Alzheimer’s Disease: Causes, symptom and treatment

Introduction

Alzheimer’s disease (AD) is a worsening brain disease that mostly harms older people, causing memory issues, thinking problems, and changes in behavior.

It was named after Dr. Alois Alzheimer who first identified it in 1906. Alzheimer’s is the leading cause of dementia, making up about 60-80% of cases.

The disease slowly hinders daily living activities and affects life quality. There is no cure, so Alzheimer’s is a tough health issue for many globally.

Research has helped us learn more about how it works, leading to better ways of diagnosing and treating it, but effective treatments that change the disease are still being studied.

Causes

The reasons for Alzheimer’s disease are not fully clear, but it is thought to come from a mix of genetics, environment, and habits. Important factors include:

• Amyloid Plaques: Unusual buildups of beta-amyloid proteins between brain cells are seen in Alzheimer’s. These plaques interfere with how cells communicate and activate immune cells that cause inflammation, resulting in cell death.
• Neurofibrillary Tangles: Inside nerve cells, tau proteins can become wrongly altered, creating tangles that disrupt the cell’s transport system and contribute to nerve death.
• Genetic Factors: Some genes are linked to Alzheimer’s disease. The most significant risk factor is the presence of the APOE-e4 allele, which raises the chance of getting Alzheimer’s. In rare instances, mutations in the APP, PSEN1, and PSEN2 genes can lead to early-onset Alzheimer’s, typically before age 65.
• Inflammation and Immune Factors: Long-term inflammation and problems with the immune system may harm brain cells over time in Alzheimer’s.
• Blood Vessel Factors: Poor blood vessel health can reduce brain blood flow, worsening nerve damage and possibly increasing Alzheimer’s risk.

Symptoms

Alzheimer’s disease symptoms worsen over time, starting with mild memory issues and leading to serious thinking and functioning problems. Common symptoms are:

• Memory Loss: Early-stage Alzheimer’s often begins with forgetfulness, especially of new events. Memory issues gradually get worse, affecting both recent and old memories.
• Problems with Problem Solving and Planning: Individuals may find it hard to manage money, follow directions, or organize tasks.
• Disorientation: As the disease advances, people may become confused about time, place, and even recognizable faces.
• Language Issues: Problems finding words or keeping up with conversations are common. Language difficulties can lead to repeated speech and challenges in complex talks.
• Bad Judgment: Individuals may show poor decision-making, affecting safety, money handling, and social interactions.
• Behavioral and Mood Changes: Feelings of anxiety, sadness, anger, and social withdrawal may occur in Alzheimer’s patients, especially in later stages.
• Loss of Physical Skills and Coordination: In advanced stages, individuals may have physical problems, like difficulty swallowing and loss of control over bowel or bladder functions.

Risk Factors

Several factors can raise the chance of getting Alzheimer’s disease:

• Age: Risk for Alzheimer’s rises greatly with age, especially after 65.
• Genetics and Family Background: Those with a family history of Alzheimer’s or specific gene variations, mainly APOE-e4, are at higher risk.
• Gender: Women have a higher chance of getting Alzheimer’s than men, may be due to living longer and hormone issues.
• Heart Health: Conditions like high blood pressure, high cholesterol, and diabetes can heighten Alzheimer’s risk by affecting brain blood flow. flow to the brain.
• Lifestyle and Environmental Factors: Smoking, not exercising, bad food choices, and limited social interaction have been linked to a higher chance of getting Alzheimer’s.
• Head Injury: Serious or repeated head injuries raise the risk of developing Alzheimer’s as one gets older.
• Education Level and Cognitive Reserve: Less education and lower mental activity during life may be connected to a greater risk of Alzheimer’s, as cognitive reserve may help delay progression of the disease.

Differential Diagnosis

Multiple other medical conditions can show symptoms similar to Alzheimer’s, making it important to differentiate:

• Vascular Dementia: This type is caused by reduced blood flow to the brain from strokes or small vessel disease. It shows a stepwise progression that is unlike the slow decline seen in Alzheimer’s.
• Lewy Body Dementia: This type involves fluctuating cognitive abilities, visual hallucinations, and motor symptoms like those in Parkinson’s. It is often confused with Alzheimer’s, yet requires a different treatment approach.
• Frontotemporal Dementia (FTD): FTD mainly impacts personality, behavior, and language more than memory in its early phases, setting it apart from Alzheimer’s.
• Parkinson’s Disease Dementia: Dementia in Parkinson’s relates to motor symptoms and usually arises in the later stages of the condition.
• Normal Pressure Hydrocephalus: This issue involves fluid build-up in the brain and can cause cognitive decline, balance problems, and urinary incontinence, sometimes reversible with treatment.
• Depression: Depression in older adults can look like dementia, referred to as “pseudodementia.” Addressing depression can greatly enhance cognitive function.

Investigation

To diagnose Alzheimer’s disease, a mix of medical history, cognitive tests, imaging, and lab analyses is used:

• Medical History and Physical Examination: A comprehensive history and exam assist in ruling out other sources of cognitive decline, such as medications or recent injuries.
• Cognitive Tests: Screening tools like the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) evaluate cognitive functions, including memory, attention, language, and problem-solving skills.
• Neuroimaging:
  • MRI and CT Scans: These imaging methods help visualize brain structure and spot brain shrinkage, helping to exclude other structural reasons for cognitive issues.
  • PET Scans: Positron Emission Tomography (PET) scans can find amyloid plaques in the brain with special tracers, aiding Alzheimer’s diagnosis.
• Laboratory Tests: Blood tests can rule out metabolic reasons for cognitive decline, such as vitamin shortages, thyroid problems, and infections.
• CSF Biomarkers: Examining cerebrospinal fluid (CSF) for markers like beta-amyloid and tau protein can give evidence of Alzheimer’s pathology.
• Genetic Testing: Testing for APOE-e4 or other genes linked to Alzheimer’s may be done in early-onset cases or with a strong family history.

Treatment

While there is no cure for Alzheimer’s disease, several treatments are available to manage symptoms and enhance quality of life:

1. Pharmacologic Treatment

• Cholinesterase Inhibitors: Medications like donepezil, rivastigmine, and galantamine boost acetylcholine levels in the brain, possibly aiding memory and cognition in early to moderate stages.
• NMDA Receptor Antagonists: Memantine acts as an NMDA receptor antagonist that helps manage glutamate activity, possibly enhancing cognition and lessening symptoms in moderate to severe Alzheimer’s.
• Antipsychotic Medications: For behavioral symptoms such as aggression and agitation, antipsychotics may be used in serious cases, but with caution due to side effects and the risk of worsening cognitive symptoms.
• Antidepressants and Anxiolytics: Depression and anxiety are common in Alzheimer’s, and medications such as SSRIs (selective serotonin reuptake inhibitors) are used to manage these issues.

2. Non-Drug Treatment

• Cognitive Stimulation Therapy: Doing activities that make people think, like puzzles, memory games, and socializing, might slow down the decline in thinking skills.
• Physical Activity: Exercising regularly can help brain health, possibly slowing down disease progress and boosting mood and overall functioning.
• Diet and Nutrition: Eating a diet high in antioxidants, like the Mediterranean diet, might lower the chance of cognitive decline and can help those with Alzheimer’s.
• Sleep Management: Poor sleep is linked to worse cognitive function, and better sleep habits can improve life quality.
• Occupational Therapy: Occupational therapists can assist people in keeping their independence with daily tasks, adjusting home surroundings for safety, and giving caregivers ideas for dealing with difficulties.

Preventive Measures

While Alzheimer’s cannot be entirely prevented, some lifestyle changes may lessen risk:

• Regular Physical Activity: Exercise is important for heart health, which is vital for brain health.
• Healthy Diet: Eating many fruits, vegetables, whole grains, and healthy fats is linked to a reduced risk of Alzheimer’s.
• Cognitive Engagement: Keeping the mind active through learning, social events, and mentally challenging tasks may help slow the onset of the disease.
• Managing Chronic Conditions: Taking care of issues like diabetes, high blood pressure, and high cholesterol can lower risks linked to Alzheimer’s.
• Avoiding Smoking and Excessive Drinking: These activities can raise the risk of Alzheimer’s and contribute to cognitive decline.

Conclusion

Alzheimer’s disease is a complex and progressive brain disorder marked by memory loss, thinking difficulties, and behavior changes.

While the exact cause is still being studied, factors such as amyloid plaques, tau tangles, genetics, and lifestyle can significantly affect it. Diagnosis is based on cognitive tests, imaging, and biomarker evaluation.

Though there is no cure, treatments like drugs and lifestyle changes can help with symptoms and enhance quality of life. Ongoing studies are working to find treatments that can change the disease, giving hope for future improvements in Alzheimer’s care.