Alzheimer’s is a disease that impairs the neurological function of the brain. Colloquially referred to as loss of memory disease, it has a negative effect on memory, cognitive function, and language comprehension skills. The disoriented brain response also leads to unpredictable behaviour among patients diagnosed with this illness. Per a study by the Alzheimer’s Association, approximately 4 million people in India have some form of dementia, which includes Alzheimer’s. The onset of the disease is primarily noticeable in people aged above 65 years. But in rare cases, one could be diagnosed of this illness early.
Alzheimer’s disease typically starts as short episodes of forgetfulness and gradually progresses into patients losing their ability to perform everyday tasks. There is no known cure for this illness till date and patient’s symptoms and life condition depends on the types of Alzheimer’s disease or the stage to which it has progressed. But certain treatments help with slowing the disease progression and make living with it easier.
Types of Alzheimer’s Disease
Alzheimer’s is mainly categorised into three types:
- Early-onset Alzheimer’s When people aged below 65 years, develop the symptoms of Alzheimer’s they are known to have an early-onset condition. Such occurrence is rare, but usually occurs when you are aged between 45 to 50 years. The risk increases for people with genetic conditions – Down Syndrome for instance, that causes developmental problems. Early onset Alzheimer’s is also linked to the development of tangles and loss of brain volume. Affected patients may notice signs like muscle twitching and spasms.
- Late-onset Alzheimer’s: Alzheimer’s that develops after one crosses the age of 65 years is called late-onset Alzheimer’s. The exact cause of the condition is still unknown. It may or may not occur due to genetic history. There is no particular gene that causes it based on the research data till date. Ageing, environmental factors, and mental behavioural are known to influence its onset. This type of Alzheimer’s is medically characterised by a deficit in episodic memory and varying degrees of impairment in cognitive response.
- Familial: In this type of Alzheimer’s, the definitive cause is genes. Familial Alzheimer’s disease (FAD) is prevalent in families where at least two generations have suffered from the condition. A study by the University of California, San Francisco states that 5% of cases are attributed to genetic mutation transmitted in families. The symptoms of FAD usually show up in the early 30s or 40s. The genes linked to the early onset of FAD are presenilin 1 on chromosome 14, presenilin 2 on chromosome 1, and amyloid precursor protein on chromosome 21. There are other gene varieties like apolipoprotein that may increase the risk of Alzheimer’s but not necessarily cause the disease.
Causes of Alzheimer’s
The primary cause of Alzheimer’s is associated with two abnormal structures that damage the nerve cells in the brain.
- Plaques: Plaques are large masses of a larger protein called beta-amyloid, i.e., the naturally occurring protein deposits in clusters between brain cells when you develop the loss of memory disease. An increase in abnormal functioning leads it to clump together to form plaques. Such formation has a negative effect on neurological communication between the brain cells. The result is disrupted cell function.
- Tangles: In regular brain functioning, tau protein is supported by structures called microtubules that transport nutrients from the cell body to axons and dendrites. The function of tau is to bind and stabilise microtubules. But in Alzheimer’s, tau proteins go through chemical changes and lodge themselves in the structures called the neurofibrillary tangles. This abnormal activity disrupts the neuron’s transport system and damages cells.
Progression of Symptoms in Different Stages of Alzheimer’s
Alzheimer’s disease progresses as per the following stages:
- Preclinical Stage: Changes in the brain give rise to the onset of the disease years before one get diagnosed. Affected individuals or anyone around them will not notice any symptoms of Alzheimer’s in the preclinical stage. Only researchers can identify the signs through advanced imaging tests when patients participate in clinical trials. They assess the presence the amyloid-beta protein to confirm the condition. In case of no diagnosis, the preclinical stage can last for years before the symptoms surface.
- Mild Cognitive Impairment Stage: In this stage, the first sign of Alzheimer’s – forgetfulness is noticeable. As it normally occurs in older people, it may be confused with loss of memory due to ageing. Besides memory loss, a person with Alzheimer’s may also have trouble concentrating, remembering names or words, managing time, finding familiar objects, etc. Such mild symptoms do not interfere with performing regular activities and the affected patient can live independently. The mild cognitive impairment stage may reverse or remain stable in some cases.
- Moderate Stage: When the disease progresses from mild cognitive impairment, you reach the moderate stage where the symptoms are more pronounced. As a result, patients with this condition require extra care and supervision from their guardians. Due to increased confusion, irritation and unexpected behaviour may surface. Additionally, expressing thoughts becomes difficult as nerve cells in the brain are damaged. This stage lasts for a longer period, typically years. With time, symptoms can progress to a stage where you may know something is familiar but fail to name it, lose track of time, need assistance with regular tasks, etc.
- Last Stage: Alzheimer’s disease has a severe impact on the physical and mental capabilities in the last stage. The patient requires care and supervision round-the-clock as there is a complete loss of awareness. Other effects include the inability to communicate coherently, susceptibility to infections, and decline in physical abilities. Engagement initiation decreases in the last stage. But guardians can comfort the patients through music, gentle touch of reassurance, proper care and attention.
Diagnosis of Alzheimer’s Disease
Traditionally, an effective method to diagnose Alzheimer’s is studying the brain tissue after death. But modern technology has enabled doctors to diagnose this difficult illness through the following methods:
- Lab Tests: Diagnosis includes analysing blood and urine samples to understand the overall health condition. Doctors also investigate the measurable changes in blood levels to identify specific markers like tau and beta-amyloids that are associated with Alzheimer’s. The urine test helps in spotting formic acid biomarkers that indicate a cognitive decline.
- Physical Examination: Analysing physical conditions is a standard diagnostic approach for all illnesses. The same goes for Alzheimer’s disease. Doctors conduct a physical examination to check reflexes, sense of sight and hearing, physical coordination, ability to perform regular tasks, etc. Such observation is aimed to spot the symptoms and recognise the stage of disease progression.
- Imaging Tests: Brain imaging is the most helpful technique in pinpointing the biomarkers causing cognitive dysfunction. Imaging tests used for the same include Computer Tomography (CT) scan and Magnetic Resonance Imaging (MRI) scan. MRI produces detailed images of the brain using radio waves. It picks up on biomarkers like brain shrinkage, inflammation, bleeding and other structural defects. A CT scan is an X-ray technology that shows abnormal characteristics in the brain. It helps doctors rule out ailments like a tumour, head injuries, and strokes. Other possible imaging tests include Position Tomography Imaging (PET) scans to measure the presence of fluorodeoxyglucose, amyloid, and tau.
- Neurological Tests: A variety of assessment tools are used to study your cognitive function in neurological testing. Such evaluation aims to understand your memory, mental status, and thinking skills. Your orientation of time, place, and objects is studied by asking questions. Some other techniques are also used for identifying memory loss and comprehension skills.
Death of nerve cells is irreversible. Hence, there is no definitive cure for Alzheimer’s disease. The only possible treatment approaches are:
The Food and Drug Administration (FDA) has approved the following drugs for managing the symptoms of Alzheimer’s:
- Cholinesterase Inhibitors: As cell-to-cell communication is disrupted in the loss of memory disease, cholinesterase inhibitors help with the preservation of chemical messengers. Doctors prescribe these drugs as the primary course of action. They ease cognitive symptoms, control judgement problems, and correct altered thought processes or confusion. Subcategories of cholinesterase inhibitors include donepezil (Aricept), rivastigmine (Exelon), and galantamine (Razadyne ER).
- Memantine: Memantine is a drug prescribed in the moderate to last stage of Alzheimer’s. It blocks the effect of glutamate, a brain chemical released excessively that damages the neurons. It is sometimes used in combination with a cholinesterase inhibitor to manage memory loss symptoms better. Memantine increases awareness and helps with the ability to perform daily tasks.
- Antidepressants: Symptoms progress beyond the decline in chronic memory and thinking ability in Alzheimer’s. As the condition worsens, there is a possibility of experiencing delusions, hallucinations, sleep disturbances, agitation, irrational beliefs, and restless pacing. Doctors may prescribe antidepressants, antipsychotics, or anti-anxiety medications to treat such symptoms.
Brain stimulation is the main focus of different types of cognitive therapies to address cognitive defects and improve neurological functioning. Some therapy practices adopted for the same include skills training, activities that boost memory, and making changes in the way regular tasks are approached. Cognitive therapy also includes making lifestyle changes in terms of maintaining a familiar environment, offering mental comfort, and methods to redirecting attention.
As there is no cure, there is no definitive method that can prevent the occurrence of Alzheimer’s. But some practices that protect cognitive health include:
- Mental Activity
You can engage in cognitive training activities like playing board games, solving puzzles, and playing musical instruments to improve brain power.
- Physical Exercising
Staying physically active increases the blood, nutrient, and oxygen flow to brain cells, enhancing neurological health.
- Social Engagement
Interaction with friends and family preserves emotional well-being, which directly affects mental health. Social engagement is also possible through volunteer work and participating in social groups, book clubs, like-minded communities, etc.
- Healthy Diet
A healthy diet with a balance of vegetables, fruits, proteins, and other nutrients helps maintain physical, emotional, and mental well-being. It preserves your immunity against various diseases, including cognitive abnormalities.
- Avoiding Smoking
Smoking gives rise to abnormal functioning of the cardiovascular system. As a result, the blood vessels and heart struggle with transporting nutrients and oxygen to the brain cells. This, in turn, stresses neurons and damages them. Avoiding smoking helps prevent such detrimental effects.
How to distinguish between memory loss due to ageing and Alzheimer's disease?
Age-related memory changes do not interfere with your ability to perform regular tasks. They occur occasionally and mostly lead to misplacing objects, forgetting the names of acquaintances, and general forgetfulness. But Alzheimer's symptoms are recurring, relatively severe and interfere with your normal functioning.
As a caregiver, how can I support a loved one with Alzheimer's?
The condition affects people differently based on their overall well-being and the extent of cognitive decline. Hence, the best way to support your loved one with Alzheimer's is to ask the doctor for suggestions. Some other standard approaches include being patient, listening, staying emotionally connected, watching for signs of trouble, etc.
What is the life expectancy of an Alzheimer's patient after being diagnosed of the illness?
The disease progresses at its own pace depending on the severity of symptoms and cognitive function of the affected person. On average, patients with Alzheimer's can live for up to four to eight years after diagnosis. But with mild symptoms, the survival period can extend to 20 years.
What should I avoid doing as a caregiver for an Alzheimer's patient?
Being patient and understanding is extremely crucial while supporting an Alzheimer's patient. You want to avoid anything that can aggravate their cognitive ability and mental health. Hence, do not tell them when they are wrong, avoid arguing with them, and restrict prodding them to remember things.
How is Alzheimer's different from dementia?
Alzheimer's and dementia differ in the sense that the former is a specific disease, while the latter refers to the general decline of mental ability. Dementia is a group of disorders that affect the ability to think, control emotions, remember, and make a decision. Alzheimer's is one of these disorders, but has specific symptoms associated with memory that worsen over time.