MRI characteristics predicting seizure threshold in patients undergoing electroconvulsive therapy: a prospective...

Area of Science:

• Neuroscience
• Medical Imaging
• Psychiatry

Background:

• Electroconvulsive therapy (ECT) requires electrical current to overcome anatomical barriers including scalp, skull, cerebrospinal fluid (CSF), and brain tissues to reach the seizure threshold (ST).
• Understanding the influence of these anatomical factors on ST is crucial for optimizing ECT efficacy and safety.

Purpose of the Study:

• To investigate the relationship between head anatomical structures and the seizure threshold (ST) in both right unilateral (RUL) and bifrontotemporal (BL) ECT.
• To determine if anatomical measurements can predict the required electrical stimulus for effective ECT.

Main Methods:

• An observational prospective study involving 74 patients undergoing ECT for depression.
• Seizure thresholds (STs) were measured across multiple ECT sessions.
• Magnetic Resonance Imaging (MRI) was used to measure scalp/skull thickness, intracranial volume (ICV), and CSF volume; multivariate regression analyses were performed for RUL and BL ECT groups.

Main Results:

• Cerebrospinal fluid (CSF) volume was a strong and independent predictor of the initial seizure threshold (ST) in both RUL and BL ECT, even after adjusting for age, gender, and ICV.
• CSF volume also showed a significant association with ST throughout the course of RUL ECT.
• Patient demographics included a mean age of 57.7 years, with 39% males.

Conclusions:

• The volume of CSF is a significant independent predictor of the initial seizure threshold (ST) in ECT.
• Relying solely on age-based dosing for ECT may lead to suboptimal electrical stimulus in patients with non-average CSF volumes.
• Individualized assessment of CSF volume may be necessary for precise ECT electrical dosing.