Introduction to Nonconvulsive Brain Stimulation: Focus on Transcranial Magnetic Stimulation

2015 ◽  
pp. 149-164
Author(s):  
Masashi Hamada ◽  
John C. Rothwell
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Brain Stimulation ◽  
Magnetic Stimulation

scholarly journals Focal brain stimulation with repetitive transcranial magnetic stimulation (rTMS): implications for the neural circuitry of depression

2002 ◽  
Vol 33 (1) ◽  
pp. 7-13 ◽  
Author(s):  
SARAH H. LISANBY
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Side Effects ◽  
Major Depression ◽  
Brain Stimulation ◽  
Magnetic Stimulation ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Severe Depression ◽  
Medical Procedure ◽  
Variable Degree ◽  
Cognitive Side Effects

BRAIN STIMULATION IN THE TREATMENT OF MAJOR DEPRESSIONRepetitive transcranial magnetic stimulation (rTMS) is an experimental medical procedure that is currently under investigation for its potential therapeutic value in major depression and other psychiatric and neurological disorders (Wassermann & Lisanby, 2001). The idea of using brain stimulation to treat depression dates back to the origins of ECT, and includes more recently developed techniques such as deep brain stimulation and vagus nerve stimulation. The value of brain stimulation in psychiatry is still most clearly seen in the, as yet, unparalleled efficacy of ECT in treating severe depression (American Psychiatric Association, 2001). While ECT is the most effective and most rapidly acting treatment for depression, it also causes a variable degree of undesirable cognitive side effects that limit its clinical utility and prevent many patients who could benefit from receiving this often life-saving treatment (McElhiney et al. 1995; Lisanby et al. 2000b). The search for an effective somatic treatment for medication resistant depression with fewer cognitive side effects than ECT has motivated much of the work with rTMS in psychiatry.

scholarly journals Multi-locus transcranial magnetic stimulation system for electronically targeted brain stimulation

2021 ◽  
Author(s):  
Jaakko O. Nieminen ◽  
Heikki Sinisalo ◽  
Victor H. Souza ◽  
Mikko Malmi ◽  
Mikhail Yuryev ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Brain Stimulation ◽  
Magnetic Stimulation ◽  
Motor Evoked Potential ◽  
Optimization Method ◽  
Cortical Region ◽  
Precentral Gyrus ◽  
Motor Mapping ◽  
Field Programmable ◽  
Contralateral Hand

Background: Transcranial magnetic stimulation (TMS) allows non-invasive stimulation of the cortex. In multi-locus TMS (mTMS), the stimulating electric field (E-field) is controlled electronically without coil movement by adjusting currents in the coils of a transducer. Objective: To develop an mTMS system that allows adjusting the location and orientation of the E-field maximum within a cortical region. Methods: We designed and manufactured a planar 5-coil mTMS transducer to allow controlling the maximum of the induced E-field within a cortical region approximately 30 mm in diameter. We developed electronics with a design consisting of independently controlled H-bridge circuits to drive up to six TMS coils. To control the hardware, we programmed software that runs on a field-programmable gate array and a computer. To induce the desired E-field in the cortex, we developed an optimization method to calculate the currents needed in the coils. We characterized the mTMS system and conducted a proof-of-concept motor-mapping experiment on a healthy volunteer. In the motor mapping, we kept the transducer placement fixed while electronically shifting the E-field maximum on the precentral gyrus and measuring electromyography from the contralateral hand. Results: The transducer consists of an oval coil, two figure-of-eight coils, and two four-leaf-clover coils stacked on top of each other. The technical characterization indicated that the mTMS system performs as designed. The measured motor evoked potential amplitudes varied consistently as a function of the location of the E-field maximum. Conclusion: The developed mTMS system enables electronically targeted brain stimulation within a cortical region.

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