I have written in the past about the most cost effective techniques to assess a patient with acute dizziness during a series on this blog titled “Acute Vertigo: Could It Be A Stroke?” The five part series was published just about one year ago. The main point of the series was that current imaging techniques typically used in the Emergency Room are far less effective than some simple screening protocols. Well, last month, a study was published in the ED Management Journal reporting a three year study performed at Henry Ford Hospital in Detroit.  They specifically looked at the diagnostic yield of CT (Computerized Tomographic) scans ordered by emergency department physicians for the complaint of dizziness, and found that less than one percent of these CT scans yielded any significant information. The cost for these scans performed over three years, in just one emergency room, approached one million dollars. In the very few patients with positive findings on CT scan, the dizziness was accompanied by headache or other neurological deficit. For the more common complaints of dizziness, which are usually lightheadedness, positional vertigo or isolated dizziness, there is little value in performing a CT Scan.
A second, but just as important factor to consider, is the sensitivity of CT scans in detecting cerebellar stroke (presumably the main concern of the ordering physician). CT scans are frequently normal in the first few hours following acute ischemic stroke, therefore, a normal CT scan cannot rule out cerebellar stroke . As many as 50% of cerebellar stroke patients may be missed if diagnosis is dependent on CT scanning.
Bottom line, CT scans ordered for dizziness hardly ever provide pertinent diagnostic information, and may miss a high percentage of the very few with potentially worrisome intra-cranial pathologies.