Epilepsy is a neurological disease that affects 1.2% of the United States population. For treatment, there were two primary options before responsive brain stimulations. A patient could either receive medication or undergo surgery to remove the origin site of their seizures, or their seizure focus. However, a problem arose after drug-resistant patients had seizures starting in a part of the brain that was essential for a function, such as movement or speech. This problem was solved by using different types of responsive brain stimulations. These different types of biomedical technologies were called responsive neurostimulation (RNS), vagus nerve stimulation (VNS), or deep brain stimulation (DBS). RNS and VNS work similarly to a pacemaker. In RNS systems, biomedical engineers were able to create an implanted device that monitors the brain waves at the spot where the seizures begin, detects abnormal electrical activity at that spot, and then responds quickly by sending a small pulse of stimulation that causes the brain waves to normalize. This system could essentially prevent the abnormal electrical activity from turning into a seizure.The RNS system consists of a stimulator and small wires with four electrodes each. The electrodes are placed where the seizure originates and monitor brain waves in the form of ECoG, or electrocorticography. The article also discusses a different type of stimulation called vagus nerve stimulation, or VNS. The vagus nerve is the tenth cranial nerve that connects the body to the brain. Vagus nerve stimulation connects to the vagus nerve. Therefore when the generator sends stimulation through the small wires, it travels to the vagus nerve which will then signal to the brain. Continuous brain deep stimulation has not been approved for treatment of epilepsy in the United States, but it has been in Europe. DBS is placed in the anterior nucleus of the thalamus within the brain and also gives stimulation to the location of the electrodes.
During the discussion of RNS, VNS, and DBS the study refers back to the initial clinical studies that studied both stimulations and highlights the statistics and the results. For example, the article includes the information that 44% of the patients who participated in the initial experiment of VNS experienced a 50% or higher decrease in the number of seizures within two years of the stimulation. The article effectively and efficiently describes the distinctions between the three responsive stimulation devices, adding valuable knowledge to readers trying to differentiate between them. For instance, the article includes that DBS, in contrast to RNS, it was founded on the idea of affecting seizure networks, rather than the actual onset site. The only questions and topics within this article I had to do additional research on were the ECoG graphs. The article did not go in depth on reading the brain wave graphs present, making it hard to determine what they were portraying. Future directions or research emerging is the approval of DBS in the United States. Using these devices, RNS in particular since the electrodes rest on the seizure foci, may teach scientists and doctors the hidden mechanisms behind epilepsy.
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