Dementia is a disorder characterized by serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal ageing. Alzheimer's Disease is the most common form of dementia. It is more common in older individuals.
Alzheimer’s disease is an irreversible, progressive brain disease that slowly destroys memory and thinking skills, and eventually, the ability to carry out the simplest tasks of daily living. Although scientists are learning more every day, right now, they still do not know what causes Alzheimer’s disease. Thus it is an Idiopathic disease.
DSM 5 has changed the terminology of Alzheimer’s Disease as “Major or Mild Neurocognitive Disorder Due to Alzheimer’s Disease”
The content of this module has been validated by Dr K.S. Anand, Department of Neurology, Dr RML Hospital, New Delhi on 26/3/2015
Pre-dementia or Mild Cognitive Impairment (MCI) or Mild Neurocognitive Disorder Due to Alzheimer’s Disease: Characterized by level of cognitive decline that requires compensatory strategies and accommodations to help maintain independence and perform activities of daily living.
Mild Alzheimer’s dementia or Major Mild Neurocognitive Disorder Due to Alzheimer’s Disease- Mild: Characterized by symptoms which mildly impair activities of daily living so that patient needs supervision over complex tasks, like managing finances etc.
Moderate Alzheimer’s dementia or Major Neurocognitive Disorder Due to Alzheimer’s Disease- Moderate: Characterized by symptoms which moderately impair activities of daily living so that patient needs assistance for some of the activities.
Severe Alzheimer’s dementia or Major Neurocognitive Disorder Due to Alzheimer’s Disease- Severe: Characterized by symptoms which severely impair activities of daily living such that patient is completely dependent on others for basic needs.
Patients with severe dementia may lose the ability to walk, talk, and take care for themselves. They need to rely on caregivers to handle even their most basic needs, including eating, washing, and going to the bathroom. They may also have difficulty in communication including telling names of things, or finding appropriate words to express themselves.
Scientists have not yet understood the exact cause of Alzheimer's disease. It is postulated to have multifactorial etiology like:
Genetic: The Apolipoprotein E (ApoE) gene is implicated in Alzheimer’s Disease. This gene has several forms. One of them, ApoE ε4, seems to increase a person’s risk of getting the disease. However, carrying the ApoE ε4 form of the gene does not necessarily mean that a person will develop Alzheimer’s disease, and people carrying no ApoE ε4 can also develop the disease. Most experts believe that additional genes like Presenilin 1, mutation on chromosome 14, APP (Amyloid Precursor Protein) mutation on chromosome 21 and Presenilin 2, mutation on chromosome 1 may influence the development of late-onset Alzheimer’s. Scientists around the world are searching for other genes that may increase a person’s risk for developing Alzheimer’s disease.
Environmental/ Lifestyle factors: Diseases like heart disease, stroke, high blood pressure, diabetes, obesity, hyperlipidemia etc. have also shown to be linked with the Alzheimer's disease.
Early, accurate diagnosis is crucial for several reasons. It can tell people whether their symptoms are due to Alzheimer’s disease or another cause, such as stroke, tumour, Parkinson’s disease, sleep disturbances, side effects of medications, or other conditions that may be treatable and possibly reversible.
It also help families plan for their future, make living arrangements and develop support networks. In addition, an early diagnosis can provide greater opportunities for people to get involved in clinical trials.
Although definitive diagnosis of Alzheimer's can be made only after death, yet the doctors can usually diagnose the disease with the help of:
There is no cure for Alzheimer's disease; though symptomatic relief can be provided. Current treatments can be divided into Medical, Psychosocial and Care giving.
Cholinesterase Inhibitors - Acetylcholine is a chemical that keeps the nerve signals charged and helps the messaging system within the brain cells. Various medications to treat Alzheimer's are:
These are used to treat mild to moderate Alzheimer's disease
NMDA Receptor blocker
Psychosocial interventions are used as an adjunct to medicinal treatment and can be classified as supportive, cognitive and behavioural approaches.
Since patient with Alzheimer's has no cure, it gradually renders people incapable of tending for their own needs, thus care giving essentially is the treatment and must be managed carefully over the course of the disease.
There is no definitive evidence to support that any particular measure is effective in preventing. However, there are certain steps that could be taken which may help to delay the onset of dementia. Staying mentally healthy by: