Transient ischemic attacks (TIAs) can be difficult to diagnose because the symptoms are often gone by the time the patient seeks medical help. Plus, those symptoms can mimic other disorders.
Neurologists at Rush University Medical Center in Chicago have found three clinical factors that can help distinguish TIAs from other neurologic disorders (Cerebrovasc Dis. 2008;26:630-635). Shyam Prabhakaran, MD, and Vivien Lee, MD, examined records of 100 consecutive patients who came to the emergency department with transient focal neurologic episodes that lasted <24 hours. All of these patients were initially diagnosed with TIA and were admitted for further evaluation, but TIA was confirmed in only 40 people.
Drs. Prabhakaran and Lee identified three independent clinical features that together correctly classified 79% of the cases:
- Gradual symptom onset (odds ratio [OR] 6.7). “I typically ask my patients if their symptoms came on within seconds,” notes Dr. Prabhakaran. “With other neurologic problems that can mimic TIA (e.g., migraines or seizures), symptoms can take more than a minute to manifest.”
- Previous history of unexplained transient neurologic attack (OR 10.6) in which TIA had been ruled out.
- Presence of such nonspecific symptoms (OR 4.2) as lightheadedness, tightness in the chest, or stomach upset along with the neurologic dysfunction.
“It’s important not to miss a diagnosis of TIA,” Dr. Prabhakaran adds, “as these attacks can be harbingers of stroke.” But at the same time, overdiagnosis subjects patients to the risks of unnecessary and potentially dangerous medications and tests and leaves their actual condition untreated or inadequately managed.