Neuromodulation, Surgery For Psychiatric Disorders

Despite the advances in pharmacotherapy in the treatment of some psychiatric disorders like schizophrenia, anxiety disorders, obsessive-compulsive disorder, and depression, a significant number of patients become refractory and will not respond to pharmacologic treatments[1]. Clinicians are beginning to reconsider neuromodulation surgery as a last resort for the treatment of these patients. Neurosurgical interventions aimed at treating psychiatric disorders are grouped into two categories: destructive (ablative psychosurgery) or selective stimulation (neuromodulation psychosurgery)[1]. Neuromodulation surgery involves implanting a device in the brain that modulates the neural networks within the brain. The use of surgery for the treating of psychiatric diseases is not a new concept. Historically, the concept of psychosurgery always raised general skepticism and stigma because of the way that it was erroneously used in the past despite the high rate of complications and mortalities with little improvement in patients' lives[2][1][3]. A brief history about psychosurgery is essential to understand the reason behind the skepticism toward it. In the 1930s, a Portuguese neurologist by the name Egas Moniz first introduced a surgical procedure called prefrontal leucotomy[3]. Moniz believed that some psychiatric problems were caused by abnormal connections to the frontal lobe and that surgically removing the white fibers connecting the frontal lobe with the rest of the brain will help mental health conditions. Moniz technique was later widely utilized in Europe and the United States. In the United States, prefrontal leucotomy was modified by an American neurosurgeon named Walter Freeman who developed a procedure called Transorbital Leucotomy[1][2][1]. Unlike the original lobotomy that involved an open surgery, transorbital leucotomy was a closed surgery, lasted about 10 to 20 minutes and was aimed at separating the frontal lobe from the thalamus by accessing the brain through the back of the orbits. Clinicians often used this treatment even though, at the time, there was not much data to evaluate the effectiveness of this method, and because of the lack of alternative treatment for patients who had debilitating mental health problems. Later, retrospective studies showed that while Dr. Freeman's method helped calmed some severely agitated patients, others ended up with numerous complications[1]. In the 1950s pharmacotherapy was introduced, which change the approach in treating psychiatric conditions[1]. While pharmacotherapy led to the demise of psychosurgery, physicians were laying the groundwork for the development of stereotactical microsurgery techniques. Furthermore, there was the rapid development of numerous modalities that helped in the understanding of the structure and function of the brain. These new advances, coupled with the frustrations of the significant percentage of patients not responding to pharmacotherapy and positive results in the use of neuromodulation surgery like deep brain stimulation in the treatment movement disorders like parkinsonian diseases, has lead clinicians to revisit the use of neuromodulation surgery for the treatment of psychiatric disorders. In addition to the old concerns, there is a new wave concern as to what the limits of what some of these neuromodulatory surgical procedures will be. Professionals debate whether these techniques will be used only as a last resort for the treatment of refractory psychiatric symptoms, or if they will be used for other purposes like to modify the cognition of healthy individuals[1][4].