Neurological asymmetries immediately after unilateral ECT.

Abstract

Diseases, Queen Square, London S U M M A R Y Twenty-nine right handed patients were examined neurologically before and immediately after each of 62 unilateral ECTs to the dominant and non-dominant hemispheres. Most convulsions were followed by signs of transitory neurological dysfunction referable to the treated hemisphere. These signs included deep tendon reflex asymmetry, hemiparesis, tactile and visual inattention, and homonymous hemianopia. After treatment to the right hemisphere some patients had left visuospatial neglect, while all patients who had dominant hemisphere ECT were transiently dysphasic. All neurological abnormalities tested resolved within 20 minutes of treatment.We have previously reported results of separate electrophysiological investigations in which the EEG, flash evoked potential (VEP), and somatosensory evoked potential (SEP) were monitored during the half hour period after unilateral ECT (Kriss et al., 1975(Kriss et al., , 1977a(Kriss et al., ,b, 1978. Briefly, these studies showed that during the induced seizure the EEG had significantly larger epileptic slow wave activity on the treated side. In the immediate postictal period there was a clear asymmetry with the treated side producing significantly more delta and less alpha and beta activity than the contralateral side. These hemisphere differences, though becoming less marked, persisted beyond the end of the recording. Evoked potential studies showed differing results for the flash VEP and SEP. The VEP was markedly asymmetrical for 15 minutes after the shock with the major positive component (P140) being significantly smaller and later on the treated side. The SEP, however, showed no significant hemisphere differences. In view of these findings we decided to examine patients during the immediate post-ictal period to determine whether there was any clinical evidence of concomitant dysfunction, and to assess the severity and duration of any neurological asymmetries found.

Transient Hemiparesis (Todd’s Paralysis) After Electroconvulsive Therapy (ECT) in a Patient With Major Depressive Disorder

“…3 Proposed mechanisms for neuronal dysfunction underlying such deficits include transient hyperpolarization of cells, cellular toxicity mediated by N-methyl-D-aspartate receptors, and localized changes in cerebral blood flow and metabolism. 2 Transient hemiparesis and other focal neurologic dysfunction immediately after ECT have been previously documented as both single case reports and as a case series. 4 Presumably, the mechanism of postictal focal dysfunction after ECT is similar to that of postictal focal dysfunction after spontaneous seizure.…”

“…However, the exact mechanism remains unclear. 2,5,6 However, in the former, cerebrovascular ischemia was the identified mechanism; whereas in the latter, cerebral imaging was not obtained. Of note, the duration of our patient's appreciable deficit was shorter relative to that usually seen in epileptics after spontaneous focal seizures; a finding reported previously in a larger case series.…”

“…2 Because all observed deficits in the series had resolved within 30 minutes, their etiology was assumed to be electrophysiological rather than ischemic. A lower percentage of patients developed higher-order dysfunction such as hemianopia or hemineglect.…”

A systematic review of left unilateral electroconvulsive therapy

“…Kriss et al (1978) examined a variety of neurological effects after RUL and LUL ECT in 29 right‐handed patients. They found that patients tended to have transient muscle weakness, reduced reflexes, and visual attention deficits contralateral to the treated side.…”

Continuation of ECT After Recovery From Transient, ECT-Induced, Postictal Cortical Blindness

“…It is less well known that ECT may also induce transient neurological adverse effects; these may be lateralizing, such as when unilateral ECT is administered. 1 Transient blindness after ECT, albeit rare, is one such neurological adverse effect. To the best of our knowledge, there have been only 2 cases of ECT-induced blindness reported in literature.…”