Alzheimer's disease is a neurological disorder in which the death of brain cells causes memory loss and cognitive decline. A neurodegenerative type of dementia, the disease starts mild and gets progressively worse.
- Alzheimer's disease is the most common cause of dementia.
- The word dementia describes a set of symptoms that can include memory loss and difficulties with thinking, problem-solving or language. These symptoms occur when the brain is damaged by certain diseases, including Alzheimer's disease.
- Alzheimer's is a progressive disease. This means that gradually, over time, more parts of the brain are damaged. As this happens, more symptoms develop. They also become more severe.
- In 2010, some 4.7 million people of 65 years of age and older were living with Alzheimer's disease in the US.
Symptoms of Alzheimer's disease:
Early signs of Alzheimer's:
- Memory loss that disrupts daily life
- Challenges in planning and problem solving
- Confusion with time and place
- Difficulty completing familiar task at home, place or leisure.
- Trouble understanding visual images and spatial relations.
- New problems with words in speaking and writing.
- Decreased or poor judgement.
- Withdrawal from work or social life
- Misplacing things and decreasing the ability to retrace steps
- Changes in mood and personality
Several different parts of the brain can be destroyed, which can provide different symptom:
- Posterior cortical atrophy (PCA)-It occurs when there is damage to areas at the back and upper-rear of the brain.
- These are areas that process visual information and deal with spatial awareness.
- Early symptoms of PCA are often problems identifying objects or reading, even if the eyes are healthy. Someone may also struggle to judge distances when going down stairs, or seem uncoordinated (for example when dressing).
- Logopenic aphasia -itinvolves damage to the areas in the left side of the brain that produce language.
- The person's speech becomes laboured with long pauses.
- Frontal variant Alzheimer's disease-It involves damage to the lobes at the front of the brain.
- The symptoms are problems with planning and decision-making.
- The person may also behave in socially inappropriate ways or seem not to care about the feelings of others.
Stages of Alzheimer's disease:
The progression of Alzheimer's can be broken down into three basic stages:12
- Preclinical (no signs or symptoms yet)
- Mild cognitive impairment
These three stages can be further broken down into seven stages.
Causes of Alzheimer's disease:
Alzheimer's disease damages and kills brain cells. A brain affected by Alzheimer's disease has many fewer cells and many fewer connections among surviving cells than does a healthy brain.
- The total brain size shrinks with Alzheimer's - the tissue has progressively fewer nerve cells and connections
- People with Alzheimer's also have a shortage of some important chemicals in their brain. These chemical messengers help to transmit signals around the brain.
- Tiny inclusions in the nerve tissue, called plaques and tangles.
- Plaques are found between the dying cells in the brain - from the build-up of a protein called beta-amyloid.
- The tangles are within the brain neurons - from a disintegration of another protein, called tau.
Risk factors of Alzheimer's disease:
Risk factors associated with Alzheimer's disease may include-
- Age - the disorder is more likely in older people, and a greater proportion of over-85-year-olds have it than of over-65s.
- Family history (inheritance of genes) - having Alzheimer's in the family is associated with higher risk. This is the second biggest risk factor after age.
- Having a certain gene (the apolipoprotein E or APOE gene) puts a person, depending on their specific factors.
- Neurological disorders- People with previous neurological disorders, such as Parkinson's or multiple sclerosis are at higher risk of Alzheimer's.
- Infectious diseases: Some brain infections such as chronic syphilis, chronic HIV, or chronic fungal meningitis can cause dementia.
- Tumours: Many primary and metastatic brain tumours can cause dementia.
- Metabolic Disorders: Thyroid dysfunction, some steroid disorders, and nutritional deficiencies such as vitamin B12 deficiency or thiamine deficiency are sometimes associated with cognitive impairment.
- Psychiatry disorder: In older persons, some forms of depression can cause problems with memory and concentration that initially may be indistinguishable from the early symptoms of Alzheimer's disease
- Side effects of medications: Many medicines can cause cognitive impairment, especially in elderly patients. Perhaps the most frequent offenders are drugs used to control bladder urgency and incontinence
- Factors that increase blood vessel (vascular) risk - including diabetes, high cholesterol and high blood pressure.
- Prior head injury- Increases the risk to many fold.
- Sleep disorders.
Genetics are behind early-onset familial Alzheimer's disease, which presents typically between the ages of 30 and 60 years and affects people who have a family history of it. Young-onset disease is uncommon and account accounting 5% of all Alzheimer's cases.
Treatments of Alzheimer's disease:
- Medications-Current Alzheimer's medications can help for a time with memory symptoms and other cognitive changes. Two types of drugs are currently used to treat cognitive symptoms:
- Cholinesterase inhibitors. These drugs work by boosting levels of a cell-to-cell communication by providing a neurotransmitter (acetylcholine) that is depleted in the brain by Alzheimer's disease.
- Commonly prescribed cholinesterase inhibitors include donepezil (Aricept), galantamine (Razadyne) and rivastigmine (Exelon). The main side effects of these drugs include diarrhea, nausea, loss of appetite and sleep disturbances. In people with cardiac conduction disorders, serious side effects may include a slow heart rate and heart block.
- Memantine (Namenda). This drug works in another brain cell communication network and slows the progression of symptoms with moderate to severe Alzheimer's disease. It's sometimes used in combination with a cholinesterase inhibitor. Side effects may include constipation, dizziness and headache.
- Anti-anxiety and anti-depressant drugs- This drugs can release the symptoms for a particular time period. But this drugs can cause serious side effects as a confusion, dizziness, even severity of the symptoms.
- Creating a safe and supportive environment- Alzheimer patients undergo mood swings, and certain emotional ups and downs. The patients should be handled with care and support from their surroundings and most importantly from family. Support from the close and loved ones can be their most important and successful treatment.
- Exercise and diet- Leading a healthy and active lifestyle can help the patients to overcome their symptoms and lead a normal healthy life.
Diagnosis of Alzheimer's:
- Lab test-Blood tests may help your doctor rule out other potential causes of memory loss and confusion, such as thyroid disorders or vitamin deficiencies.
- Mental status and neuropsychological testing-Conducting a brief mental status test to assess the memory and other thinking skills.
- Brain imaging-Images of the brain are now used chiefly to pinpoint visible abnormalities related to conditions other than Alzheimer's disease - such as strokes, trauma or tumors - that may cause cognitive change.
- Brain-imaging technologies include:
- Magnetic resonance imaging (MRI)
- Computerized tomography (CT)
- Positron emission tomography (PET)
- Cerebrospinal fluid. In special circumstances such as rapidly progressive dementia or very young onset dementia, a cerebrospinal fluid examination may be performed. The spinal fluid can be tested for bio markers that indicate the likelihood of Alzheimer's disease.