Numerous researchers have noted a correlation between vestibular disorders and anxiety or panic disorder. As noted last week, whether vestibular disorders may lead to panic disorder or whether vestibular complaints are consequential of panic disorder is a subject of much speculation and research. Here is a short summary (with my snarky comments inserted in parentheses) of some research on the subject:
Alvord (1991) noted that “dizzy” patients scheduled for ENG had a much higher self-assessment of anxiety than did their non-dizzy patients scheduled for auditory-evoked potential tests or subjects with no medical complaints. (After seeing both hearing and balance patients for thirty years, I can tell you the anxiety level is MUCH higher for the dizzy patients. Patients with hearing complaints often wait several years before it bothers them enough to seek help. In our balance clinic, the most frequent complaint we get is that it took too long to get an initial appointment).
Hoffman, O’Leary, and Munjack (1994) reported abnormal scores on the vestibular autorotation test on all patients seen in a panic disorder clinic. These patients were not selected or excluded based on a complaint of dizziness. (The authors hypothesized that “the resulting experience of a visual- vestibular disturbance-perhaps in a biologically or psychologically predisposed individual-is catastrophically misinterpreted, leading to more bodily symptoms and anxiety. These could then contribute to more misinterpretation in a positive feedback sense, ultimately leading to a panic attack.” While I agree that the thinking here is plausible, it might be a bit of a stretch. At this time, the vestibular autorotation test has not been subjected to the scrutiny of the AMA, and does not have a CPT code assigned to it. While I feel it is a useful test, I would not make a diagnosis of vestibular dysfunction on this test in isolation.)
Jacob (1988) offers a historical perspective on the subject and proposes possible theories as to the cause and effect relationship of panic disorder and the vestibular system: Vestibular evaluations were performed on 21 patients with a history of panic disorder or agoraphobia. He found a high (71 to 75%) incidence of abnormal caloric and posturography scores in these patients. (Abnormal calorics could not be the result of an anxiety disorder, abnormal posturography scores could).
Sklare, Stein, Pikus, and Uhde (1990) also report that 71% of patients with a history of panic disorder had some abnormality on ENG testing. (‘Some’ abnormality on ENG testing is pretty non-specific. In the past, I have seen reports that state “the ENG was abnormal.” What does that mean? To me, it means the person dictating the report has a poor understanding of the various systems being tested in an ENG/VNG battery. Thankfully, I see this rarely these days.)
We will finish up our review of anxiety and dizziness next week.