Background
Many conditions called “stroke mimics” may resemble acute stroke. The converse of
the “stroke mimic” is a presentation suggestive of another condition, which actually
represents stroke. These would be “stroke chameleons.” The recognition of a chameleon
as stroke has implications for therapy and quality of care.
Methods
We performed a retrospective chart review, including all cases for 1 year in which
patients had a stroke missed on hospital presentation. Initial erroneous diagnoses
were compared for all patients correctly admitted with those diagnoses to determine
positive predictive value (PPV) for each chameleon.
Results
Ninety-four cases were identified as chameleons where brain imaging revealed acute
stroke. The common chameleons were initially diagnosed as altered mental status (AMS)
(29, 31%), syncope (15, 16%), hypertensive emergency (12, 13%), systemic infection
(10, 11%), and suspected acute coronary syndrome (ACS) (9, 10%). The total number
of patients who were diagnosed with these conditions over the same year were AMS (393),
syncope (326), hypertensive emergency (144), systemic infection (753), and suspected
ACS (817) (total N = 2528). For each chameleon diagnosis, the PPV of each presentation
for acute stroke was AMS (7%), syncope (4%), hypertensive emergency (8%), systemic
infection (1%), and suspected ACS (1%).
Conclusions
Stroke chameleons may result in patients not receiving appropriate care. The largest
proportions of chameleons were AMS, syncope, hypertensive emergency, systemic infection,
and suspected ACS. Patients diagnosed with hypertensive emergency or AMS had an 8%
and 7% chance of having an acute stroke. Physicians should consider stroke in patients
with these diagnoses with a lower threshold to obtain neuroimaging with subsequent
appropriate management.
Key Words
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Article info
Publication history
Published online: August 19, 2013
Accepted:
July 8,
2013
Received in revised form:
June 4,
2013
Received:
May 10,
2013
Footnotes
Contributions: C.M.D. performed all chart reviews, participated in data review and interpretation, and drafted the initial manuscript and subsequent revisions. R.L. is responsible for study mentorship and conceptualization and also data review and revision of the manuscript for intellectual content. S.I.D. performed all statistics, tables, and figures and was instrumental in overall study design. J.M.K., I.R., and T.K. are responsible for editorial review and making significant contribution in revising the manuscript for intellectual content.
Disclosures: This study was unsponsored, and all authors report no disclosures.
Identification
DOI: https://doi.org/10.1016/j.jstrokecerebrovasdis.2013.07.015
Copyright
© 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.
