Thrombolysis ‘low-risk’ strategy for stroke mimic patients
MedWire News: Administrating intravenous tissue plasminogen activator (tPA) to patients with conditions that mimic stroke is a low-risk strategy that helps to ensure prompt treatment of patients with genuine strokes, say researchers.
The policy of clinicians at the University of Texas Medical School at Houston, USA, is to thrombolyze all eligible patients thought to have acute cerebral ischemia, even if alternative diagnoses are still being considered.
The team led by Sean Savitz (University of Texas Medical School at Houston, USA) found that, over a 4-year period, 21% of 512 thrombolyzed patients did not have an infarct on follow-up imaging, at least 24 hours after treatment. An alternative diagnosis – primarily seizure, complicated migraine, and conversion disorder – was ultimately given to 14% of patients, while 7% most likely had stroke, but without an infarct on imaging.
The latter group of patients “may have recanalized rapidly after tPA, before imaging could show damage,” say the researchers in the journal Neurology.
Patients with stroke mimics were younger than other patients, at 55 versus 61 years, and had fewer vascular risk factors. The two groups had the same median admission and discharge National Institutes of Health Stroke Scale scores (7 and 0, respectively) and both remained in hospital for a median of 3 days.
No patient in either group suffered a symptomatic intracerebral hemorrhage, and most were functionally independent at discharge, with 87% of stroke mimic patients and 91% of imaging-negative stroke patients having a discharge modified Rankin Scale score of 0 or 1.
Editorialists Jeffrey Saver (University of California at Los Angeles Stroke Center, USA) and William Barsan (University of Ann Arbor, Michigan, USA) commented that although the ideal rate of thrombolysis among patients with stroke mimics is zero, this is thwarted by lack of imaging facilities beyond noncontrast computed tomography (CT) in most hospitals.
“Often physicians confront a tradeoff between treating early based on initial clinical presentation and absence of hemorrhage on CT or delaying therapy to acquire more diagnostic information,” they said.
The results of Savitz et al favor the “quick-draw” approach to treatment, they said, but also noted that complications in patients with stroke mimics are “especially dispiriting,” which supports avoiding treatment if diagnosis is uncertain.
“The ‘sweet spot’ for target diagnostic accuracy rates merits further investigation,” concluded Saver and Barsan.
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By Eleanor McDermid