Alzheimer’s disease: Causes, symptoms, diagnosis, and treatment

Alzheimer's disease is a type of dementia that is most prevalent amongst people over the age of 60.
Alzheimer's disease is a type of dementia that is most prevalent amongst people over the age of 60.
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What you need to know:

  • Alzheimer's disease is a deteriorative condition of the brain.
  • It results in progressive loss of cognitive and memory function, and is most associated with ageing.

Alzheimer's disease is an irreversible, progressive brain disease characterised by the destruction and loss of function of brain cells. The destruction and loss of function of the brain cells leads to dementia i.e., the loss of cognitive function - memory, reasoning, and thinking.

Based on this relationship, Alzheimer's disease is described both as a cause and a type of dementia. As the condition progresses, the loss of cognitive function hinders the person's ability to carry out the simplest tasks of daily living. Advanced Alzheimer's disease also affects the patients' social well-being as they forget the people in their lives and their relationship.

What causes Alzheimer's?

It has been over a century since Alois Alzheimer observed anomalies in the brains of patients with dementia. Since then, scientists have quite a clear understanding of the biochemical changes that happen in the brain of patients with Alzheimer's disease.

Despite the remarkable progress in understanding the disease, it is still not clear what causes the biochemical changes that lead to the deterioration of the brain and subsequent dementia.

However, some risk factors have been identified as possible contributors to the development of the disease. These include:

  • Old age

Alzheimer's is most common among people above 65 years of age. However, this does not mean that old age causes Alzheimer's. A lot of old people, even those with dementia, do not have Alzheimer's. Also, many younger people have also been diagnosed with the illness. The prevalence among old people might also be due to the slow progression of the illness.

  • Heredity or genetic disposition

People with a family member who has Alzheimer's disease are at an increased risk of developing the condition, first, due to genetic make-up. A gene known as apolipoprotein E type 4 (APOE e4) is associated with late-onset Alzheimer's disease. If you inherit this gene from one parent, your chances of developing Alzheimer's disease are quite high. The probability increases almost eight-fold if you inherit the genes from both parents.

Secondly, people from the same family have similar chances of getting Alzheimer's disease because they are exposed to the same factors such as diet, lifestyle, and genetic illnesses. These could either increase or reduce the family's predisposition to develop Alzheimer's disease.

The US Center for Disease Control (CDC) estimates that over 30 per cent of people with Down syndrome develop Alzheimer's disease at around 50 years of age. In relation to Alzheimer's, this is a quite a young age. By the age of 60 years, this increases to over 50 per cent. For comparison, in the general population, Alzheimer's average prevalence is at 10 per cent for people above the age of 65.

For years, it has been theorised that head injuries may aggravate the formation of Amyloid Beta (Aβ). The Amyloid Beta protein is associated with the degeneration of the brain leading to Alzheimer's dementia. Studies have shown a strong correlation between head injuries in older people and Alzheimer's. However, scientists still recommended further research because the causality has not been determined conclusively.

Symptoms of Alzheimer's Disease

One of the first and most noticeable symptoms of Alzheimer's disease is memory loss. This could manifest as forgetting recent events, conversations, or appointments. This is beyond the normal forgetfulness, and it gets progressively worse. In some cases, patients may even forget their close relatives and friends, and how to do simple tasks such as brushing their teeth or cooking a meal.

As the disease progresses, patients may find it hard to complete familiar tasks. This could be because they forget how to do them or because the task has become too complicated for them. For instance, someone who has been driving for many years may find it hard to follow the rules of the road or operate a vehicle. 

It also affects body functions such as swallowing. Swallowing is notable because food and drinks get misdirected to the windpipe instead of the oesophagus. The food particles cause infections, notably pneumonia, which is a major cause of death for people with Alzheimer's.

  • Problems with language

Patients with Alzheimer's disease may have trouble following or joining a conversation. They may also stop in the middle of a sentence and have no idea how to continue or they may repeat themselves. In more advanced stages, patients may have trouble understanding common words and expressions.

  • Disorientation

Patients with Alzheimer's disease may lose track of time, place, and even people. For instance, they may get up in the middle of the night and wander around aimlessly. This could be because they forget where they are or who the people around them are.

  • Changes in mood and behaviour

Patients with Alzheimer's disease may experience changes in their mood and behaviour. This could manifest as anxiety, depression, irritability, aggression, or apathy.

Diagnosis of Alzheimer's 

There is no one test that can diagnose Alzheimer's disease. Doctors use a combination of physical examinations, medical history, and cognitive tests.

Brain imaging is also done to detect and identify changes in the brain that are associated with Alzheimer's disease and dementia in general. The doctor may also carry other tests to rule out other causes of the changes you may have observed. 

The doctor may recommend that a close relative or friend accompany the patient so they can provide the behavioural changes that they have observed.

Treatments options for Alzheimer's Disease

There is currently no cure for Alzheimer's disease. However, there are treatments available to help manage the symptoms. For example, cholinesterase inhibitors and Memantine boost inter-cell communications, which is inhibited by Alzheimer’s. This improves the cognitive function of the patient. Further research is still ongoing on medications that can slow down its progression.

If you suspect that your loved one may have Alzheimer's disease, have them assessed by a doctor as soon as possible. Early diagnosis will help you start treatment and take measures to assist and protect them.

For example, you may need to modify the house arrangements to improve their safety, and to assign a caregiver to help them during episodes of disorientation.