Uses of Deep TMS

I had previously mentioned the new deep transcranial magnetic stimulation (deep TMS) created by the company brainsway that is currently undergoing several clinical trials. This specific technology can excite or inhibit more areas of the brain than conventional TMS. Regular TMS is basically limited the brain's outer layer, the neocortex, and can only reach about 1 to 2 centimeters into the brain. So it is limited in its ability to affect many brain areas. The new deep tms can stimulate inner brain areas without inducing unbearable magnetic fields cortically. This device currently has almost magical properties and it is somewhat difficult to distinguish company hype from real clinical benefit. I'm not sure at this point how selective this targeting technique is. I think it will be fairly difficult to selectively turn on or off specific brain areas without having unintentional effects. However this technology is certainly promising for a number of brain disorders.

Researchers are testing the device to treat obesity. They are targeting the hypothalamus which is a deeper brain structure. The hypothalamus secretes various hormones and is involved in the metabolic processes of the body. This area is involved with weight gain, so by stimulating this area researchers may allow a person to shed the pounds without actually having to do anything. Researchers have already performed trials using deep brain stimulation devices to target this area. Apparently they have found that stimulation of this area has an impact on animal weight gain in tests. So it should be interesting if they can get a weight loss response by targeting this area.

They are also testing the deep TMS on alzhiemer's patients. Alzheimer's patients undergo a fairly precipitous cognitive decline over the course of the disease and current treatments leave a lot to be desired. Researchers have found that by using deep TMS, they were able to positively improve a person's spatial memory. For alzhiemer's patients, they are targeting an area of the brain called the dorsal septal region that has cholinergic nuclei. Presumably they are targeting the cholinergic nuclei to increase the neurotransmitter acetylcholine that is often deficient in patient's with alzhiemer's. I'm doubtful that the deep tms will have a huge impact on alzhiemer's patients. There are already drugs that increase acetylcholine and their efficacy is fairly limited. It seems improbable that the deep TMS will have much impact on the alzhiemer's disease process. However it may be able to improve specific symptoms of alzhiemer's temporarily. They have already tested it on single alzhiemers patients and claimed that it improved visual memory, executive functions and orientation. I think any improvements will likely be fairly limited in scope.

The researchers are also testing it to reduce auditory hallucinations in people with schizophrenia. Approximately 5o to 70 percent of schizophrenic patients hear voices that aren't really there. This can be extremely distressing and frightening as the voices can often be mean or disparaging to the person. The voices can range from commentary about the person life to verbal commands. The left temporoparietal cortex has been shown to be activated during auditory hallucinations. A recent meta-analysis has shown that using conventional TMS at a frequency of 1-Hz to this area is superior to sham in treating auditory hallucinations. Several deeper brain areas located in thalamic, limbic and paralimbic regions have been shown to be activated when a person is experiencing auditory hallucinations. So decreasing activity in these areas may lead to a reduction in hearing voices. Presumably they are going to target several of these other areas that have now become available for stimulation. I think the evidence for conventional TMS on auditory hallucinations is already pretty sound, so this new technology may allow an even greater improvement in these symptoms.

Researchers are testing this device for depression and negative schizophrenia (both have similar symptoms). It appears that they are targeting deeper prefrontal areas. The left dorsolateral prefrontal cortex in the front part of the brain has been stimulated with conventional TMS. Researchers have found this to have a good mood elevating effect and it also leads to a reduction in negative schizophrenic symptoms. With the new deeper TMS they may be able to target deeper into this specific area of the brain and get a better antidepressant response by stimulating more neurons that were previously out of reach. Stimulating this area may improve a person's interest, motivation, mood and attention. I am under the impression that they are also going to directly target the brain's reward system as well by stimulating areas like the nucleus accumbens. This will be done to improve the ability to experience pleasure in drug addicts, depressed patients and schizophrenics. Overall this technology sounds almost too good to be true. Imagine having this treatment performed on you to make you lose weight, allow you to quit your addictions and improve your mood and pleasure. All of this would be done non-invasively without the need for brain surgery. I will certainly be keeping an eye out for future developments of this new way to manipulate brain functioning.