What is Mild Cognitive Impairment?
Did you know that approximately 80% of all individuals with an amnestic form of Mild Cognitive Impairment progress to a status of Alzheimer's disease within about 6yrs (Whitwell et al., 2007)?
Clinical Science has now determined that Mild Cognitive Impairment (MCI) is a prodromal stage on the path to dementia. It precedes dementia-specific decline, and can occur for years or decades prior.
Clinical Science has also begun to focus more on triaging dementia when diagnosed as well as target early interventions at the MCI stage. These approaches/interventions may span clinical, epidemiological, neuroimaging, biomarker, neuropathological, cognitive, mechanistic and outcome-based perspectives of MCI.
MCI is distinct from "normal aging" --> it is an overall slowing that does not significantly impede one's abilities to complete activities of daily living. There is a corresponding overall reduction in the amount of white matter in the central nervous system and affects on the gyri/sulci of the cerebral cortex. There can also be a restructuring of the neurocognitive networks that support activities of daily living, however, it is unknown whether this is an adverse effect of the decline or a compensatory technique of our neurocognitive system.
MCI is distinct from dementia in several ways (Whitwell et al., 2007); for example, there are differences in the amount of tissue available in the MCI vs. dementia stages and the severity of cognitive impairment(s). Basically, dementia and MCI progress in a way that gets faster and more severe the further along the progression of the disease.
The amnestic forms of MCI may lead to Alzheimer's forms of dementia, dementia due to vascular impairment and/or dementia due to diabetes mellitus, The non-amnestic forms of MCI may lead to other types of cognitive impairment such as aphasia, visuospatial deficits, Parkinsonian dementia, Lewy Body dementia, Frontotemporal dementia, etc.
The subgroups of MCI include amnestic vs. non-amnestic, and single vs. multiple domain. Single vs. multiple domains means, is the impairment concentrated in one cognate (e.g. a single domain) or across more than one cognate (e.g. memory AND executive function, etc.). This results in 4 specific subtypes of MCI:
1. Single Domain Amnestic
2. Multiple Domain Amnestic
3. Single Domain Non-amnestic
4. Multiple Domain Non-amnestic
These can also likely progress to different forms of dementia, based on the initial MCI diagnosis (Fischer et al., 2007).
1. Single domain Amnestic
May progress to dementia (especially if diabetes is a comorbidity) but it also may not progress any further
2. Multiple domain Amnestic
Highly likely to progress to Alzheimer’s or Vascular dementia
3. Single domain non-amnestic
Visual or spatial deficits, aphasia, etc.
4. Multiple domain non-amnestic
Likely to develop into Parkinson’s or Lewy Body Dementia
The signs and symptoms of dysphagia that this group may experience is largely going to be reflective of the subtype of MCI they are diagnosed with. If it is amnestic in nature, then those signs and symptoms related to Alzheimer's Dysphagia, or other forms of dysphagia, are likely going to be seen in the MCI group but in fewer numbers and in less severity. If their MCI subgroups are the non-amnestic type, then the same idea applies: they may have signs and symptoms more related to Parkinson's disease, stroke, Frontotemporal dementia and/or Lewy Body dementia but these signs and symptoms are in less frequency and in less severity.
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