1989 (Brott et al.): Developed as a 15-item scale for research trials to provide an objective, reproducible measure of stroke-related neurological deficit.
2001–2009 (Lyden et al.): Introduction of the Modified NIHSS (mNIHSS). Analysis revealed that items like Ataxia, Facial Palsy, and Dysarthria had poor inter-rater reliability (Kappa < 0.50) and redundancy.
2023 (Cummock et al.): Confirmed "Excellent" inter-rater reliability ($ICC=0.95$) between ER and Neurology teams, validating the safety of handover based on ER scores.
2025 (Alamri et al.): Validated the r-NIHSS (Retrospective NIHSS), proving that clinicians can accurately reconstruct scores from EHR data using GCS and MRC scales ($ICC=0.99$).
