The Neuroscience of Memory Research
Memories are like the threads of a tapestry, weaving the fabric of a life.
Though we live in the present, it is our recall of the past and how we came to be the people we are that anchors our sense of self.
As memory disorders unravel that tapestry thread by thread, they rob people of the life they knew, impair their ability to function in the present, and turn an uncertain future into an increasing burden for families as they watch the people they love disappear before their eyes.
“When there is a disabling problem with memory, look to a disease state in the body—Alzheimer’s, stroke, injury or other neurodegenerative conditions,” David Geldmacher, MD said. A specialist in memory disorders, the UAB neurologist said that while memory loss shouldn’t be assumed to be part of the normal aging process, the raw numbers go up as people live longer and acquire more health problems.
“At age 65, there’s only a one percent risk of Alzheimer’s, but the frequency doubles every five years after that. By 90, 35% to 50% of people are showing signs of the disorder. As more people are living to advanced ages, more patients and their families are dealing with memory disorders.”
In the southeastern stroke belt, the long-term effects of uncontrolled hypertension also take a toll. “Even small strokes can add up to memory loss and cognitive decline over time,” Geldmacher said. “Parkinson’s, head injuries, tumors and similar disorders can also be involved.”
Memory loss and confusion may also be due to temporary causes that are easier to reverse. “Hospitalization and acute illnesses can increase confusion. Depression, nutritional problems related to alcohol, and injuries also affect memory. A sudden onset of symptoms may be related to an adverse reaction to medication. Sometimes simply changing medications or adjusting dosages can make a difference,” Geldmacher said.
A leader in memory research, UAB and its neuroscience investigators are targeting several key areas of inquiry.
“We want to understand what is going on in Alzheimer’s, Parkinson’s and other neurodegenerative conditions. What is happening at the cellular level? What broke, how did it break, and how do we fix it?” Geldmacher said. “Our second target is earlier diagnosis. The Holy Grail would be a blood test for Alzheimer’s, but that it likely to be a while in coming. The technology is advancing. There are new PET scan approaches that can detect some changes early, possibly before patients become symptomatic. Spinal fluid gene testing is another possibility. A new method for detection came out in June of this year, but it is still being evaluated by Medicare and insurers.”
Perhaps the most eagerly awaited area of research is new therapies to slow down or stop Alzheimer’s.
“The last new drug for Alzheimer’s was released in 2004,” Geldmacher said. “There have been several high profile failures in the field, but research is continuing. UAB is involved in small molecule research and in a gene therapy using nerve growth factor. Other approaches use antibodies to remove an amyloid protein. It’s a normal protein that everyone has in the brain, and it resembles a signaling peptide. In Alzheimer’s, it accumulates in plaques. It seems to be a downstream effect from a failure in the body’s ability to remove the protein.”
Another area of interest is the use of intranasal insulin in treatment.
“Recently some researchers have been referring to Alzheimer’s as ‘type three diabetes’ because of similarities in insulin resistance in brain tissue,” Geldmacher said. “There is lag time between the onset of diabetes and dementia, so the relationship between the two is difficult to define. High central obesity and type two diabetes seem to factor into risks, but we also need to know whether successfully treating type two diabetes can help prevent the brain tissue changes found in Alzheimer’s.”
Genetic predisposition seems to be an influence in some cases, but genetics are known to be causative in only one to two percent of patients who usually become symptomatic at an earlier age.
“There may be a familial link in the body’s ability to remove the protein. As it builds up, it attacks the hippocampus, affecting memory first, and other thought processes and core function later. Areas of the brain controlling movement aren’t affected, which can create difficulties for families weighing the need to compromise autonomy for safety. Patients may think they are okay to drive when they aren’t,” Geldmacher said.
Although being diagnosed with a memory disorder is devastating for patients, sometimes there is an even stronger long-term impact on families and their quality of life as patients becomes less connected with the world and more dependent on everyone else.
“Patients need more integrated help to cope—that can include rehabilitation, psychology and occupational therapy to help them be more independent at home longer, as well as more services for family members providing care,” Geldmacher said.
While we await advances in early detection, what are some of the clues that memory problems need follow-up?
“It’s important to differentiate between being distracted in the middle of a task and actual forgetting,” Geldmacher said. “People with serious memory issues may forget that they forgot. If they forget recent conversations, miss appointments and it becomes repetitive, that should be evaluated. When the family notices, it’s time to take a closer look.”
While waiting for new therapies to prevent or cure memory disorders, how can we best reduce our risk of developing them?
“Maintain a healthy blood pressure and blood sugar, eat a healthy diet, and make your overall health a priority,” Geldmacher said.