What is dementia?
Dementia should not be thought of as a single disease. It is a neuropsychiatric term that represents many different findings which are signs of a deterioration in the individual’s intellectual and social abilities. According to its definition the symptoms have to be serious enough to interfere with the person’s daily activities. The signs and symptoms of dementia can be caused by a variety of conditions. One of the most common form of dementia is called Alzheimer’s disease, which is a dementia that progresses over the years and leads to the loss of many abilities the patient used to have.
Forgetfulness and memory impairment are the most common complaints in dementia. However forgetfulness alone does not mean that the person has dementia. In dementia at least two of the three most important cognitive abilities have to be affected; these are memory, problem solving (reasoning) and language. Some people with dementia appear confused and have difficulties understanding. They may for instance confuse names, recent dates and locations. Others may have no memory problems but may display marked changes in their personality and social behaviour. Some of the diseases that cause dementia are treatable, in fact with some diseases it is possible for the patient to regain lost abilities (in other words, a complete or partial recovery from the illness may be possible).
What are the complaints and symptoms we see in dementia patients?
The findings vary according to the underlying illness. The most common findings are as follows: :
• Memory impairment
• Speech problems, difficulties expressing themselves
• Difficulties in learning new information or remembering recent events
• Difficulties in planning and programming daily activities
• Significant changes in personality
• Inability to think logically or to asses events correctly
• Inappropriate and unusual behaviour
• Paranoia (suspiciousness)
• Anger, aggression
• Hallucinations (distorted perception)
When should a doctor be consulted?
If you or a relative of yours experiences memory problems or displays one of the above symptoms, a psychiatrist, neurologist or geriatric specialist should be consulted. If the dementia has occurred in connection with certain medical conditions, the chances of it being treated are high. In such cases the progression of the illness can be stopped or even reversed completely. It is for this reason that it is very important for each dementia case to undergo detailed assessment and tests.
Causes of dementia
Dementia can have a variety of causes. Some forms of dementia like Alzheimer’s are independent diseases in their own right, where the dementia is not a feature of another illness.
Forms of progressive dementia
In progressive dementia the disease progressively gets worse. The cases given below are the most common ones:
Alzheimer’s disease is the most common cause of dementia in people over the age of 65. Symptoms tend to appear around the age of 60, and in rarer cases before that age, and show familial features. Although the definite cause of Alzheimer’s disease is not understood fully, the main findings are two types of damage in the brain cells (neurons). These are the plaques and glomus. The plaques are formed by the aggregation of a normally harmless protein called beta-amyloid, whereas the glomus are a threadlike aggregation of an abnormal protein called Tau. Alzheimer’s disease progresses slowly over 7-10 years, causing a progressive deterioration of the cognitive functions of the individual. In its final stage the areas of the brain that deal with memory, movement, language, reasoning, behaviour and abstract thinking no longer function.
Lewy bodies dementia is one of the most common causes of dementia and forms 20% of all dementia cases. It generally sets in at a late age. Lewy bodies are associated with Lewy bodies dementia, Alzheimer’ disease and Parkinson’s disease, and are clumps of an abnormal protein, that form in the brain. Although the findings resemble that of Alzheimer’s, there are some findings that are specific to this disease, like mental confusion and fluctuating cognition during alert periods, visual hallucinations, and motor features of a mild Parkinson’s disease, for instance trembling and stiffness of movement. These patients also experience involuntary eye movements during the dream stage of sleep, which is called REM sleep behaviour disorder.
Vascular dementia is the second most common form of dementia after Alzheimer’s disease. It is caused by problems in the supply of blood to the brain. Typically, the symptoms of vascular dementia start suddenly, for example after a stroke. Vascular dementia can occur in connection with a brain haemorrhage, amyloid deposits that form in the walls of the blood vessels of the brain (amyloid angiopathy), or a blood clot produced in the heart and dislodged. Although in this form of dementia, symptoms tend to worsen over time, in some cases they can also regress after their initial appearance. Vascular dementia can occur at the same time as Alzheimer’s disease.
Frontotemporal dementia is a less common form of dementia which tends to occur at an early age. It is characterised by degeneration of the brain cells in the frontal (front) and temporal (side) lobes which leads to a marked deterioration in personality, language and behaviour. Socially unacceptable behaviour, loss of mental flexibility, speech problems, problems in cognition and concentration are common. Like with many of the other forms of dementia, its causes are not yet fully understood. Genetic mutation has been found in a large percentage of cases, but in many patients there was no family history of the disease.
In Pick’s disease the changes in behaviour and personality are very marked.
Other conditions that lead to dementia
Huntington’s disease is a genetic disorder that usually starts between the ages of 30-40. The initial signs are mild personality changes like irritability, stress disorder and depression. Over the years it leads to severe dementia, together with difficulties in walking, movement problems and involuntary body movements.
Dementia associated with HIV: an HIV infection leads to the HIV disease and causes degeneration of the white brain matter. This in turn leads to memory problems, withdrawal and concentration difficulties. Problems with movement are also common.
Creutzfeldt Jakob disease: the cause of this rare and fatal disease is not known. In some cases it is genetic, in others it develops due to diseased brain and nerve tissues. In its variant type for instance in cattle it is believed to be caused by the destruction of the diseased brain and nerve tissues (Mad Cow disease). Common symptoms of the disease which usually occurs around the age of 60, are difficulties in walking, personality changes, deterioration of memory, reasoning, cognitive abilities and visual functions. Within a few years the disease leads to certain death.
Dementia associated with movement disorders: In their later stages some movement disorders, particularly Parkinson’s disease, can lead to dementia.
Types of dementia that can be reversed or treated to a large extent.
Infections and immune disorders: Dementia can be associated with meningitis, encephalitis, syphilis, Lyme’s disease or leukaemia. Dementia is also seen in later stages of Multiple Sclerosis (MS).
Metabolic or hormonal disorders: major hypoglycaemic attacks, thyroid dysfunction, changes in blood calcium level, deficiency in vitamins like vitamin B12.
Substances or poisoning: severe poisoning by heavy metals like lead or manganese or certain agricultural pesticides, heavy alcoholism.
Cases of cardiac arrest or carbon monoxide poisoning, where the brain is deprived of oxygen, can also lead to dementia.
Risk factors in dementia
Age, smoking, excessive alcohol consumption, high blood pressure, diabetes, family history of dementia, depression at a late age, arteriosclerosis, high cholesterol are the main factors that increase the risk of dementia.
What are the effects of dementia?
As the dementia progresses, many body functions start deteriorating.
• Poor nutrition: In advanced stages of dementia we see a reduction in the patient’s food intake, they may even stop eating altogether. In advanced stages of the disease the muscles used for chewing and swallowing food weaken, and the risk of food going down into the lungs and suffocation increases. This can be fatal, or it can lead to pneumonia. In the advanced stages the patient often no longer feels hunger and loses the drive to eat. Depression, certain side effects of the drugs, constipation, and generally feeling down are other symptoms associated with dementia which reduce the patient’s appetite.
• Lack of oxygen: In advanced and moderate dementia there is a loss of important everyday functions. Activities like taking a bath, getting dressed, brushing one’s teeth or going to the toilet are adversely affected.
• Psychological deterioration: Dementia patients undergo changes in behaviour and personality. Dementia can lead to depression, anger, mental confusion, anxiety and inappropriate behaviour.
• Lack of communication: As dementia advances, the patient starts to forget or confuse names of people, dates and places. This leads to serious difficulties in the communication between the relatives who are in the position of carers, and the patient, and often lead to misunderstandings.
• Sleep problems: sleeplessness during the night and sleepiness during daytime are quite common.
• Getting lost, accidental falls, starting fires due to carelessness, being the cause of traffic accidents are also common problems related to personal safety.
Which examinations and tests need to be done?
Neuropsychological tests to asses brain functions, neurological and psychiatric examinations, blood tests, brain MR and EEG will establish whether there is a case of dementia and will help in finding the cause.
What is treatment in dementia?
After establishing the cause of dementia with the help of examinations and tests, if the cause turns out to be a reversible illness (for instance vitamin deficiency, hormonal problems or a particular infection) priority is given to treating that particular illness. Although this is not often the case, it is sometimes possible with this approach to stop the progression of dementia or even reverse it . However, these cases are fairly rare amongst dementia cases.
• Cholinesterase inhibitors: These are drugs used primarily in Alzheimer’s disease but also in various other types of dementia. They do not affect the progression of the disease, but can lead to a moderate improvement in memory functions. They can cause side effects like nausea, vomiting and diarrhoea.
• Drugs that act on the glutamatergic system are used in the advanced stages of Alzheimer’s and other various other types of dementia. These do not stop or slow down the progression of the disease, but lead to a moderate improvement in memory functions and some behavioural problems.
• Treatment of risk factors like high blood pressure and DM play a an important role in the treatment of vascular dementia.
• Psychological problems like paranoia, depression, anxiety disorder, anger attacks which often accompany dementia, are treated with antipsychotics, antidepressants or other psychiatric drugs.
(Reference was made to Mayo Clinic’s article on the subject)