Neuroethical Considerations Regarding Transcranial Magnetic Stimulation

Along with advances in brain technologies comes the ability to enhance the cognitive and affective states of normal people. In this essay, I examine a relatively young technology used in cognitive neuroscience called transcranial magnetic stimulation (TMS). I explain what it is, how it works and what some of its applications are. I suggest that a potential source of reservation one might have regarding brain-altering enhancement is the threat it seemingly poses to the subjective importance of mental states. I then consider the possibility of its being used as an enhancement device and question the authenticity of abilities of individuals that are enhanced by use of TMS. I conclude that judgments regarding the appropriateness of such neurocognitive enhancements should be considered on a case by case basis

O retorno da estimulação cerebral na terapêutica dos transtornos neuropsiquiátricos: o papel da estimulação magnética transcraniana na prática clínica

Estimulação magnética transcraniana (EMT) é uma nova técnica capaz de estimular o cérebro humano com algumas vantagens sobre as já existentes. A EMT é indolor, não-invasiva, simples de ser aplicada e, mais importante, é considerada de baixo risco para pesquisas em seres humanos. Essa nova ferramenta tem sido proposta para ser usada como tratamento de diversas doenças neurológicas e psiquiátricas. A EMT pode atuar modulando a excitabilidade cortical no cérebro humano. Portanto, essa técnica pode ser usada no tratamento de patologias cerebrais que cursem com alterações de excitabilidade cortical, como epilepsia, acidente vascular cerebral, distonia, doença de Parkinson, depressão e esquizofrenia. Alguns desses transtornos têm sido extensivamente estudados, tal como a depressão, porém os resultados ainda não permitem a aplicação desse método na prática clínica. Entretanto, no futuro, a EMT pode se tornar uma poderosa ferramenta na terapêutica em neuropsiquiatria. O objetivo do autor nesta revisão foi de apresentar os princípios básicos da EMT e discutir os resultados preliminares dos estudos publicados sobre o uso dessa técnica no tratamento das doenças psiquiátricas e neurológicas.Transcranial magnetic stimulation (TMS) is a new technique capable of stimulating the brain with some advantages over existing ones. TMS is painless, non-invasive, simple to apply and, more importantly, it is considered of low risk for research in human. This new tool has been proposed to be used in several neurologic and psychiatric diseases. The mechanism of TMS action might be based on the modulation of cortical brain excitability. Therefore, brain disorders with cortical excitability dysfunction such as epilepsy, stroke, distonia, Parkinson disease, depression and schizophrenia may be benefited from this method. Some of these disorders have been extensively studied during the last decade - such as depression - but the results to date are still not strong enough to prove the real clinical benefit of this technique. TMS is still experimental and more work is needed, but in the future, TMS may become a major therapeutic tool in neuropsychiatry. The objective of the authors in this article is to review the basic principles of TMS and discuss the results of published studies about the clinical applications of TMS

O retorno da estimulação cerebral na terapêutica dos transtornos neuropsiquiátricos: o papel da estimulação magnética transcraniana na prática clínica

Estimulação magnética transcraniana (EMT) é uma nova técnica capaz de estimular o cérebro humano com algumas vantagens sobre as já existentes. A EMT é indolor, não-invasiva, simples de ser aplicada e, mais importante, é considerada de baixo risco para pesquisas em seres humanos. Essa nova ferramenta tem sido proposta para ser usada como tratamento de diversas doenças neurológicas e psiquiátricas. A EMT pode atuar modulando a excitabilidade cortical no cérebro humano. Portanto, essa técnica pode ser usada no tratamento de patologias cerebrais que cursem com alterações de excitabilidade cortical, como epilepsia, acidente vascular cerebral, distonia, doença de Parkinson, depressão e esquizofrenia. Alguns desses transtornos têm sido extensivamente estudados, tal como a depressão, porém os resultados ainda não permitem a aplicação desse método na prática clínica. Entretanto, no futuro, a EMT pode se tornar uma poderosa ferramenta na terapêutica em neuropsiquiatria. O objetivo do autor nesta revisão foi de apresentar os princípios básicos da EMT e discutir os resultados preliminares dos estudos publicados sobre o uso dessa técnica no tratamento das doenças psiquiátricas e neurológicas.Transcranial magnetic stimulation (TMS) is a new technique capable of stimulating the brain with some advantages over existing ones. TMS is painless, non-invasive, simple to apply and, more importantly, it is considered of low risk for research in human. This new tool has been proposed to be used in several neurologic and psychiatric diseases. The mechanism of TMS action might be based on the modulation of cortical brain excitability. Therefore, brain disorders with cortical excitability dysfunction such as epilepsy, stroke, distonia, Parkinson disease, depression and schizophrenia may be benefited from this method. Some of these disorders have been extensively studied during the last decade - such as depression - but the results to date are still not strong enough to prove the real clinical benefit of this technique. TMS is still experimental and more work is needed, but in the future, TMS may become a major therapeutic tool in neuropsychiatry. The objective of the authors in this article is to review the basic principles of TMS and discuss the results of published studies about the clinical applications of TMS

Cervical dystonia : abnormal cerebral activation patterns related to preparation and execution of hand movement

Cervical dystonia (CD) is a movement disorder characterized by sustained involuntary muscular contractions which cause repetitive twisting movements and abnormal postures of the head. CD is primarily a brain disorder. Several studies show that CD patients have abnormal brain activity not only during movement execution but also movement preparation. An important area for movement preparation is the parietal cortex where sensory information is integrated in the movement preparation plan. In CD, this parietal cortex seems to function abnormally since extra sensory information (by touching the chin or cheek) can temporarily reduce dystonia. This thesis investigated execution and preparation of movement in CD and healthy controls by letting the subjects perform and imagine a flexion/ extension movement in a normal, non-dystonic hand. Imagination of movement activates specific brain areas which are related to preparation of movement. Both tasks showed lower parietal cortex activity in CD compared to healthy controls. Induced impairment of the parietal cortex by transcranial magnetic stimulation (TMS) in healthy controls showed specific brain activation changes that were similar to brain activation patterns in CD patients without TMS. Parietal cortex TMS in CD reduced the already low activity even further and increased activity in other brain regions. These results confirm that the parietal cortex is impaired in CD. This functional impairment seems to be compensated by other brain regions during movement in normal, non-dystonic body parts. However, the electromyography study in this thesis showed that full compensation is not reached, although visually the movement looked normal. Execution of a flexion/ extension movement of a normal, non-dystonic hand in CD patients demonstrated lower muscle strength during wrist flexion and longer muscle activation during wrist extension. Nevertheless, in CD other factors besides impaired compensation mechanisms may be in play to undermine the neck movements in CD patients in such a way that it becomes dystonic.