What is Dementia disease - Symptoms, Risk Factors & Diagnosis

Dementia is a decline in cognitive function severe enough to disrupt everyday activities. It encompasses various symptoms affecting memory, thinking, and social abilities. Alzheimer's disease is the most common form of dementia, but it is not the only one. Understanding the differences between Alzheimer's and other forms of dementia is crucial for accurate diagnosis, treatment, and support for those affected.

What is Dementia?

Dementia is a term that describes a set of symptoms that affect how our brains work, such as memory, reasoning, and communication skills. It's not a specific illness but rather a group of problems caused by different conditions that affect the brain. While Alzheimer's disease is the most common type, accounting for 60–80% of cases, there are other forms of dementia, like vascular dementia, Lewy body dementia, frontotemporal dementia, and mixed dementia. Each type has unique symptoms and progression, making it important to understand the differences to provide proper care and support.

Alzheimer's Disease: The Most Common Form

Alzheimer's disease is the most common type of dementia, causing gradual memory loss and cognitive decline, mainly in older adults, but also affecting some individuals under 65 with early-onset Alzheimer's. Typical symptoms include forgetfulness, confusion, language difficulties, and impaired problem-solving skills. The disease is caused by the accumulation of toxic proteins called amyloid plaques and tau tangles in the brain, which damages brain cells and disrupts communication between them, leading to cell death and progressive brain damage.

Symptoms of Alzheimer's Disease

• Memory Loss: Usually, this is the first and most noticeable symptom. Individuals may forget recent conversations, names, and events but retain long-term memories.
• Disorientation: People with Alzheimer's often lose track of dates, seasons, and the passage of time.
• Difficulty with Familiar Tasks: Routine tasks, such as cooking or managing finances, become challenging.
• Language Problems: Finding the right words, following conversations, and understanding language can become difficult.
• Mood and Behaviour Changes: Depression, apathy, social withdrawal, and personality changes are common.

Vascular Dementia: A Blood Flow Issue

Vascular dementia, the second most common dementia type, occurs when reduced blood flow to the brain, often due to strokes, causes sudden and varied symptoms, depending on the affected brain areas.

Symptoms of Vascular Dementia

• Impaired judgement and planning: Early symptoms often include difficulties with decision-making and problem-solving.
• Memory Loss: Memory may be less affected than in Alzheimer's, but short-term memory problems are common.
• Confusion: Especially following a stroke or mini-stroke, individuals may experience confusion and disorientation.
• Physical Symptoms: Vascular dementia may cause physical symptoms such as difficulty walking, balance problems, and limb weakness.

Causes and Risk Factors

There is a significant link between vascular dementia and cardiovascular health, as various conditions impacting the heart and blood vessels can greatly elevate the likelihood of developing this form of dementia. High blood pressure, high cholesterol, diabetes, and smoking may damage blood vessels and reduce the blood flow to the brain, leading to vascular dementia.

However, by taking proactive steps to improve heart health, the risk of developing vascular dementia can be reduced. Achieving this goal involves adopting a variety of healthy practices, such as consuming a well-rounded diet that includes ample fruits, vegetables, whole grains, and beneficial fats; participating in regular physical exercise; maintaining optimal blood pressure; quitting smoking; and managing blood sugar levels for those with a diabetes diagnosis.

Adopting these healthy habits can help individuals maintain healthy blood flow to the brain, reduce the risk of vascular dementia, and promote overall brain health.

Lewy Body Dementia: The Parkinson's Connection

Lewy body dementia (LBD) is a complex condition characterised by abnormal protein deposits in the brain, sharing symptoms with Alzheimer's and Parkinson's diseases, and affecting 5-10% of dementia cases, often leading to misdiagnosis.

Symptoms of Lewy Body Dementia

• Fluctuating Cognition: Unlike the steady decline seen in Alzheimer's, LBD patients may experience varying levels of alertness and confusion from day to day or even hour to hour.
• Visual Hallucinations: Vivid, well-formed visual hallucinations are common and can occur early in the disease.
• Movement Problems: LBD typically has symptoms similar to Parkinson's disease, such as muscle stiffness, tremors, and a shuffling gait.
• REM Sleep Behaviour Disorder: Patients may act out their dreams, leading to sleep disturbances.

Challenges in Diagnosis

Lewy body dementia is usually misdiagnosed due to overlapping symptoms with other conditions, making accurate diagnosis crucial as some Alzheimer's medications can worsen LBD symptoms, particularly movement issues.

Frontotemporal Dementia: A Younger Person's Dementia

Frontotemporal dementia (FTD) is a group of rare disorders affecting the brain's frontal and temporal lobes, impacting personality, behaviour, and language, and is the leading cause of dementia in people under 60, despite being less common than Alzheimer's.

Symptoms of Frontotemporal Dementia

• Behavioural Changes: Individuals with FTD may exhibit significant changes in personality, including inappropriate social behaviour, lack of empathy, and compulsive actions.
• Language Problems: Difficulty speaking, understanding language, or finding the right words are common in FTD.
• Movement Disorders: Some types of FTD are associated with motor problems similar to those seen in Parkinson's disease or amyotrophic lateral sclerosis (ALS).

Differences from Alzheimer's Disease

Frontotemporal dementia (FTD) typically strikes at a younger age and advances more rapidly than Alzheimer's disease. Unlike Alzheimer's, where memory loss is a defining early symptom, FTD often begins with subtle changes in behaviour and language, which can be easily overlooked. However, these changes can quickly escalate, causing significant disruptions to daily life, social relationships, and careers, making early detection and intervention crucial.

Importance of Accurate Diagnosis

Accurate diagnosis of the specific type of dementia is crucial for several reasons:

• Treatment: Different forms of dementia may require different treatment approaches. For example, certain medications effective in Alzheimer's disease may not work for, or could even worsen, other types of dementia.
• Prognosis: Understanding the type of dementia can help predict disease progression and potential complications.
• Support and Care Planning: Knowing the type of dementia can help caregivers and healthcare providers develop more effective care strategies tailored to the individual.

Risk Factors and Prevention

Although certain risk factors for dementia, such as age and genetic factors, are unchangeable, lifestyle choices significantly influence the likelihood of developing the condition. General strategies for reducing the risk include:

• Healthy Diet: A diet with fruits, vegetables, whole grains, and lean proteins is beneficial for maintaining good brain health. The Mediterranean and DASH diets have been linked to a lower risk of dementia.
• Regular Physical Activity: Exercise improves cardiovascular health, supports brain health, and reduces the risk of vascular dementia.
• Cognitive Engagement: Engaging in activities like reading, solving puzzles, connecting with others, and acquiring new skills can help maintain cognitive function.
• Avoid Smoking and Excessive Alcohol Use: Smoking and drinking can increase the risk of dementia.

Conclusion

Alzheimer's disease is the most prevalent form of dementia, but it's just one of several types that impact millions globally. Recognising the distinct characteristics of Alzheimer's and other dementias, such as vascular, Lewy body, frontotemporal, and mixed dementia, is crucial for precise diagnosis and personalised care.

It's important to suspect and diagnose Alzheimer's disease early in the course because now we have the availability of disease-modifying drugs called immunotherapy, which can improve memory and cognitive functions if used in the early stages of the disease. 

These drugs, like Lecanemab and Donanemab, are being used in Western countries and are likely to be launched in our country, too. As research advances, we look forward to improved prevention methods, treatments, and, potentially, a cure for these devastating conditions, offering new hope for a brighter future.