Alzheimer’s disease is the most common type of dementia. The disease was first observed by a German psychiatrist and neuropathologist Alois Alzheimer in 1906 and is named after him. Alzheimer’s disease is an incorrigible neurodegenerative disorder generally occurring in individuals above 65 years of age but cases with early onset of the disease are not uncommon. A report presented in 2006 specified that about 26.6 million individuals suffer from this neurodegenerative disease. The symptoms of this disorder are although inimitable for every individual but there are many symptoms that are common. The initial symptoms of the disease are loss of the capability to form new memories and inability to recall current events. Diagnosis of Alzheimer’s disease is based on cognitive tests and brain scan. As the disease advances the individual shows the symptoms of confusion, irritability, aggression, mood fluctuations, language problems and finally long-term memory loss. The vivacious functions of body fail to operate and death is the decisive fate. Less than 3% percent live for about fourteen years after the diagnosis of the disease.
The precise cause of Alzheimer’s disease is still not understood. Researches carried out all over the world designate that the disease is caused due to the accretion of plaques and tangles in the brain. Although treatment for this disorder is available but the chances of complete recovery is less. More than 500 clinical trials have been carried out but meticulous reason for the occurrence of this disorder is yet not available. Mental stimulation, balanced diet and exercise are recommended for the patients of this disorder. As Alzheimer’s disease is degenerative and incurable disease proper management of the patient is essential. Family support is sturdily required.
Who are at risk?
The prime factor blamable for Alzheimer’s disease is increased age and as the age of the individual increases the risk of this disease also increases. According to a report about 10% of the individuals belonging to the age group of 65 and 50% of the individuals of the age group of 85 suffer from Alzheimer’s disease. According to a guesstimate the number of patients of this disease will increase to 14 million by 2050. Genetic factors are also thought to be responsible for this disease and most of the individuals develop this disorder after the age of 70.
However, about 2-5% of the individuals develop the symptoms in their early forties and fifties. The children of a person with early onset of the symptoms of Alzheimer’s disease are at 50% risk of developing this disorder. The gene located on chromosome 19 is believed to be responsible for this disease. However, in majority of cases specific genetic risks have not been identified yet. Other risk factors associated are high blood pressure, coronary artery disease, high blood cholesterol and diabetes. All the patients of Down syndrome develop this disorder in their forties.
The onset of the disease is gradual but the symptoms become more penetrating as the disease advances. Problems associated with short-term memory normally arise in the earlier phase of the disease. Mild personality changes also occur in the preliminary phase of the disorder. With the advancement of the disease the patient develops symptoms of difficulty in abstract thinking and other intellectual impairments. The patient feels difficulty in carrying out the office work also. Behavioral changes also take place. In later cases the person becomes confused and disoriented in relation to month, time, people and places. The person is also at the jeopardy of getting infected with pneumonia and the condition become worse before the death of the patient.
Ten warning signs of Alzheimer’s disease and mild cognitive impairment
The Alzheimer’s Association has developed a list of warning signs that can help the medical expert to ascertain whether a person is suffering from Alzheimer’s disease or not. These signs are memory loss, difficulty if performing duties coupled with family. Problems with language, disorientation in relation to time and place, decreased judgment ability and difficulty in abstract thinking. Misplacing things, mood fluctuations, behavioral changes and loss of ability to take initiative for any task are also common. The advancement of this disorder is precarious and sluggish and the memory status of the patient becomes inferior day by day but he or she may not develop dementia as there are convinced criteria that form the baseline of dementia. This syndrome is recognized as Mild Cognitive Impairment (MCI) and can be analyzed only after neurophysiological testing. There are numerous forms of MCI but the most common one is associated with memory impairment. The aptitude to plan a work and the cognitive ability of the individual are not affected in this syndrome. Individuals with this type of MCI are known as amnestic MCI and have a high risk of getting affected with Alzheimer’s disease. Individuals with incapability of decision making are at low risk of developing Alzheimer’s disease.
Causes and risk factors
The rigorous cause of the disease is still vague but the amyloid cascade hypothesis is most extensively discussed and agreed in this context. The data that supports this hypothesis actually comes from the early onset of Alzheimer’s disease that had a genetic basis. In about half of the patients with early onset of symptoms of Alzheimer’s disease, mutations play a key role. In all these patients mutations result in the disproportionate production of a protein fragment known as ABeta in brain. In the present scenario much of the research is focused on finding out the ways to slow down the extreme production of this protein in Alzheimer’s disease. The biggest and the principal significant factor of this disorder is the increased age. The individuals belonging to the age group of 65-85 are at the double risk of developing this disease. Only 1-2% of individuals of 70 years of age develop Alzheimer’s disease however, about 40% individuals of 85 years of age develop this disorder. The individuals that lived in the past for about 95 years were not the sufferers of this disease.
There are many genes that can be considered responsible for the development of this disease but they may not develop the disorder every time. The major risky gene that is generally considered responsible for AD is apoE that encodes for apolipoprotein E. This gene apoE occurs in three alleles namely apoE2, apoE3 and apoE4. The allele apoE4 is believed to upsurge the risk of the disease and the frequency lies below 30%. The individuals with one copy of apoE4 have two-three times increased risk of developing Alzheimer’s disease and those with two copies of this allele have nine-fold increased risk. Generally individuals with two copies may not suffer from the disease always but only one copy of E4 is generally found in individuals with late onset of the disorder. We can predict here that genetic basis does not form a strong baseline for Alzheimer’s disease. Genetic tests also do not forecast that the children of the patients of this disease are at the risk of developing this disorder in their lifetime. Majority of the studies carried out have signposted that females are at a superior risk of developing Alzheimer’s disease in comparison to males. It is clear that the lifespan of females is longer than males but this criterion cannot be correlated with the occurrence of AD. Scientists believe that the estrogen level can be compared with the risk of developing the disease, so much research is now focused on this issue. Even studies have indicated that the individuals who have received traumatic head injuries are at an elevated risk of developing Alzheimer’s disease.
Diagnosis and importance of clinical evaluation
No specific blood test and imaging technique can predict that whether a person is suffering from Alzheimer’s disease. For the diagnosis of this disorder a person must fulfill the criteria that form the baseline for dementia. A number of factors can be considered responsible for the development of dementia. Neurological disorders namely Parkinson’s disease, brain tumors, blood clots, cerebrovascular disease and strokes can be sometimes associated with dementia. Chronic syphilis, chronic HIV can also sometimes develop the symptoms of dementia. Many medications namely those used for the control of bladder urgency and incontinence can also cause cognitive impairment. Psychiatric and neurological medications are also responsible for cognitive impairment. If the medical expert finds these medication problems in the patient he sturdily recommends halting the usage of these drugs. In older individuals that usually suffer from depression also develop the problems associated with memory and concentration loss and such a condition can be specified as pseudodementia. Excessive use of alcohol and illegal drugs can be sometimes responsible for the symptoms of dementia. Thyroid dysfunction, thiamine deficiency and steroid disorders can also lead to cognitive impairment. Blood clots outside the brain region can also cause symptoms of dementia. Carbon monoxide poisoning leads to encephalopathy that develops symptoms of dementia. Sometimes heavy metal poisoning is also considered responsible for dementia.
Since a number of disorders are often confused with Alzheimer’s disease a comprehensive clinical evaluation is very important for the accurate diagnosis of the disease. Three procedures are generally followed while diagnosing the disorder and these are a complete medical workup, neurological examination and psychiatric evaluation. These evaluations usually continue for at least an hour. In the United States healthcare system a combined help of neurologists, psychiatrics and geriatrics is taken. Even a single physician can also perform the evaluation well. The American Academy of Neurology has given some guidelines that include brain imaging while working with the patients of dementia. These imaging techniques comprise non-contrast CT scan or MRI scan. SPECT, fMRI, PET can also be of help but are not used. In areas outside the United States brain imaging is considered an important part while diagnosing Alzheimer’s disease. The search for an efficient blood test for the perfect diagnosis of Alzheimer’s disease is still going on.
Alzheimer’s disease is customarily a progressive disorder that reaches its peak within the interval of 8-15 years. The patients generally do not die with the disorder alone but they also suffer from a number of others problems also like they feel difficulty in swallowing, walking and are at an elevated risk of getting infected with pneumonia. In the later courses of the disease strongly family assistance is required. A patient of Alzheimer’s disease is however unable to solve numerical problems but can feel interest in reading a magazine. Playing of piano may be too difficult for the patient as he commits many mistakes but the ability of singing and listening to music remains unaffected. Playing chess may be too difficult for the patient but he or she may feel pleasure while playing tennis.
The treatment of Alzheimer’s disease can be placed under medication based and non-medication based categories. FDA has classified two groups of pharmaceuticals for the treatment of this disease and these are cholinesterase inhibitors and partial glutamate antagonists. But none of the drugs can perfectly slowdown the rate of progression of Alzheimer’s disease. In patients suffering from this disorder the process of formation of the brain neurotransmitter especially the acetylcholine stops and research has indicated that this chemical plays a crucial role in memory formation. The cholinesterase inhibitors (ChEIs) participate in blocking the breakdown of this neurotransmitter and therefore, help in memory formation. FDA has approved four cholinesterase inhibitors namely donepezil hydrochloride, rivastigmine, galantamine and tacrine for the treatment of Alzheimer’s disease but only first three are used by the medical experts as the fourth one is risky and causes severe side effects. Studies have clearly indicated that these drugs slowdown the rate of disease progression only for about 6-12 months and then the disease starts advancing again.
FDA has approved the use of rivastigmine and galantamine for the treatment of mild and moderate symptoms of Alzheimer’s disease but donepezil can be used for the treatment of mild, moderate and severe symptoms. The exact reason why these two drugs are not used against the severe symptoms of the disease is not clear. The major side effects of ChIEs are associated with the gastrointestinal system and they include nausea, cramping, diarrhea and vomiting. These symptoms can be controlled by changing the timing of medication as well as intake of small amount of food and about 75-90% of the patients bear the potential of tolerating the therapeutic doses of cholinesterase inhibitors. Glutamate is the chief excitatory neurotransmitter of brain. One hypothesis suggests that excessive secretion of glutamate is harmful for brain as it damages nerve cells. Memantine is a drug that slows down the rate of activation of nerve cells by glutamate and is therefore, reducing the progression of this disorder. This drug can be used for treating both mild and severe disease. The patient recovers faster if a dose of cholinesterase inhibitors and memantine are given together.
Non-medication based treatments include orientation of the patient towards social activities like singing, dancing, walking etc. Cognitive rehabilitation may be helpful in this regard. The chief psychiatric symptoms associated with Alzheimer’s disease are irritation, depression, hallucinations, anxiety and sleep disorders. Standard psychiatric drugs are although used for the treatment of these symptoms but none of the drugs have been approved by the FDA. These symptoms become as intense as disease advances that treatment with medication becomes necessary. Agitation becomes very much severe in the later stages of the disease. Agitation is controlled by a number of agents for example, beta-blockers, anxiolytics, antipsychotics and mood stabilizing anticonvulsants. Newer antipsychotic drugs have taken the place of the older drugs and are giving fruitful results for example, risperidone, clozapine and olanzapine.
Depression is another very common symptom of Alzheimer’s disease and the patients can be treated with antidepressants namely sertraline and citalopram. Anxiety in this disorder can be treated with benzodiazepines for example, diazepam. Non-benzodiazepines anxiolytics like buspirone are generally preferred for the treatment. Insomnia is another symptom that can crop up in patients of Alzheimer’s disease at any part of their life. Trazodone is a promising drug used for overcoming this symptom. A number of clinical research trials have been carried with increasing or decreasing the amount of Aβ1-42 but no successful result has been achieved.
Caring for the caregiver is an essential aspect while dealing with the patient of Alzheimer’s disease. Caregiving is a distressing experience and proper education of the caregiver is essential. The 3Rs namely repeat, reassure and redirect can help a caregiver in reducing the troublesome behavior as well as limiting the use of medication in the patients. The short-term training programs can help a caregiver to increase his or her confidence while dealing with the patients. Alzheimer’s disease is a curse and it makes the condition of a person worse and death is the ultimate fate in later stages. Love, care and support can however, help the patient to enjoy life.