Prediction of acute stroke progression by the National Institutes of Health Stroke Scale

Objective To determine the occurrence of neurological changes during the first 48 hoursafter acute stroke as it relates to the initial stroke severity assessment. Methods The assessment with the National Institutes of Health Stroke Scale (NIHSS) was performed serially for the first 48 hours on 68 consecutive ischemic stroke patients admitted to the Department of Geriatric Cardiology at the Khanh Hoa Hospital, Nha Trang, Vietnam. Incidence of stroke progression (a?Y3-point increase on the NIHSS) was recorded and analysis performed to determine its association with initial stroke severity and other demographic and physiological variables. Deficit resolutionby 48 hours, defined as an NIHSS score of 0 or 1, measured thefrequency of functional recovery predicted by the initial deficit. Results Overall progression was noted in 28% of events (19/68). Applying Bayes’ solution to the observed frequency of worsening, the greatest likelihood of predicting future patientprogression occurred with NIHSS score of =7 and >7. Patients with an initial NIHSS score of =7 experienced a 13% (6/47) worsening rate versus those of an initial score of >7 with a 62% (13/21) worsening rate (P7 returned to a normal examination within this period (÷2, P<0.05). Conclusions This study suggests that the early clinical course of neurological deficit after acute stroke be dependent on the initial stroke severity and that a dichotomy in early outcome exist surrounding an initial NIHSS score of 7. These findings may have significant implications for the design and patient stratification in treatment protocols with respect to primary clinical outcome.