Parkinson-Plus Syndromes: Dementia with Lewy Bodies

00:01 Now let's talk about Lewy Body Dementia.

00:04 Lewy Body Dementia is a progressive degenerative brain disorder characterized by dementia, psychosis, hallucinations, and a Parkinsonism, often with frequent neuroleptic sensitivity.

00:18 And it's in the differential diagnosis for both a Parkinsonism because patients present with prominent Parkinsonism as well as dementia, and it's in our dementia differential as well.

00:28 It kind of lives in the middle of the dementia and parkinsonism evaluations.

00:34 When we think about Parkinsonism and dementia, there are two ways in which that can present.

00:40 We can see patients with Parkinson's disease, idiopathic Parkinson's disease that develop dementia, and that's called PD dementia.

00:47 We also see dementia in dementia with Lewy bodies and the timeline of onset, the sequence of those findings are critically important.

00:55 With PD dementia, patients develop early Parkinsonism and late cognitive dysfunction.

01:01 And by rule the cognitive dysfunction should develop at least 1 year after the onset of Parkinsonism in PD dementia patients.

01:09 The cognitive dysfunction is late.

01:11 The Parkinsonism is early.

01:14 In dementia with Lewy bodies the opposite is true.

01:17 Here, the pathology begins in the cortex, and then descends rapidly into the subcortical basal ganglia structures.

01:23 We see early memory loss and by rule that should be within 6 months of the onset of Parkinsonism.

01:30 Now not every patient reads the book.

01:32 It should be how the test questions are written.

01:34 And in clinical practice, we see some variability.

01:37 But in dementia with Lewy bodies, we're looking for early onset memory loss in relation to the Parkinsonism.

01:44 In terms of clinical manifestations, this is a Parkinsonism with prominent dementia features.

01:50 We see dementia often with visual hallucinations, and that's a hallmark of dementia with Lewy bodies.

01:55 We can see fluctuating cognition that can look like a delirium.

02:00 REM behavior disorder is not uncommon and Parkinsonism is a hallmark.

02:05 In terms of the natural history, the dementia occurs before, at, or just at the beginning of the onset of the Parkinsonian signs and that time course is really important to sort out in our history taking.

02:19 In terms of diagnosis, this is also a clinical diagnosis.

02:22 And we're using that combination of history, physical exam, and some of those wildcard features neuroleptics sensitivity to establish the diagnosis.

02:33 In terms of treatment, there is no disease modifying therapy for Lewy body dementia.

02:38 We will often consider a levadopa challenge as we do for other Parkinson's-plus syndromes and typically that is incomplete or no response to levadopa can be seen.

02:49 Cholinesterase inhibitors can be important for supporting cognitive function.

02:53 Atypical antipsychotics can be used but we must consider the possibility of neuroleptic sensitivity.

03:00 And so we start with low doses, and typically agents that are less likely to offend second or third line agents, third generation agents.

03:07 And regular exercise is probably the most helpful treatment for any neurodegenerative degenerative condition.

03:14 When we look at all the studies that have been performed, regular physical activity is it promotes active mental health and reduces neurodegenerative dysfunction over time.