TIA often misdiagnosed in emergency department
MedWire News: More than one-third of patients who are diagnosed with transient ischemic attack (TIA) in the emergency department receive a different diagnosis after neurologic evaluation, US researchers have found.
However, they admit that the clinical implications of this discordance, and the frequency of the opposite phenomenon (TIAs missed in the emergency department), remain to be determined.
Jon Schrock (MetroHealth Medical Center, Cleveland, Ohio) and co-workers retrospectively reviewed all patients diagnosed with TIA in a single emergency department over a 4-year period.
A total of 429 patients were included in the analysis. All were diagnosed with TIA by the emergency physician but on subsequent evaluation by a neurologist 156 (36%) patients were diagnosed with conditions other than TIA.
Schrock's team used logistic regression analysis to investigate factors that significantly predicted a discordant diagnosis. Risk factors included headache on presentation (odds ratio [OR]=2.52), involuntary movement (OR=3.19), and dizziness (OR=1.92) whereas protective factors included tingling (OR=0.54) and a high ABCD2 score (OR=0.53).
Incontinence, confusion, and visual disturbances were unrelated to the likelihood of a discordant diagnosis.
Emergency department physicians had an average of 6 years' experience in clinical practice. There was a nonsignificant trend for physicians with less than 6 years' experience to be more likely to give a discordant diagnosis of TIA (OR=1.20), the researchers remark.
Discussing their findings, Schrock et al say that the retrospective nature of the study and differing amounts of diagnostic information are potential sources of bias and preclude definitive conclusions.
Nevertheless, the rate of discordant diagnosis observed in this study is "suboptimal," they say, and may be partially explained by the absence of a definitive diagnostic test for TIA.
"Although diffusion-weighted MRI is often used by neurologists to assist in decision-making in patients with possible TIA, this imaging modality is not widely available for use in acute emergency department evaluations," the researchers observe, adding that this "creates a dilemma for the emergency physician caring for a patient with an acute neurologic event."
By Joanna Lyford