Anxiety Disorders and Abnormal Movements: A Darkly Interface

Randolph B. Schiffer

ABSTRACT

The anxiety disorders are a heterogeneous group of neuropsychiatric syndromes characterized by nervousness, fearfulness, and psychomotor activation. Some are episodic (panic disorder), some are generalized and pervasive (generalized anxiety disorder), and some are conditioned to categories of environmental stimuli (phobias). Although a movement disorder dimension is not generally considered to be part of the phenomenology of the anxiety disorders, in fact, these patients often seem “fidgety” and “shaky.” Anecdotal observations suggest that mild action and postural tremors are seen in these patients with some frequency, but also a variety of more elaborate psychogenic movement syndromes of the hyperkinetic sort. The neurochemical systems which are activated in the anxiety disorders are similar to those systems which become dysfunctional in Parkinson disease (PD) (noradrenergic, dopaminergic, serotonergic). There are no systematic reports, however, of movement disorders which occur in the course of the anxiety syndromes. Both episodic and generalized anxiety syndromes have been reported to occur in Parkinson patients prior to the first motor symptoms. When the anxiety disorders are successfully treated, the movement dimension of them improves.

INTRODUCTION

We do not currently know the causes of the psychogenic disorders. We do not know the neuropsychiatric conditions that confer vulnerability to the development of these disorders, although these vulnerabilities are generally considered to be psychological in some form or other. It is possible, however, that neurobiological variables also have some role in the genesis of the psychogenic movement disorders, even as Charcot believed over a century ago (1). It may also be true that the risk factors or vulnerabilities to the development of psychogenic movement disorders differ according to the type of movement mimicked by the psychogenic disorder. In this chapter, our current, limited knowledge of the interface between anxiety disorders and the parkinsonian movement disorders is reviewed, and some areas for future clinical and translational research are suggested.

MOVEMENT DISORDERS AMONG PATIENTS WITH ANXIETY SYNDROMES

The anxiety disorders are a heterogeneous group of neuropsychiatric syndromes characterized by clinical features
of nervousness, fearfulness, and psychomotor activation (2). Some are episodic (panic disorder), some are generalized and pervasive (generalized anxiety disorder), and some are conditioned to certain discrete stimuli (the phobias, posttraumatic stress disorder). A listing of these disorders according to the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), is included here as Table 17.1 (3).

TABLE 17.1 ANXIETY DISORDERS IN THE DIAGNOSTIC AND STATISTICAL MANUAL OF MENTAL DISORDERS, FOURTH EDITION

Agoraphobia

Panic disorder

Specific phobia

Social phobia

Obsessive-compulsive disorder

Posttraumatic stress disorder

Acute stress disorder

Generalized anxiety disorder

Anxiety disorder due to substance abuse

Anxiety disorder due to general medical condition

These disorders may be the most common of the Axis I psychiatric disorders, with lifetime prevalence rates exceeding 30% for women, and 19% for men (4). There is considerable comorbidity between the anxiety disorders and other psychiatric disorders, especially depression (5). Familial clustering is commonly seen in the anxiety disorders, and is considered to derive from a mix of not yet identified genetic risk factors, as well as environmental or psychosocial experiences (6). These disorders can occur across the lifespan of the individual, but most commonly symptoms first occur in the second and third decades of life.

The clinical symptomatology of the anxiety disorders crosses several neuropsychiatric functional domains (7). Subjective distress is common, including such symptoms as dread, nervousness, and fearfulness. Sometimes patients with anxiety disorders complain of cognitive changes, especially inattention and difficulty in concentrating. They may also present with a variety of somatic complaints, such as chest pain, shortness of breath, irritable bowel symptoms, and others. Occasionally, sleep disturbance is the most prominent complaint.

Patients with generalized anxiety disorders may also demonstrate a variety of hyperkinetic movement disorders. Action and postural tremulous movement disorders are observed according to anecdote in such patients. More overt hyperkinetic movement disorders can also be seen in such patients, occasionally mimicking parkinsonian syndromes.

The obsessive-compulsive disorders (OCD) are related neuropsychiatric disorders in which patients are bothered by recurrent, inappropriate thoughts or impulses, or compulsions to perform repetitive behaviors which are also perceived as inappropriate or alien (8). Imaging studies implicate various basal ganglion and medial temporal lobe structures in the generation of the OCD behavioral pathologies (9). Patients with OCD also demonstrate a spectrum of motor symptomatologies which are reminiscent of certain movement disorders, such as repetitive self-injurious behavior, hair pulling, and repetitive stereotypical behaviors such as “evening-up” and hand tapping (10).

The tic disorders and Tourette disorder, although not listed as anxiety disorders in DSM-IV, occur with considerable overlap alongside OCD symptomatology (11). The repetitive motor, vocalizations, and coprophenomena which occur in these disorders are also quite reminiscent of movement disorders. The overlap between OCD and these disorders is not fully understood, but is felt to be substantially genetic (12).

There are currently no systematic reports in the neuropsychiatric literature of movement disorders which occur in the course of the anxiety syndromes (13). It might be quite useful for one or two groups of clinical investigators to conduct a systematic survey of an anxiety disorders patient cohort to establish point prevalence rates and descriptive types of movement disorders in such a population.

CASE VIGNETTE

A 38-year-old married man was seen on urgent referral from an emergency room for evaluation of a recent-onset movement disorder. The emergency room physicians wondered if he might have “acute Parkinson disease.”

He had been an anxious person since his teenage years. He described himself as “a chronic worrier,” and “seeing the worst” that could conceivably emerge from every situation. His nervousness and low self-esteem had led him to feel self-conscious in social situations, where he acted shy and unassertive. By his late twenties, sudden attacks of palpitations and fear of death or suffocation had occurred, for which he saw several physicians in consultation. A diagnosis of panic disorder had been given, and he had been treated more or less continuously to the present with benzodiazepines. From time to time he had also experienced depressive symptoms, and he had seen a counselor for treatment of depression on at least one previous occasion.

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