Dementia is the progressive decline in cognitive function due to damage or disease in the brain beyond what might be expected from normal aging. Although dementia is far more common in the geriatric population, it may occur in any stage of adulthood. This age cutoff is defining, as similar sets of symptoms due to organic brain dysfunction are given different names in populations younger than adulthood.
In dementia, affected areas in cognition may be memory, attention, language, and problem solving. Higher mental functions are affected first in the process. Especially in the later stages of the condition, affected persons may be disoriented in time (not knowing what day of the week, day of the month, month, or even what year it is), in place (not knowing where they are), and in person (not knowing who they are).
Symptoms of dementia can be classified as either reversible or irreversible depending upon the etiology of the disease. Less than 10 percent of cases of dementia are due to causes which may presently be reversed with treatment. Of these cases almost 100% are elderly people. Dementia is a term for a non-specific illness syndrome (set of symptoms) which is caused by many different specific disease processes, in the same way that symptoms of organ dysfunction such as shortness of breath, jaundice, or pain are attributable to many etiologies.
Without careful assessment of history, the short-term syndrome of delirium can easily be confused with dementia, because many of the symptoms of these are also present in dementia. Some mental illnesses including depression and psychosis may also produce symptoms which must be differentiated from both delirium and dementia.
Types:
Cortical dementias-
1) Alzheimer's disease.
2) Vascular dementia (also known as multi-infarct dementia), including Binswanger's disease.
3) Dementia with Lewy bodies (DLB).
4) Alcohol-Induced Persisting Dementia.
Korsakoff's syndrome
Wernicke's encephalopathy
5) Frontotemporal lobar degenerations (FTLD), including Pick's disease.
Frontotemporal dementia (or frontal variant FTLD)
Semantic dementia (or temporal variant FTLD)
Progressive non-fluent aphasia
6) Creutzfeldt-Jakob disease.
7) Dementia pugilistica.
8) Moyamoya disease.
Subcortical dementias-
* Dementia due to Huntington's disease.
* Dementia due to Hypothyroidism.
* Dementia due to Parkinson's disease.
* Dementia due to Vitamin B1 deficiency.
* Dementia due to Vitamin B12 deficiency.
* Dementia due to Folate deficiency.
* Dementia due to Syphilis.
* Dementia due to Subdural hematoma.
* Dementia due to Hypercalcaemia.
* Dementia due to Hypoglycemia.
* AIDS dementia complex.
* Pseudodementia (associated with clinical depression and bipolar disorder).
* Substance-induced persisting dementia (related to psychoactive use and formerly Absinthism).
* Dementia due to multiple etiologies.
Causes:
The slowly progressing destruction of nerve cells in the brain leads to the previously mentioned symptoms of Alzheimer's disease. It is a natural phenomenon to loose a certain number of nerve cells during ageing but this loss occurs much more rapidly in people suffering from Alzheimer's disease. As a result the brain of the patient does not function normally any longer.
In rare cases, the disease is caused by genetic changes (mutations) in the family. In these cases symptoms usually occur before the age of 60 and progress rapidly. All currently known mutations result in an overproduction of a protein which destroys the nerve cells. In most cases the exact cause remains largely unexplained; interaction of several factors probably leads to the onset. Everybody is at risk of developing this disease. Several genetic factors are known to increase the risk, without themselves being the cause. These include a (normal) variant of the gene apolipoprotein E which encourages the deposition of the harmful protein.
The probability of developing Alzheimer's disease increases with advancing age. The probability is higher for women and for people having a lower standard of education.
Symptoms:
Alzheimer's disease was first described in 1907 by the physician Alois Alzheimer. The most commonly known symptom of Alzheimer's disease is confusion. This behaviour in particular causes us to become 'estranged' from others and to be unpredictable in our interactions. Confusion can also occur 'acutly' i.e. suddenly and limited in time - for example triggered by a hospital stay, directly after heart surgery etc. It is difficult to understand this estrangement and it cannot be explained away - on the other hand everybody also experiences similar situations from time to time: we forget, misplace, can not remember names, cannot find our car in the car park and similar lapses. So both aspects are present: dementia is not familiar but also not entirely alien to us.
People with Alzheimer suffer mainly from impaired memory and orientation, limitations of concentration, planning and judgement, personality changes and later also perceptual, speech and walking disorders; in the final stage, various other body functions such as swallowing and the excretion process are also affected. During the course of Alzheimer's disease, patients lose their independence in managing everyday life. There are effects on perception and social relationships; people become more and more dependent on care.
Diagnosis:
Proper differential diagnosis between the types of dementia will require, at the least, referral to a specialist,
e.g. geriatric internist, geriatric psychiatrist, neurologist, neuropsychologist or geropsychologist. However, there exist some brief tests (5-15 minutes) that have reasonable reliability and can be used in the office or other setting to screen cognitive status for deficits which are considered pathological. Examples of such tests include the abbreviated mental test score (AMTS), the mini mental state examination (MMSE), Modified Mini-Mental State Examination (3MS), the Cognitive Abilities Screening Instrument (CASI), and the clock drawing test. An AMTS score of less than six (out of a possible score of ten) and an MMSE score under 24 (out of a possible score of 30) suggests a need for further evaluation. Scores must be interpreted in the context of the person's educational and other background, and the particular circumstances; for example, a person highly depressed or in great pain will not be expected to do well on many tests of mental ability.
Laboratory tests:
Routine blood tests are also usually performed to rule out treatable causes. These tests include vitamin B12, folic acid, thyroid-stimulating hormone (TSH), C-reactive protein, full blood count, electrolytes, calcium, renal function, and liver enzymes. Abnormalities may suggest vitamin deficiency, infection or other problems that commonly cause confusion or disorientation in the elderly. The problem is complicated by the fact that these cause confusion more often in persons who have early dementia, so that "reversal" of such problems may ultimately only be temporary.
Chronic use of substances such as alcohol can also predispose the patient to cognitive changes suggestive of dementia.
Imaging:
A CT scan or magnetic resonance imaging (MRI scan) is commonly performed, although these modalities do not have optimal sensitivity for the diffuse metabolic changes associated with dementia in a patient who shows no gross neurological problems (such as paralysis or weakness) on neurological exam. CT or MRI may suggest normal pressure hydrocephalus, a potentially reversible cause of dementia, and can yield information relevant to other types of dementia, such as infarction (stroke) that would point at a vascular type of dementia. However, the functional neuroimaging modalities of SPECT and PET have shown similar ability to diagnose dementia as clinical exam. The ability of SPECT to differentiate the vascular cause from the Alzheimer disease cause of dementias, appears to be superior to differentiation by clinical exam.
Treatment:
Except for the treatable types listed above, there is no cure to this illness, although scientists are progressing in making a type of medication that will slow down the process. Cholinesterase inhibitors are often used early in the disease course. Cognitive and behavioral interventions may also be appropriate. Educating and providing emotional support to the caregiver (or carer) is of importance as well.
A Canadian study found that a lifetime of bilingualism has a marked influence on delaying the onset of dementia by an average of four years when compared to monolingual patients. The researchers determined that the onset of dementia symptoms in the monolingual group occurred at the mean age of 71.4, while the bilingual group was 75.5 years. The difference remained even after considering the possible effect of cultural differences, immigration, formal education, employment and even gender as influences in the results.
Medications:
Tacrine (Cognex), donepezil (Aricept), galantamine (Reminyl), and rivastigmine (Exelon) are approved by the United States Food and Drug Administration (FDA) for treatment of dementia induced by Alzheimer disease. They may be useful for other similar diseases causing dementia such as Parkinsons or vascular dementia.
N-methyl-D-aspartate Blockers like Memantine (Namenda) is a drug representative of this class. It can be used in combination with acetylcholinesterase inhibitors.
Haloperidol (Haldol), risperidone (Risperdal), olanzapine (Zyprexa), and quetiapine (Seroquel) are frequently prescribed to help manage psychosis and agitation. Treatment of dementia-associated psychosis or agitation is intended to decrease psychotic symptoms (for example, paranoia, delusions, hallucinations), screaming, combativeness, and/or violence.
In dementia, affected areas in cognition may be memory, attention, language, and problem solving. Higher mental functions are affected first in the process. Especially in the later stages of the condition, affected persons may be disoriented in time (not knowing what day of the week, day of the month, month, or even what year it is), in place (not knowing where they are), and in person (not knowing who they are).
Symptoms of dementia can be classified as either reversible or irreversible depending upon the etiology of the disease. Less than 10 percent of cases of dementia are due to causes which may presently be reversed with treatment. Of these cases almost 100% are elderly people. Dementia is a term for a non-specific illness syndrome (set of symptoms) which is caused by many different specific disease processes, in the same way that symptoms of organ dysfunction such as shortness of breath, jaundice, or pain are attributable to many etiologies.
Without careful assessment of history, the short-term syndrome of delirium can easily be confused with dementia, because many of the symptoms of these are also present in dementia. Some mental illnesses including depression and psychosis may also produce symptoms which must be differentiated from both delirium and dementia.
Types:
Cortical dementias-
1) Alzheimer's disease.
2) Vascular dementia (also known as multi-infarct dementia), including Binswanger's disease.
3) Dementia with Lewy bodies (DLB).
4) Alcohol-Induced Persisting Dementia.
Korsakoff's syndrome
Wernicke's encephalopathy
5) Frontotemporal lobar degenerations (FTLD), including Pick's disease.
Frontotemporal dementia (or frontal variant FTLD)
Semantic dementia (or temporal variant FTLD)
Progressive non-fluent aphasia
6) Creutzfeldt-Jakob disease.
7) Dementia pugilistica.
8) Moyamoya disease.
Subcortical dementias-
* Dementia due to Huntington's disease.
* Dementia due to Hypothyroidism.
* Dementia due to Parkinson's disease.
* Dementia due to Vitamin B1 deficiency.
* Dementia due to Vitamin B12 deficiency.
* Dementia due to Folate deficiency.
* Dementia due to Syphilis.
* Dementia due to Subdural hematoma.
* Dementia due to Hypercalcaemia.
* Dementia due to Hypoglycemia.
* AIDS dementia complex.
* Pseudodementia (associated with clinical depression and bipolar disorder).
* Substance-induced persisting dementia (related to psychoactive use and formerly Absinthism).
* Dementia due to multiple etiologies.
Causes:
The slowly progressing destruction of nerve cells in the brain leads to the previously mentioned symptoms of Alzheimer's disease. It is a natural phenomenon to loose a certain number of nerve cells during ageing but this loss occurs much more rapidly in people suffering from Alzheimer's disease. As a result the brain of the patient does not function normally any longer.
In rare cases, the disease is caused by genetic changes (mutations) in the family. In these cases symptoms usually occur before the age of 60 and progress rapidly. All currently known mutations result in an overproduction of a protein which destroys the nerve cells. In most cases the exact cause remains largely unexplained; interaction of several factors probably leads to the onset. Everybody is at risk of developing this disease. Several genetic factors are known to increase the risk, without themselves being the cause. These include a (normal) variant of the gene apolipoprotein E which encourages the deposition of the harmful protein.
The probability of developing Alzheimer's disease increases with advancing age. The probability is higher for women and for people having a lower standard of education.
Symptoms:
Alzheimer's disease was first described in 1907 by the physician Alois Alzheimer. The most commonly known symptom of Alzheimer's disease is confusion. This behaviour in particular causes us to become 'estranged' from others and to be unpredictable in our interactions. Confusion can also occur 'acutly' i.e. suddenly and limited in time - for example triggered by a hospital stay, directly after heart surgery etc. It is difficult to understand this estrangement and it cannot be explained away - on the other hand everybody also experiences similar situations from time to time: we forget, misplace, can not remember names, cannot find our car in the car park and similar lapses. So both aspects are present: dementia is not familiar but also not entirely alien to us.
People with Alzheimer suffer mainly from impaired memory and orientation, limitations of concentration, planning and judgement, personality changes and later also perceptual, speech and walking disorders; in the final stage, various other body functions such as swallowing and the excretion process are also affected. During the course of Alzheimer's disease, patients lose their independence in managing everyday life. There are effects on perception and social relationships; people become more and more dependent on care.
Diagnosis:
Proper differential diagnosis between the types of dementia will require, at the least, referral to a specialist,
e.g. geriatric internist, geriatric psychiatrist, neurologist, neuropsychologist or geropsychologist. However, there exist some brief tests (5-15 minutes) that have reasonable reliability and can be used in the office or other setting to screen cognitive status for deficits which are considered pathological. Examples of such tests include the abbreviated mental test score (AMTS), the mini mental state examination (MMSE), Modified Mini-Mental State Examination (3MS), the Cognitive Abilities Screening Instrument (CASI), and the clock drawing test. An AMTS score of less than six (out of a possible score of ten) and an MMSE score under 24 (out of a possible score of 30) suggests a need for further evaluation. Scores must be interpreted in the context of the person's educational and other background, and the particular circumstances; for example, a person highly depressed or in great pain will not be expected to do well on many tests of mental ability.
Laboratory tests:
Routine blood tests are also usually performed to rule out treatable causes. These tests include vitamin B12, folic acid, thyroid-stimulating hormone (TSH), C-reactive protein, full blood count, electrolytes, calcium, renal function, and liver enzymes. Abnormalities may suggest vitamin deficiency, infection or other problems that commonly cause confusion or disorientation in the elderly. The problem is complicated by the fact that these cause confusion more often in persons who have early dementia, so that "reversal" of such problems may ultimately only be temporary.
Chronic use of substances such as alcohol can also predispose the patient to cognitive changes suggestive of dementia.
Imaging:
A CT scan or magnetic resonance imaging (MRI scan) is commonly performed, although these modalities do not have optimal sensitivity for the diffuse metabolic changes associated with dementia in a patient who shows no gross neurological problems (such as paralysis or weakness) on neurological exam. CT or MRI may suggest normal pressure hydrocephalus, a potentially reversible cause of dementia, and can yield information relevant to other types of dementia, such as infarction (stroke) that would point at a vascular type of dementia. However, the functional neuroimaging modalities of SPECT and PET have shown similar ability to diagnose dementia as clinical exam. The ability of SPECT to differentiate the vascular cause from the Alzheimer disease cause of dementias, appears to be superior to differentiation by clinical exam.
Treatment:
Except for the treatable types listed above, there is no cure to this illness, although scientists are progressing in making a type of medication that will slow down the process. Cholinesterase inhibitors are often used early in the disease course. Cognitive and behavioral interventions may also be appropriate. Educating and providing emotional support to the caregiver (or carer) is of importance as well.
A Canadian study found that a lifetime of bilingualism has a marked influence on delaying the onset of dementia by an average of four years when compared to monolingual patients. The researchers determined that the onset of dementia symptoms in the monolingual group occurred at the mean age of 71.4, while the bilingual group was 75.5 years. The difference remained even after considering the possible effect of cultural differences, immigration, formal education, employment and even gender as influences in the results.
Medications:
Tacrine (Cognex), donepezil (Aricept), galantamine (Reminyl), and rivastigmine (Exelon) are approved by the United States Food and Drug Administration (FDA) for treatment of dementia induced by Alzheimer disease. They may be useful for other similar diseases causing dementia such as Parkinsons or vascular dementia.
N-methyl-D-aspartate Blockers like Memantine (Namenda) is a drug representative of this class. It can be used in combination with acetylcholinesterase inhibitors.
Haloperidol (Haldol), risperidone (Risperdal), olanzapine (Zyprexa), and quetiapine (Seroquel) are frequently prescribed to help manage psychosis and agitation. Treatment of dementia-associated psychosis or agitation is intended to decrease psychotic symptoms (for example, paranoia, delusions, hallucinations), screaming, combativeness, and/or violence.
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