Sometimes, physicians also want to observe brain patterns that occur during sleep. For sleep tests, the patient may be asked to stay awake most of the night prior to the EEG appointment or in some cases may be given a mild sedative. EEGs assist physicians in the diagnosis of a variety of neurological problems, from common headaches and dizziness to seizure disorders, strokes, and degenerative brain disease. The EEG is also useful to look for organic causes of psychiatric symptoms and disabilities in children, and can assist physicians in determining irreversible brain death. A PSG is a recording during sleep that uses EEG and other physiological measures to evaluate sleep disorders.
Patients usually spend one or two nights in the lab being monitored.
A technologist records various information for interpretation by a special physician. The test is used to help evaluate patients who experience excessive sleepiness during the day or who have trouble falling asleep or staying asleep at night. Three common sleep disorders are sleep apnea, insomnia, and narcolepsy. Nerve Conduction Studies are performed by placing surface electrodes over a particular nerve, or a muscle innervated by that nerve, and using electrical stimulation to activate the nerve. When the nerve is stimulated, the patient feels a tingling sensation.