After stroke, neurological deficits improve in most patients over the subsequent several months, and the improvements are faster early on [1, 2]. However, individual neurological deficit improvements have rarely been reported [3, 4]. We studied improvements on each National Institutes of Health Stroke Scale (NIHSS) item in the acute stroke clinical trial TOAST (Trial of ORG10172 in Acute Stroke Treatment) . The TOAST trial was a randomized, placebo-controlled trial of anticoagulation therapy in patients with mild to moderate stroke severity, starting within 24 h after symptom onset. No significant treatment effect was found.
The TOAST Data Management Center in Iowa City, Iowa, kindly provided the data. We analyzed the NIHSS scores at baseline, seven-days, and three-months. Percent NIHSS change was (baseline score − subsequent score) / baseline score times 100.
Of 1275 enrolled patients, 1269 had the data needed for this analysis. Table 1 shows the proportions of patients with individual NIHSS deficits and those with improvements at seven-days and at three-months. The majority of patients who improved began to do so during the first week. A smaller proportion of patients improved between seven-days and three-months. This improvement pattern was similar in patients with lacunar (small subcortical, n = 305) and nonlacunar (n = 957) stroke subtypes. The total NIHSS in all patients decreased from baseline by a median 36% at seven-days and by 60% at three-months.
|NIHSS item||Deficit present at baseline, n (%)||Percent of patients improved at seven-days/three-months|
|LOC questions||225 (18.4)||62.0/67.6|
|LOC commands||126 (10.1)||62.6/68.6|
|Gaze deviation||234 (18.4)||66.4/76.7|
|Visual fields||298 (24.0)||46.7/63.4|
|Facial palsy||990 (78.0)||45.1/64.3|
|Motor L-arm||524 (41.3)||46.3/60.6|
|Motor R-arm||531 (41.8)||48.1/65.1|
|Motor L-leg||468 (36.9)||47.3/63.4|
|Motor R-leg||449 (35.5)||52.6/65.7|
|Limb ataxia||469 (41.5)||52.3/73.1|
Although the mechanisms of recovery of neurological function after stroke in different brain regions may vary, all neurological deficits on the NIHSS appear to follow a similar pattern of improvement. Improvements are considerably faster during the first week than later. Future studies could further evaluate the relative contribution of each neurological deficit or a combination of deficits to favorable clinical outcome.