Memory Loss Temporarily Reversed With Brain Zapping Technique

memory loss
Stock photo: A brain stimulation technique has reversed age-related memory loss in a study. iStock

Electromagnetic stimulation of an area of the brain known as the hippocampus has improved the memory of older adults with age-related memory loss, according to the results of a study published in the journal Neurology.

Researchers from Northwestern University Feinberg School of Medicine used a noninvasive technique known as transcranial magnetic stimulation (TMS) to target the hippocampus—an area of the brain that degenerates as people age, leading to memory loss—with a powerful electromagnet that generates electrical activity.

"Everyone experiences memory decline with age," Joel Voss, lead author of the study from Northwestern, told Newsweek. "My laboratory has been working on ways to improve memory ability using noninvasive stimulation for a number of years, and so we tested for the first time whether the methods we've developed work in older adults experiencing memory decline."

"[The hippocampus] is the part of the brain that links two unrelated things together into a memory, like the place you left your keys or your new neighbor's name," Voss said in a statement. "Older adults often complain about having trouble with this."

The hippocampus is actually too deep into the brain to stimulate directly with TMS, so instead the team targeted an adjacent brain region, closer to the surface of the skull, that has strong connections to it.

"We stimulated where brain activity is synchronized to the hippocampus, suggesting that these regions talk to each other," Aneesha Nilakantan, first author of the study, said in the statement.

Before the stimulation took place, the researchers gave younger and older adults a memory task. The older adults—who ranged between ages 64 and 80—scored around 40 percent on this, whereas the young adults in their 20s and 30s managed about 55 percent.

Then, the older adults were given five consecutive days of TMS for durations of 20 minutes each session.

"During a stimulation session, individuals sit in a chair while a technician aims the transcranial magnetic stimulation device at the targeted brain area," Voss said. "The stimulator looks sort of like a high-tech vacuum cleaner attachment wand that is held up against the head. The stimulation feels like a slight tapping sensation and produces a clicking sound."

Functional magnetic resonance imaging (fMRI) showed that these sessions improved the activity of certain brain regions important for memory that were damaged by aging.

Finally, one day after the final stimulation session, the older participants were given a new memory test—in which they scored similarly to the young adults, suggesting that one form of memory ability had been improved, at least temporarily. It is important to note, however, that the study only involved a small sample of 16 people, so the findings should be viewed with caution.

"We were able to increase brain activity in exactly the areas of the hippocampal network that we targeted, and this improved memory ability in older adults," Voss said. "Unsurprisingly, older adults started off performing the memory task worse than younger adults in their 20s and 30s—performing the same task."

"After stimulation, memory improved such that older adults were no longer impaired relative to younger adults," he said. "The memory task assessed people's ability to remember where objects are located and in what types of places. This is the type of memory that declines the most with aging and the type of memory that specifically was improved due to stimulation in our study."

Voss said that this memory boost was measured a full day after older adults stopped receiving stimulation, and lingered in reduced form for up to a week later. Future studies will be able to determine if tweaking the stimulation parameters will produce longer-lasting improvements.

"There is no previous evidence that the specific memory impairments and brain dysfunction seen in older adults can be rescued using brain stimulation or any other method," he added.

The next step, the researchers say, is to test the technique on people with mild cognitive impairments, such as those suffering from the early stages of Alzheimer's, and to refine the methods with the aim of producing more "robust and longer-lasting affects," Voss said.

Aaron Ritter, an Alzheimer's and dementia researcher at Cleveland Clinic Lou Ruvo Center for Brain Health, who was not involved in the study, said that the findings were a good base for future investigations to build on.

"This study provides preliminary evidence that we can affect networks in the brain that support memory function," he told Newsweek. "To know we can have an effect with a non-invasive procedure provides a pathway forward to impact memory function in both neurodegenerative and age-related memory decline. There has been similar research, like that of Neuronix's neuroAD Therapy System, that has shown positive results, so it appears to be a trend worth pursuing in larger studies."

Steven DeKosky, a neuroscientist from the Center for Translational Research in Neurodegenerative Diseases, who was also not involved in the study, described the latest results as "very interesting."

"The findings, although from a small group of people, do show a very selective improvement in recall of material they had just learned—recall being the most troublesome memory complaint of people with age associated memory complaints," he told Newsweek. "The issue appears to be with their retrieval mechanism, as they may come up with the memory later, indicating that they did "encode" it into the short-term memory circuitry, but could not produce it at will."

"On the other hand, these normal people had no trouble with recognition memory—they remember things they've seen before if they are shown to them again," he said. "That is in contrast to degenerative diseases such as Alzheimer's disease, in which the circuit failure includes impaired encoding—so they will not remember it at some future time, even under trials of recognition (when they are shown the object and asked if they remembered it.)"

According to DeKosky, the study has shown that the problem of recollection in older people can be improved, at least transiently, with TMS and that to get the desired effect, one must stimulate the brain in very specific areas which are known to project to and activate the hippocampus, part of the "RAM chip" circuity of the human brain.

"The importance: first, these "memory circuits," which decline in aging, appear able to be activated by the TMS enabling better performance; the possibility exists that if the booster effect lasts for a period of time it might be reasonable to repeat the procedure to maintain improved memory," DeKosky said. "We know that certain specific intracranial stimulation can boost or restore normal function, for example in Parkinson's or essential tremor, however these procedures are invasive, have some degree of risk, and are only done at a critical point in the progression of the symptoms."

"The advantage of the TMS is that if the stimulator is placed in the correct position, its extracranial location poses no danger, at least such symptoms have not emerged at this point in our research with the procedure," he said. "And it is used therapeutically for depression, where it has effects as well—with different areas of the skull surface."

This article was updated to include additional comments from Joel Voss Aaron Ritter and Steven DeKosky.