For centuries, many societies realised that advanced age accompanies changes in mental abilities. Senility incurred deterioration, not only of physical competence but also of mental faculties. That was not always true, as many senior citizens maintained a productive, independent and wise mind. In the past, mental health problems in the elderly were lumped together under the title of senile dementia. By the 19th century, doctors started to distinguish dementia from other mental health problems in old age like depression or psychosis.
Dementia is a term that covers many conditions that cause deterioration in memory, language, thinking, emotions, judgement and daily living activities without a change in alertness or consciousness.
There are several types of dementia. The most common and well-known type is Alzheimer's Disease. The second type is vascular dementia which arises from problems in the blood vessels of the brain. In Vascular dementia, multiple tiny strokes clog small vessels in the brain with blood clots. This dementia may burst in by partial paralysis, sudden loss of movement or sensation in a limb, drop in the face or unexpected impaired speech. Vascular dementia is rightly called Multi-Infarct Dementia.
Memory decline is not the only trouble in dementia, though the inability to register recent information is the most distinctive feature. The person starts to be forgetful about recent events, but soon other signs of change in higher mental abilities appear. Emotional problems like depression or decreased motivation make the person less interested in his surroundings. Language problems make expressing one's thoughts more difficult. Finding the correct words to express what is on the person's mind is evident.
Common symptoms involve progressive impairments in memory, thinking, and behaviour. They affect the ability to look after oneself or carry out everyday activities. The symptoms occur in a continuum over several stages.
Someone with early symptoms of Alzheimer's may become repetitious and may ask the same question every few minutes, or mention the same point of view more than once. Getting lost is a problem if they have to navigate their way outside home. Inside their house, where they lived for years, they find no difficulties as they have memories of every corner of the house. Difficulties tracking bills, financial omissions and mistakes need special attention from family. Problems with cooking the favourite meals are observed. Forgetting to turn off the cooker can be sometimes dangerous. The person usually forgets to take medication, which complicates the treatment of people with multiple health conditions like hypertension, heart conditions and diabetes.
Visual and spatial brain functions, perception and orientation, language, attention and problem-solving is affected. The person becomes forgetful for recent events: what happened yesterday or in the last few hours not accessible to recall. Personal items are lost because they are left somewhere out of mind. Denial of the memory problem makes the individual suspicious. He may believe someone within the household has stolen his items.
Behavioural symptoms, such as agitation, restlessness, inappropriate behaviour, sexual disinhibition and aggression (both verbal or physical) result from deterioration in cognitive inhibition. Psychological symptoms include depression, psychotic hallucinations and delusions, apathy, and anxiety. Behavioural and psychological symptoms of dementia may need specialised treatment. Medication like antipsychotics calm agitation and reduce abnormal thoughts and paranoia. These drugs are commonly used, but not usually recommended, due to the limited benefit and side effects.
Simple tasks like cooking or tying the shoelaces can be a hurdle. Dressing and undressing may become a problem in moderate stages.
Disorientation to place, time and person make the affected individual unable to find his way in unfamiliar places. Change of his usual abode may result in more confusion and disorientation. Time is difficult to know without resorting to watches and calendars. In advanced conditions, day and night may be confused. The person may wake up at night thinking it is daytime. Familiar people may not be easily identifiable in very advanced stages of dementia, for example, a woman with dementia may not recognise her life-long husband.
In dementia, consciousness is not usually affected. Confusion or delirium may occur during the illness when the brain capabilities are taxed, like during a fever or intoxication. Someone with delirium may get drowsy, disorientated, panicky and hallucinating: a state which rises and fall. That person gets confused during a dimly lit room at night or in an unfamiliar place.
A diagnosis of dementia requires a noticeable change from the person's usual mental functioning. A remarkable cognitive decline more than that due to normal ageing is needed.
We diagnose dementia through examination of cognitive tasks by screening tests like Mini-Mental State Examination (MMSE). It is a questionnaire (a list of questions) of 30 points to measure cognitive impairment that only takes 5 to 10 minutes to complete. Its items include registration (repeating names), attention and calculation, recall, language, ability to follow simple commands and orientation.
Diagnosis is a process that starts with exploring the history of the illness, how it started? What made the family seek help? What sort of decline they have seen?. Cognitive testing is a step in the assessment. Brain imaging and a Computerised Brain Scan are used to reach a more accurate diagnosis in addition to cognitive psychological tests. The scan could show a cause of deterioration in cognitive functions, such as the presence of a brain tumour. Otherwise, a scan helps determine the degree of shrinkage in particular brain areas. Scanning after one or two years assists the clinician to judge the speed of loss of brain cells. Blood tests rule out other possible reversible causes such as underactive thyroid or vitamin deficiencies.
Dementia has a significant effect on the individual, relationships and caregivers. It is a disorder of the higher brain functions, with varying degrees of severity and multiple causes. The illness starts slowly and progresses gradually, so it is a long-term illness. It is an ongoing illness that goes from bad to worse ending in death in most cases. Alzheimer's disease slowly progresses over many years, and other dementias vary in their course. Early in the disease, the change is limited and the person may cope with daily needs, but he or she may become more and more dependent on the support provided near the final stage of total dependence.
Alzheimer's disease accounts for 60–70% of cases of dementia worldwide. The most common symptoms of Alzheimer's disease are short-term memory loss and word-finding difficulties. The trouble with visuospatial functioning (getting lost often), reasoning, judgment and insight fail. Insight refers to whether or not the person realises they have memory problems.
In contrast to Alzheimer's disease that runs a slow downhill course, multi-infarct dementia runs in a descending stepwise fashion. The person may start with some small infarcts, which improve slightly, and his condition remains the same. Another shower of infarcts, or a new clot in another vessel, add to the previous one after a period of relative stability. There are many other types which we will explain later, such as Lewy body disease and frontotemporal lobe degeneration. The rate of symptoms progression occurs in a continuum over several stages and it varies across the dementia subtypes.
Most types of dementia are slowly progressive. Sometimes, deterioration of the brain is well established before signs of the disorder become apparent. Often, there are other conditions present, such as high blood pressure or diabetes.
Dementia may also occur as a set of related symptoms when the brain suffers damaged by injury or disease. Repeated head injury in a professional boxer may lead to dementia. Inflammation of the brain (encephalitis) by a virus or other organisms can also end in dementia. Degenerative disease like Parkinson's disease or Huntington's disease bring about dementia as a consequence. Frontotemporal lobe degeneration causes a particular type of dementia.
Uncommon deposits (called Lewy bodies) inside the brain cells are seen in another rare type of dementia: Lewy body disease or dementia with Lewy bodies. More than one type of dementia occur together, i.e. mixed dementia, may also exist. We will discuss some of the other causes of dementia in this book.
The part of the brain most affected by Alzheimer's is the hippocampus. The hippocampus is part of an area of the brain known as the limbic system. The centre of emotional life lies in that system which is also involved in the formation of memories. The hippocampus plays a vital role in the consolidation of memory through the transfer of information from short-term to long-term memory. Spatial memory (remembering the plan of a location in space) enables navigation around the environment. Other parts that show atrophy (shrinking) in dementia include the temporal and parietal lobes. These are areas at the side of the brain, corresponding to the large area in the skull above the ears. Although this pattern of brain shrinkage suggests Alzheimer's, it is variable, and a brain scan is insufficient for a diagnosis.
Treatment of dementia is mainly through supportive care. There is no known cure. Some drugs are used early in the illness. Acetylcholinesterase inhibitors, such as donepezil (Aricept), may be beneficial in mild to moderate disorder. The overall benefit, however, may be minor.
The group of drugs known as Acetylcholinesterase inhibitors can provide some small benefit to patients, but they do not change the course of the illness. Acetyl Choline is a chemical substance in the brain, a nerve messenger, that transfer impulse between nerve cells. It acts on nerve cells responsible for movement of the body, arousal, attention, memory and motivation. It is broken down and become inactive by an enzyme called cholinesterase. Acetylcholine esterase inhibitors block that enzyme action. The process allows more Acetylcholine to boost its action and the nerve impulse transmission between neurones.
Managing high blood-pressure, obesity and smoking may prevent brain damage in dementia. Social engagement and life-long mental activity can reduce the impact of dementia on cognitive functions.
Many measures can improve the quality of life of people with dementia and their caregivers. Cognitive and behavioural interventions may be appropriate. Educating and providing emotional support to the caregiver is beneficial. Exercise programs may benefit activities of daily living and may potentially improve outcomes. Social stigma against those affected is common.
The significant risk factor for developing dementia is ageing, although dementia is not a normal part of ageing. Several risk factors for dementia exist. Some, such a,s smoking, and obesity are preventable and modifiable through a change of lifestyle.