There are different types of dementia. Here are the main differences between cortical and subcortical dementia.
When we talk about dementia we mean progressive overall cognitive decline. Contrary to what many may think, aging is not the cause of neurodegenerative diseases, and although there is comorability, there is no causality.
- In fact.
- 30% of people with Parkinson’s disease have dementia.
- But not the remaining 70%.
- So.
- Aren’t all dementia the same? There are two types of dementia.
- Associated with different diagnoses.
- So.
- In this article.
- We’ll talk about the differences between cortical and subcortical dementia.
In the first half of the 20th century, dementia amounted to progressive intellectual disability. In 1987, the APA (American Psychology Association) established a diagnostic criterion: cognitive impairment was accompanied by memory impairment and at least one of the following deficits: aphasia, apraxia or agnosia.
In 2012, the term dementia, replaced by a neurocognitive disorder, was removed.
The differences between cortical and subcortical dementia begin with the location of the disease; in Alzheimer’s disease, a prototype of cortical dementia, there is a temporoparial cortical predominance (Gustafson, 1992), so these dementias usually have short-term memory, episodic memory deficit and verbal fluency.
However, Alzheimer’s disease isn’t the only cortical dementia that exists. We also found Pick’s disease dementia or Lewy body dementia, the latter being the third leading cause of dementia, behind dementia due to Alzheimer’s disease and vascular dementia.
Let’s take Alzheimer’s disease as a reference to explain some of the consequences that cortical dementia can have on the cognition of those who suffer from it.
In the differences between cortical and subcortical dementia, we have the fact that subcortical dementia develops in areas such as the central gray nucleus and the hippocampus.
There are cognitive changes as the prefrontal area is strongly connected to subcortical areas, and a problem in these areas involves functional deactivation of the cortex.
Subcortical dementias, by antonomyasia, are Huntington’s disease and Alzheimer’s disease; however, dementia does not always occur in these two diseases, in fact, only 20 to 30% of Parkinson’s patients have sufficient diagnostic criteria to diagnose dementia.
In this section we will use Parkinson’s and Huntington’s diseases as a model to expose the main characteristics of subcortical dementia, some of them are:
Undoubtedly the differences between cortical and subcortical dementia are striking, however, the great difference we can find is the severity of both and their impact on a person’s daily life, although not all changes in both types of dementia were exposed, we may see less cognitive decline in subcortical dementia than in cortical dementias.
The differences are not limited to the degree of cognitive impairment, but are also based on the absence of aphasia, agnosia, and apraxia in the subcorticals, which occur in cortical dementia.
In short, it seems necessary to remember that the main differences between cortical and subcortical dementias lie in core executive capabilities, memory and language; Executive skills such as planning and problem solving are preserved in the cortex, while there is severe amnesia and affasic tongue.
In subcortical dementias, on the other hand, there are executive skills that have been severely impaired from the beginning, memory with slight forgetfulness and language without aphasia, perhaps with excessive production; the two dementias converge in perspective and visuospatial capacity, in both cases, there are changes in these aspects.