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

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.