Causes of the dementia syndrome
Many different disease states can produce the clinical syndrome of dementia. These can be divided into two groups:
Reversible dementia syndrome
The term reversible or potentially/ partially reversible is used to define a cognitive disorder in which normal or nearly normal function may be restored. The potential to reverse or delay deterioration emphasizes the importance of an early diagnosis of a reversible dementia. The most common causes of reversible dementia are depression, delirium, and drug toxicity. Other causes include normal pressure hydrocephalus, neoplasms, metabolic disorders, trauma, medications and infections.
Irreversible dementia syndrome
The most common causes of irreversible dementia include:
* Alzheimer’s disease
* Vascular dementia
These account for at least 7080% of all cases.
Less common, and more difficult to recognize clinically, are:
* Dementia of Lewy body type
* Pick’s disease (dementia of the frontal lobe-type [DFT])
Patients, especially geriatrics, with irreversible dementia are commonly placed in nursing homes for special care.
Diagnosing Alzheimer’s disease
Previously, the definite diagnosis of AD was based purely on neuro-pathological findings. Reliably diagnosing the disease during the lifetime of the patient, without a brain biopsy, was considered impossible. Opinions have changed. The implementation of existing skills, the development of new diagnostic techniques, coupled with a greater appreciation of the disease, now makes the clinical diagnosis of AD a realistic possibility during the lifetime of the patient.
AD is no longer considered to be a diagnosis of exclusion. AD has a relatively consistent onset, clinical presentation and course which makes it one of the most characteristic of mental disease processes. Although it is still necessary to eliminate the possibility of other dementia syndromes, the clinical symptoms of AD are clearly defined and can be evaluated using a variety of assessment techniques.
One of the most serious and dangerous of all side effects is anaphylactic reaction. An anaphylactic reaction is defined as a life-threatening type 1 hypersensitivity reaction to a drug which is given internally or orally. Around 1500 patients die yearly due to an anaphylactic reaction in the United States. However, this serious allergic response of the body only occurs in those patients that have a true allergy to penicillin and its derivatives, as opposed to people who present with pseudo-anaphylaxis or an anaphylactoid reaction. An anaphylactic reaction is characterized by the following signs and symptoms:
– Normally, a true anaphylactic reaction with systemic signs and symptoms begin showing within 72 hours of exposure to the allergen, without the need of further exposure. Skin involvement is one of the first signs seen. This includes generalized hives, skin rashes, itchiness, flushing. Fever is often experienced by people, along with the skin rashes.
– Swelling of lips, tongue and/or throat is also seen, as this is the body’s way of responding and fighting the inflammation.
– Respiratory distress, in the form of difficulty in breathing, shortness of breath, wheezing etc. may also be seen.
– Some patients may also complain of gastrointestinal problems like severe abdominal cramps, stomach pain, diarrhea etc.
– Other serious effects that may occur if immediate action is not taken to deal with the symptoms includes coronary artery spasms, which may lead to myocardial infarction. Consequently, there may also be a sudden drop in blood pressure, which may lead to lightheadedness and fatigue, along with loss of consciousness.
Although the prospect of developing a cure is unlikely in the foreseeable future, new symptomatic treatments are becoming available. This further supports the value of early recognition of AD.
Many approaches are currently being investigated in the search for symptomatic therapies. These include the development of cholinergic agonists, in particular muscarinic and nicotinic agonists, and the use of neurotropic factors. Cholinesterase (ChE) inhibitors are the first agents approved for use in clinical practice.
In addition, the escalating number of people with AD in society demands greater efforts to reduce or delay the effects of the disease. This, coupled with the demand that this will place on limited healthcare resources, emphasizes the need for early diagnosis and intervention.
The process of making a diagnosis provides an opportunity to address other important issues. It will determine how well patients and caregivers are coping. Providing families with an understanding of what to expect can reduce the levels of stress and anxiety, making it easier to cope. Caregiver support programs also ease the burden and play an important role in the management of AD.
Figure 2. National history of Alzheimer’s disease (Feldman and Gracon 1996. Reproduced by kind permission of Martin Dunitz Publishers)
AD is a progressive neurodegenerative disease, characterized by an insidious onset and a gradual decline in cognition and functional ability (Figure 2). It is the most common cause of dementia (Figure 3). Establishing the diagnosis of AD makes it easier to help both the patient and the caregiver.
Figure 3. Causes of dementia (Gauthier, Burns and Pettit 1997. Reproduced by kind permission of Martin Dunitz Publishers, adapted from Katzman and Kawas, Lippincott-Raven Publishers, New York)
Although there is currently no cure, slowing the symptomatic decline of the patient and maintaining the level of functional ability would present clear advantages to patients, caregivers and physicians. With this in mind, however, treatment expectations should be realistic. This will reduce frustration both for the patient and for the caregiver.
Developed from scientific presentations at a special IPA meeting.
Sponsored by an educational grant from Pfizer Inc and Eisai Ltd.
International Psychogeriatric Association