The manifestations of hyperventilation syndrome are listed in Table 1. Patients with different symptoms may see different specialists. Cardiologists may see those with complaints of chest pain, palpitations, and shortness of breath. Neurologists frequently see patients describing dizziness and paresthesias (Pincus 1978; Perkin and Joseph 1986).
Table 1. Symptoms and Signs of Hyperventilation Syndrome
The most common cause of distal symmetrical paresthesias is hyperventilation syndrome (Macefield and Burke 1991). Although physicians generally recognize bilateral paresthesias of the face, hands, and feet as due to hyperventilation syndrome, many neurologists are not aware that hyperventilation can cause unilateral paresthesias. In 2 studies of volunteer groups, hyperventilation produced predominantly unilateral paresthesias in 16%, and these involved the left side in over 60% (Tavel 1964; Evans 1995; 2005). Of those with hand numbness, often only the fourth and fifth fingers are involved. Unusual patterns of numbness reported include 1 side of the forehead, the shoulders, and 1 side of the abdomen. Unilateral paresthesias more often involving the left side have also been reported (Tavel 1964; Blau et al 1983; Perkin and Joseph 1986; Brodtkorb et al 1990; O'Sullivan et al 1992).
Patients may report a variety of psychological complaints, commonly including anxiety, nervousness, unreality, disorientation, or feeling "spacy." Impairment of concentration and memory may be described as part of episodes or alternatively as symptoms of an underlying anxiety neurosis or depression. A patient's concern about the cause of the various symptoms of hyperventilation may result in feelings of impending death, fear, or panic, which may accentuate the hyperventilation. Patients with hyperventilation syndrome have a mean group profile very similar to patients with pseudoseizures: a neurotic pattern where patients respond to psychological stress with somatic symptoms (Brodtkorb et al 1990). Other complaints such as déjà vu or auditory and visual hallucinations are rare (Allen and Agus 1968; Evans 1995; 2005).