August 29, 2014
A small study has found that electrical stimulation to certain parts of the brain can improve memory. The study included 16 adults, ages 21 to 40. They took a test in which they tried to associate a given word with a photo of a face. Then they underwent 20 minutes of transcranial magnetic stimulation (TMS) once a day for 5 days. During TMS, an electrode is placed on the scalp and current goes to certain areas of the brain. In this study, the current was aimed at a cluster of cells involved in memory. After 3 days of TMS, people’s test scores started to improve. They continued to get better after the fifth treatment. During a separate week, they received placebo TMS, in which the electrode was still placed but no current was given. Test scores did not improve during that week. TMS is approved for some cases of depression that don’t respond to other treatments. Years of research still are needed before it could be used to help treat memory problems, such as those caused by Alzheimer’s disease or stroke. The study was published in the August 29 issue of Science. HealthDay News wrote about it.
By Howard Lewine, M.D.
Harvard Medical School
What Is The Doctor's Reaction?
Electrical stimulation of the brain is approved by the U.S. Food and Drug Administration (FDA) to treat severe depression. The results of this study suggest it also may offer help for people with memory problems.
The technique is called repetitive transcranial magnetic stimulation (rTMS). It’s a painless procedure with almost no risks. A technician places an electromagnetic coil against the person’s scalp on one side of the head. The device sends out magnetic impulses to the brain. It’s similar to the magnetic impulses used when a person has an MRI.
These researchers were specifically interested in whether rTMS could enhance associative memory. Associative memory allows us to recall something from the past when we experience or think about something in the present time. For example, you might see that a particular old movie is playing on TV and it reminds you of a girlfriend you took to see that movie years before.
The part of the brain called the hippocampus plays a dominant role in memory function, especially associative memory. The initial brain activity, before a memory becomes a memory, starts in another part of the brain. Usually that is the outer layer, called the cortex.
The researchers aimed the electromagnetic waves to stimulate brain connections between the cortex and the hippocampus. By using a special type of MRI, called functional MRI, they could see if they were directing the magnetic impulses to the right areas. Once the right spot was located, each volunteer received 20 minutes of rTMS every day for 5 consecutive days.
Associative memory was tested daily and then again 24 hours following the last session. The rTMS enhanced associative memory in these volunteers by as much as 30%. Improvements were still seen 24 hours after the last rTMS session.
What Changes Can I Make Now?
The researchers are not suggesting that rTMS be used by people that already have well functioning memories. In people treated with rTMS for depression, there is a very small risk of seizures.
There are other healthier ways to help maintain memory and potentially boost brain function:
- Don't smoke or use other tobacco products.
- Exercise regularly. Make it your goal to get at least 150 minutes of moderate-intensity exercise per week.
- Use alcohol in moderation. That means no more than one drink per day for women and no more than two per day for men.
- Maintain a healthy body weight. In particular, try not to let your waist expand. People with more fat around the middle have a higher risk of developing dementia, even if their body weight is normal.
- Eat a Mediterranean-style diet. Increase the amounts of fish, vegetables, legumes, olive oil and whole grains you eat.
- Keep your blood pressure in the normal range. To do this, get regular exercise, eat lots of fruits and vegetables and cut down on salt. Your doctor can prescribe medicines if needed.
- Stay socially engaged with family and friends.
What Can I Expect Looking To The Future?
Over the next few years, more studies will be done to test rTMS in people with brain disorders affecting memory. People with Alzheimer’s and traumatic brain injury would be excellent candidates for such studies.