What is multi-infarct dementia?
Multi-infarct dementia is the most common form of vascular dementia, which is a deterioration in mental function caused by narrowing of blood vessels in the brain. This narrowing results from an accumulation of atherosclerotic plaques in these vessels. "Multi-infarct" means that there are numerous areas where this process has killed or damaged cells.
Multi-infarct dementia is associated with atherosclerosis, a condition where fatty deposits occur in the inner lining of the arteries. Atherosclerotic plaque damages the lining of arteries. Platelets clump around the area of injury (a normal part of the clotting and healing process). Cholesterol and other fats also collect at this site, forming a mass within the lining of the artery. Multi-infarct dementia is not caused directly by the deposits of atherosclerotic plaque in the blood vessels of the brain, but by a series of strokes that leave areas of dead brain cells (infarction). This occurs when atherosclerotic plaques facilitate the formation of blood clots (thrombi) that block off the small blood vessels and prevent localized areas of the brain from receiving nutrients and oxygen from the blood flow that supplies them.
The consequences vary depending on the location and severity of the infarctions. Memory impairment is often an early symptom of the disorder, followed by judgment impairment. This often progresses in a stepwise manner to delirium, hallucinations and impaired thinking. Personality and mood changes accompany the deteriorating mental condition. Apathy and lack of motivation are common. Catastrophic reactions, where a person becomes withdrawn or extremely agitated, are also common. Confusion that occurs or is worsened at night is another common symptom.
Risk factors that make the development of multi-infarct dementia likely include a history of stroke, hypertension, smoking and atherosclerosis. Atherosclerosis is the cause of numerous serious vascular problems, including heart attacks, cerebrovascular diseases, and peripheral vascular diseases (affected vessels are outside major organs, especially in the limbs), and may be associated with conditions such as diabetes mellitus, obesity, high cholesterol, and kidney disorders that require dialysis.
Some research suggests that multi-infarct dementia may help cause or hasten the progression of Alzheimer's disease. Multi-infarct dementia may be misdiagnosed as Alzheimer's or found in addition to Alzheimer's disease. Since the difference cannot always be determined without brain biopsy and since there is little effective treatment for either condition, the distinction is mainly useful to researchers, not patients. However, once more carefully targeted therapies become available, the independent contribution of multi-infarct dementia and Alzheimer's disease to the burden of dementia might become important to tailor these treatments accordingly in affected individuals.
This disease mainly affects elderly people with arteriosclerosis (hardening of the arteries). Risk factors for arteriosclerosis include high blood pressure, raised cholesterol and smoking. An irregular heart beat (atrial fibrillation) can give rise to tiny blood clots, which can lodge in the brain and cause strokes too.
When the disease is diagnosed, nothing can be done about the damage that has occurred. But there are possibilities of preventing further brain damage. The cause of this disease is in principle identical to that of a stroke caused by a large blood clot. But in a person with multi-infarct dementia, the clots occur only in the small diameter blood vessels.
Symptoms of multi-infarct dementia, which often develop in a stepwise manner, include confusion, problems with recent memory, wandering or getting lost in familiar places, loss of bladder or bowel control (incontinence), emotional problems such as laughing or crying inappropriately, difficulty following instructions, and problems handling money. Usually the damage is so slight that the change is noticeable only as a series of small steps. However over time, as more small vessels are blocked, there is a gradual mental decline. Multi-infarct dementia, which typically begins between the ages of 60 and 75, affects men more often than women. Multi-infarct dementia affects approximately 4 out of 10,000 people. It is estimated that 10 to 20% of all dementias are caused by blood vessel (vascular) narrowing, making multi-infarct dementia the third most common cause of dementia in the elderly, behind Alzheimer's disease and Dementia of Lewy Bodies (DLBD). MID affects men more often than women. The disorder usually affects older people, over 55 years, with the onset averaging around age 65.
The disorder is diagnosed based on history, symptoms, signs, and tests, and by ruling out other causes of dementia, including dementia due to metabolic causes. History may include a history of stroke or hypertension. History of the dementia often shows stepwise progression of the condition: periods of abrupt decline alternating with "plateau" periods of minimal decline. Other characteristics that suggest multi-infarct dementia rather than Alzheimer's disease include: abrupt onset, somatic (physical) complaints, emotional changes, and focal (localized) neurologic signs and symptoms (modified Hachinski ischemia scale).
A neurologic examination shows variable deficits depending on the extent and location of damage. There may be multiple, focal neurologic deficits (localized areas with specific loss of function). Weakness or loss of function may occur on one side or only in one area. Abnormal reflexes may be present. There may be signs of cerebellar dysfunction such as loss of coordination. A head CT scan, and even more likely, MRI of the brain may show changes that suggest multi-infarct dementia because areas of dead tissue may be visible.
There is no known definitive treatment for multi-infarct dementia. Treatment is based on control of symptoms and the correction of the precipitating risk factors (high blood pressure and high cholesterol, especially). Other treatments may be advised based on the individual condition. The damage already done is irreversible but further progress of the disease may be prevented by medication to stop the blood clotting. You may be prescribed acetylsalicylic acid (aspirin) or dipyridamole, or clopidogrel. If you have cardiac irregularities as well, powerful anticoagulants are necessary such as warfarin or phenindione. The dementia itself is untreatable and the patient may eventually need constant care.
More information on dementia (Alzheimer's disease, vascular dementia, lewy body dementia, Pick's disease)
What is dementia? - Dementia is a deterioration of intellectual function and other cognitive skills. Dementia may involve progressive deterioration of thinking, memory, behavior, personality and motor function.
What types of dementia are there? - Types of dementia include Alzheimer's dementia, vascular dementias, Parkinson disease, Lewy body dementia, alcohol-related dementia, and Pick disease.
What're the risk factors for dementia? - The main risk factor for dementia is age. People who have sustained serious head injuries through boxing are prone to dementia pugilistica.
What causes dementia? - Dementia is caused by degeneration in the cerebral cortex including death of brain cells, conditions that impair the vascular or neurologic structures of the brain.
What're the symptoms of dementia? - The early symptom of dementia is diminished short-term memory. Patients with severe dementia cannot perform activities of daily living.
How is dementia diagnosed? - Diagnosis of dementia begins with a thorough physical exam and complete medical history, and followed by information-concentration-orientation test of Blessed et al. and the mini-mental state exam of Folstein et al.
What's the treatment for dementia? - The goal of treatment is to control the symptoms of dementia. Treatment of dementia begins with treatment of the underlying disease.
What's the long term dementia care? - Long-term dementia care may be needed for some patients with dementia. Possible options include in-home care, boarding homes, adult day care, and convalescent homes.
What's alcohol-related dementia? - Alcohol related dementia is a form of dementia related to the excessive drinking of alcohol. Alcohol abuse can lead to several forms of dementia.
What's frontal lobe dementia? - Frontal lobe dementia is a set of degenerative diseases producing many of the same symptoms as vascular dementia. The frontal lobe governs people's mood and behaviour.
What's senile dementia? - Senile dementia is the mental deterioration (loss of intellectual ability) that is associated with old age. Senile dementia is often used when referring to Alzheimer's disease.
What's early onset dementia? - Early onset dementia is a term that covers a range of diseases affecting memory and thinking in people under the age of 65.
What's AIDS related dementia? - HIV associated dementia (HAD) is comprised of a spectrum of conditions from the mild HIV-1 motor cognitive-motor disorder to severe and debilitating AIDS dementia.
What's Alzheimer's disease? - Alzheimer's disease is a form of degenerative brain disease resulting in progressive mental deterioration with disorientation, memory disturbance and confusion.
What types of Alzheimer's disease are there? - Types of Alzheimer's disease include early onset Alzheimer's, late-onset Alzheimer's, and familial Alzheimer's disease (FAD).
What're the stages of Alzheimer's disease? - Stages of Alzheimer's disease include no cognitive impairment, mild cognitive decline, moderate cognitive decline, moderately severe cognitive decline...
What causes Alzheimer's disease? - The ultimate cause or causes of Alzheimer's disease are still unknown, there are several risk factors that increase a person's likelihood of developing the disease.
What're the risk factors for Alzheimer's disease? - The risk for Alzheimer's disease increases with age. People with a family history of Alzheimer's have a greater risk.
What're the warning signs of Alzheimer's disease? - The warning signs of Alzheimer's disease include memory loss, difficulty performing familiar tasks, problems with language, poor or decreased judgment.
What're the symptoms of Alzheimer's disease? - The symptoms of Alzheimer's disease include memory lapses, perform routine tasks, loss of judgment, and personality or behavior changes.
How is Alzheimer's disease diagnosed? - Diagnosis of Alzheimer's disease is complex. Diagnosis of Alzheimer's disease begins with a thorough physical exam and complete medical history.
What's the treatment for Alzheimer's disease? - Some treatments for Alzheimer's disease that can be used to help manage and ease the symptoms. Medications help alleviate the symptoms of depression, anxiety, and delusions.
What medications treat Alzheimer's disease? - Four medications, tacrine, donepezil, rivastigmine tartrate and galantamine, are used to improve intellectual function in some patients with Alzheimer's disease.
What's the dietary therapy for Alzheimer's disease? - Dietary therapy for Alzheimer's disease involves appropriate intake of darkly colored fruits and vegetables, soy, alcohol, folate and vitamin B12.
What's the exercise therapy for Alzheimer's disease? - Aerobic exercise is very important for helping to protect against mental decline during aging due to Alzheimer's disease.
What's the prognosis of Alzheimer's disease? - A person with Alzheimer's disease lives an average of eight years and as many as 20 years or more from the onset of symptoms.
What's vascular dementia? - Vascular dementia is a common form of dementia in older persons that is due to cerebrovascular disease, usually with stepwise deterioration.
What types of vascular dementia are there? - There are a number of different types of vascular dementia. Two of the most common are multi-infarct dementia, binswanger's disease.
What's multi-infarct dementia? - Multi-infarct dementia is the most common form of vascular dementia. Multi-infarct dementia is associated with atherosclerosis.
What is Binswanger's disease? - Binswanger's disease is a progressive neurological disorder characterized by injuries to the blood vessels supplying the deep white-matter of the brain.
What causes vascular dementia? - Vascular dementia can be caused in several different ways. Most commonly there is blockage of small blood vessels (arteries) deep within the brain.
What're risk factors for vascular dementia? - The risk factors for vascular dementia are high blood pressure, high cholesterol, diabetes and heart rhythm problems.
What're the symptoms of vascular dementia? - Symptoms of vascular dementia include memory loss, difficulty doing usual daily activities, and a tendency to wander.
How is vascular dementia diagnosed? - Vascular dementia is diagnosed based on history, symptoms, signs, and tests, and by ruling out other causes of dementia.
What's the treatment for vascular dementia? - Treatment of vascular dementia is aimed at reducing the risk factors including stroke, high blood pressure, diabetes, high cholesterol and heart disease.
What's lewy body dementia? - Lewy body dementia is a progressive cause of dementia characterised by both cognitive problems and motor impairments.
What causes lewy body dementia? - Lewy body dementia is caused by abnormal microscopic deposits of protein in nerve cells. Lewy bodies appear in deteriorating nerve cells.
What're the symptoms of lewy body dementia? - Symptoms of lewy body dementia include a gradual loss of mental abilities, including orientation and memory, reasoning and intelligence.
How is lewy body dementia diagnosed? - Lewy body dementia is diagnosed by taking a careful history of the pattern of symptoms, and by excluding other possible causes.
What's the treatment for lewy body dementia? - There's no specific treatment for lewy body dementia. Treatment is directed at managing the signs and symptoms of the disease.
What is Pick's disease? - Pick disease is a brain disorder that causes slowly worsening decline of mental abilities. Pick's disease is a less common type of dementia.
What causes Pick's disease? - Pick's disease is a rare disorder similar to senile dementia/Alzheimer's type. Behavioral changes are prominent with loss of inhibition.
What're the symptoms of Pick's disease? - The signs and symptoms of Pick's disease include loss of intellectual abilities and changes in behavior and personality.
How is Pick's disease diagnosed? - Diagnosis of Pick's disease is based on initial diagnosis on history and symptoms, signs, and tests, and by ruling out other causes of dementia.
What's the treatment for Pick's disease? - There is no proven effective treatment for Pick's disease. Monitoring and assistance with self-care may be required.