Improving prediction of outcome in "good grade" subarachnoid hemorrhage.

Objective: We hypothesize that subtle neurological signs at baseline could be present in some "good grade" subarachnoid hemorrhage (SAH) patients and that they would have negative prognostic implications.

Methods: We analyzed data from 1000 patients randomized to the Intraoperative Hypothermia for Aneurysm Surgery Trial (World Federation of Neurological Societies Grades I, II, and III). Nine hundred and forty-four patients had a complete National Institutes of Health Stroke Scale (NIHSS) examination performed at baseline. We analyzed the relationship between baseline NIHSS scores and Glasgow Outcome Scale scores at 3 months. Using stepwise logistic regression, we identified the individual NIHSS items that independently predicted outcome to construct a useful shorter version of the scale for SAH.

Results: The NIHSS was abnormal at baseline in 23% of the Grade I patients and 82% of the Grade II patients. Baseline NIHSS scores strongly predicted 3-month outcomes (P < 0.001). The NIHSS items that were relevant to predict outcome were level of consciousness, dysarthria, visual fields, and worst motor score for the arms. Baseline NIHSS-SAH scores also independently predicted 3-month outcomes (P < 0.001).

Conclusion: Subtle neurological signs at baseline are common in World Federation of Neurological Societies Grades I and II patients and are associated with a worse outcome at 3 months. These signs are not detected by the World Federation of Neurological Societies classification. A better stratification of "good grade" SAH patients to predict long-term outcomes may be desirable for clinical trials and practice. Either using the full NIHSS or a shortened version testing level of consciousness, visual fields, dysarthria and worst arm motor score will help to better stratify "good-grade" SAH patients.