Progressing stroke: towards an internationally agreed definition.

BACKGROUND

The study of early neurological deterioration (progression) in acute stroke has been hampered by a lack of standardisation in the terminology or assessment procedures. An international panel was therefore convened, to agree on robust operational definitions for future studies and to validate them in an observational study involving 10 centres from the European Stroke Database Collaboration.

METHODS

Standardised neurological assessments were performed daily for the first 3 days on patients with acute stroke, consecutively admitted within 24 h of onset, using the Scandinavian Stroke Scale (SSS) scoring system. An early deterioration episode (EDE) was defined as a >/=2 SSS-point worsening in either conscious level, arm, leg or eye movement scores, and/or a >/=3 SSS-point worsening in speech score, between consecutive neurological assessments. Stroke progression (SP) was defined as a similar neurological worsening comparing the day 3 assessment with the baseline assessment, or death occurring within 72 h of onset. The ability of SP to predict poor outcome (death or a Barthel ADL score <15/20 at 3 months), independently of initial stroke severity or other prognostic factors, was compared with possible alternative definitions, including one based on the Canadian Stroke Scale.

RESULTS

The occurrence of EDEs and SP within the first 3 days of admission could be determined in 563 cases. EDEs occurred in 33% and SP in 26% of cases. Both were strong independent predictors of poor outcome. The prognostic efficiency of the European Progressing Stroke Study (EPSS) definition of SP was better than any of the alternatives examined, and clearly better than a definition based on changes in the total SSS score.

CONCLUSIONS

The EPSS definitions of EDEs and SP have good construct and prognostic validity. They can be recommended as a standard for future studies on the aetiology and mechanisms of this common and important phenomenon.