Causes of Memory Loss

What is memory loss?

Most people are familiar with the concept of memory loss. We all know that it's a natural part of aging, but what does memory loss actually mean? 

Memory loss is usually categorized by short-term or long-term problems in the ability to recall information. Short-term issues can be serious or benign. Long-term memory problems are more serious and can interfere with daily life and activities. Memory loss is a natural part of the aging process, but it can also be influenced by many other factors; some common causes are stress, depression, anxiety, and Alzheimer's disease. If you or any of your family members are experiencing any symptoms that could indicate memory loss, you should make an appointment with your healthcare provider to discuss your concerns and experience. 

Causes of short-term memory loss

There are many causes of short-term memory loss. Whether we like it or not, the most common cause is due to the natural aging process. As we age we lose brain cells, particularly in certain brain regions such as the hippocampus. This seahorse-shaped area of the brain is responsible for forming new memories and connecting them to emotions.  As short-term memory loss patients lose brain cells, they also experience decreased amounts of acetylcholine, a naturally occurring chemical which allows brain cells to communicate. While people with Alzheimer's can experience short-term memory loss due to the disease, other patients may experience short-term memory loss due to brain injuries, seizures or stroke.

But how do we define short-term memory loss? While forgetfulness is a normal part of aging, short-term memory loss is an inability to form memories of recent experiences. Short-term memory issues are often associated with:

• Forgetting something you saw or read recently
• Difficulty with recall of recent events in your life
• Asking the same questions repeatedly
• Forgetting where you put something
• Having trouble processing new information you just heard, such as a recipe or directions
• Trouble multitasking

Causes of long-term memory loss

While the underlying causes of long-term memory loss are still debated in scientific circles, we do know that much like short-term memory loss, long-term memory loss is also associated with the depletion of brain cells in regions of the brain important to the storage of memory. Mental health issues, stress, and medications can also influence our ability to access long-term memories. Additionally, various diseases such as Alzheimer's disease, dementia and epilepsy are known for causing this type of irreversible memory loss.

Our long-term memory allows us to recall past events or experiences from our lives and plays a key role in managing routine and daily tasks. Simple tasks like how to get home, how to cook a meal, or completing familiar tasks become infinitely more difficult when we are struggling with long-term memory issues. 

Long-term memory issues can lead to:

• Change in behavior or mood
• Consistency mixing up words or using the wrong words
• Consistently forgetting common words
• Forgetting the names of family members or close friends 
• Inability to perform routine tasks
• Getting lost in familiar places
• Forgetting what you are thinking about
• Taking a long time to do simple tasks 

Mild Cognitive Impairment (MCI)

MCI is a memory impairment that can be considered early stage Alzheimer's disease. MCI is a cognitive condition that affects the way someone thinks and remembers. There is not one single factor that causes this decline, but many things can contribute to it such as depression, diabetes, a history of head injuries, genetic factors, and stroke. The underlying pathology of MCI is similar to that seen in Alzheimer’s disease, and involves the buildup of toxic products which result in the death of neurons.

According to the Alzheimer's Association, approximately 12-18% of people aged 60 or older are living with MCI. Though every case is unique to the individual experiencing it, it is generally thought to be less  severe than dementia or Alzheimer’s, as in most cases the patient is still able to manage their daily functions and take care of themselves. 

The medical community is still trying to learn more about MCI. For many, MCI eventually progresses into dementia due to Alzheimer’s disease or another memory disorder. However, it is important to note that MCI progression into Alzheimer’s disease is not a guarantee and many elderly live out their lives without an Alzheimer’s diagnosis.

Here are a few symptoms of MCI:

• Trouble remembering words
• Difficulty following conversations 
• Difficulty making decisions
• Losing things
• Forgetting appointments

Various causes of memory loss

Now that we understand the general categories of memory loss and some of the most common symptoms, let's explore the root causes and expressions of memory loss.  

Alzheimer’s Disease

Alzheimer's is the most common type of dementia and can cause progressive and irreversible memory loss. While memory loss is often an early symptom, other symptoms can include difficulty with thinking, confusion, mood swings, personality changes, trouble speaking in a coherent way, problems with judgment and reasoning skills, as well as an impaired ability to perform daily tasks. Other types of dementia also lead to memory loss, as well as behavior changes that could easily go unnoticed. If you think you or a loved one might have dementia, talk to your doctor. Behavioral tests such as the mini-mental status examination (MMSE) are used by physicians to diagnose Alzheimer’s disease.

Medication

Some medications or a combination of them can cause forgetfulness and confusion. Decisions about continuing or stopping medication should only be made with the input of your physician.

Alcohol use

Chronic alcohol abuse reduces overall brain health and poses a risk for a specific disease associated with memory loss. Alcohol can also interact with medications and cause poor health outcomes, especially in cases where the person is on several different medications at once or has been taking them regularly over time. The University of Michigan notes that alcohol, if combined with either depressants, stimulants, or opioids, can result in severe cognitive difficulties such as memory loss

Sleep deprivation or lack of sleep

Work has shown that memory consolidation - from short-term to long-term - occurs during sleep, thereby highlighting the importance of sleep to memory formation. Additionally, recent research has shown that while we sleep, important cells in the brain clear up toxic byproducts and keep the brain cells  functioning in a healthy way. So, sleep is really important for memory and overall brain health.

 One chronic problem associated with lack of sleep is sleep apnea. Sleep apnea is a disorder in which breathing stops and starts irregularly; this unnatural pattern of breaths can cut  oxygen off from the brain, which can eventually lead to memory loss and impairment. Fortunately, treatment options are available for sleep apnea. Sleep studies can help identify and treat other causes of sleep impairment.

Mental Health

While we tend to focus on physical health as we age, we need to increase awareness of the role that mental health plays in memory loss. Mental health issues such as  depression have been positively correlated to memory loss.  Additionally, data suggests that stress and anxiety result in lowered memory formation and retrieval. Why this happens is unknown, but may include over-activation of hormones involved in the fight or flight response. 

To mitigate the impact of mental health issues on your memory (not to mention your overall aging experience), try to prioritize sleep and attend wellness events such as stress reduction programs.  You can also speak with your doctor about taking antidepressant medication to help alleviate some symptoms.

Diet and Nutrition

Nutritional deficiency is common among older adults, but they're also at risk for cognitive issues due to the lack of vitamins and nutrients in their diets. Emerging evidence suggests that a diet rich in grains, fruit, vegetables and fish, and low in trans-fat and red meat, may be healthy for brain performance (including memory). While many older adults suffer from vitamin B-12 deficiency, we know that  B-12 plays a particularly important role in maintaining healthy nerve cells and red blood cells.  Load up on foods rich in B12, such as milk, cheese, fish and eggs.  

Other Conditions

• Infection in the brain or a tumor can cause memory problems or other dementia-like symptoms. Your physician may recommend blood tests and/or brain imaging to diagnose such a condition.
• Concussions may cause memory loss short-term or long-term. The link between concussion and repetitive head impacts and long-term memory problems remains under investigation.
• Oxygen deprivation (such as that in stroke, traumatic brain injury or drowning accidents) can cause temporary loss of memory if specific brain regions are affected.
• Seizures  are caused by abnormal electrical activity in the brain. Seizures, for reasons we do not understand, seem to affect areas close to the hippocampus (responsible for making new memories). Memory problems occur due to the gradual loss in brain cells in the hippocampus.
• Stroke can result in the death of brain cells and thereby can result in a loss of memory. Depending on the severity of the stroke, memory loss from a stroke can be permanent, however, an individual may also slowly recover through cognitive rehabilitation.
• Transient Global Amnesia (TGA) is a rare condition where a person may experience a sudden loss of memory. When a TGA episode occurs, a person is unable to recall recent events and memories. 
• Hypothyroidism can result in forgetfulness as well as other thinking problems. 
• Anesthesia has been reported to have a short-term impact (several days) on memory loss.
• Cancer treatments such as chemotherapy, radiation, and bone marrow transplants can be a cause of memory loss. 

There are many potential causes for memory loss, including long-term stress, brain trauma, aging or aging-related disease. Memory loss can also be attributed to several other biological factors such as genetics, disease process, or aging-related deterioration in brain function. In addition, some medications may contribute to cognitive impairment, as well as substance abuse issues like alcohol addiction; these habits typically result in short-term memory loss as opposed to long-term memory loss. The above list, while not covering every existing cause for memory loss, gives you a good idea about what can create memory problems. Seeking professional help for any of the above -instead of self-diagnosis- is very important, as there may be more to your memory loss than you are aware of. 

When to see a doctor

While short-term and long-term memory loss is a normal part of aging it is always better to talk to your doctor about the traits you are worried about; if memory loss starts to interfere with your daily life and activities, seek professional advice immediately. 

In addition to testing your overall thinking skills, your doctor may also order blood tests and brain-imaging tests to help identify if your condition can be reversed. Your doctor may also refer you to a neurologist, psychiatrist, psychologist, or geriatrician to help diagnose dementia or memory disorders.

Memory loss treatment

Getting a proper diagnosis is important, as memory loss may be reversible with treatment. An early diagnosis of diseases such as Alzheimer’s can increase treatment options. Your doctor can help identify resources for you, such as the Alzheimer’s Association, so that you can get more information, emotional support, and even financial assistance or advice. 

A special note for caregivers

If you are a caregiver supporting an individual with a memory diagnosis, please know there is support for you too. Navigating your relationship and role with a loved one who is undergoing a memory care assessment or has received a memory care diagnosis can be difficult.  The Alzheimers Association hosts a wonderful set of resources and support groups for caregivers of Alzheimer's patients. Whether you find support in a formal or informal structure, make sure you are taking time for yourself.

Works cited: Alzheimer’s Association. “Mild Cognitive Impairment (MCI).” Accessed on November 29, 2021. https://www.alz.org/alzheimers-dementia/what-is-dementia/related_conditions/mild-cognitive-impairment.