Main Methods:

• Utilized a discovery cohort of 478 supratentorial ICH patients and an external validation cohort of 242 patients.
• Analyzed 85 infratentorial ICH patients from both cohorts.
• Evaluated the association between admission NIHSS and 3-month favorable outcome (modified Rankin Scale score ≤2) using AUC-ROC and Youden's index.

Main Results:

• An NIHSS cutoff of 6 was optimal for defining supratentorial mICH (AUC-ROC 0.815-0.819).
• An NIHSS cutoff of 4 was optimal for infratentorial mICH (AUC-ROC 0.771).
• Using these cutoffs, 40.5% of ICH cases were classified as mICH, with 70.2% achieving a favorable 3-month outcome compared to 11.3% in non-mICH cases.

Conclusions:

• The proposed NIHSS cutoffs (6 for supratentorial, 4 for infratentorial ICH) effectively define minor ICH.
• This definition aids in identifying ICH patients likely to have a good 3-month outcome.