Level of consciousness at discharge and associations with outcome after ischemic stroke

Background: Many factors may potentially complicate the stroke recovery process, including persistently impaired level of consciousness (LOC)-whether from residual stroke effects or from superimposed delirium. We aimed to determine the degree to which impaired LOC at hospital discharge is associated with outcomes after ischemic stroke.

Methods: We conducted a single-center retrospective cohort study using prospectively-collected data from 2015 to 2017, collecting total NIHSS-LOC score at discharge as well as subscores for responsiveness (LOC-R), orientation questions (LOC-Q), and command-following (LOC-C). We determined associations between LOC scores and 3-month outcome using logistic regression, with discharge location (skilled nursing facility [SNF] vs. inpatient rehabilitation) representing a pre-specified secondary outcome.

Results: We identified 1003 consecutive patients with ischemic stroke who survived to discharge, of whom 32% had any LOC score > 0. Total LOC score at discharge was associated with unfavorable 3-month outcome (OR 4.9 [95% CI 2.4-9.8] for LOC = 1; OR 8.0 [2.7-23.9] for LOC = 2-3; OR 6.3 [2.1-18.5] for LOC = 4-5; all patients with LOC = 6-7 had poor outcomes), as were subscores for LOC-R (OR 5.3 [1.3-21.2] for LOC-R = 1; all patients with LOC-R = 2-3 had poor outcomes) and LOC-Q (OR 4.1 [2.1-8.3] for LOC-Q = 1; OR 4.9 [1.8-13.5] for LOC-Q = 2). Total LOC score (OR 2.6 [1.3-5.3] for LOC = 1; OR 3.1 [1.2-8.2] for LOC = 2-3) and LOC-Q (OR 3.3 [1.6-6.6] for LOC-Q = 1; OR 3.4 [1.3-9.0] for LOC-Q = 2) were also associated with discharge to SNF rather than to inpatient rehabilitation.

Conclusions: The presence of impaired consciousness or disorientation at discharge is associated with markedly worse outcomes after ischemic stroke. Further studies are necessary to determine the separate effects of residual stroke-related LOC changes and those caused by superimposed delirium.