Case report: multiple negative polysomnograms in patients with obstructive sleep apnea

A single overnight polysomnogram usually is adequate to exclude a diagnosis of obstructive sleep apnea. We report three patients who had multiple negative polysomnograms before a diagnosis of sleep apnea was made. Factors that may cause a false-negative polysomnogram include reduced total or rapid eye movement sleep time, sleeping in the lateral posture, manifestation of the disease predominantly by hypopneas, and recent medical therapy to treat sleep apneas. In patients with a strong clinical suspicion of sleep apnea and a negative polysomnogram, sleep and clinical parameters should be reevaluated and a repeat polysomnogram may be indicated.