Repetitive Transcranial Magnetic Stimulation/ Deep Brain Stimulation

Topic 1. Repetitive Transcranial Magnetic Stimulation

Repetitive Transcranial Magnetic Stimulation (rTMS) is a noninvasive way to stimulate nerve cells in areas of the brain. rTMS therapy, a cost-effective, noninvasive, nondrug outpatient treatment administered under the supervision of a doctor. The FDA-approved treatment is administered in a device that resembles a comfortable dentist’s chair, which has a headrest and reclines. The patient remains awake during the treatment; it does not require any sedation or anesthesia. Except for the initial treatment, the sessions last about a half-hour. The typical course of therapy consists of five treatments per week for four to six weeks. With this outpatient treatment, patients can immediately return to normal activities after treatment and can even drive home.

During rTMS, an electrical current passes through a wire coil placed over the scalp. The current induces a magnetic field that produces an electrical field in the brain that then causes nerve cells to depolarize, resulting in the stimulation or disruption of brain activity.

The exact details of how TMS functions are still being explored. Researchers have investigated rTMS as an option to treat auditory hallucinations, Major Depressive Disorder (MDD), as an add-on to drug therapy, and, in particular, as an alternative to electroconvulsive therapy (ECT) for patients with treatment-resistant depression.

The advantages of rTMS over ECT for patients with severe refractory depression   are that general anesthesia  s not needed, it is an outpatient procedure, it requires less energy, the   simulation is specific and targeted, and convulsion is not required. The advantages of rTMS as an add-on treatment to drug therapy may include hastening of the clinical response when used with antidepressant drugs.

TMS is generally not painful, but can be uncomfortable insofar as a tingling or knocking sensation is produced against the scalp. Scalp muscle contractions sometimes occur during the treatment. There is a very small risk of seizure associated with TMS, but for the frequency of stimulation used in this study (one stimulation per second) the risk is significant only for patients who have a prior history of seizures. We remain concerned regarding any risk to concentration or memory, although the occurrence of concentration and memory problems in our studies has been very rare (occurring in less than 5% of participants). If we encounter such problems the trial is stopped. In those few patients where such difficulties seem to have emerged, these complaints have disappeared following the halt of the trial. No difficulties in perceiving speech have arisen from TMS in any of our studies to date.

Reading:

Croarkin, P. E., & MacMaster, F. P. (2019). Transcranial Magnetic Stimulation for Adolescent Depression. Child and adolescent psychiatric clinics of North America, 28(1), 33–43. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6221455/

Aleman, A. (2013) Use of Repetitive Transcranial Magnetic Stimulation for Treatment in Psychiatry. Clinical Psychopharmacology and Neuroscience. 11(2) Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3766755/

Wexler A. (2017). The Social Context of "Do-It-Yourself" Brain Stimulation: Neurohackers, Biohackers, and Lifehackers. Frontiers in human neuroscience, 11, 224. https://doi.org/10.3389/fnhum.2017.00224

Topic 2. Deep Brain Stimulation

Deep brain stimulation (DBS) is a surgical treatment in which a device called a neurostimulator delivers tiny electrical signals to the areas of the brain that control movement.

The DBS system consists of three parts:

· A thin, insulated wire called a lead, or electrode that is placed into the brain

· The neurostimulator, similar to a heart pacemaker, which is usually placed under the skin near the collarbone, but may be placed elsewhere in the body

· Another thin, insulated wire called an extension that connects the lead to the neurostimulator

DBS requires surgery to correctly place each part of the neurostimulator system. DBS in adults usually involves two separate surgeries.

Stage 1 is usually performed under local anesthesia, meaning the patient is awake but pain-free. (If the procedure is done in children, general anesthesia is given.)

· The patient's head is placed in a special frame using screws to keep it still during the procedure. Numbing medicine is applied where the screws contact the scalp. Sometimes, the procedure is done in the MRI and a frame is not used around your head.

· Numbing medicine is also applied to the scalp at the site where the surgeon drills a small opening in the skull and places the lead into a specific area of the brain.

· If both sides of the brain are being treated, the surgeon will make an opening on both sides of the skull, and two leads will be inserted.

· The surgeon may need to send small electrical impulses over the lead to make sure it is connected to the area of the brain responsible for the patient’s symptoms. Different neurological tests may be done.

Stage 2 is done under general anesthesia, meaning the patient is asleep and pain-free. The timing of this stage of surgery depends on where in the brain the stimulator will be placed.

· The surgeon makes a small opening, usually just below the collarbone and implants the neurostimulator. (Sometimes it is placed under the skin in the lower chest or belly area.)

· The surgeon makes another small opening behind the ear and passes the extension wire under the skin of the head, neck, and shoulder.

· The extension wire connects the lead to the neurostimulator.

· The skin is closed, and the device and wires cannot be seen outside the body.

Once connected, electrical pulses travel from the neurostimulator, along the extension wire, to the lead, and into the brain. These tiny pulses interfere with and block the electrical signals that cause tremors and movement disorder symptoms, such as those that occur with Parkinson’s disease, essential tremor, or obsessive-compulsive disorder.

Why is DBS Procedure is Performed?

This surgery may be an option for patients with very severe Parkinson's disease symptoms that cannot be controlled by medications. The surgery does not cure Parkinson’s disease, but can help make reduce the severity of symptoms such as:

· Tremors

· Rigidity

· Stiffness

· Slow movements

· Walking problems

DBS may also be used to treat the following conditions:

· Essential tremor

· Dystonia

· Arm tremors related to multiple sclerosis

· Tourette syndrome (in rare cases)

· Obsessive-compulsive disorder

· Major drepression that does not respond well to medicines

· Epilepsy

Risks

DBS is considered to safe and effective when performed in properly selected patients. Risks associated with deep brain stimulation placement may include:

· Allergic reaction to the DBS parts

· Difficulty concentrating

· Dizziness

· Infection

· Leakage of cerebrospinal fluid, which can lead to headache or meningitis

· Loss of balance

· Reduced coordination

· Shock-like sensations

· Slight loss of movement

· Speech or vision problems

· Temporary pain or swelling at the site where the device was implanted

· Temporary tingling in the face, arms, or legs

Problems may also occur if parts of the DBS system break or move. For example, this may include:

· Breakage of the device, lead, or wires, which can lead to another surgery to replace the broken part

· Failure of the battery, which would cause the device to stop working properly (the battery normally lasts 3 to 5 years)

· The wire that connects the stimulator to the lead in the brain breaks through the skin (this usually only occurs in very thin people)

· The part of the device places in the brain may break off or move to a different place in the brain (this is rare)

Possible risks of any brain surgery are:

· Blood clot or bleeding in the brain

· Brain swelling

· Coma

· Confusion, usually lasting only for days or weeks at most

· Infection in the brain, in the wound, or in the skull

· Problems with speech, memory, muscle weakness, balance, vision, coordination, and other functions, which may be short-term or permanent

· Seizures

· Stroke

· Risks of general anesthesia are:

· Reactions to medications

· Problems breathing

Before the Procedure

The patient will have a complete physical exam.

The patient's doctor will order many laboratory and imaging tests, including a CT or MRI scan. These imaging tests are done to help the surgeon pinpoint exact what part of the brain is responsible for the tremor and movement disorder symptoms. The images will be used to help the surgeon place the lead in the brain during surgery.

The patient may have to see more than one specialist (neurologist, neurosurgeon, psychologist, etc.) to make sure that the procedure is right for him/her and has the best chances of success.

Before surgery, the patient should tell the doctor or nurse:

· If one could be pregnant

· What drugs he/she are taking, including medicines, herbs or supplements, and vitamins you bought over-the-counter without a prescription

· If one has been drinking a lot of alcohol

During the days before the surgery:

· The patient's health care provider may tell the patient to stop taking drugs that make it hard for the blood to clot, such as warfarin (Coumadin), aspirin, ibuprofen, naproxen, and other nonsteroidal anti-inflammatory drugs (NSAIDs) .

· If the patient is taking other medications, he/she should ask the doctor if it is okay to take them on the day of or in the days before the surgery.

· Always try to stop smoking. Ask the doctor for help.

· The doctor or nurse may ask the patient to wash his/her hair with a special shampoo the night before surgery.

On the day of the surgery:

· The patient will usually be told not to drink or eat anything for 8 to 12 hours before the surgery.

· Take the drugs the doctor told you to take with a small sip of water.

· Arrive at the hospital at the time specified by the doctor or nurse.

After the procedure

Most people who have DBS are in the hospital for about 3 days. The doctor may prescribe antibiotics to prevent a possibly infection.

The patient will return to your doctor’s office a few weeks after surgery so that the stimulator can be turned on, and the amount of stimulation can be adjusted, if necessary. This can easily be done, without further surgery. It is often referred to as “programming.”

The patient is instructed to notify the doctor if he/she develops any of the following after DBS surgery:

· Fever

· Headache

· Itching or hives

· Muscle weakness

· Nausea and vomiting

· Numbness or tingling on one side of the body

· Pain

· Redness, swelling, or irritation at any of the surgery sites

· Trouble speaking

· Vision problems

Outlook (Prognosis)

DBS is generally well tolerated and does not damage nerve cells like other surgical treatments for Parkinson’s disease. Many patients report significant improvement in their symptoms after having this treatment. However, most of them still need to take medication, although at lower doses, which improves their quality of life.

This surgery, and surgery in general, is riskier in people over age 70 and those with health conditions such as high blood pressure and diseases that affect blood vessels in the brain. You and your doctor should carefully weigh the benefits of this surgery against the potential risks.

The DBS procedure can be reversed, if needed.

Alternative Names

Globus pallidus deep brain stimulation; Subthalamic deep brain stimulation; Thalamic deep brain stimulation; DBS

Reading:

Graat, I., Figee, M., & Denys, D. (2017). The application of deep brain stimulation in the treatment of psychiatric disorders. International review of psychiatry (Abingdon, England), 29(2), 178–190. https://www.tandfonline.com/doi/full/10.1080/09540261.2017.1282439

References

Bartsch T, Paemeleire K, Goadsby PJ. Neurostimulation approaches to primary headache disorders. Curr Opin Neurol. 2009 Jun;22(3):262-8.

Burns B, Watkins L, Goadsby PJ. Treatment of medically intractable cluster headache by occipital nerve stimulation: long-term follow-up of eight patients. Lancet. 2007 Mar 31;369(9567):1099-106.

Weaver FM, Follett K, Stern M, et al. Bilateral deep brain stimulation vs best medical therapy for patients with advanced Parkinson disease: a randomized controlled trial. JAMA. 2009;301(1):63-73.

NINDS Deep Brain Stimulation for Parkinson's Disease Information Page National Institute of neurological disorders and stroke Last updated December 18, 2009 Last updated December 18, 2009 Accessed February 6, 2010

Patterson JT, Hanbali F, Franklin RL, Nauta HJW. Neurosurgey. In: Townsend CM, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 72.

Black KJ. Patient page. Deep brain stimulation for Tourette syndrome. Neurology. 2009 Oct 27;73(17):e87-90.

Holtzheimer PE, Mayberg HS. Deep brain stimulatin for psychiatric disorders. Annual Review of Neuroscience. 2011;34:289-307.