CLINICAL HANDBOOK OF SCHIZOPHRENIA

200 III. SOMATIC TREATMENTsubconvulsive stimulus that is followed by restimulation with increased intensity afteran interval of 20 seconds until motoric or EEG manifestation of a seizure is observed.The ETP is used to provide an amount of stimulus dosage with a high efficacy:low sideeffects ratio.Seizure MonitoringSeizures are monitored during ECT based on EEG, motor convulsion, tachycardia, andblood pressure. Tachycardia signals the ECT-induced cerebral seizure. The motor convulsionsare observed in the isolated limb. It is recommended that both the motor seizureand the EEG be observed.The EEG monitoring of ECT treatments shows characteristic patterns of the tonicand clonic phases of seizure activity (see Figure 20.2). The sites for EEG recording arefrontal–mastoid and frontal–frontal montage. The frontal–mastoid montage is preferredbecause it maximizes the EEG seizure expression. During the tonic phase, hypersynchronouspolyspike complexes are followed by polyspike and slow wave complexes. Theclonus phase of the seizure is evidenced by sudden or gradual suppression of thepolyspike and slow wave complexes. Most ECT-induced seizures last less than 90 seconds.For a seizure to have therapeutic benefit, it must be adequate, which means themotoric seizure activity should last for a minimum of 20 seconds; the EEG seizure activityshould last a minimum of 30 seconds, and it should also show bilateral generalization(i.e., grand mal seizure). Regarding motoric manifestation, if there is an adequate seizurewithout motor activity, it may be possible that the cuff was inflated late or an increase inictal blood pressure exceeded the restriction in circulation.FIGURE 20.2. EEG recording. The top image is a normal EEG. The bottom EEG was created duringa seizure (notice the sharp peaks and valleys).