Facilitating psychological intervention for a patient with unilateral vestibular hypofunction

Neurology Report, Jun 2003 by Swan, Laurie

ABSTRACT

Background and Purpose: Patients with vestibular dysfunction often have concurrent anxiety. Although physical therapists are not licensed to evaluate or treat anxiety, they can be alert to signs and symptoms of anxiety and facilitate referral to the appropriate practitioner. The purpose of this case report is to describe how clinicians can recognize psychological symptoms and to provide a model for facilitating psychological intervention that includes the use of screening tools to assist in determining the need for psychological referral. Case Description: The patient was a 49-year-old man with a diagnosis of unilateral vestibular hyporunction and signs of a developing anxiety disorder that included the use of anti-anxiety medication and self-imposed limitations in leaving the home environment, in exercising, and in driving at work. The efforts of the physical therapist in identifying signs and symptoms of anxiety and in facilitating the patient's acceptance of a psychological referral are discussed. Outcomes: After physical therapy intervention there was a decrease in the physical symptoms of dizziness. In addition, after receiving education from the physical therapist, the patient initiated concurrent psychological treatment. Discussion: The high incidence of concurrent anxiety disorders for patients with vestibular dysfunction is an important modifier for the plan of care. Specific suggestions based on the model are offered for facilitating psychological referral.

Key Words: anxiety disorders, physical therapy, psychological referral, vestibular dysfunction

BACKGROUND AND PURPOSE

Physical therapists who work with patients with vestibular dysfunction often encounter the additional challenge of patients presenting with a concurrent anxiety disorder.1 The anxiety disorder may present as a panic attack, as agoraphobia, as a specific phobia, or as anxiety due to a general medical condition, and the patient may have various combinations of these presentations.2 Physical therapists may facilitate optimal outcomes for these patients by recognizing signs and symptoms of anxiety disorders and directing patients to appropriate intervention.

Three models have been developed to explain the link between vestibular dysfunction and anxiety disorders: the somatopsychic model, the psychosomatic model, and the neurological linkage hypothesis. In the somatopsychic model, the vestibular dysfunction occurs first, and the anxiety disorder develops as a psychological reaction to the symptoms of dizziness.3-6 In the psychosomatic model, anxiety occurs first. Symptoms of vestibular dysfunction emerge secondarily as a behaviorally reinforced consequence of anxiety.4-7 These 2 models were developed by identifying the prevalence of anxiety in patients with a primary complaint of dizziness (somatopsychic model) and by identifying the prevalence of vestibular dysfunction in patients with an anxiety disorder (psychosomatic model). A third model, the neurological linkage hypothesis, proposes shared neural pathways for vestihular processing, autonomic function, emotional responses, and anxiety.5,8 This theory focuses on the overlapping and interconnected regions of the nervous system rather than isolating symptoms into a specific time course that identifies vestibular dysfunction or anxiety as the origin.

Research has provided evidence to support the somatopsychic link between vestibular dysfunction and anxiety disorders. Stein et al9 measured rates of anxiety and depression in 87 patients with complaints of dizziness. Fifteen per cent of these patients met the criteria for having panic disorder, agoraphobia, or both. This is in contrast to the prevalence of panic disorder in the general population, which was approximately 2%. Clark et al10 screened 50 patients with dizziness and 50 patients with hearing loss for panic disorder. None of the patients with hearing loss had symptoms of panic disorder, but 20% of the patients with dizziness did. Jacob3 has proposed that patients with vestibular dysfunction may continue to elicit symptoms of panic even after central compensation of the vestibular dysfunction has occurred. The panic attacks become a conditioned response to factors such as environments or interoceptors of the body.

Evidence supporting the psychosomatic model was first reported by Hallpike et al.11 These researchers performed caloric irrigations on a group of patients with anxiety neurosis and a control group. The patients with anxiety neurosis had an elevated duration of caloric response and severity of directional preponderance in comparison to the control group. Since this initial study, numerous researchers have examined the integrity of the vestibular and auditory systems in patients with panic attacks, anxiety, and agoraphobia.12-15 The common finding of these research studies is that patients with anxiety disorders demonstrate abnormalities of vestibular function that is higher than a control population.

The neurological linkage hypothesis can be viewed as a reconciliation between the somatopsychic and psychosomatic models. Numerous areas of the central nervous system have been identified as components of this network.8,16 A simplified explanation of this theory is that certain types of vestibular stimulation can cause a change in autonomic activity.5 The increase in autonomic arousal at the brainstem level is transmitted to the cerebral cortex for conscious awareness. The cortex determines the danger level of the stimulus. If the stimulus is seen as an eminent threat, this information is transmitted by descending pathways to the brainstem. The resultant cyclical transmission of information between the brainstem and cerebral cortex, and to other associated areas of the brain, results in escalating feelings of panic. Readers interested in further details of the neurological linkage hypothesis are referred to Balaban and Thayer.8