Preclusion of ischemic stroke patients from intravenous tissue plasminogen activator treatment for mild symptoms should not be based on low National Institutes of Health Stroke Scale Scores

Abstract

Background: Intravenous tissue plasminogen activator (IV tPA) improves neurologic outcome after stroke, but is not recommended for patients with minor neurologic deficits commonly classified by a lower cutoff on the National Institutes of Health Stroke Scale (NIHSS). Because not all stroke signs are captured on the NIHSS, the use of a strict cutoff may exclude functionally impaired stroke patients from IV tPA treatment.

Methods: We described functional impairment, safety, and clinical outcome in patients derived from our hospital thrombolysis database who had stroke that was considered disabling despite a neurologic deficit that was considered mild. We used 2 cutoffs: NIHSS score ≤ 4 and ≤ 3. Functional impairment was assessed with the modified Rankin Scale (mRS).

Results: Between 2008 and 2011, a total of 670 acute ischemic stroke patients received IV tPA in our institution. 107 (16%) of these patients presented with a NIHSS score ≤ 4; 65 (10%) patients presented with a NIHSS score ≤ 3. All of these patients were considered functionally impaired (mRS score ≥ 2). The most frequent symptoms were language impairment (two-thirds), distal (hand) paresis (one-third), and gait disorder in both groups. Symptomatic intracerebral hemorrhage occurred in 1 patient with a NIHSS score of 4 (1%). Despite IV tPA therapy, 26% had a nonfavorable outcome (mRS score 0-1) after 3 months, and 52% had persisting symptoms in both groups.

Conclusions: Language impairment, distal (hand) paresis, and gait disorder are common disabling deficits in patients with low NIHSS scores. Judgment of whether a stroke is disabling should not be based on the NIHSS score but on the assessment of the individual neurologic deficits and their impact on functional impairment.