Understanding Dementia: Symptoms, Types, Causes and Treatments

Accounting for 60-80% of all cases of dementia, Alzheimer's is a progressive disease in which a patient's memory or cognitive processes slowly decline. It is most common in those who are 65 and older, though early-onset Alzheimer's may affect those under 65. Early on, Alzheimer's typically presents as difficulty remembering new information, but it can cause disorientation, confusion, more serious memory loss and difficulty speaking, swallowing or walking as the disease progresses. There is no cure for Alzheimer's, but treatment can slow its effects and improve quality of life for patients and caregivers alike.

Vascular dementia occurs when blood flow to the brain is blocked or limited, like during a stroke. Confusion, disorientation, trouble speaking or difficulties understanding speech are symptoms that may appear in the immediate aftermath. Severity of symptoms and rate of decline depend on which part of the brain had reduced blood flow and how badly the blood vessels were damaged. Damage to parts of the brain critical for storing and retrieving information may result in memory loss or other common dementia symptoms. Only 5-10% of people have vascular dementia alone. It usually occurs alongside another form.

The third most common type of dementia, Lewy body dementia, occurs when alpha-synuclein protein forms deposits (Lewy bodies) in the brain. Over time, the deposits damage the brain and lead to difficulty thinking and reasoning. Impaired judgment and behavioral changes are early symptoms. It is linked with Alzheimer's disease and Parkinson's disease dementia, and patients may experience overlapping symptoms. For example, a Lewy body dementia diagnosis may coincide with physical symptoms (tremors, muscle weakness) common to Parkinson’s disease. While memory loss can occur, it is usually not as severe as seen in patients with Alzheimer’s disease.

Frontotemporal dementia is caused by the loss of nerve cells within the frontal or temporal (side) lobes of the brain. As cells are lost or damaged, abilities associated with those areas become impaired. There are two primary types. Behavior variant frontotemporal dementia typically occurs in patients in their 50s and 60s and results in changes to personality and behavior. Primary progressive aphasia is usually diagnosed before age 65 and is associated with declining speaking, writing and comprehension skills.

Mixed dementia is when more than one cause of dementia occurs at the same time. It usually presents as Alzheimer's disease tied to vascular dementia or as Alzheimer's disease with the presence of Lewy bodies. Because many symptoms of dementia overlap, mixed dementia is difficult to diagnose and treat. In many cases, symptoms of mixed dementia may be indistinguishable from other types of dementia.

Learn more about the stages of progressive dementia

Parkinson's disease dementia is a decline in cognitive skills occurring at least one year after a diagnosis of Parkinson’s. It is associated with the buildup of “Lewy body” protein deposits, also found in Alzheimer’s disease and Lewy body dementia. Parkinson’s disease symptoms generally begin as difficulty with movement, such as tremors and muscle stiffness. Over time, those symptoms may progress to include difficulty with memory or paying attention. Of patients with Parkinson’s, approximately 50-80% may experience dementia, with an average time of onset 10 years after the first diagnosis. 

Huntington's disease is caused by a defective gene, which prevents the body from properly producing the Huntington protein. This improperly formed protein causes brain changes and involuntary movements, trouble thinking and reasoning, and irritability or depression. With Huntington's disease dementia, as the brain is damaged further, patients experience increasing difficulty with movement, mood changes and declining thinking skills. Symptoms of Huntington's disease usually develop between ages 30-50, with symptoms of dementia occurring as the disease progresses. 

An extremely rare brain disorder that affects 1 in 1 million people per year worldwide, Creutzfeldt-Jakob disease occurs when prion protein begins folding into an abnormal shape. Eventually, prion protein in the brain begins to fold as well, destroying brain cells and causing a sudden onset of dementia. The damage leads to rapid decline in thinking and reasoning as well as involuntary muscle movements, confusion, difficulty walking and mood changes.

Korsakoff syndrome results in chronic memory loss due to a thiamine deficiency. When thiamine levels are too low, brain cells are unable to transmit signals effectively, and it can affect how we store and retrieve memories. Korsakoff syndrome is often seen in those who have abused alcohol, those who have AIDS, certain cancers or chronic infections, and those with eating disorders. Korsakoff syndrome sometimes follows Wernicke encephalopathy, which is when the brain reacts to lack of thiamine and causes confusion, staggering and stumbling and lack of coordination. 

Posterior cortical atrophy occurs when the outer layer of the brain in the back of the head slowly deteriorates. It is one of the least understood disorder-linked dementias, with widely varying symptoms and brain changes. Most common symptoms include difficulties with visual tasks. While memory loss is not usually a symptom of early-stage posterior cortical atrophy, it can be more severe in later stages.

Sometimes a vitamin deficiency can result in symptoms similar to those of dementia. Severe dehydration or vitamin B-1, B-6, B-12, D, copper, or E deficiencies can cause dementia-like symptoms that can often be reversed by addressing the underlying deficiency. Our ability to absorb certain vitamins declines as we age, which may put older people at a higher risk of developing these symptoms and being misdiagnosed with dementia.

Some medications may cause side effects such as confusion, loss of memory, feelings of distress, inability to pay attention or difficulty speaking or reasoning. In particular, antidepressants, antipsychotics, cardiac medications, antispasmodics, antivertigo medications and antiparkinsonian medications can produce these symptoms. Benzodiazepines or drugs used to treat anxiety or insomnia, corticosteroids, pain relievers or anti-cancer drugs are also known to cause cognitive changes. Be sure to monitor behavior when you or a loved one starts a new medication to quickly identify side effects like these.

When suffering from an infection or an immune disorder, some people can experience dementia-like symptoms. High fevers or widespread infection can cause confusion, disorientation or loss of memory, while autoimmune disorders like multiple sclerosis can also result in similar symptoms. 

Some conditions like thyroid issues, chronic low blood sugar or difficulty processing sodium or calcium may cause a person to develop symptoms that appear similar to dementia, like loss of memory, difficulty communicating or other personality changes. 

A subdural hematoma is when bleeding occurs in the space between the skull and the brain tissue, and it is most often caused by a head injury. Older adults are more at risk of developing this type of bleed, sometimes exacerbated by certain medications or health conditions. A subdural hematoma is typically accompanied by the sudden appearance of symptoms like vomiting, loss of consciousness or inability to walk normally, which leads to faster diagnosis and treatment. However, “chronic” subdural hematomas develop more slowly. More common in older people, they cause memory loss, confusion, and personality changes and may be misdiagnosed as dementia.

Normal pressure hydrocephalus is a brain disorder that causes cerebrospinal fluid to build up in certain chambers in the brain. As the chambers expand, they put pressure on or damage surrounding brain tissue. Depending on the damage done, patients can experience difficulty walking, thinking and reasoning. Normal pressure hydrocephalus primarily affects people in their 60s and 70s and is often misdiagnosed as Alzheimer’s or Parkinson’s disease.

The earliest signs of many dementias include short-term memory loss and extreme forgetfulness. Other early signs include drastic changes in personality or behavior—mood swings, depression or acting out of character. You may also notice a loved one having trouble with simple tasks, such as taking their medicine correctly, preparing meals or bathing. Read the full article Top 10 Warning Signs of Memory Loss & How to Seek Help.

Doctors and scientists don't yet fully understand what causes Alzheimer's disease and other dementias, but many common forms of dementia are thought to be caused by cell damage and abnormal protein buildup in the brain. Studies show that age-related brain changes, genetic factors, family history and lifestyle choices can all increase the risk of cognitive decline. 

It's normal for everyone to occasionally forget things. However, some indicators of more serious issues include trouble retracing steps, finding things in unusual places (e.g., keys in the freezer) or trouble recognizing familiar people or surroundings. 

It's common to forget names of people you've just met—especially if you're distracted. However, if you or your loved one has trouble remembering the name of someone you see regularly, that could be a cause for concern. 

This happens to everyone from time to time. It's not necessarily a sign of dementia. There could be a simple explanation, such as a distraction or a competing memory. However, if this is a consistent problem, it could be a sign of more significant memory loss.

This is a more profound level of memory loss. Likely this person is also forgetting recent events, appointments, not paying bills, having trouble finding the right words, relying more on others to handle things they normally would have taken care of themselves, and forgetting or refusing to perform basic activities like cooking, laundry and grooming. If you're noticing these changes, it's crucial to get an assessment by a healthcare professional.

It can be hard to determine exactly when you should be concerned with cognitive changes you're noticing in yourself or a loved one. What's normal for one person may not be normal for someone else. A doctor can help assess whether a symptom may be related to medication or any underlying medical conditions. One of Belmont Village's family advisors can help you determine next steps.

First, understand that you are not alone. Receiving the diagnosis of dementia or Alzheimer's is a major life change and is never easy. It's normal to experience a range of emotions—anger, sadness, grief. Acknowledging these complex feelings is the first step to moving forward. You may find it helpful to join a support group, spend time with your family or ask your doctor some questions.