Interactive Transcript
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Dr. Laser,
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this 63-year-old's main symptoms
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are ataxia and memory loss.
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So, we're into that neurodegenerative
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group of disorders.
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Before we start down the differential of
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this case and point out some of the findings,
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if we take the main dementias,
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I use the clinical as well as the visual as
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tip-offs to segregate into various diagnoses.
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For instance, you know, movement disorders.
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Most patients with ALZ,
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at least in the early to mid-stage,
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don't have a lot of movement disorder
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associated with their syndrome.
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So if they've got tremor and rigidity,
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I'm in the Parkinsonian group,
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whether it's multisystem,
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atrophy or classic Parkinson's disease.
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If they've got hallucinations,
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granted hallucinations do occur with ALZ,
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but prominent visual hallucinations
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pretty early on in somnolence,
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seen with dementia with Lewy bodies.
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Then ALZ is really characterized,
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not just by cognitive decline
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and short-term memory loss.
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The patients have enormous capacity to remember
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back 30, 40, 50 years,
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but short-term memory,
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not so much.
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Their daily function is impaired.
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They can't remember what they said 30 seconds ago.
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They have aphasia, paraphasia,
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and they may even have semantic aphasia
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where the meaning of words is lost.
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Then you've got frontotemporal dementia syndromes,
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of which Pick's disease was included in that in the past.
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We don't use that name so much anymore.
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There are heredofamilial types
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and non-heredofamilial types.
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But this disorder is characterized,
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not just by frontal or frontotemporal involvement,
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but by disinhibition, disexecutive behavior,
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you know,
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eating with your feet at the dinner table,
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making weird and lascivious comments
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early on in the disease.
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So they lose their inhibitory capacity.
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They are, in other words, unfiltered.
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And then you've got vascular disease.
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That one's a little bit easier,
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that's kind of a stuttering decline.
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But because there's vascular disease,
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you may see macro infarcts or you may see,
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as you've described before,
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with the Fazekas scale,
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multiple confluent areas of white matter
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signal alteration,
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commensurate with Binswanger syndrome.
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So now let's scroll this case.
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And we've got left greater than right,
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both parietal and frontal cortical atrophy,
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at least moderate in severity.
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And then in the sagittal projection,
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we've got some parietal occipital atrophy,
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some occipital atrophy.
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Here is the precuneus right here.
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Also a little bit of atrophy,
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some atrophy of the cingulate sulcus
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going all the way forward.
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And there's also some brain stem involvement.
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You commented on this in the report,
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the midbrain is atrophic.
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It looks a little bit like a hummingbird.
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The superior colliculus off to the side.
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It's pretty good, actually.
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It's pretty juicy in the midline.
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It's a little small,
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but they always are in the midline.
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But that at least raised the possibility
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of progressive supranuclear palsy.
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So, ignoring the visual abnormalities that include
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lens replacement and the patient's
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been treated with a band
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for I think possibly retinal detachment or nearsightedness.
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I'm not sure which.
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Tell us about the differential diagnosis of
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ALZ and other disorders, including MCI.
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And what is MCI?
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Mild Cognitive Impairment Syndrome
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is MCI.
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Okay.
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And that term is used a lot,
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and we frequently use that term in place of ALZ
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because if you put the term ALZ in a report,
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it has emotional consequences,
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it has insurance consequences,
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and it has general relationship consequences.
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I once did that in a report to a neurologist's
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mother, and he came in.
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He said, my mother is not demented.
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He was absolutely incensed.
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Turned out she developed dementia about a year later,
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and she did have some cognitive impairment.
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So what is cognitive...
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Mild Cognitive Impairment Syndrome?
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When do we use that term or pull that term out?
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So, typically,
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the way I do it is I look at all the scales that
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we've discussed prior,
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the global cortical atrophy scale,
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the medial temporal lobe atrophy scale,
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the Fazekas scale,
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the codom scale.
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And I try to form a picture of what's going on
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with the patient.
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I try to grade it subjectively,
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but with those scales in mind.
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So I look at the hippocampi,
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which is probably the most important scale
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to look at, and the degree of atrophy,
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the degree of volume loss of the hippocampi.
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In this case,
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as Dr. Pomeranz is pointing out on the left,
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the medial temporal lobe atrophy scale would be
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a two to three, almost a three in this case.
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So, there's profound left hippocampal volume loss.
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And let's redefine what that is.
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The choroidal fissure is big.
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The temporal horn is big,
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and there is at least moderate to
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severe hippocampal atrophy.
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All these structures that live in here,
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the dentate gyrus, the amygdala, and others,
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nice and juicy on the right,
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very small and lobulated on the left.
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And as you and I have discussed before,
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the number one biomarker for ALZ is hippocampal
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volume loss, and this patient has it.
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Now, in somebody where you want to suggest
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the diagnosis of ALZ,
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but they don't give you a strong
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cognitive decline history,
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one way to say it in code is findings are highly
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suggestive of Mild Cognitive Impairment Syndrome,
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or progression thereof.
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Which is your way of saying,
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I'm worried about MCI progressing to ALZ.
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Now, what percent of patients that don't have a florid
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ALZ go on to MCI that have perihippocampal
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or hippocampal involvement?
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It's about 12% per year.
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If they've got some cognitive decline that's mild,
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will go on to flat-out ALZ.
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And over five years,
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80% will end up with ALZ.
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So this patient, you know, is a big candidate,
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a strong candidate for ALZ
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if they don't have it already.
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We haven't physically examined this individual.
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And this patient also has a fair
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amount of frontal involvement,
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which makes the case a little more challenging.
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Right?
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The left is involved more than the right,
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so you might consider a more
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atypical form of frontolobar dementia
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or frontotemporal dementia with parietal extension back
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rather than ALZ with extension forward,
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except there's no behavioral disturbance.
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The patient only has memory loss.
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So that really clinically favors ALZ over FLD,
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Frontal Lobar Dementia,
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But there is involvement of the olfactory area,
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which at least raises the possibility
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of a frontolobar dementia.
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So, we've got a pretty broad differential here.
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Any other comments before we exit this case?
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I would.
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One other thing that you could show is if
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you show the FLAIR sequence,
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that there is very little white matter disease
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for a 63-year-old.
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He has some punctate white matter lesions,
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but the degree of white matter is essentially
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normal for a patient of this age.
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That's a very good point.
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You know, his Fazekas scale is one.
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And one of your charges, one of your jobs,
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is to try and tease out what kind of dementia
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you're dealing with.
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And if you can exclude vascular disease...
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And by the way,
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vascular disease and neurodegenerative disease combined,
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account for 15% of all dementia.
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So, it's pretty common.
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15% are purely vascular.
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So now you've got 30% are attributable
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to vascular disease.
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So if you've got vascular disease
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that's very prominent,
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you may want to treat that patient with, say,
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a statin,
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very aggressive statin therapy to try and halt the
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progression of microvascular
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or macrovascular dementia.
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So, very little white matter disease makes this
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unlikely to be a vasculopathic dementia and more
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likely to be a primary neurodegenerative disease.
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And some of the ones we were
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considering here were PSP,
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which we eventually excluded because
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of the collicular plate,
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even though there is a hummingbird sign,
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frontolobar dementia
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or related Picks disease and ALZ
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or MCI Alzheimer's disease
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or mild cognitive impairment syndrome.
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Any other comments before we quit?
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Nope.
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Okay, P and Laser out.
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