We use the term anxiety to denote an emotional state characterized by subjective feelings of nervousness, irritability, uneasy anticipation, and apprehension, often but by no means always with a definite topical content and the physiologic accompaniments of strong emotion, that is, one or more of the symptoms of breathlessness, tightness in the chest, choking sensation, palpitation, increased muscular tension, dizziness, trembling, sweating, and flushing. The vasomotor and visceral accompaniments are mediated through the autonomic nervous system, particularly its sympathetic part, and involve also the thyroid and adrenal glands.
The symptoms of anxiety may be manifest either in acute episodes, each lasting several minutes or up to an hour, or as a protracted state that may last for weeks, months, or years. In the panic attack, the patient is suddenly overwhelmed by feelings of apprehension, or a fear that he may lose consciousness and die, have a heart attack or stroke, lose his reason or self-control, become insane, or commit some horrible crime. These experiences are accompanied by a series of physiologic reactions, mainly sympathoadrenal hyperactivity, resembling the “fight-or-flight” reaction. Breathlessness, a feeling of suffocation, dizziness, sweating, trembling, palpitation, and precordial or gastric distress are typical but not invariable physical accompaniments. As a persistent and less-severe state, the patient experiences fluctuating degrees of nervousness, palpitation or excessive cardiac impulse, shortness of breath, light-headedness, faintness, easy fatigue, and intolerance of physical exertion.
Attacks tend to occur during periods of relative calm and in nonthreatening circumstances. Usually, the apprehension and physical symptoms escalate over a period of minutes to an hour and then abate over 20 to 30 min, leaving the patient tired, weak, and perplexed. The dramatic symptoms of the panic attack have usually abated by the time the patient reaches a doctor’s office or an emergency department, but the blood pressure may still be elevated, and there may be tachycardia. Otherwise, the patient looks remarkably collected. Often, discrete anxiety attacks and persistent states of anxiety merge with one another. The fear of further attacks leads many patients, particularly women, to become agoraphobic and homebound, fearing public places, especially if alone.
Because panic is a common disorder, affecting 2 to 4 percent of the population at some time in their lives as cited by Roy-Byrne and colleagues, and the symptoms mimic acute neurologic disease, the neurologist is often called upon to distinguish panic attacks from temporal lobe seizures or from vertiginous disorders. Except for the occasional inability of the patient to think or articulate clearly during a panic attack, the manifestations of epilepsy are quite different. Practically never is consciousness lost during a panic attack. If dizziness predominates in the attacks, there may be concern about vertebrobasilar ischemia or labyrinthine dysfunction (see Chap. 14). Vertigo from any cause is accompanied by many of the autonomic symptoms displayed during a panic attack, but careful questioning in the latter will elicit the characteristic apprehension, breathlessness, and palpitations, and the absence of ataxia or other neurologic signs.
Recurrent panic attacks and chronic anxiety have a familial aspect, with one-fifth of first-degree relatives affected and a high degree of concordance in monozygotic twins. The panic symptoms tend to be periodic, beginning in the patient’s twenties; a later onset is more usually coupled with depression, treatment of which is discussed in Chap. 48. Most often, panic in younger persons is a component of a generalized anxiety disorder (see below), but it may stand alone as the only mental symptom or be an opening feature of schizophrenia.