Individualized Low-Amplitude Seizure Therapy: Minimizing Current for Electroconvulsive Therapy and Magnetic Seizure Therapy.

Electroconvulsive therapy (ECT) at conventional current amplitudes (800-900 mA) is highly effective but carries the risk of cognitive side effects. Lowering and individualizing the current amplitude may reduce side effects by virtue of a less intense and more focal electric field exposure in the brain, but this aspect of ECT dosing is largely unexplored. Magnetic seizure therapy (MST) induces a weaker and more focal electric field than ECT; however, the pulse amplitude is not individualized and the minimum amplitude required to induce a seizure is unknown. We titrated the amplitude of long stimulus trains (500 pulses) as a means of determining the minimum current amplitude required to induce a seizure with ECT (bilateral, right unilateral, bifrontal, and frontomedial electrode placements) and MST (round coil on vertex) in nonhuman primates. Furthermore, we investigated a novel method of predicting this amplitude-titrated seizure threshold (ST) by a non-convulsive measurement of motor threshold (MT) using single pulses delivered through the ECT electrodes or MST coil. Average STs were substantially lower than conventional pulse amplitudes (112-174 mA for ECT and 37.4% of maximum device amplitude for MST). ST was more variable in ECT than in MST. MT explained 63% of the ST variance and is hence the strongest known predictor of ST. These results indicate that seizures can be induced with less intense electric fields than conventional ECT that may be safer; efficacy and side effects should be evaluated in clinical studies. MT measurement could be a faster and safer alternative to empirical ST titration for ECT and MST.

Ultrabrief (0.3 ms) or brief (0.5 ms) pulses for right unilateral electroconvulsive therapy: is there a difference in seizure thresholds?

OBJECTIVES: To compare the minimum charge to elicit a seizure using 2 different pulse widths, the brief pulse (0.5 milliseconds [ms]) and the ultrabrief pulse (0.3 ms). METHODS: We compared retrospectively the last 30 patients in our ECT unit whose seizure thresholds were titrated using a pulse width of 0.5 ms to the last 30 patients whose seizure thresholds were titrated using a pulse width of 0.3 ms. The former were regular clinical patients, and the latter were participating in a clinical trial on the use of ultrabrief pulse treatment. All titrations were performed with right unilateral electrode positioning. Most patients continued to use psychotropic medications. RESULTS: Initial seizure threshold (as measured in millicoulombs [mC]) for the brief pulse group (0.5 ms) was 16 (n = 1); 32 (n = 21), and 64 (n = 8); whereas for the ultrabrief pulse group (0.3 ms), it was 9.2 (n = 3), 38.4 (n = 21), 19.2 (n = 3), 76.8 (n = 2), and 307.2 (n = 1). Excluding the outlier, there was no statistical difference between mean seizure thresholds. CONCLUSIONS: If we exclude the outlier from the ultrabrief group (seizure threshold [ST], 307 mC), we can observe that most of the patients in both groups had an ST between 30 and 40 mC. No patient in the brief pulse group showed a lower ST than 16 mC, probably because this was the first step of titration for this group. The data suggest that the difference between 0.3 and 0.5 ms may not be big, although randomized prospective studies with a more precise and similar steps used for titration are needed. Clinical efficacy was not compared in the present study.

Somatic treatments for mood disorders.

Somatic treatments for mood disorders represent a class of interventions available either as a stand-alone option, or in combination with psychopharmacology and/or psychotherapy. Here, we review the currently available techniques, including those already in clinical use and those still under research. Techniques are grouped into the following categories: (1) seizure therapies, including electroconvulsive therapy and magnetic seizure therapy, (2) noninvasive techniques, including repetitive transcranial magnetic stimulation, transcranial direct current stimulation, and cranial electric stimulation, (3) surgical approaches, including vagus nerve stimulation, epidural electrical stimulation, and deep brain stimulation, and (4) technologies on the horizon. Additionally, we discuss novel approaches to the optimization of each treatment, and new techniques that are under active investigation.

Electroconvulsive therapy stimulus parameters: rethinking dosage.

In this article, we review the parameters that define the electroconvulsive therapy (ECT) electrical stimulus and discuss their biophysical roles. We also present the summary metrics of charge and energy that are conventionally used to describe the dose of ECT and the rules commonly deployed to individualize the dose for each patient. We then highlight the limitations of these summary metrics and dosing rules in that they do not adequately capture the roles of the distinct stimulus parameters. Specifically, there is strong theoretical and empirical evidence that stimulus parameters (pulse amplitude, shape, and width, and train frequency, directionality, polarity, and duration) exert unique neurobiological effects that are important for understanding ECT outcomes. Consideration of the distinct stimulus parameters, in conjunction with electrode placement, is central to further optimization of ECT dosing paradigms to improve the risk-benefit ratio. Indeed, manipulation of specific parameters, such as reduction of pulse width and increase in number of pulses, has already resulted in dramatic reduction of adverse effects, while maintaining efficacy. Furthermore, the manipulation of other parameters, such as current amplitude, which are commonly held at fixed, high values, might be productively examined as additional means of targeting and individualizing the stimulus, potentially reducing adverse effects. We recommend that ECT dose be defined using all stimulus parameters rather than a summary metric. All stimulus parameters should be noted in treatment records and published reports. To enable research on optimization of dosing paradigms, we suggest that ECT devices provide capabilities to adjust and display all stimulus parameters.

Recovery after ECT: comparison of propofol, etomidate and thiopental / Recuperação pós-eletroconvulsoterapia: comparação entre propofol, etomidato e tiopental

OBJECTIVES: To compare post anesthetic time for patient recovery after electroconvulsive therapy, as measured by the post anesthetic Recovery Score of Aldrete and Kroulik, using three different types of hypnotic drugs (propofol, etomidate and thiopental). METHOD: Thirty patients were randomized to receive one of the three drugs (n = 10 in each group), during a course of electroconvulsive therapy treatment. Patients and raters were blinded to which drug was received. Main treatment characteristics were recorded (as total electric charge received seizure threshold, number of treatments, and the mean time for recovery) along the whole treatment. RESULTS: Thiopental and propofol were associated with a significance increase in charge needed to induce a seizure (p < 0.0001) when compared to etomidate, as well as a significant decrease of time for recovery (p = 0.042). CONCLUSIONS: These findings suggest that, although there seems to be no difference in the clinical outcome across these three drugs, propofol offers the best recovery profile. However, it makes a higher mean electric charge necessary.

OBJETIVOS: Comparar o tempo de recuperação dos pacientes após eletroconvulsoterapia avaliada com a escala de recuperação pós-anestésica de Aldrete e Kroulik, utilizando três tipos de medicações anestésicas (propofol, etomidato and tiopental). MÉTODO: Trinta pacientes foram randomizados para receber uma das medicações (n = 10 em cada grupo) durante uma série de tratamentos com eletroconvulsoterapia. Os pacientes e o examinador ficaram cegos para o tipo de anestésico utilizado. As principais características do tratamento foram avaliadas (como carga total de eletricidade recebida, limiar convulsivo, número de sessões e o tempo médio para recuperação) ao longo de toda a série de tratamentos. RESULTADOS: Tiopental e propofol se associaram a um aumento significativo na carga elétrica total utilizada (p < 0,0001) quando comparados com etomidato, bem como uma diminuição significativa no tempo de recuperação pós-anestésica (p = 0,042). CONCLUSÕES: Estes achados sugerem que, apesar de não haver diferença na evolução clínica entre os três grupos estudados, a droga propofol oferece o melhor perfil de recuperação apesar de requerer uma carga elétrica média maior.

Recovery after ECT: comparison of propofol, etomidate and thiopental.

OBJECTIVES: To compare post anesthetic time for patient recovery after electroconvulsive therapy, as measured by the post anesthetic Recovery Score of Aldrete and Kroulik, using three different types of hypnotic drugs (propofol, etomidate and thiopental). METHOD: Thirty patients were randomized to receive one of the three drugs (n = 10 in each group), during a course of electroconvulsive therapy treatment. Patients and raters were blinded to which drug was received. Main treatment characteristics were recorded (as total electric charge received seizure threshold, number of treatments, and the mean time for recovery) along the whole treatment. RESULTS: Thiopental and propofol were associated with a significance increase in charge needed to induce a seizure (p < 0.0001) when compared to etomidate, as well as a significant decrease of time for recovery (p = 0.042). CONCLUSIONS: These findings suggest that, although there seems to be no difference in the clinical outcome across these three drugs, propofol offers the best recovery profile. However, it makes a higher mean electric charge necessary.

Effects of repetitive transcranial magnetic stimulation on auditory hallucinations refractory to clozapine.

OBJECTIVE: To study the therapeutic effects on auditory hallucinations refractory to clozapine with 1-Hz repetitive transcranial magnetic stimulation (rTMS) applied on the left temporoparietal cortex. METHOD: Eleven patients with schizophrenia (DSM-IV) experiencing auditory hallucinations (unresponsive to clozapine) were randomly assigned to receive either active of rTMS (N = 6) or sham stimulation (N = 5) (with concomitant use of clozapine) using a double-masked, sham-controlled, parallel design. A total of 160 minutes of rTMS (9600 pulses) was administered over 10 days at 90% motor threshold. The study was conducted from January 2003 to December 2005. RESULTS: There was a reduction in hallucination scores in both groups, which persisted during follow-up in the active group for the items reality (p = .0493) and attentional salience (p = .0360). Both groups showed similar patterns of symptomatic changes on subscales (negative symptoms, general psychopathology) and total scores of the Positive and Negative Syndrome Scale, Clinical Global Impressions scale, and Visual Analog Scale. CONCLUSION: Active rTMS in association with clozapine can be administered safely to treat auditory hallucinations, although its clinical utility is still questionable. No significant clinical effects were observed in the sample studied, possibly because it was too small and/or due to its high refractoriness.

Accidental seizure with repetitive transcranial magnetic stimulation.

Accidental induction of convulsions by using repetitive transcranial magnetic stimulation (rTMS) has been reported to have occurred in 6 normal voluntary subjects, in 1 patient with depression and in 1 patient who had temporal lobe epilepsy, with secondary generalization. In addition, 3 other cases have been published relating its use with seizure induction and in 1 case, using 1-Hz stimulation. In this paper, we report a patient who was participating in a protocol for the use of rTMS in chronic pain, with stimulation in the motor cortex, who developed a generalized seizure in the fifth application. Intertrain interval was within safety guidelines, but the combination of 10 Hz for 10 seconds was excessive and must be considered the main cause for the episode. No further complication has been noted after she was withdrawn from the study protocol.

Information for assistants of repeated transcranial magnetic stimulation.

Repeated transcranial magnetic stimulation (rTMS) is an exciting new technology being used in psychiatric and neurological research in many centres around the world. rTMS has been accepted as a routine treatment of depression in Canada and Israel. To this point, it has been exclusively conducted by medical officers. As knowledge and experience grows, it is probable that professionals with other backgrounds will have the opportunity to play a role. The aim of this paper is to provide information that will be valuable to assistants. Electromagnetic principles are harnessed to deliver electric currents to localized regions of the cortex. rTMS does not involve anaesthesia or seizure. Side-effects appear to be few. Much remains uncertain, however, even including the most appropriate treatment parameters.