Development of temporal lobe epilepsy during maintenance electroconvulsive therapy: A case of human kindling?

A case with temporal spikes on electroencephalography induced by over 80 sessions of electroconvulsive therapy

Background

Electroconvulsive therapy (ECT) is widely recognized as one of the most effective treatments for various psychiatric disorders and is generally considered safe. However, a few reports have mentioned that multiple ECT sessions could induce electroencephalography (EEG) abnormalities and epileptic seizures, a serious side effect of ECT. We experienced a case with EEG abnormalities after multiple ECT sessions and aimed to share our insights on conducting ECT safely.

Case Presentation

We present the case of a 73-year-old female diagnosed with major depressive disorder. She underwent regular ECT sessions to alleviate her psychiatric symptoms. However, after more than 80 sessions, previously undetected EEG abnormalities were observed. Since the patient did not have clinical seizures, we were able to continue ECT at longer intervals without the use of antiepileptic drugs.

Conclusion

Our case suggests the importance of routine EEG testing in patients undergoing prolonged ECT. While careful monitoring is necessary, continuing ECT without antiepileptic medication in patients with EEG abnormalities could be permissible.

Tardive Seizures After Electroconvulsive Therapy

OBJECTIVES

Seizures that occur spontaneously after termination of an electroconvulsive therapy (ECT) seizure are termed tardive seizures. They are thought to be a rare complication of ECT, influenced by risk factors that affect seizure threshold. However, there has been limited review of tardive seizures with modified ECT. We aimed to review the literature to provide clinical guidance for the use of ECT after tardive seizures.

METHODS

PubMed, EMBASE, PsycInfo, and CINAHL databases were searched from inception to May 2021 to identify cases of modified ECT, with evidence of a seizure occurring within 7 days of a terminated ECT seizure. Data for demographic, medical, pharmacological, anesthetic, and ECT variables as well as management strategies were collected.

RESULTS

There have been 39 episodes of modified ECT-related tardive seizures published over a period of 40 years. In 97.4% of cases, there was at least 1 identified potential risk factor for seizures, including use of a seizure-lowering medication and/or preexisting neurological injury. Major complications were uncommon (<15% of cases); however, 1 fetal death and 1 subsequent suicide were reported. No case was diagnosed with epilepsy, although around 20% continued on antiepileptic medications. More than half of the included patients were retrialed on ECT, with only 15% developing further tardive seizures.

CONCLUSIONS

Seizures that occurred spontaneously after the termination of an ECT seizure are a rare complication of modified ECT. Recommencing ECT after a tardive seizure may occur after review of modifiable seizure risk factors and with consideration of antiepileptic medication and extended post-ECT monitoring.

Methohexital-Induced Seizure in a Patient Undergoing Conscious Sedation

BACKGROUND

Methohexital is a short-acting barbiturate used for procedural sedation in the emergency department (ED). As with other sedatives, adverse effects with methohexital include excess sedation and hypotension, but this agent can also lower the seizure threshold. We report a patient who developed a generalized seizure after administration of methohexital.

CASE REPORT

A 60-year-old man presented to the ED by ambulance with chest pain and shortness of breath. Paramedics had administered adenosine for supraventricular tachycardia without conversion before arrival to the ED. He had no history of seizures. His initial vital signs in the ED included heart rate of 189 beats/min with a supraventricular rhythm, blood pressure 137/108 mm Hg, respiration 22 breaths/min, and oxygen saturation of 98% on room air. It was decided to attempt synchronized electrical cardioversion, and methohexital 1 mg/kg (120 mg) was administered over 2 min for moderate sedation. Within 15 s of methohexital administration, the patient developed a generalized seizure that lasted for 90 s. After seizure termination, he was successfully cardioverted, returned to his previous baseline level of consciousness within 20 min, and discharged without further problems with a follow-up referral to neurology. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Methohexital is a short-acting barbiturate used for moderate sedation. Its adverse effects are unique in that it can lower the seizure threshold in some patients. Alternative agents for sedation should be considered in individuals with possible seizure disorders.