Comment

Good to know that computed tomography (CT) scans are worthless in these cases. I will be sure to send a copy of this article to the patient I recently saw with dizziness and an acute brainstem infarct on CT scan. He had just been sent home from a stroke center with no CT scan.

How does this balance with the malpractice payout for missed stroke diagnosis? How about factoring in the time spent responding to patient complaints and to peer review?

Take-home point: CT is not worthless in the evaluation of dizziness. It is what the patient expects; it is what the peer-review panel (in retrospect) will expect. A normal CT makes for a happy patient and protects the doctor, very worthwhile in my opinion.

—Alan J. Sorkey, MD
Shreveport, Louisiana

Response

Alan, I sense some tension in your voice. You are wise to recognize that many patients do not fit our anticipated paradigm(s) for stroke presentation and do not have to conform to our diagnostic expectations either. Having said that, I think the question at hand is whether to image or not as opposed to the use of CT or magnetic resonance imaging (MRI). The data are clear. Compared to CT, diffusion-weighted MRI is better suited for the evaluation of acute cerebral ischemic events in general and, in particular, posterior fossa ischemia. I would speculate that this patient presented with enough clinical findings (ie, not isolated dizziness) that appropriately prompted the need for imaging, and if MRI were selected, the referenced patient’s brainstem infarct would have been identified. Thus, the identification of the infarct on CT, to me, speaks more to the severity of the infarct than it does to the superiority of CT to diffusion-weighted MRI.

I couldn’t agree with you more that if MRI is not available, CT may be the only alternative. However, providers should be well aware of its limitations and consider informing patients of the same. I would also suggest that whenever possible, we begin to change our ordering patterns to move from CT to MRI for evaluation of posterior fossa ischemia, which may eventually improve availability of this important diagnostic modality.

As risk managers, we have to part ways in our thinking. First, as outlined in my original article, appropriate patient selection is key. If the patient is very low risk for posterior fossa ischemia, imaging may not be indicated (ie, isolated dizziness odds ratio 0.20 for serious neurological cause). Although reducing utilization, meeting patient expectations, and reducing one’s professional liability risk is a challenging and fine balance, I would suggest that overutilization of CT, which is known to be inferior for the disease being looked for, shouldn’t be the answer. I do agree that patients have expectations. However, until we ask each individual patient, we cannot presume to know what those expectations are; communication is key. I do agree that many may expect imaging. However, most patients will not possess the sophistication to fully understand if imaging is indicated or not and which imaging modality is best for their presentation. It is our job to shape expectations, educate our patients, and employ shared decision making to meet the patient’s needs. I believe that this approach substantially reduces risk to the patient and the providers. Again, if CT is utilized, the provider should include an explanation of its limitations. Otherwise, patients may be left with the impression that normal CT means no stroke or serious neurological disease, and that is a path toward medical-legal disaster.