Trillions of cells in our body communicate with each other electromagnetically. Energy is dynamic and electromagnetic. If there is a disruption in the electromagnetic energy flow in the cells, the cell metabolism and function may be disrupted and disease may occur.
With TMS (Transcranial Magnetic Stimulation), the nervous system is stimulated externally. TMS creates a magnetic field and local small electrical currents in the cerebral cortex. The cerebral cortex acts as a secondary coil. As the magnetic current passes through the secondary coil, that is the brain, it transforms into an electrical current, stimulating neurons and their extensions. These pulse stimulations help recovery by restoring impaired cell functions.
Working with similar rules, repetitive-TMS (rTMS) also has an observable clinical improvement effect. The effect of rTMS stimulation on the cortical surface differs according to the frequency of its waves. rTMS up to 1 Hz is low-frequency and has an inhibitory (quenching) effect on the cortex, while stimulation above 5 Hz is high-frequency and has an excitatory (stimulating) effect. Depending on the disease, the inhibitory or excitatory effects of TMS are used in the treatment.
How Is Stimulation Intensity Determined?
In TMS studies, stimulus intensity is determined by cortical excitability, either the resting motor threshold (RMT) or the motor evoke potential (MEP). RMT is the minimal stimulation intensity required to achieve the appropriate motor response (twitch) in the peripheral muscle. The intensity of the stimulus is adjusted to be 120% of the RMT.
Warning Depth
Depending on the type of coil used and the intensity of the stimulus, the depth of stimulation may go 2-4 cm below the cortical surface. This means that only superficial brain structures are stimulated. Eight (8) shaped coils have a deeper effect than others.
Session duration and number
The session duration is 20-30 minutes and the number of sessions is usually 10 to 20, depending on the disease and the patient. The treatment is applied as 5-6 sessions per week in succession.
During the treatment, the patient remains awake and there is no activity limitation. A crackling sound is heard at each electromagnetic pulse during the application.
Diseases for which TMS is Effective
Neurological Diseases:
- MS (Multiple Sclerosis)
- Stroke
- Parkinson's Disease
- Migraine
- Dystonia
- Aphasia
- Alzheimer's Disease
- Epilepsy
Psychiatric Diseases:
- Major depression (unipolar)
- OCD (Obsessive Compulsive Disorder)
- Panic attack
- Anxiety
- Auditory hallucinations (schizophrenia)
- Addiction such as smoking and alcohol
- Autism spectrum disorder
- Attention deficit, Hyperactivity
Other:
- Pain
- FMS (fibromyalgia)
- Neuropathic pain
Use in Children, Elderly and Pregnancy
While there is a lot of data on the effect of TMS in adults, it is very few in children. However, studies on its application in children are increasing rapidly. TMS is used as a new, noninvasive, nonpharmacological, diagnostic, and therapeutic tool in many neurological disorders in adults. Its use in children continues to evolve. Due to the absence of cognitive side effects and few drug interactions, TMS has become a preferred treatment for the elderly. TMS also has a therapeutic effect on cognitive disorders.
It is safe and effective to use in pregnant and lactating women and has no contraindications.
It can be used in patients having heart problems.
Its effect lasts for a long time.
Risk and Side Effects
Few patients experience skull pain (35%) and local discomfort (10%) after four weeks of rTMS treatment. These side effects are temporary and disappear on their own within a few minutes or hours. Rare side effects are syncope, hearing loss, seizures, deterioration of implants such as a pacemaker, displacement, and heating of metals in the head and neck.