Seizure threshold rise during electroconvulsive therapy in schizophrenic patients

Dosing methods in electroconvulsive therapy: should the Scandinavian time-titration method be resumed?

AIM

To describe and evaluate the different dosing methods in ECT, and bringing back into focus the Scandinavian time-titration method.

METHOD

A narrative, unsystematic, and selective review and discussion.

RESULTS

There are five dosing methods: 1) The Scandinavian time-titration to tonic convulsion, using low-frequency pulses and a long maximal pulse train duration, was highly efficacious with right unilateral (RUL) ECT, comparable to bitemporal (BT) ECT. However, the device used went out of production in the 1990s. Because US devices until 1990 had a short maximal pulse train duration, time-titration went out of use. 2) Fixed high dosing at 50-100% of the device's maximal output, and 3) Formula-based dosing, initially the Age method, long prevailed in USA. Later, the Half-Age method was introduced for BT ECT. 4) Charge-dosing as a multiple of titrated seizure threshold (ST) demonstrated RUL and BT ECT to have comparable outcomes when dosed about six and two times the ST, respectively. 5) Dosing from benchmark is based on a high dose at the first session, to ensure a high peak heart rate and tonic-clonic convulsions. In later sessions the lowest dose producing similar outcomes is chosen.

CONCLUSIONS

No dosing method is documented superior to the others. Seizure threshold-based and benchmark dosing seems to be more accurate than fixed high and formula-based dosing. However, time-titration dosing makes it possible to adjust the dose at every session, and may be the most efficient method.

Initial Seizure Threshold in Brief-Pulse Bilateral Electroconvulsive Therapy in Patients with Schizophrenia or Schizoaffective Disorder

OBJECTIVE

The present study aimed to report the initial seizure threshold (IST) of a brief-pulse bilateral electroconvulsive therapy (BP-BL ECT) in Korean patients with schizophrenia/schizoaffective disorder and to identify IST predictors.

METHODS

Among 67 patients who received ECT and diagnosed with schizophrenia/schizoaffective disorder based on the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, we included 56 patients who received 1-millisecond BP-BL ECT after anesthesia with sodium thiopental between March 2012 and June 2018. Demographic and clinical information was gathered from electronic medical records, and a multiple regression analysis was conducted to identify predictors of the IST.

RESULTS

The mean age of the patients was 36.9±12.0 years and 30 (53.6%) patients were male. The mean and median IST were 105.9±54.5 and 96 millicoulombs (mC), respectively. The IST was predicted by age, gender, and dose (mg/kg) of sodium thiopental. Other physical and clinical variables were not associated with the IST.

CONCLUSION

The present study demonstrated that the IST of 1-ms BP-BL ECT following sodium thiopental anesthesia in Korean patients was comparable to those reported in previous literature. The IST was associated with age, gender, and dose of sodium thiopental.

Brief vs. ultrabrief pulse ECT: focus on seizure quality

The effect of electroconvulsive therapy (ECT) performed with ultrabrief pulse (UBP) stimulation has been found inferior to brief pulse (BP) ECT in various studies. We reinvestigated this issue using a new dosing strategy that is based on seizure quality instead of seizure threshold. There is a long history of studies associating ictal characteristics of ECT with the clinical outcome. Accordingly, we used the clinical status of the patient and the quality of the prior seizure to determine the dosage for the upcoming treatment-referred to as Clinical and Seizure Based Stimulation (CASBAS). This approach aims at continuously providing high-quality seizures to optimize the outcome. While this dosing strategy was applied in our department, the pulse width was changed for a period of time from BP to UBP. It was hypothesized that the procedure would: (1) maintain seizure quality and clinical outcome under both conditions and would; and (2) compensate the lesser clinical efficacy of UBP by an increase in stimulus intensity. 245 patients received an ECT course according to the dosing strategy described, 162 with brief pulse (BP) and 83 with ultrabrief pulse ECT (UBP). In a retrospective evaluation, seizure quality and clinical outcome (available in a 20% subgroup of patients) did not differ between both groups in most of the examined parameters, while stimulus intensity was found to be significantly higher in the UBP group. As hypothesized, UBP was less efficient than BP in providing comparable ictal quality and clinical outcome. In a first test of concept the dosing strategy CASBAS seemed suitable to continuously adjust the stimulus intensity in ECT and maintain the seizure quality.

Polymorphism of the brain-derived neurotrophic factor and dynamics of the seizure threshold of electroconvulsive therapy

During a course of electroconvulsive therapy (ECT), the level of currency necessary to induce an epileptic seizure in a patient may either remain relatively stable or-more often-may require repeated upward adjustment over time due to a constantly increasing seizure threshold. We aimed to determine whether a common polymorphism of the brain-derived neurotrophic factor (BDNF), which constitutes an important and ubiquitously expressed neurotrophine in the brain, affects the stimulation threshold of ECTs required to induce an epileptic seizure over time. Twenty-seven adult patients who underwent at least 12 consecutive ECT sessions were analyzed for the stimulation intensities required during the course of the stimulation as well as their BDNF gene status. We could not find a relation between the Val/Met polymorphism of the BDNF and the development of the seizure threshold during the course of the ECT sessions. Mechanisms and predispositions other than the BDNF polymorphism investigated in this study are responsible for the change in seizure thresholds over the course of ECT.

Effects of Psychotropic Drugs on Seizure Threshold during Electroconvulsive Therapy

OBJECTIVE

To analyze the relationship between seizure threshold (ST) and psychotropic drugs in patients treated with ECT.

METHODS

We examined clinical data from 43 patients. ST was titrated at each treatment session. We examined associations between ST and psychotropic drugs using multivariate correlation analyses. Data are presented as initial ST, the difference in ST between the first and 10th sessions (ΔST_10th), and the mean difference in ST between the first and last sessions (mean ΔST_last).

RESULTS

Multivariate regression analyses showed associations between initial ST and the total chlorpromazine-equivalent dose of antipsychotics (β=0.363, p<0.05). The total fluoxetine-equivalent dose of antidepressants was associated with ΔST_10th (β=0.486, p<0.01) and mean ΔST_last (β=0.472, p<0.01).

CONCLUSION

Our study elucidated possible effects of psychotropic drugs on ST shifts. Larger doses of antipsychotics were associated with higher initial ST, whereas higher doses of antidepressants were associated with stronger shifts in ST.

Effect of age and anticonvulsants on seizure threshold during bilateral electroconvulsive therapy with brief-pulse stimulus: A chart-based analysis

BACKGROUND

Efficacy and adverse effects of electroconvulsive therapy (ECT) depend on the extent to which the electrical stimulus exceeds patients' seizure thresholds (STs). Titration method of estimating ST is recommended. Age and co-prescribed anticonvulsants (ACs) are known to affect ST. Literature on ST in bilateral ECT (BLECT) is sparse.

OBJECTIVE

To explore the clinical and demographic determinants of ST in a clinically representative sample of patients prescribed with BLECT.

MATERIALS AND METHODS

ECT records of 640 patients who received BLECT in 2011 in an academic psychiatric setting were studied. Demographic, clinical, pharmacological, and ECT details were analyzed. As per the standard practice, during the 1(st) ECT session, ST was determined by titration method, starting with 30 milli-Coulombs (mC) and increasing by 30 mC and thence in steps of 60 mC. Increase in ST over up to 6(th) session of ECT was noted. Receiver operating characteristic curve was used to find age cut-off with high specificity for ST ≥120 mC. The associations of ST and increase in ST with the age cut-off and other clinical factors were assessed using Chi-square test and logistic regression analysis.

RESULTS

The mean age was 30.98 years (+11.23 years) and mean ST at 1(st) ECT session was 130.36 mC (+51.96 mC). There was significantly high positive correlation (r = 0.37, P < 0.001) between age and ST. Cut-off age of 45 years had high specificity: Only 4.6% of those older than 45 years had ST <120 mC. Higher proportion of patients on AC had ST ≥120 mC. These associations were seen even after controlling for potential confounds of each other using logistic regression analysis. The results were similar for increase in ST over the course of ECT. Sex, diagnosis, use of antipsychotics, antidepressants, lithium, and benzodiazepines (BZPs) had no effect on ST or its increase.

CONCLUSIONS

For BLECT using brief-pulse stimulus, ST depends on age and use of AC. For patients above the age of 45 years, ST estimation may be started at 120 mC with least risk of using unduly higher stimulus. Other medications including BZPs have little influence on ST.

Seizure threshold and the half-age method in bilateral electroconvulsive therapy in Japanese patients

AIM

Seizure threshold (ST) in electroconvulsive therapy (ECT) has not been reported previously in Japanese patients. We investigated ST in bilateral ECT in Japanese patients using the dose-titration method. The associations between demographic and clinical characteristics and ST were analyzed to identify the predictors of ST. Finally, the validity of the half-age method for the stimulus dose was evaluated.

METHODS

Fifty-four Japanese patients with mood disorder, schizophrenia, and other psychotic disorders received an acute course of bilateral ECT using a brief-pulse device. ST was determined at the first session using a fixed titration schedule. ST was correlated with age, sex, body mass index, history of previous ECT, and psychotropic drugs on multiple regression analysis. Furthermore, the rate of accomplished seizures was calculated using the half-age method.

RESULTS

Mean ST was 136 mC. ST was influenced by age, sex, history of previous ECT, and medication with benzodiazepines. The accomplished seizure rate using the half-age method was 72%, which was significantly lower in men and subjects on benzodiazepines.

CONCLUSION

ST in Japanese patients was equal to or slightly higher than that previously reported in other ethnic groups, which might be attributable, at least in part, to high prevalence of and large-dose benzodiazepine prescription. Higher age, male gender, no history of ECT, and benzodiazepines were related to higher ST. The half-age method was especially useful in female patients and subjects without benzodiazepine medication.

Clinical predictors of seizure threshold in electroconvulsive therapy: a prospective study

At the start and during the course of electroconvulsive therapy (ECT), estimation of the seizure threshold (ST) is useful in weighing the expected effectiveness against the risks of side effects. Therefore, this study explores clinical factors predicting initial ST (IST) and levels of ST during the ECT course. This prospective observational study included patients aged ≥18 years receiving ECT without contraindications for dose titration. At the first and every sixth consecutive ECT session, ST level was measured. Using multivariate linear regression and multilevel models, predictors for IST and change in ST levels were examined. A total of 91 patients (mean age, 59.1 ± 15.0 years; 37 % male; 97 % diagnosis of depression) were included. In multivariable analysis, higher age (β = 0.24; P = 0.03) and bifrontotemporal (BL) electrode placement (β = 0.42; P < 0.001) were independent predictors for higher IST, explaining 49 % of its variation. Also, these two variables independently predicted higher ST levels at different time points during the course. Using multilevel models, absence of a previous ECT course(s) predicted a steeper rise in ST during the course (P = 0.03 for the interaction term time*previous ECT). The age-adjusted dose-titration method is somewhat crude, resulting in some measurement error. Concomitant medication use could have influenced ST levels. Increasing age and BL electrode placement predicted higher (I)ST, which should be taken into account when selecting ECT dosage. Previous ECT course(s) may avoid an increase in ST during the course of ECT.

The schizoictal syndrome

There are several common denominators of schizophrenia and epilepsy including models of pathogenesis as well as their clinical occurrence mainly referring to schizophrenia-like syndrome in epilepsy or similar clinical entities [1]. Up to now it has not been emphasized that a process of synchronization or desynchronization of neuronal cell structures within the context of neuronal plasticity might be a plausible pathogenetic mechanism of epilepsy as well as schizophrenia. Clinical as well as therapeutical implications of this hypothesis on the basis of scientific evidence are discussed.

Meta-analysis of initial seizure thresholds in electroconvulsive therapy

In electroconvulsive therapy (ECT), electrical dosage is determined using 'fixed-dose', 'age-based' dose, or empirical titration methods. Estimation of initial seizure threshold (IST) has been claimed to be imperative for suprathreshold dosing. This systematic review aimed to determine common levels of IST, to define cut-off values for high IST, and to summarize reported IST associated factors. Medline and PsycINFO were searched from 1966 to January 2008 and relevant references were cross-checked. Subject headings including ECT, seizure threshold, dosage, and dosing were used. All articles reporting on levels of IST and/or associated factors were included. Of 395 potentially relevant reports, 46 studies on 70 samples concerning 3,023 patients were selected. Nine samples (n = 306 patients) without available standard deviation and four samples (n = 275 patients) treated with mixed electrode placement were excluded. Meta-analysis was done on 30 unilaterally treated samples (n = 1,326 patients) and 27 bilaterally treated samples (n = 1,116 patients). In unilateral ECT, weighted mean of IST was 68.2 milliCoulombs (mC; 95% CI 63.2-73.3 mC), and in bilateral ECT 111.6 mC (95% CI 103.7-119.4 mC). Calculated cut-off values for high IST were 121 mC for unilateral ECT and 221 mC for bilateral ECT. According to the literature, male gender and use of bilateral electrode placement appeared to increase IST most prominently. In conclusion, calculated electrical doses for 'suprathreshold' right unilateral ECT and for 'moderate above threshold' bilateral ECT, using commonly reported IST levels, were in the same though narrower ranges as provided in 'fixed-dose' and 'half-age' based strategies, respectively.

Treatment of Catatonic Stupor with Combination of Modified Electroconvulsive Treatment and Olanzapine

This case report is about the combined use of modified electroconvulsive treatment and an atypical antipsychotic drug, olanzapine, in the treatment of a 20-year-old man with chronic and refractory catatonic stupor. This patient, with a preexisting diagnosis of autism, posturing, nonverbal communication, and contracture of lower extremities, displaying mutism, akinesia, and an extreme level of rigidity, waxy flexibility, and posturing, was diagnosed as with catatonic stupor. After hospitalization, the disease had progressed despite the treatment with an atypical antipsychotic drug, olanzapine. Modified electroconvulsive treatment together with olanzapine caused a dramatic clinical improvement. Follow-up outpatient treatment with olanzapine improved his social functions.

The combined use of electroconvulsive therapy and antipsychotics in patients with schizophrenia

OBJECTIVES

We sought to review the literature on the use of combined antipsychotic medications and electroconvulsive therapy (ECT) for the treatment of schizophrenia, with regard to efficacy, side effects, and ECT technique.

METHODS

A computerized search of the literature published from 1980 to 2004 was conducted on Medline and PsychoInfo using the words schizophrenia, antipsychotic, neuroleptic, psychotropic, and ECT. Only studies including patients with the diagnosis of schizophrenia were included.

RESULTS

We identified 42 articles including 1371 patients. The majority of the reports consist of uncontrolled studies (n = 31), mostly with typical antipsychotics (n = 23). Results from open studies suggest that the combination of ECT and antipsychotics is a very useful and safe strategy for the treatment of refractory schizophrenia. Double-blind controlled studies (n = 8) were inconclusive. Twelve articles were on the combination of clozapine and ECT. Initial concerns about the safety of the coadministration of clozapine and ECT were not substantiated, but despite the auspicious results from several case reports and 2 open trials, this combination remains understudied. Most studies preferred the bitemporal placement (n = 28), but because of insufficient data derived from direct comparisons, no conclusion on placement superiority can be reached. One study indicates that with the bilateral placement higher electrical dosages yields faster responses in this population.

CONCLUSIONS

The body of the data provided by research is still insufficient to allow definitive conclusions on the combination of antipsychotics and ECT. However, the literature reviewed indicates that the combination is a safe and efficacious treatment strategy for patients with schizophrenia, especially those refractory to conventional treatments.

Ictogenesis: the origin of seizures in humans. A new look at an old theory

Seizure (ictal) behavior in humans has been observed and recorded since ancient times. A satisfactory solution to this vexing problem continues to elude medical science. Antiepileptic drug (AED) therapy fails to control seizures in 20% of patients with primary generalized epilepsy and 35% of patients with partial epilepsy and has many side effects, including death. This paper cites evidence from the current literature that supports a plausible hypothesis of seizure genesis that was published in 1942, but somehow escaped recognition. It presents a concept that challenges contemporary thinking and may provide the basis for a much needed paradigm shift in the understanding of the nature of seizures and an approach to their management. The theory views a seizure as a natural reflex defense response to a lethal threat to the brain. Although capable of inflicting bodily injury due to falls, drowning, etc., the seizure is not considered inherently harmful to the brain and may be associated with beneficial circulatory changes. Efforts to control and prevent seizures should be directed away from pharma-chemical suppression towards developing methods and bioactive agents that promote neuroplasticity, neurogenesis, and an optimized physiological milieu within the brain.

Initial seizure threshold of bilateral electroconvulsive therapy in Chinese

INTRODUCTION

This preliminary study examined the initial seizure threshold for bilateral electroconvulsive therapy (ECT) in Chinese and the correlates of this seizure threshold.

METHOD

Fifty-four patients underwent stimulus dose titration in a standardized protocol.

RESULTS

The mean initial seizure threshold was 117 mC (range 48-403 mC). Stepwise regression analysis showed that age, body mass index, and gender were independently related to seizure threshold and accounted for 36, 7, and 6% of its variance, respectively. Determination of a relationship between gender and seizure threshold was limited by the higher starting electrical dosage in men.

DISCUSSION

This preliminary study suggests that the seizure threshold for bilateral ECT in Chinese is comparable with that in the Western population. Our finding that body mass index is related to seizure threshold has not been reported previously. We also propose several differences between bilateral and unilateral ECT in the determinants of seizure threshold.