INTERFACE BETWEEN VESTIBULAR DYSFUNCTION AND ANXIETY: MORE THAN JUST PSYCHOGENICITY (2001)

Evaluating and treating patients who present with dizziness is often challenging, and this is especially true for patients who have concomitant symptoms of anxiety. Anxiety is frequently a significant component in a dizzy patient's presentation. A patient's anxiety may be the cause of the complaint of dizziness, but the patient's anxiety also may be a direct result of an underlying vestibular disorder. Alternatively, the patient's dizziness and anxiety may be two different manifestations of a common underlying disorder. Proper treatment of patients who present to the otolaryngologist with both dizziness and anxiety requires an understanding and recognition of the interface between anxiety disorders and vestibular disorders. As we discuss briefly below, certain anxiety symptoms may actually suggest a higher likelihood of a vestibular disorder rather than accounting entirely for the patient's dizziness in the absence of a vestibular disorder. Recently, a workshop was held regarding the interface of balance disorders and anxiety disorders. The workshop was jointly sponsored by the National Institute on Deafness and other Communication Disorders, the National Institute of Mental Health, and the Office of Rare Diseases of the National Institutes of Health. An outgrowth of the ideas discussed at that workshop and of subsequent research is a series of papers that will appear in the Journal of Anxiety Disorders in early 2001. The purpose of this communication is (1) to inform the otolaryngology community of the publication regarding the NIH symposium; (2) to highlight the clinical issues regarding the interface between dizziness and anxiety; and (3) to apprise the otolaryngology community of the potential diagnostic and therapeutic implications of recognizing the relationship between dizziness and anxiety. Dizziness is the primary complaint in 2.6% of primary care visits (1). In those patients whose dizziness cannot be attributed to a general medical disorder, some have a well-defined vestibular syndrome; many patients do not. Those patients without a clearly defined vestibular syndrome may have historical, examination, or laboratory findings that strongly suggest a vestibular disorder; other patients may not (2,3). In patients in whom a confident diagnosis of vestibular disease cannot be made, it is tempting to assign a diagnosis of “psychogenic dizziness.” This designation is especially common for patients who report anxiety symptoms. Unfortunately, assigning a label of psychogenic dizziness may preclude the diagnosis of an underlying, treatable, vestibular disorder that can be managed successfully and furthermore can lead to iatrogenic distress in the patient (4). The series of articles from the Journal of Anxiety Disorders addresses various issues regarding the interface between dizziness and anxiety. Discussed in detail are the historical background for the relationship between anxiety disorders and vestibular disorders, suggestions for appropriately classifying patients who present with both dizziness and anxiety, the neurologic basis for a linkage between vestibular disorders and anxiety disorders, and the visual disorientation experienced by such patients. Three papers in the series discuss treatment implications. Of particular note is that some patients with panic disorder and/or agoraphobia can benefit from vestibular rehabilitation therapy in addition to psychiatric treatments. A historical review shows that the co-occurrence of dizziness and anxiety has been recognized since antiquity (5). In the works of Plato, the same terms were used in the context of vertigo, inebriation, height vertigo, disorientation, and mental confusion. In ancient medicine, vertigo had the ambiguous status of being both a disease per se and a symptom of other diseases. In the course of the development of a detailed neurologic taxonomy of vertigo in the latter half of the 19th century, a debate ensued whether agoraphobia was a form of vertigo (such as the `ocular vertigo') or a distinct psychiatric condition. During the 1870s, psychiatrists identified a population of patients without a neurologic form of vertigo but with a fear of open spaces, which they designated as agoraphobia. By the close of the 19th century, though, a neurologic or otologic disorder of vertigo and a psychiatric disorder of agoraphobia were established clearly, with only rare acknowledgment of comorbidity in patients. Anatomic and physiologic evidence has uncovered neurologic bases that may explain the close association of balance disorders and anxiety (6). A primary component of the linkage appears to be a parabrachial nucleus network, consisting of the brainstem parabrachial nucleus and its reciprocal relationships with the vestibular nuclei, extended central amygdaloid nucleus, infralimbic cortex, and the hypothalamus. The parabrachial nucleus is clearly a site of convergence of vestibular information processing and somatic and visceral sensory information processing in pathways that appear to be involved in avoidance conditioning, anxiety, and conditioned fear. Monoaminergic influences on these pathways are potential modulators of both the effect of vigilance and the effect of anxiety on balance control and the development of anxiety and panic. These central pathways may represent a biologic basis for the co-occurrence of balance disorders and anxiety. A questionnaire-based study (7) has indicated that about one third of primary care patients report dizziness, anxiety, or both. About one third of these patients reported both dizziness and anxiety. This prevalence of comorbid dizziness and anxiety is significantly higher than what would have been expected from chance alone (8). The basis for the co-occurrence of vestibular disorders and anxiety disorders is uncertain. There may be a cause and effect relationship such that anxiety leads to vestibular dysfunction based on psychosomatic mechanisms, or vestibular dysfunction leads to anxiety based on somatopsychic mechanisms. Alternatively, results from basic science and theoretical discussions suggest that in some patients vestibular abnormalities and anxiety may be common manifestations of an underlying brainstem dysfunction. For diagnostic purposes it is essential not to categorically dismiss the presence of a vestibular disorder in patients who present with both dizziness and anxiety. Several studies have suggested that certain types of anxiety complaints are associated with a higher likelihood of an underlying vestibular disorder (9–11). Only in limited circumstances can anxiety alone account for a patient's dizziness, such as dizziness during a panic attack. Complicating the process of establishing a diagnosis in many dizzy patients is the concept of “psychiatric overlay,” wherein a psychiatric condition, such as a personality disorder, may influence the way in which a patient with a vestibular disorder presents to his or her physician. Psychiatric overlay also may lead to a diagnosis of “psychogenic dizziness” and divert attention away from a vestibular disorder (2,4). Recognizing a vestibular disorder in the dizzy patient who presents with anxiety (and conversely recognizing an anxiety disorder in a dizzy patient with a vestibular disorder) has important treatment implications. Patients who present with both vestibular dysfunction and an anxiety disorder may benefit by combined treatment of both conditions (12,13). J. M. Furman C. D. Balaban R. G. Jacob