Memory Loss: When It's Not Just Forgetfulness

We have all done it: we walk into a room and cannot remember what we went there for, or we forgot where we put our keys or cell phone or where we parked the car. This is all normal, mild forgetfulness. Memory loss, however, is an abnormal level of forgetfulness.¹ Memory loss can be sudden or gradual, permanent or temporary, or selective for anterograde memory, retrograde memory, or a combination of the two.¹

The brain is constantly taking in experiences and organizing and filing them for later retrieval. The cerebral cortex, thalamus, and hippocampus all play important roles in memory. The Figure provides a diagram of these structures. The cerebral cortex is the “file” that stores previously formed memories. The thalamus is thought to help form new memories through the connection with the hippocampus and because the thalamus is important for mental alertness. The hippocampus is a region of the brain involved in the formation and retrieval of memories.²

Diagnosis

According to Ranjit Mani, MD, a neurologist and medical reviewer in the FDA’s Division of Neurology Products, doctors use a combination of strategies to diagnose memory loss, including medical history, mental ability tests, physical and neurologic exams, blood and urine tests, and brain imaging. “The goal is to rule out factors that are potentially reversible and determine if the memory loss is due to a more serious brain disease,” says Mani.²

Causes

Anything affecting cognition can affect memory. Medications (Table 1) can interfere with memory in a variety of ways,³ and drug and alcohol abuse can result in deficiencies in vitamin B₁ and change chemicals in the brain that affect memory. Stress, particularly emotional trauma, can cause memory issues, as can depression and thyroid dysfunction.

Head injury, brain tumors, and some infections—such as HIV, tuberculosis, syphilis, and herpes—can damage the lining or substance of the brain, resulting in memory loss. Sleep deprivation, deficiencies in vitamins B₁ and B₁₂, and normal aging are also common culprits.^4-6 Mild cognitive impairment and dementia are characterized by a memory deficit more severe and persistent than that anticipated based on age (Online Table 2).^7,8

Prevention

The best way to boost brain function and prevent memory loss is to make positive lifestyle changes. Eating a balanced, nutrition-rich diet consisting of fruits and vegetables, and foods high in omega-3 fats, such as salmon, tuna, trout, walnuts, and flaxseed, can keep brain cells from “rusting.” Green tea is also known to contain an abundance of antioxidants that work to keep brain cells sharp.² These eating habits often result in lower cholesterol and blood pressure levels.⁹ Smoking cessation is also encouraged, as smoking heightens the risk of vascular disorders and restricts oxygen delivery to the brain.²

Table 2: Symptoms of Memory Changes

Normal Age-Related Changes

Mild Cognitive Impairment

Dementia

Able to function independently and pursue normal activities with occasional memory lapses

Frequently forgets conversations, appointments, or events

Difficulty performing simple tasks and forgetting how to do things done many times before

Able to recall and describe incidents of forgetfulness

Often loses or misplaces things

Unable to recall and describe incidents of forgetfulness

Does not get lost in familiar places

Difficulty remembering names of new acquaintances

Gets lost or disoriented in familiar places

Occasional trouble finding the right word with no trouble holding a conversation

Difficulty following the flow of conversation

Forgets, misuses, or garbles words; repeats phrases in the same sentence

Unchanged decision-making skills

Unchanged decision-making skills

Indecisive, with poor judgement or behavior

A regular exercise regimen boosts brain growth factors and facilitates development of new brain cells. Exercise also helps to manage stress, improve sleep, alleviate anxiety and depression, and reduce the risk for conditions that lead to memory loss, such as diabetes and cardiovascular disease.² Memory consolidation occurs during sleep. This is the process of forming and storing memories for later retrieval. Sleep deprivation restricts the growth of the neurons required for consolidation, thereby causing problems with memory, concentration, and decision making.²

Ginkgo biloba is one of the top-selling herbs in the United States due to its ability to improve blood flow in small blood vessels. However, although a variety of supplements on the market tout brain-boosting benefits, most lack research to support these claims. Other supplements that theoretically improve brain function include omega-3 fatty acid, huperzine A, acetyl-Lcarnitine, vitamin E, and ginseng.¹⁰

Dr. Kenny earned her doctoral degree from the University of Colorado Health Sciences Center. She has 20-plus years’ experience as a community pharmacist and works as a clinical medical writer based out of Colorado Springs, Colorado. Dr. Kenny is also the Colorado education director for the Rocky Mountain Chapter of the American Medical Writer’s Association.

References

• Stöppler MC. Memory loss. MedicineNet website. www.medicinenet.com/memory_loss/symptoms.htm. Accessed September 7, 2015.
• Coping with memory loss. FDA website. www.fda.gov/forconsumers/consumerupdates/ucm107783.htm. Updated January 6, 2010. Accessed September 10, 2015.
• Neel AB Jr. 10 drugs that may cause memory loss. AARP website. www.aarp.org/health/brain-health/info-05-2013/drugs-that-may-cause-memory-loss. Published May 10, 2013. Accessed September 3, 2015.
• Memory loss. University of Maryland Medical Center website. http://umm.edu/health/medical/ency/articles/memory-loss. Accessed September 7, 2015.
• Memory loss. MedlinePlus website. www.nlm.nih.gov/medlineplus/ency/article/003257.htm. Updated February 10, 2014. Accessed September 3, 2015.
• Brain & Nervous System Health Center: memory loss. WebMD website. www.webmd.com/brain/memory-loss. Accessed September 3, 2015.
• Forgetfulness: knowing when to ask for help. National Institute on Aging website. www.nia.nih.gov/health/publication/forgetfulness. Published May 2015. Updated July 20, 2015. Accessed September 10, 2015.
• 4 ways to stop age-related memory loss. WebMD website. www.webmd.com/healthy-aging/features/4-ways-stop-age-related-memory-loss. Accessed September 10, 2015.
• Stuart A. Vitamins and supplements lifestyle guide: fortifying your memory with supplements. WebMD website. www.webmd.com/vitamins-and-supplements/lifestyle-guide-11/fortifying-your-memory-with-supplements. Published 2008. Accessed September 5, 2015.