Multi-infarct Dementia

What is Multi-Infarct Dementia

Multi-infarct dementia is the most common form of vascular dementia, which describes a loss of cognitive function from damaged blood vessels in the brain. "Multi-infarct" means that multiple areas of the brain have been injured due to a lack of blood from a series of small strokes.

Blockages in the arteries of the brain usually cause a stroke (infarction), but sometimes there are no stroke symptoms. These "silent" strokes increase a person's risk of vascular dementia. If there are a number of small strokes experienced over time, multi-infarct dementia may result. For more information about multi-infarct dementia or to schedule an appointment, call (206) 341-1900.

Risk Factors for Multi-Infarct Dementia

Because symptoms of multi-infarct dementia can develop in stages, they can be easily confused with Alzheimer's disease. But very often forms of vascular dementia do occur with Alzheimer's, and some research suggests that multi-infarct dementia may cause Alzheimer's disease or lead to its progression. 

Risk factors for multi-infarct dementia and other forms of vascular dementia include:

  • Age - Age is a major risk factor since vascular dementias are more likely to occur in the 80s or 90s. They are less common in the 60s and 70s, and rarely occur before age 65.
     
  • History of stroke - The brain damage that can occur with strokes increases the risk of developing dementia.
     
  • Hardening of the arteries (atherosclerosis) - Atherosclerosis causes blood vessels to narrow due to plaque build-up in the arteries.
     
  • High blood pressure - The wear and tear on blood vessels caused by hypertension increases the risk of vascular problems in the brain.
     
  • Diabetes - The risk of stroke and other vascular problems increases if high glucose levels damage blood vessels.
     
  • Smoking - Smoking can cause hardening of the arteries and other vascular diseases, including vascular dementia.
     
  • High cholesterol - High levels of LDL cholesterol are associated with an increased risk of vascular dementia, and possibly with a higher risk of Alzheimer's disease.

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Symptoms of Multi-Infarct Dementia

Multi-infarct dementia symptoms can vary, depending on the portions of the brain that are affected. People with this disorder can experience:

  • Confusion and agitation
  • Problems with memory or difficulty thinking
  • Numbness or tingling
  • Urinary frequency or incontinence
  • Difficulties with attention, concentration and judgment
  • Lack of emotion
  • Withdrawal from social interaction
  • Difficulty planning ahead
  • Delusional thinking
  • Hallucinations
  • Problems with language

Diagnosing Multi-Infarct Dementia

If multi-infarct or another form of vascular dementia is suspected, diagnostic procedures may include:

  • Computerized tomography (CT) - A CT scan is a special X-ray that can show a cross-sectional image of the brain. Sometimes a contrast material is injected to help find any abnormalities in the brain's blood vessels.  
     
  • Magnetic resonance imaging (MRI) - An MRI scan uses radio waves and a magnetic field to create detailed images of the brain. In some cases, contrast material is injected to help identify abnormalities. 
     
  • Positron emission tomography (PET) - PET scanning uses a low-level radioactive material which binds with substances that travel to the brain. The scan tracks the material as it shows which parts of the brain aren't functioning properly. This test can be particularly useful in determining the type of dementia. 
     
  • Doppler ultrasound - Doppler ultrasound can be used to determine if there are blockages or narrow places impeding blood flow to the brain by way of the carotid arteries.   
     
  • Neuropsychological tests - As with diagnosing other forms of dementia, neuropsychological testing assesses memory, perception, language and other skills to evaluate cognitive deficits.  While results for people with multi-infarct dementia typically show the same types of cognitive deficits as those of people who have Alzheimer's disease, one important difference is memory function. Some people with multi-infarct dementia don't experience memory problems until the condition progresses, unless there has been a stroke that directly affects the memory portion of the brain.

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Treatment of Multi-Infarct Dementia

There is no cure for multi-infarct dementia and no drugs have been approved by the Food and Drug Administration to treat it. However medications that treat behavior problems may be useful to control symptoms such as loss of judgment, agitation and confusion. Possible medications include:

  • Antipsychotics (haloperidol, risperdal, olanzapine)
  • Beta blockers
  • Drugs affecting serotonin levels (trazodone, buspirone)
  • Stimulants (methylphenidate)

Stopping or changing medications that worsen or cause confusion may improve mental function. It is important to first consult with the treating physician before stopping or changing any medications. Medications that may cause or increase confusion in some patients include:

  • Anticholinergics (including antidepressants such as amitriptyline or imipramine)
  • Cimetidine
  • Lidocaine
  • Pain relievers

Additionally, if the risk factors that contribute to multi-infarct dementia are treated, the progression of the disease may be slowed. Such treatment includes controlling blood pressure, cholesterol levels and diabetes, as well as quitting smoking. Doctors may also prescribe a medication to help keep arteries clear, such as ticlopidine (Ticlid) and clopidogrel (Plavix).

In general, people with dementia should be encouraged to engage in their normal activities as long as they're safe and don't cause frustration or confusion. A stable home environment with established routines is an essential element for maintaining the patient's well-being. As with other similar conditions, providers from Speech and Language, Occupational Therapy and Physical Therapy can assist with setting up compensatory systems and programs of physical and cognitive activation to help sustain function and maximize abilities.

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