Lewy Body Dementia

Educational Objectives

The goal of this program is to improve the diagnosis and management of Lewy body dementia. After hearing and assimilating this program, the clinician will be better able to:

1. Identify the core clinical criteria for diagnosing Lewy body dementia.
2. Differentiate among indicative and supportive biomarkers in Lewy body dementia.

Summary

Lewy body disease (LBD) pathology: affects ≈5% of the older population; LBD does not always occur in isolation and likely contributes to some cognitive, behavioral, and physical symptoms of other types of dementia; in LBD, there is excessive accumulation of synuclein protein in the nuclei of spherical (Lewy) bodies, which are also seen in Parkinson disease (PD); LBD and PD share symptoms, eg, motor symptoms; synuclein is also seen in multiple system atrophy, although it does not present with the same Lewy bodies as those in PD and LBD

Core clinical criteria for diagnosis: diagnosis of LBD requires the presence of 2 of 4 core clinical features (ie, fluctuating attention and alertness, recurrent visual hallucinations, rapid eye movement [REM] sleep behavior disorder, or spontaneous cardinal features of PD); fluctuations — long naps (>2 hr) during the day, staring spells, and sudden episodes of confusion can indicate LBD and distinguish symptoms from Alzheimer disease (AD), vascular condition, or frontotemporal dementia; recurrent visual hallucinations — usually take the form of animals or people and become more complex over time; hallucinations in LBD do not have an auditory component and are usually not tied to a delusional system, although this can occur; REM behavior disorder — individuals act out their dreams while having them; features of parkinsonism — include rigidity, rest tremor, and bradykinesia; parkinsonism in LBD must be spontaneous (the patient should not be or have been taking dopamine-blocking medication for 6 mo prior to detection of parkinsonism); multiple studies have shown that in some people with PD and LBD, the tremor is not one that is typical of PD (can be a sustention or intention tremor)

Indicative biomarkers (IB): relatively specific to LBD or, at least, to the presence of synuclein in the brain; supportive biomarkers (SB) are seen frequently in LBD but are not necessarily specific to LBD; IBs include reduced dopamine transporter (DAT) protein on DAT imaging, with or without single-photon emission computed tomography (SPECT); DAT imaging is also abnormal in PD, progressive supranuclear palsy, and cortical basal degeneration, but LBD is the more common diagnosis; REM sleep without atonia (the biological identification of REM sleep behavior disorder) is also an IB and can be detected on a sleep study in cases with suspected dream enactment; abnormal iodine-metaiodobenzylguanidine (MIBG) scintigraphy (not widely used in the United States) can be used to evaluate the sympathetic supply to the heart (diminished in LBD)

Supportive biomarkers: a preserved mesial temporal lobe in an individual with dementia can be evaluated with volumetric magnetic resonance imaging; a normal mesial temporal lobe in a patient with degenerative dementia (DD) indicates LBD (after AD, LBD is the most likely cause of DD); hypometabolism in the occipital region (detected on fluorodeoxyglucose-positron emission tomography) supports the diagnosis of LBD; slow waves in the posterior region of the brain on electroencephalography suggest LBD

Supportive clinical features: occur frequently in LBD but are not particularly specific to LBD; psychiatric signs and symptoms — hallucinations in nonvisual modalities; although visual hallucinations are the most prominent and occur in ≥80% of patients with LBD, it is not unusual for patients to have hallucinations in other sensory modalities; visual hallucinations in LBD typically are not tied to delusions, however, patients can develop systematized delusions, in which they have a delusional view of the world that is somewhat similar to that seen in schizophrenia; this delusional syndrome occurs at a much later age in those with LBD than those with schizophrenia; apathy, anxiety, depression, and hypersomnia are also supportive clinical features of LBD

Severe antipsychotic sensitivity: LBD, as indicated by abnormal DAT, is associated with low dopamine supplies because of death of dopaminergic cells; dopamine-blocking agents in patients with LBD cause severe side effects related to movement (eg, extrapyramidal symptoms or tardive dyskinesia) as well as coma and escalated behavior

Other supportive clinical features: include postural instability, repeated falls, unresponsiveness or syncope, severe autonomic dysfunction, and hyposmia; should prompt investigation into the more specific features of LBD

Diagnosing LBD: presence of any of the core criteria indicates possible LBD; presence of any core criteria plus the supportive clinical criteria indicates probable LBD, with a sensitivity and specificity at autopsy of 85% to 95%

Treatment of anxiety and depression: patients with LBD often have atypical and paradoxical reactions to medications that affect the central nervous system; therefore, it is important to exercise caution with medications that block acetylcholine and dopamine; the same antipsychotic agents that are typically used for PD can be used to treat LBD; some antidepressants have anticholinergic and antidopaminergic effects; benzodiazepines and other medicines with sedating effects may complicate loss of alertness and awareness

Readings

Galasko D. Lewy body disorders. Neurol Clin. 2017;35(2):325-338. doi:10.1016/j.ncl.2017.01.004; Jellinger KA. Dementia with Lewy bodies and Parkinson's disease-dementia: Current concepts and controversies. J Neural Transm (Vienna). 2018;125(4):615-650. doi:10.1007/s00702-017-1821-9; Knuffman J et al. Differentiating between Lewy body dementia and Alzheimer's disease: A retrospective brain bank study. J Am Med Dir Assoc. 2001;2(4):146-148.; Matar E et al. Clinical features of Lewy body dementia: insights into diagnosis and pathophysiology. J Neurol. 2020;267(2):380-389. doi:10.1007/s00415-019-09583-8; Schumacher J et al. Dysfunctional brain dynamics and their origin in Lewy body dementia. Brain. 2019;142(6):1767-1782. doi:10.1093/brain/awz069; Tampi RR et al. Behavioral symptomatology and psychopharmacology of Lewy body dementia. Handb Clin Neurol. 2019;165:59-70. doi:10.1016/B978-0-444-64012-3.00005-8; Taylor JP et al. New evidence on the management of Lewy body dementia. Lancet Neurol. 2020;19(2):157-169. doi:10.1016/S1474-4422(19)30153-X; Yamada M et al. Diagnostic criteria for dementia with Lewy bodies: Updates and future directions. J Mov Disord. 2020;13(1):1-10. doi:10.14802/jmd.19052.

Disclosures

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning committee to disclose relevant financial relationships within the past 12 months that might create any personal conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, members of the faculty and planning committee reported nothing to disclose

Acknowledgements

Dr. Wint was recorded exclusively for Audio Digest, using virtual teleconference software, in compliance with current social-distancing guidelines during the COVID-19 pandemic. Audio Digest thanks Dr. Wint for his cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

PS501802

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.

More Details - Certification & Accreditation