Psychiatric and neurologic disorders that affect sleep.

Neurologic and psychiatric disorders that affect sleep are linked by a common symptom: insomnia. For this reason the overnight attended polysomnogram is a vital diagnostic tool for the clinician who wishes to determine the cause of the sleep disturbance. The role of a well-trained and competent polysomnographer is vital to the collection of reliable diagnostic data. Understanding the symptoms and clinical manifestations of these disorders helps the polysomnographer recognize and address the challenges that can arise during the overnight polysomnographic record collection and ensure an accurate diagnosis.