Magnetic Seizure Theraphy (MST):
Magnetic Seizure Theraphy (MST) is a novel method of convulsive therapy using rapidly alternating strong magnetic fields. MST offers great control of intracerebral current intensity. MST is an alternative to Electro Convulsive Therapy (ECT). A recent study done with 10 patients concludes that It seems that MST is a promising anti depressive treatment without any side effect. In the research projects done so far the side effects which are often seen in ECT: Headache, nausea, dizziness or cognitive disorder have not been observed and a faster recovery of orientation compared to ECT patient has been reported.
The first use of therapeutic magnetic seizure induction in a psychiatric patient took place in Bern, Switzerland, in May 2000. Since then a number of patients have gone through controlled studies. Although promissing, all researchers points out the need for further investigation in the area, to evaluate the anti depressive effect of more patients to make MST an established tool for anti depressive therapy.
The most efficient tool for these investigations is now available to a wider public: The MagPro MST.
Method:
In the research projects done so far, the treatment procedure is very simular to a regular ECT treatment.
- Seizures were elicited under general anesthesia (propofol).
- The patient was oxygenated during anesthesia with 100 % O2.
- The motor activity of the right foot is assessed visually in order to track the duration of motor seizures, and bilateral frontal-mastoid EEG recordings is obtained by an EEG device.
- Treatments are delivered with a magnetic stimulator (MagVenture MagPro MST) using the highly efficient “Twin Coil”.
- Stimulation repetition rate 100 pps. Number of pulses: 100-600 (duration 1-6s)
- Stimulation amplitude 100%.
- During the stimulations, the center of the coil is placed at the vertex.
- The peak magnetic field induced above 2 Tesla at the coil surface.
- Two MST sessions per week.
The procedure and protocol used so far can probably be further optimized.
Equipment
MagVenture has developed the new magnetic stimulator for Magnetic Seizure Therapy (MST): The powerful high speed magnetic stimulator is the first commercial available stimulator which can always induce the seizures necessary for MST. So far the main obstacle for MST has been lack of sufficient power to create a seizure with certainty for every session. The new MagPro MST now makes research in this field more straight forward.
A number of MagPro MST devices are currently in use worldwide for ongoing research projects.
The first published trials show that MagPro MST device is able to induce seizures in the patients which are necessary to treat severe depression.
The MagPro MST has a pulse intensity around 200% compared to the standard MagPro. Remarkably when noticing the MagPro has the most powerful pulses in the market place. The repetition rate of the MagPro MST goes as high as to 250 pps – enabling all sorts of new research !
To learn more about this new product, please contact MagVenture directly or through our global sales network.
Stimulation Coil - the MagVenture Twin Coil
To elicit a seizure an extraordinary magnetic coil to utilize the high stimulator output is required.
We therefore developed the unique Twin Coil for use with the MagPro MST. The MagVenture Twin Coil consists of two individual coneshaped coils.
The position of each coil is easily adjustable to minimize the distance from the coil to the scalp and to ensure a deep penetration of the magnetic field.
Scientific background:
Cognitive side effects limit the clinical use of electroconvulsive therapy (ECT), currently the most effective and rapidly acting treatment for severe depression. Studies suggest that prefrontal cortical involvement may be important to preserve the efficacy of ECT, while seizure spread to the medial temporal lobes may be related to its amnesic side effects. However, the scalp and skull shunt the flow of electricity, limiting control over current spread with ECT. The Magnetic Fields used by MST enter the brain almost unimpeded, allowing enhanced control over the site of stimulation and seizure initiation compared to ECT. Magnetic Seizure Therapy (MST) involves the induction of a seizure under general anesthesia using high-frequency repetitive Transcranial Magnetic Stimulation. MST was developed to reduce the cognitive side effect burden of convulsive therapy through focal seizure induction in the prefrontal cortex. Preliminary results indicate that seizures induced with MST are more focal, result in less involvement of hippocampal and deep brain structures, and have a better acute side effect profile than those induced with ECT.
Magnetic seizure Therapy gives the researcher the possibility to stimulate the brain in a more focal fashion than is possible with Electro Convulsive Therapy.
Study Papers on MST:
Quick recovery of orientation after 100 Hz magnetic seizure therapy (MST) for major depressive disorder
Magnetic Seizure Therapy of Treatment Resistant Depression in a patient with Bipolar Disorder
Electric field strength and focality in electroconvulsive therapy and magnetic seizure therapy: a finite element simulation study
Selected references:
1: Marcolin MA, Padberg F (eds): Transcranial Brain Stimulation for Treatment of Psychiatric Disorders. Adv Biol Psychiatr. Basel, Karger, 2007, vol 23, pp 155-171
2: Hoy KE, Fitzgerald PB: Introducing magnetic seizure therapy: A novel therapy for treatment resistant depression. Australian and New Zealand Journal of Psychiatry 2010; 44:591-598
3: LisanbySH, SchlaepferTE, Fisch HU, et al. Magnetic seizure therapy of major depression. Arch Gen Psychiatry. 2001 Mar;58(3):303-305.
4: Krystal AD, West M, Prado R, et al. EEG effects of ECT: implications for rTMS. Depress Anxiety. 2000;12(3):157-165.
5: KoselM, Frick C, LisanbySH, et al. Magnetic seizure therapy improves mood in refractory major depression. Neuropsychopharmacology. 2003 Nov;28(11):2045-2048.
6: George Kirov, Klaus P. Ebmeier, Allan I F Scott, Maria Atkins, Najeeb Khalid, Lucy Carrick, Andrew Stanfield, Ronan E. O'Carroll, Mustafa M. Husain, and Sarah H. Lisanby. Br J Psychiatry. 2008 August; 193(2): 152–155.Quick recovery of orientation after 100 Hz magnetic seizure therapy (MST) for major depressive disorder
