Definition:Multi-infarct dementia (MID) is the second most
common form of dementia after Alzheimer's disease. Patients with MID
experience periodic strokes that impair their mental abilities. The
effects accumulate over time, ultimately resulting in dementia.
Diagnosis: The course of MID differs from that of Alzheimer's.
Patients with Alzheimer's disease generally decline slowly and steadily;
MID patients get worse all of a sudden (when they have a stroke), then
remain stable for a time, then suddenly get worse again (when they have
another stroke). This stepwise course distinguishes MID from
Alzheimer's. MID patients may also exhibit lesions on MRI scans
(particularly in the hippocampus and frontal lobe); they may report
dizzy spells, temporary hemiplegia, or other signs and
symptoms of minor stroke. Note that patients can suffer from
both Alzheimer's and MID at the same time; this syndrome is called "mixed
dementia."
Treatment: Physical and behavioral therapy can partially
alleviate the physical and cognitive problems that the strokes cause; however, they cannot always return the patient to full health, and if the strokes continue the patient will likely end up demented. Patients
can also take steps to reduce the likelihood of stroke by reducing
dietary fat and cholesterol, taking appropriate medication, and so
forth.