Abstract 2200: Altered Mental Status “Code Strokes” Rarely Result in Ischemic Diagnosis

Abstract

Background: The clinical diagnosis of acute ischemic stroke remains challenging, especially with many diagnoses mimicking ischemia. Frequently, Code Stroke activations are initiated in patients who are found not to have focal brain ischemia. To better understand the frequency, diagnoses and outcomes of mimics, we analyzed our Code Stroke population for patients with altered mental status (AMS) but without focal neurological deficits. Methods: We analyzed all patients from the University of California San Diego (UCSD) Code Stroke database, in whom scoring of the entire NIHSS upon admission was available, from 2004 to 2010. Patients with AMS but without focal neurological deficit were defined by initial NIHSS score: On questions 1a or 1b or 1c: ≥ 1; and 5a=5b (motor arm) and 6a=6b (motor leg) and 9=0 (aphasia). The final diagnosis was based on Code Stroke review by a panel of cerebro-vascular subspecialty trained physicians. Univariate logistic regression was used to examine the association between outcomes (90 day mRS, discharge disposition and death) and age, gender, race, ethnicity, baseline NIHSS, pre-stroke modified Rankin score, prior stroke, hypertension and diabetes. Good outcome was defined at mRS (0-1) at 90 days. Good discharge disposition was defined as discharge home or to acute rehabilitation. Results: We identified 108 patients who met our inclusion criteria. Of those, 18 (17%) had a diagnosis of acute ischemic stroke, 10 (9%) TIA and 75 (69%) were categorized as other. Of those “other” patients, 14/75 (19%) were diagnosed with seizure post-ictal, 15 (20%) with toxic-metabolic encephalopathy, 6 (8%) somatization and 7 (9%) intoxication. Only 5/108 patients were treated with thrombolysis. Discharge dispositions were known in 107/108 (99%). 73/107 (68%) of all patients and 56 out of the 75 (75%) patients diagnosed with “other” had good outcomes. Only baseline NIHSS was associated with discharge disposition with p=0.0025. Conclusion: Only 1 in 4 (26%) Code Stroke patients that presented with AMS and no signs of focal neurological impairment were noted to have a cerebral ischemia diagnosis. Alteplase was rarely used (none in the non-ischemic patients) and most of the “other” non-ischemic patients (75%) had good discharge disposition and clinical outcome. In this cohort, most patients who presented with AMS but without lateralizing signs on their neurological exam were not diagnosed with acute ischemic event. Therefore perhaps more common etiologies should be explored prior to initiating a code stroke solely for the presentation of AMS.