Patients with primary disorders of impaired wakefulness exhibit adrenergic hyperactivity and a high prevalence of mitral valve prolapse, which may explain associated fatigue and difficulties with stimulant treatments.
Symptoms suggesting autonomic instability and increased adrenergic effect were identified in 53 patients with primary disorders of impaired wakefulness. Urine and plasma catecholamine concentrations were significantly increased in patients with sleep apnea. Excessive increases in heart rate during isoproterenol infusions suggested adrenergic hyperresponsiveness as an alternative explanation for symptoms of catecholamine excess in some individuals. Twenty-two patients demonstrated mitral valve prolapse (MVP), implicating primary neurologic disturbances as potential factors in the fatigue and lassitude often associated with MVP. The catecholamine abnormalities may explain some of the difficulties frequently encountered in using stimulants to treat sleep disorders.
Clark et al. (Fri,) studied this question.