Psychiatry - G.T. Sonnyk 2003

Methods of Examination of Psychiatric Patients
Neurophysiological Studies

These Methods include Electroencephalography (EEG), rheoencephalography (REG), and echo-encephalography (Echo-EEG).

Electroencephalography (EEG) records the bioelectric currents of Brain Cells, utilizing amplifiers for signal detection. This method is most informative for diagnosing Epilepsy (including both seizure manifestations and epileptic psychoses). Typical EEG signs of this pathology include sharp waves, spike-wave complexes, and the like. Sometimes, these patterns are recorded in patients without clinical signs of epilepsy ("hidden epilepsy"). Special activation Procedures, such as hyperventilation, are also employed to provoke these EEG signs in patients who lack them during interictal periods.

Diffuse changes on the EEG, occasionally predominating in specific areas of one or both hemispheres, are observed in organic brain lesions, whereas a shortening of the slow delta-wave phase is characteristic of endogenous depressions, which requires continuous nighttime monitoring for detection.

Rheoencephalography (REG) is the recording of cerebral Blood supply by measuring fluctuations in the electrical resistance of HEAD Tissues. The REG curve is synchronous with the pulse. This research method helps detect cerebrovascular damage. Normally, the peaks of REG waves are sharp and arch-like, whereas in cerebral atherosclerosis, they become smoothed out.

Echo-encephalography (Echo-EEG) is based on THE PRINCIPLE OF echolocation. This method is primarily used to determine whether a mental disorder is associated with a focal brain lesion (such as a tumor or hematoma). In the presence of a space-occupying brain lesion, a lateral displacement of midline brain structures toward the healthy side is detected. The reverse picture—namely, the displacement of midline structures toward the pathological formation—is observed in cases of massive atrophic processes within a hemisphere.