Hello and welcome to the lecture on Dementia, The Challenge of Diagnosis.
The objectives for this lecture are first,
to describe the diagnostic criteria for dementia.
Then to consider different clinical indicators that are used to diagnose
the different types of dementia, and what clinical indicators are necessary for
a diagnosis of dementia.
Third, we're going to contrast how mild cognitive impairment
differs from dementia.
This diagnostic criteria were originally developed in 1984 and
recently revised in 2011.
We'll consider all-cause dementia diagnosis, because increasing
recognition that many individuals have what's called a mixed form of dementia.
They may have Alzheimer's disease but also some have cardio vascular changes
that would contribute to a vascular form of dementia.
And we're going to think about the different ways of considering
differential diagnosis for these different types of dementia.
How they look a little bit different at presentation.
So the dementia diagnosis requires cognitive or behavioral symptoms,
that must interfere with a person's ability to function in everyday life.
And they represent a slow and progressive decline that is irreversible.
And that they're not explained by some underlying medical condition,
such as a delirium or a major psychiatric disorder.
And so usually in the diagnostic process, we do some lab work to rule
out any underlying medical condition that could explain these changes in function.
Once those are ruled out, we then may consider a dementia diagnosis.
These cognitive symptoms and
the cognitive impairment is detected through a combination of history taking.
We talk with the individual who is experiencing the symptoms, and
a knowledgeable informant, usually a family caregiver, to get a good sense of
the slow progressive decline in memory, and in other functional symptoms.
And then we also do an objective cognitive assessment,
some test of different aspects of memory.
Usually this cognitive assessment maybe something like the Mini-Mental State Exam
or the MMSE, or the Montreal Cognitive Assessment, also called MoCA.
It also may involve neuropsychological testing in order to get a deep dive into
the aspects of memory that are being affected.
In order for a confirmed diagnosis of dementia, the impairment in behavior and
in cognition must involve two of the following.
And this is where we may begin to understand the differential diagnosis.
The first is an impaired ability to acquire and
remember new information, so problems with new memory formation.
And this is a classic symptom in Alzheimer's disease,
as well as other types.
The second is impaired reasoning, impaired ability to handle complex tasks,
and sometimes poor judgement, or being uninhibited.
And this uninhibited nature or poor judgement, is a classic symptom in
those individuals who have a frontotemporal form of dementia.
Impaired visuospatial abilities, and sometimes hallucinations,
are symptoms that may be more common in individuals with Lewy bodies disease.
Impaired language, or impaired ability to find words, is a classic symptom,
an early symptom often in individuals with Alzheimer's disease.
And changes in personality is another symptom.
Oftentimes apathy is a symptom that is more common in
individuals with Lewy bodies disease.
Mild cognitive impairment is different in dementia in its degree of severity.
Individuals with mild cognitive impairment have trouble with memory, but not to
the ability that it interferes with their ability to carry out daily activities.
So these are individuals who still have functional ability to carry out their
daily lives.
However, individuals who have mild cognitive impairment
should be followed up because these individuals are at much higher risk for
going on to develop dementia.
So in summary, a diagnosis of dementia requires first the presence of
a progressive, irreversible change in memory cognition, and
behavior that interferes with daily functioning, and
represent a decline from over the person previous level of functioning.
This diagnosis must be made using a comprehensive history, and
an objective cognitive assessment.
And the combination of both are required in order to make the diagnosis.
The diagnostic criteria also must include
two levels of impairment in cognitive or behavioral impairments.
And finally, mild cognitive impairment is not a form of dementia,
however it could be a precursor or an early stage of dementia.
So it doesn't interfere with a person's ability to function everyday life, but
does put that individual at increased risk for
possibly going on to developed dementia.