Epidemiology of Neurologic Deterioration in Acute Stage of Ischemic Stroke or Transient Ischemic Attack

Abstract

Objective: Neurologic Deterioration (ND) is known to be related to disability and poor outcomes. However, no large epidemiologic study on ND has been reported.

Methods: Patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA) admitted within 7 days of symptom onset were identified. Under a component of a quality assurance program of stroke care, we have captured ND during hospitalization prospectively with regular monitoring and systemic audits. ND was defined as any new neurological symptoms/signs or neurological worsening within 3 weeks of onset, satisfying one or more of the followings: increase of total NIHSS score ≥ 2, subscore 1a, 1b, or 1c (level of consciousness) ≥ 1, or subscore 5a, 5b, 6a, or 6b (motor)≥1, or any new neurological deficit (even unmeasurable by NIHSS scores). We investigated the incidence, timing, causes and outcomes of ND.

Results: From December 2010 to September 2015, 29446 patients with AIS or TIA were admitted to 15 participating centers. Seventy-one percent of the patients were hospitalized within 24hours of onset. Deterioration occurred in 18.2% during median 10.1 days of hospitalization, its cumulative incidence was 5.6% at 1 day, 9.1% at 2 days, 10.9% at 3 days, 14.2% at one week. As causes of ND, progression was most common (73%), followed by recurrence (8.5%). Compared to those without ND, patients with ND were more likely to be older, be females, be hospitalized earlier, have stroke subtypes of large arterial disease or cardioembolism, have relevant steno-occlusion of major cerebral arteries, and have severer neurologic deficits. ND was independently associated with poorer functional outcome (modified Rankin scale 3 or more) at 3 months (adjusted odds ratio, 5.58; 95% confidence intervals (CI), 5.10-6.11) and one year (4.85; 4.43-5.32), and incidence of major vascular events (stroke, myocardial infarction, all-cause death) up to one year (adjusted hazards ratio, 1.64; 95% CI, 1.50-1.79).

Conclusions: Our study reveals that about one fifths of AIS or TIA patients deteriorate neurologically during hospitalization and this deterioration is associated with poor functional outcome and subsequent major vascular events. Further researches for its prediction, detection and treatment are warranted.