The first edition of this blog series on Brain Stimulation Therapies focused on ECT and VNS. In this blog, the rest of the therapies, namely, Repetitive transcranial magnetic stimulation (RTMS), Magnetic seizure therapy (MST) and Deep brain stimulation (DBS) will be discussed.
Repetitive Transcranial Magnetic Stimulation
Repetitive transcranial magnetic stimulation (rTMS) uses a magnet to activate the brain.In 2008, rTMS was approved for use as a treatment for major depression for patients who do not respond to antidepressant medication. rTMS has also been studied as a treatment for psychosis, anxiety and other disorders.
How it works
A typical rTMS session lasts 30 to 60 minutes and does not require anesthesia.
An electromagnetic coil is held against the forehead near an area of the brain that is thought to be involved in mood regulation.
Small electromagnetic pulses are administered. The magnetic pulses easily pass through the skull and cause small electrical currents that stimulate nerve cells in the targeted brain region.
Generally, the person feels a slight knocking or tapping on the head as the pulses are administered.
Discomfort at the site on the head where the magnet is placed.
The muscles of the scalp, jaw or face may contract or tingle during the procedure.
Mild headaches or brief lightheadedness.
rTMS can be targeted to a specific site in the brain. Scientists believe that focusing on a specific site in the brain reduces the chance for the types of side effects associated with ECT however, they do not yet know if rTMS works best when given as a single treatment or combined with medication and/or psychotherapy.
Magnetic Seizure Therapy
Magnetic seizure therapy is a mixture of both Electroconvulsive therapy (ECT) and Repetitive transcranial magnetic stimulation (rTMS). Like rTMS, MST uses magnetic pulses instead of electricity to stimulate a precise target in the brain and like ECT, MST aims to induce a seizure.
How it works
The pulses are given at a higher frequency than that used in rTMS.
Patient must be anesthetized and given a muscle relaxant to prevent movement.
The goal of MST is to retain the effectiveness of ECT while reducing its cognitive side effects.
fewer memory side effects
allows for a shorter recovery time than ECT
side effects that can be caused by anesthesia exposure and the induction of a seizure.
Deep Brain Stimulation
Deep brain stimulation (DBS) is used as a treatment to reduce tremor, stiffness, walking problems and uncontrollable movements. DBS has been studied as a treatment for depression or obsessive compulsive disorder (OCD).
How it works
DBS requires brain surgery. The head is shaved and attached with screws to a sturdy frame that prevents the head from moving during the surgery.
Patients are awake during the procedure to provide the surgeon with feedback, but are sedated with local anesthesia.
A slender tube is sent down the brain to place electrodes on each side of a specific area of the brain.
The electrodes are then attached to wires that are run inside the body from the head down to the chest, where a pair of battery-operated generators are implanted.
electrical pulses are continuously delivered over the wires to the electrodes in the brain.
Bleeding in the brain or stroke
Disorientation or confusion
Unwanted mood changes
it is still unclear exactly how the device works to reduce depression or OCD, scientists believe that the pulses help to "reset" the area of the brain that is malfunctioning so that it works normally again.