Updated calculations estimate that about 6.2 million Americans over the age of 65 are currently living with Alzheimer’s disease in 2021, making it one of the most common disorders in the country. The symptoms of Alzheimer’s disease can vary, but it is characterized primarily by dementia, which comprises a long list of symptoms related to cognition, memory, mood, and behavior.
Alzheimer’s disease is by no means the only cognitive function disease that causes dementia, and there are plenty of diseases that can be mistaken for Alzheimer’s for other reasons. Read on to learn more about diseases that are similar to Alzheimer’s.
1. Parkinson’s Disease
Wondering what the physical symptoms of Alzheimer’s are or what the difference is between Alzheimer’s and Parkinson’s? Much like Alzheimer’s, Parkinson’s disease is a neurodegenerative disease with symptoms that can get worse over time. While both are noted for damage to nerve cells, or neurons, Parkinson’s disease is caused by damage to the cells responsible for producing dopamine. Low dopamine levels result in abnormal brain cell activity, which then results in impaired movement and muscle control. By contrast, Alzheimer’s is characterized by the failure of certain brain cells proteins, which disrupts neuronal function. This eventually causes damage to the neurons, resulting in brain atrophy.
The symptoms of Parkinson’s disease are most often associated with movement and muscle control. Tremors, which involve involuntary shaking in the limbs, are the most common symptom in people with Parkinson’s, along with muscle rigidity and bradykinesia (slow movement). However, Parkinson’s disease can potentially spread to other parts of the brain involved with mental function. This can lead to a form of dementia called Parkinson’s disease dementia, which poses similar symptoms as dementia in Alzheimer’s patients.
Although Alzheimer’s is not associated with motor function symptoms, studies show that the brain disorder can potentially lead to mobility and motor symptoms in its later stages. This may include trouble walking without aid, poor balance, and even tremors, all of which also overlap with Parkinson’s disease.
2. Lewy Body Dementia
Depending on who you talk to, Lewy body dementia is the second or third most common cause of dementia. Similar to the cognitive impairment of Alzheimer’s, Lewy body dementia is a progressive neurological disease, but it works through different mechanisms. Lewy bodies are abnormal protein deposits that build up in the brain.
Lewy bodies are also associated with Alzheimer’s disease and Parkinson’s disease. In fact, there is an overlap of behavioral symptoms between Lewy body dementia and Parkinson’s. As mentioned, later stages of Parkinson’s can result in memory loss and reasoning problems often associated with dementia, while people with Lewy body dementia may experience motor function symptoms, including muscle rigidity, posture issues, and trouble initiating movement. This overlap in physical symptoms suggests a link between Lewy bodies and Parkinson’s.
Similarly, many people with Lewy body dementia also display plaques and tangles. Plaques and tangles are two abnormal structures that are also characterized by different protein deposits, and they can both contribute to nerve cell damage the results in the cognitive symptoms of Alzheimer’s.
Lewy body dementia does present with some specific differences compared to Alzheimer’s disease. Delusions and hallucinations are more common in the early stages of Lewy body dementia, while they tend to be rare in Alzheimer’s until later stages. Although Lewy body dementia can contribute to memory issues, they generally are not prominent in early stages the way they are with Alzheimer’s. Sleep problems, specifically REM sleep disorders, are more common in Lewy body dementia.
3. Vascular Dementia
Vascular dementia is another form of dementia. Unlike Alzheimer’s or Lewy body dementia, vascular dementia is characterized by damage to the brain tissue and nerve cells caused by impaired blood flow. Every part of your body needs adequate blood flow, but your brain is particularly vulnerable to low blood levels.
Most commonly, vascular dementia occurs after a stroke blocks an artery leading to the brain, though not all strokes cause vascular dementia. A brain hemorrhage or any condition that narrows or chronically damages blood vessels to the brain can also contribute to vascular dementia.
Symptoms of vascular dementia can vary based on where the blood flow is constricted or impaired. Symptoms can also occur suddenly, which is typical after a stroke. However, vascular dementia can also occur gradually over time, and it can potentially occur alongside Alzheimer’s disease.
Vascular dementia can present many of the similar signs and symptoms as Alzheimer’s, including confusion and problems focusing. However, unlike Alzheimer’s disease, vascular dementia typically does not present with memory issues, but it does more commonly involve issues with problem solving and speed of thinking.
4. Huntington’s Disease
Huntington’s disease is another neurodegenerative disease. It is relatively rare compared to Alzheimer’s or even Parkinson’s disease. Estimates suggest about 41,000 symptomatic cases of Huntington’s disease in the United States, along with over 200,000 people at-risk of inheriting the disease.
While Huntington’s disease can occur at any point, most people develop symptoms between ages 30 to 50. By contrast, Alzheimer’s is more common among those age 65 and older. Huntington’s is known to be a genetic disorder. Inherited defects in a single gene contribute to the progressive breakdown of neurons.
The actual symptoms and their severity can vary from case to case, and they can be much more comprehensive in scope than Alzheimer’s. Symptoms may include:
- Changes to personality and mood
- Memory loss
- Impaired judgment and decision-making
- Impaired gait, balance, and posture
- Problems with speech or swallowing
- Involuntary writhing or jerking movements, known as chorea
- Lack of impulse control
- Inability to focus on tasks, prioritize, or otherwise stay organized
- Trouble finding the right words for thoughts
The mix of physical, cognitive, and psychiatric issues associated with Huntington’s disease make it hard to discern from Alzheimer’s, Parkinson’s, and other neurodegenerative disorders.
Major depressive disorder, often shortened to just depression, is a common mood disorder. While most people simplify depression to “feeling sad,” it can have a significant effect on all parts of your health and life beyond just your mood. Depression is most often characterized by extreme sadness, hopelessness, and a loss of motivation or interest in life, but it can also influence your cognition, behavior, and even your physical health.
Much of that comes from depression’s effects on your brain structure and function. Depression has been linked to physical changes throughout the brain, including the amygdala, prefrontal cortex, and hippocampus. These parts of the brain are involved in emotional processing, general cognition, and executive function.
The cumulative effect of these changes has a significant impact on your brain’s ability to work during memory tasks. This specifically applies to your working memory, which is the short-term memory that you use to remember information from moment to moment. Studies suggest that up to three in five people with major depression and bipolar disorders may exhibit cognitive impairment and memory issues.
Poor working memory can mean forgetting things in conversations or repeating questions or statements. Impaired working memory also affects concentration, decision-making, and response time. You may have trouble switching between tasks or maintaining basic plans. These are symptoms that are also commonly found in the early stages of Alzheimer’s disease.
Alzheimer’s is a common disease, but many of its symptoms overlap with other health conditions and disorders. Receiving the right treatment means getting the right diagnosis in the first place. If you show any cognitive symptoms or otherwise believe that you may have Alzheimer’s, consult your doctor as soon as possible or visit Immunity Therapy Center for help.
- Alzheimer’s Association. 2021 Alzheimer’s disease facts and figures. https://www.alz.org/media/documents/alzheimers-facts-and-figures.pdf
- Alzheimer’s Association. What is Alzheimers. https://www.alz.org/alzheimers-dementia/what-is-alzheimers
- Parkinsons Foundation. What is Parkinsons. https://www.parkinson.org/understanding-parkinsons/what-is-parkinsons
- Alzheimer’s Association. Parkinson’s Disease Dementia. https://www.alz.org/alzheimers-dementia/what-is-dementia/types-of-dementia/parkinson-s-disease-dementia
- Stanford Health. Alzheimer’s disease. https://stanfordhealthcare.org/medical-conditions/brain-and-nerves/alzheimers-disease/symptoms.html
- Alzheimer’s Association. Lewy Body Dementia. https://www.alz.org/alzheimers-dementia/what-is-dementia/types-of-dementia/lewy-body-dementia
- Alzheimer’s Association. Vascular Dementia.https://www.alz.org/alzheimers-dementia/what-is-dementia/types-of-dementia/vascular-dementia
- Huntington’s Disease association of America. Alzheimer’s Association. https://hdsa.org/what-is-hd/overview-of-huntingtons-disease/
- The Conversation. People with depression can sometimes experience memory problems – here’s why. https://theconversation.com/people-with-depression-can-sometimes-experience-memory-problems-heres-why-153392
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