Electroconvulsive Therapy
Dr. L.R. KHAN INTRODUCTION :
The possibility that true convulsion might influence the course of mental illness was considered as early as the sixteenth century by paracelsus. In 1785 oliver treated a manic patients with a convulsion induced by a large dose of camphor given and claimed good results. In 1938 cerletti and bini introduced the method for inducing convulsions electrically.
Clinical Features Of Convulsions :
The essential quality of the epileptic process is the occurrence of hyperactive and hypersynchronous neuronal discharges in an area of grey matter. When induced electrically, the clinal features of the convulsion are very similar to those of a spontaneous attack.
Current And Electrode Placement :
In 1942 two rectified into unidirectional ( half wave) pulses the quantity of electricity required to induce a convulsion was reduced. One of the reasons why pulsed current is to be preferred to sinusoidal current is that smaller quantity of current is required with evident clinal advantages. In the cerletti-Bini technique the electrodes were sited bilaterally and symmetrically in the front to temporal areas. A unilateral placement was first employed by Friedman and wilcox (1942) who found that if one electrode was placed on the temple just above the ear and the other convulsion was very much reduced. These early studies demonstrated that unilateral placement was associated with less postictal confusion and memory disturbance than bilateral placement and this was attributed to the smaller quantity of electricity required . There is considerable variation in the duration of convulsions in individual patients even with supraliminal stimuli. It is difficult therefore to indicate the minimum optimal period. It is about 25 to 30 second.
Anaesthesia :
It is customary to give atropine , and anaesthetic and a muscle relaxant before each ECT treatment. If these are not given other than the atropine the treatment is commonly referred to as unmodified .The main purpose of the anaesthetic anaesthetic is to allay any anxiety that might be provoked by the difficulty in breathing caused by the muscle relaxant. It is usual to give atropine intravenously immediately before the anaesthetic is given. The main reason for its administration nowadays is to prevent cardiac arrhythmia of vagal origin. The usual dose of atropine is within the range 0.4-2 mg. The drug most widely used is thiopentone sodium (Pentothal). The dosage of thiopentone varies in different patients but the initial dose is commonly 2000-300 mg given rapidly.
(Author is Consultant Psychiatrist at Raahat Hospital, Aurangabad.)