It’s Not Always What You Think
Many people regardless of age worry about becoming more forgetful. Whenever I spoke in a forum about forgetfulness and dementia, many in the audience would say they have all the symptoms I described. They think forgetfulness IS dementia. In the past, memory loss and confusion were considered a normal part of aging. However, scientists now know that most people remain both alert and able as they age, although it may take them longer to remember things.
The interest in emory and dementia has lead to an increased numbers of ‘Memory Clinics’ to spring up in most Hospitals. There has also been much progress in the understanding of this aspect of cognition, and different names have come up to describe the different stages in the continuum between normal cognition to the stage of obvious dementia:
Age associated memory impairment (AAMI):
In AAMI, the person is usually 50 years or older with subjective memory decline (i.e. person often realizes that his memory is declining) and objective evidence of memory loss (with memory test, and score of at least 1 SD below mean of younger patients). However, there is adequate intellectual function and absence of dementia or memory affecting diseases e.g. stroke, cancer or poorly controlled diabetes. By definition, AAMI does not interfere with Activities of Daily Living. Incidence of dementia among patients with AAMI is about 2.5% per year.
Mild cognitive impairment (MCI):
In MCI, the cognitive changes are serious enough to be noticed by the individual or people around them, but not severe enough to interfere with daily life or independent function. The disabilities they have also do not meet the diagnostic criteria for dementia. MCI is classified based on the cognitive skills that are affected. MCI that primarily affects memory is known as “amnestic MCI.” With amnestic MCI, a person may start to forget important information that he or she would previously have recalled easily, such as appointments, conversations or recent events.
MCI that affects thinking skills other than memory is known as “nonamnestic MCI.” Thinking skills that may be affected by nonamnestic MCI include the ability to make sound decisions, judge the time or sequence of steps needed to complete a complex task, or visual perception.
Some MCI remains stable for years; some may improve while some will progress to dementia. Some studies have suggested an annual conversion rate from MCI to dementia as 3.3 – 4.2%.
People who have serious changes in their memory, personality, and behavior may suffer from a form of brain disease called dementia. The term dementia describes a group of symptoms that are caused by changes in brain function. Dementia symptoms may include poor recent memory; asking the same questions repeatedly; getting disoriented about time, people, and places; becoming lost in familiar places; being unable to follow directions or instructions; and neglecting personal safety, hygiene and nutrition. People with dementia lose their abilities at different rates.
There are many cognitive tests that can be administered to assess functions of various parts of the brain. Most of these tests assess short-term memory (either as a 4 digit number, 3 or 5 unrelated objects to remember and recall later), orientation to time, person and place, language, ability to follow instructions and or abstract thinking skills. The commonly used ones are the Mini Mental State Examination (MMSE), Chinese Mini Mental State Examination (CMMSE), Elderly Cognitive Assessment Questionnaire (ECAQ), Abbreviated Mental Test (AMT), Montreal Cognitive Assessment (MoCA) and the Clock Drawing Test (CDT) or Clock Completion Tests (CCT). Scores that are below the ‘cut-off’ for that test indicates cognitive impairment. The various components tested in the above tests will enable us to decide if they fit into the diagnostic criteria for dementia, as dementia is a common cause of cognitive impairment in older people. In cases which are inconclusive after using these ‘bedside’ tests or when they are being assessed for decision making capacity, neuropsychological tests may be necessary.
The most commonly used criteria to diagnose dementia is the DSM IV criteria.
DSM IV criteria:
- The development of multiple cognitive deficits manifested by both
(1) Memory impairment (impaired ability to learn new information or to recall previously learned information)
(2) One (or more) of the following cognitive disturbances:
(a) Aphasia (language disturbance)
(b) Apraxia (impaired ability to carry out motor activities despite intact motor function)
(c) Agnosia (failure to recognize or identify objects despite intact sensory function)
(d) Disturbance in executive functioning (i.e., planning, organizing, sequencing, abstracting)
- The cognitive deficits in Criteria A1 and A2 each cause significant impairment in social or occupational functioning and represent a significant decline from a previous level of functioning.
- The course is characterized by gradual onset and continuing cognitive decline.
- The cognitive deficits in Criteria A1 and A2 are not due to any of the following:
(1) Other central nervous system conditions that cause progressive deficits in memory and cognition (e.g., cerebrovascular disease, Parkinson’s disease, Huntington’s disease, subdural hematoma, normal-pressure hydrocephalus, brain tumor)
(2) Systemic conditions that are known to cause dementia (e.g., hypothyroidism, vitamin B or folic acid deficiency, niacin deficiency, hypercalcemia, neurosyphilis, HIV infection)
(3) Substance-induced conditions
- The deficits do not occur exclusively during the course of a delirium.
- The disturbance is not better accounted for by another Axis I disorder (e.g., Major Depressive Episode, Schizophrenia).
There are many causes of dementia, namely, Alzheimer’s disease (AD), Vascular Dementia (VaD), Dementia with Levy Body (DLB), Frontotemporal Dementia (FTD), Dementia associated with Parkinson’s Disease etc.
The two most common forms of dementia in older people are Alzheimer’s disease and vascular dementia. These types of dementia are irreversible, which means they cannot be cured. In Alzheimer’s disease, nerve cell changes in certain parts of the brain result in the death of a large number of cells. Symptoms of Alzheimer’s disease begin slowly and become steadily worse. As the disease progresses, symptoms range from mild forgetfulness to serious impairments in thinking, judgment, and the ability to perform daily activities. Eventually, patients may need total care.
In vascular dementia, a series of small strokes or changes in the brain’s blood supply may result in the death of brain tissue. The location in the brain where the small strokes occur determines the seriousness of the problem and the symptoms that arise. Symptoms that begin suddenly may be a sign of this kind of dementia. People with vascular dementia are likely to show signs of improvement or remain stable for long periods of time, then quickly develop new symptoms if more strokes occur. Vascular dementia due to multiple small strokes is also called ‘multi-infarct dementia’. People can also develop vascular dementia without strokes, but through cerebral small vessel disease. Cerebral small vessel disease is usually caused by hypertension, diabetes, hyperlipidemia and old age. Both multi-infarcts and small vessel disease may co-exist together as causes of the dementia.
Similarly, both Alzheimer’s disease and vascular dementia may also co-exist together, and is often referred to as ‘Mixed Dementia.’
There are some conditions that may cause dementia-like symptoms, but may be reversible. Reversible conditions can be caused by infections, dehydration, vitamin deficiency and poor nutrition, abnormal electrolytes, hyper or hypoglycemia, side effects of medicines, problems with the thyroid gland or head injury.
Sometimes older people have emotional problems that can be mistaken for dementia. Feeling sad, lonely, worried, or bored may be more common for older people facing retirement or coping with the death of a spouse, relative, or friend. Adapting to these changes leaves some people feeling confused or forgetful. Some older people who became depressed from whatever reasons may present with dementia-like symptoms but are not demented, hence, the term ‘Pseudo-Dementia’.
Medical conditions like these can be serious and should be treated by a doctor as soon as possible. Therefore, when faced with a person who presents with dementia-like symptoms, the first step is to exclude reversible or treatable conditions.
Blood tests that may be done to exclude reversible or treatable causes include full blood counts, urea and electrolytes, thyroid function tests, liver function tests, glucose, calcium, Vit B12 and folic acid. A brain scan (either CT or MRI) would be needed to make a diagnosis of vascular dementia.
Even if the doctor diagnoses an irreversible form of dementia, much still can be done to treat the patient and help the family cope. A person with dementia should be under a doctor’s care, and may see a neurologist, psychiatrist, family doctor, internist, or geriatrician. The doctor can treat the patient’s physical and behavioral problems and answer the many questions that the person or family may have.
At present, there are only 2 main classes of medications that could improve cognition and reduce the rate of cognitive decline in Alzheimer’s disease. The first are the acetylcholine esterase inhibitors or AchEI, while the second are the N-methyl D aspartate antagonist or NMDA antagonist. Examples of AchEI are donepezil, rivastigmine and galantamine, while the only NMDA antagonist is memantine. Both classes of medication can be used to treat the whole range of dementia, from mild to severe dementia. They can also be used in combination between the 2 classes but not within the same class (i.e. using 2 different AchEIs). Both classes of medication can also be used for mild to moderate vascular dementia.
In vascular dementia, patients should prevent further strokes by controlling high blood pressure, monitoring and treating high blood cholesterol and diabetes, stop smoking and reduce weight. They should also be taking antiplatelet agents to prevent strokes and anticoagulants for those with atrial fibrillation.
Many people with dementia need no medication for behavioral problems. But for some people, doctors may prescribe medications to reduce agitation, anxiety, depression, or sleeping problems. These troublesome behaviors are common in people with dementia. Careful use of doctor-prescribed drugs may make some people with dementia more comfortable and make caring for them easier.
Family members and friends can assist people with dementia in continuing their daily routines, physical activities, and social contacts. People with dementia should be kept up to date about the details of their lives, such as the time of day, where they live, and what is happening at home or in the world. Memory aids may help in the day-to-day living of patients in the earlier stages of dementia. Some families find that a big calendar, a list of daily plans, notes about simple safety measures, and written directions describing how to use common household items are very useful aids. Establishing a fixed daily routine will help alleviate the anxiety of not knowing what to expect next and give them a sense of control.