Chinese Expert Consensus Statement for Diagnosis and Treatment of Dementia With Lewy Bodies 2020

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Chinese Expert Consensus Statement for Diagnosis and Treatment of Dementia With Lewy Bodies 2020

Yong Ji¹,², Yan-Feng Li³, Dan-Tao Peng⁴, Zhi-Chao Chen¹; Chinese Society of Geriatrics of Chinese Medical Association; Chinese Society of Microcirculation Neurodegenerative Diseases Committee
¹Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing 100071, China; ²Department of Neurology, Tianjin Dementia Institute, Tianjin Key Laboratory of Cerebrovascular and Neurodegenerative Diseases, Tianjin Huanhu Hospital, Tianjin 300350, China; ³Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100010, China; ⁴Peking University China-Japan Friendship School of Clinical Medicine, Beijing 100020, China

Dementia with Lewy bodies (DLB) is the second most common neurodegenerative dementia worldwide—but it’s often misdiagnosed or missed. This 2020 consensus from leading Chinese neurologists aims to clarify how to identify and care for people with DLB, based on the latest research. Here’s a breakdown of what you need to know.

What Is DLB?

DLB is a brain disorder caused by abnormal protein clumps called Lewy bodies (made of alpha-synuclein) that build up in nerve cells. These clumps damage areas of the brain responsible for thinking, movement, sleep, and mood. Unlike Alzheimer’s disease (AD), DLB often affects attention, decision-making, and spatial skills before memory loss becomes severe.

Who Does DLB Affect?

DLB is more common than many realize:

  • In rural northern China, 1.05% of people aged 60+ have DLB.
  • It accounts for 10.1% of all dementia cases in older adults.
  • In Chinese memory clinics, 5.6% of patients with dementia have DLB.
  • Men are slightly more likely to be diagnosed than women (51.7% vs. 48.3%).

Why Does DLB Happen?

Two key factors drive DLB:

  1. Pathology: Lewy bodies come in two types—brainstem (classical, found in the lower brain) and cortical (found in the outer brain layers, linked to worse cognition).
  2. Genetics: The APOE4 gene increases DLB risk. Mutations in genes like glucocerebrosidase and alpha-synuclein also raise the chance of developing DLB.

What Are the Signs of DLB?

DLB is defined by dementia (progressive trouble with thinking, memory, or daily tasks) plus four “core” features. Many patients also have “supportive” signs that help doctors confirm the diagnosis.

Core Clinical Features

These are the most telling signs of DLB:

  1. Cognitive Fluctuation (70–90% of patients): Sudden, delirium-like shifts in awareness—one moment confused and unable to communicate, the next clear and coherent. Episodes last minutes to days.
  2. Vivid Visual Hallucinations (50–80%): Recurring, detailed sights (e.g., colorful animals, small figures) that feel real, often at night. May include sounds or smells.
  3. Parkinsonism (85–89%): Slow movement (bradykinesia), muscle stiffness (rigidity), or balance problems—not caused by aging, arthritis, meds, or stroke. Unlike Parkinson’s disease, rest tremor is rare.
  4. REM Sleep Behavior Disorder (RBD, up to 80%): Acting out dreams (kicking, punching, shouting) because the body doesn’t relax during deep REM sleep. A sleep study (polysomnography, PSG) confirms this.

Supportive Clinical Features

These signs don’t confirm DLB alone but strengthen the diagnosis:

  • Psychiatric Symptoms: Depression, anxiety, apathy, delusions (e.g., believing a loved one is an imposter—Capgras syndrome), or agitation. DLB patients are often extremely sensitive to antipsychotic drugs (a key clue).
  • Autonomic Dysfunctions: Problems with “automatic” body functions—like low blood pressure when standing (orthostatic hypotension, causing falls or fainting), constipation, urinary incontinence, drooling, or erectile dysfunction. These can start 5 years before dementia symptoms.
  • Hypersomnia: Excessive daytime sleepiness linked to Lewy body damage in the brain’s outer layers.
  • Hyposmia: Reduced sense of smell, which may begin years before memory problems—earlier than in Alzheimer’s.

How Is DLB Diagnosed?

Doctors use a mix of clinical signs and biomarkers (tests that show DLB-related brain/nerve damage) to diagnose DLB. The process follows guidelines from the DLB Consortium (a global group of experts).

Key Biomarkers for DLB

These tests are “gold standard” for distinguishing DLB from other dementias (like Alzheimer’s):

  1. DAT Scans (SPECT/PET): Show reduced dopamine activity in the basal ganglia (a brain region for movement and reward). This helps tell DLB apart from AD (Ia, A recommendation).
  2. MIBG Heart Scans: Measure nerve damage in the heart (common in DLB). Combining DAT and MIBG scans correctly identifies DLB vs. AD 96% of the time (Ia, A recommendation).
  3. PSG (Sleep Study): Confirms RBD by showing no muscle relaxation during REM sleep (Ib, A recommendation).

Supportive Biomarkers

These tests add weight to a DLB diagnosis:

  • FDG-PET/CT: Shows less activity in the visual cortex (back of the brain) or a “posterior cingulate island sign” (a pattern of preserved brain activity that differs from AD).
  • EEG: Slow waves in the back of the brain with periodic shifts in brain activity—early signs that distinguish DLB from AD.

How Is DLB Treated?

DLB treatment focuses on improving quality of life—managing cognition, mood, movement, and sleep. Doctors prioritize non-drug therapies first, then medications (with caution to avoid side effects).

Nonpharmacologic Interventions

These are the foundation of DLB care:

  • Physical/occupational therapy (to maintain movement and daily skills).
  • Exercise (walking, yoga) and social interaction (reduces isolation and agitation).
  • Cognitive training (brain games, memory exercises) and mindfulness.
  • Bright light therapy (helps sleep and mood).
  • Environment changes (reducing clutter, using labels) to ease confusion.
  • Music therapy (calms agitation).

Pharmacologic Interventions

Meds target specific symptoms but are used carefully to avoid worsening DLB:

  1. Cognitive Symptoms:
    • First-line: Donepezil and rivastigmine (boost acetylcholine, a brain chemical for memory; Ia, A recommendation).
    • Second-line: Memantine (IIa, B) or galantamine (IIIb, B).
  2. Neuropsychiatric Symptoms:
    • Donepezil/rivastigmine (ease apathy, depression, hallucinations; Ia, A).
    • Memantine (improves behavior and psychosis; Ia, A).
    • Avoid first-line antipsychotics: Quetiapine (IIIb, B) is a last resort; olanzapine/risperidone (C) and clozapine (D) are riskier.
  3. Motor Symptoms:
    • Levodopa (IIb, B) for slow movement/stiffness.
    • Zonisamide (IIIb, B) for milder motor issues (fewer side effects).
  4. Sleep/RBD:
    • Clonazepam (IIIa, B) for RBD.
    • Ramelteon (IIIb, B) for “sundowning” (evening agitation).
  5. Autonomic Dysfunctions:
    • No evidence-based treatments yet. Midodrine, droxidopa, or fludrocortisone may help severe low blood pressure (V, D).

What’s the Outlook for DLB?

DLB has a poor prognosis—most patients live 5–10 years after diagnosis. Complications like falls, infections, or organ failure often shorten life.

  • Patients with non-amnestic cognitive issues (trouble with attention, spatial skills, or decision-making) live 9 months longer on average than those with amnestic DLB (memory loss first).

References

  1. Ji Y, Li YF, Peng DT, Chen ZC; Chinese Society of Geriatrics of Chinese Medical Association; Chinese Society of Microcirculation Neurodegenerative Diseases Committee. Chinese Expert Consensus Statement for Diagnosis and Treatment of Dementia With Lewy Bodies 2020. Chinese Medical Journal. 2021;134(21):2529–2531. doi:doi.org/10.1097/CM9.0000000000001754
  2. Yue W, Wang XD, Shi Z, et al. The Prevalence of Dementia With Lewy Bodies in a Rural Area of China. Parkinsonism & Related Disorders. 2016;29:72–77. doi:doi.org/10.1016/j.parkreldis.2016.05.022
  3. Gan J, Liu S, Wang X, et al. Clinical Characteristics of Lewy Body Dementia in Chinese Memory Clinics. BMC Neurology. 2021;21:144. doi:doi.org/10.1186/s12883-021-02169-w
  4. Guerreiro R, Ross OA, Kun-Rodrigues C, et al. Investigating the Genetic Architecture of Dementia With Lewy Bodies: A Two-Stage Genome-Wide Association Study. Lancet Neurology. 2018;17:64–74. doi:doi.org/10.1016/S1474-4422(17)30400-3
  5. Ferman TJ, Smith GE, Dickson DW, et al. Abnormal Daytime Sleepiness in Dementia With Lewy Bodies Compared to Alzheimer’s Disease Using the Multiple Sleep Latency Test. Alzheimer’s Research & Therapy. 2014;6:76. doi:doi.org/10.1186/s13195-014-0076-z
  6. Ballard CG, Jacoby R, Del Ser T, et al. Neuropathological Substrates of Psychiatric Symptoms in Prospectively Studied Patients With Autopsy-Confirmed Dementia With Lewy Bodies. American Journal of Psychiatry. 2004;161:843–849. doi:doi.org/10.1176/appi.ajp.161.5.843
  7. Chin KS, Teodorczuk A, Watson R. Dementia With Lewy Bodies: Challenges in the Diagnosis and Management. Australian & New Zealand Journal of Psychiatry. 2019;53:291–303. doi:doi.org/10.1177/0004867419835029
  8. Donaghy PC, Barnett N, Olsen K, et al. Symptoms Associated With Lewy Body Disease in Mild Cognitive Impairment. International Journal of Geriatric Psychiatry. 2017;32:1163–1171. doi:doi.org/10.1002/gps.4742
  9. Shimizu S, Hirao K, Kanetaka H, et al. Utility of the Combination of DAT SPECT and MIBG Myocardial Scintigraphy in Differentiating Dementia With Lewy Bodies From Alzheimer’s Disease. European Journal of Nuclear Medicine and Molecular Imaging. 2016;43:184–192. doi:doi.org/10.1007/s00259-015-3146-y

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