Will electrical stimulation help you remember everything?

From the editorial office

Very often, articles about science in national newspapers, even written by a medical editor, begin with the words "Scientists for the first time in the world...", after which there is a retelling of the content of the work "Once again to the question of..." and the answers of scientists to the questions of a correspondent who really learned something about for the first time in his life the topic of their research.

In this case, we are talking about a phenomenon discovered about half a century ago – memory stimulation when certain areas of the brain are irritated. The authors of a short message in the Annals of Neurology (Memory enhancement induced by hypothalamic/fornix deep brain stimulation) write as follows: We observed, quite unexpectedly, that stimulation evoked detailed autobiographical memories – i.e. for neurophysiologists, their observation was almost unexpected. What the Canadian researchers actually discovered in a newspaper article flashes imperceptibly and casually: "... the hypothalamus, as a rule, was not attributed to those parts of the brain through which the memory mechanism operates." And if the authors really test the effectiveness of electrical stimulation of the hypothalamus to restore memory in patients (and maybe someday in healthy people), we wish them good luck.

SCIENTISTS HAVE FOUND A WAY TO CURE AMNESIA
Jeremy Laurance, Health Editor
The Independent, 30 January 2008
Translation: InopressaDuring an experimental operation on the brain of a 50-year-old man, scientists seem to have stumbled upon a clue to the mechanism of memory.

The unexpected breakthrough was the result of an experiment whose initial task was to suppress the appetite of a man (he is obese) with the help of a deep brain stimulation technique that is giving more and more results. Surgeons inserted electrodes into the patient's brain, which were supplied with an electric current. Instead of losing his appetite, he experienced a strong rush of memories. He managed to recall the events of 30 years ago in great detail. Additional tests showed that when the current was applied due to brain stimulation, the man's cognitive abilities sharply increased.

Currently, scientists are conducting the first trials of this method on people suffering from Alzheimer's disease. If they are successful, the "pacemaker mechanism" for the brain can give hope to those who suffer from this degenerative disorder – and there are 450 thousand of them in the UK alone.

The study is led by Andres Lozano, professor of neurosurgery at Toronto Western Hospital (Ontario). According to him, the new method has been applied to three patients and the first results allow us to hope for success.

Professor Lozano said: "For the first time, electrodes have been implanted in the human brain that improve memory – and this effect has been proven. We control the activity of the brain, increasing its sensitivity and thus enhancing the action of the mnemonic mechanism. If an event activates this mechanism, the patient is more likely to retain it in memory and be able to recall it."

According to Lozano, the discovery was a "complete surprise" for both himself and his colleagues. They operated on a man weighing 190 kg (420 pounds) in order to find the part of his brain responsible for appetite, and with its help to rid the patient of obesity. All previous attempts to limit his diet failed, and neurosurgery became the last chance of the unfortunate.

The operation did not help to defeat obesity. But when scientists began to look in the hypothalamus (the feeling of hunger is associated with this area of the brain) for the points responsible for suppressing appetite, the man suddenly said that memories came flooding back to him.

"The patient said that he remembers how he and his friends walked in the park when he was about 20 years old, and as the intensity of stimulation increased, the memories became more vivid. He remembered the girl he was dating... Memories appeared before him in color. The man was able to distinguish the clothes that people were wearing, but he could not hear what they were saying," the researchers write in today's issue of Annals of Neurology.

The man, whose name was not named, was also asked to try to remember several rows of objects combined into pairs. After stimulating the hypothalamus for three weeks, the results of two mnemonic tests improved significantly. In addition, when current was applied to the electrodes, he remembered rows of unrelated objects combined into pairs much better.

In an interview with The Independent yesterday , Professor Lozano said: "His results have improved dramatically. When we applied the current, the mnemonic mechanism was activated and there was an increase in cognitive abilities. The increase in tension led to sudden memories of unrelated events. At a certain level of tension, the patient switched to the stage (in the park). As the voltage increased further, he recalled more details, but when the current was turned off, they quickly disappeared from memory."

The scientific world is surprised by this discovery, since the hypothalamus, as a rule, was not attributed to those parts of the brain through which the memory mechanism operates. The contacts whose action most quickly forced the patient to dive into memories were located next to the vault of the brain. They stimulated the nerve node responsible for the transmission of signals in the limbic system, which is located next to the hypothalamus and is involved in the mechanism of memory and, in addition, causes human emotions.

Professor Lozano is the world's leading specialist in deep brain stimulation. He has operated on about 400 patients with Parkinson's disease, and uses deep stimulation techniques to treat depression – he has performed 28 operations in this area.

According to him, the discovery shows that this technique can be useful in memory stimulation and opens up broad prospects.

"This discovery allows us to find out which areas of the brain are involved in the memory mechanism. It gives us the opportunity to carry out surgical intervention, as is already being done in the case of Parkinson's disease and mood disorders, for example, depression. This method of treatment is useful for the therapy of people with memory problems," Lozano said.

Scientists are testing the new approach on 6 patients with Alzheimer's disease. As part of the first phase of testing, it is expected to confirm the safety of the technique. Three experimental subjects have already been implanted with electrodes. They are connected to a cable that runs under the skull and then along the neck into the battery compartment located under the skin of the chest. The "pacemaker mechanism" supplies a constant low voltage current, which is not felt by the patient, but stimulates his brain.

Professor Lozano said: "The same device is used as for the treatment of Parkinson's disease. The electrodes are inserted into the same areas of the hypothalamus – we want to see if we can restore the results of the first experiment. We believe that the stimulated mnemonic mechanism is located very close, in close proximity to the hypothalamus. This method has proven itself perfectly in the treatment of motor problems that occur with Parkinson's disease, and has already been successfully applied to 40 thousand patients. We have only recently started using it for the treatment of Alzheimer's disease and do not yet know if it will work. Our task is to understand whether we can find a mnemonic mechanism and improve its efficiency. This is a new approach to solving this problem."

The British scientific community took the discovery favorably. Andrea Malizia, senior lecturer in psychopharmacology at the University of Bristol, is engaged in deep brain stimulation in relation to the treatment of depression. "If they just said: "Let's insert an electrode into the hypothalamus to partially relieve the symptoms of Alzheimer's disease," I would have a question: "Why exactly in the hypothalamus?" says Malizia. – But if they have made a discovery by a lucky chance, that's good. Many scientific discoveries are made by a happy accident."

Aisha Khan, who is responsible for interacting with the scientific world at Alzheimer's Disease Society, said: "This is the last word in science. Everything is great, but so far only one person has achieved the result. A large amount of additional research is needed."

How Deep Brain Stimulation Works

Deep brain stimulation has been used for more than 10 years to treat a wide range of diseases, including depression, chronic pain, Parkinson's disease and other motor disorders.

Therapy for Parkinson's disease has been so successful that 40 thousand patients around the world now live with electrodes implanted in the brain, which are controlled by "pacemakers" sewn into the chest.

Devices are getting smaller, their implantation requires less risky operations, and the location of the brain areas that need to be stimulated continues to be refined, so the demand for such operations is expected to grow rapidly. Although the operation is not cheap, it allows you to save a lot of money by reducing spending on patient care and treatment. After the intervention, a person does not depend on taking any medications, and the operation itself is reversible.

The electrodes are implanted under local anesthesia, and the patient is conscious. Before the operation, the neurosurgeon performs magnetic resonance imaging and determines the point where the electrodes need to be inserted. Then he performs trepanation – makes a hole in the skull – introduces electrodes and wires. By applying voltage to the electrodes and observing the patient's reaction, the surgeon can make sure that they are installed correctly.

For the treatment of various diseases, the effect is on different parts of the brain. In Parkinson's disease, electrodes are inserted into the subthalamic nerve center; in depression, into the 25th zone of the cingulate cortex.

The technique of deep brain stimulation was developed in France. The U.S. Food and Drug Administration licensed its use for the treatment of tremor in 1997. In the UK, such operations are carried out in the departments of the National Hospital for Neurology and Neurosurgery in London, Bristol, Oxford and a number of other centers.

The name of the procedure is somewhat erroneous, since it often involves the suppression of electrical activity in a particular area of the brain, and not its stimulation. Equally, this technique involves restoring balance between areas of the brain that conflict with each other, which is why tremors are observed in patients with some types of Parkinson's disease.

Portal "Eternal youth" www.vechnayamolodost.ru30.01.2008