Table 2. Criteria for the diagnosis of probable and possible dementia with Lewy bodies ² .

1. Essential: dementia is required for a diagnosis of DLB and defined as a progressive cognitive decline which affects social and occupational functions or daily activities. It mainly affects attention, executive function, and visuoperceptual abilities, worsening memory impairment as it progresses.

Core clinical features:

Fluctuating cognition with pronounced variations in alertness.

Recurrent visual hallucinations.

REM sleep behavior disorder.

One or more spontaneous cardinal features of parkinsonism (bradykinesia, rest tremor, or rigidity).*

Supportive clinical features: severe sensitivity to antipsychotic agents, postural instability, repeated falls; syncope or other transient episodes of unresponsiveness; severe autonomic dysfunction, e.g., constipation, orthostatic hypotension, urinary incontinence; hypersomnia; hyposmia; other hallucination modalities; systematized delusions; apathy, anxiety, and depression.

Indicative biomarkers:

Reduced dopamine transporter uptake in basal ganglia demonstrated by SPECT or PET.

Abnormal (low uptake) 123iodine-MIBG myocardial scintigraphy.

Polysomnographic confirmation of REM sleep without atonia.

Supportive biomarkers:

Relative preservation of medial temporal lobe structures on CT/MRI scan.

Generalized low uptake on SPECT/PET perfusion/metabolism scan with reduced occipital activity. Cingulate island sign on FDG-PET imaging.

Prominent posterior slow-wave activity on EEG with periodic fluctuations in the pre-alpha/theta range.

Diagnosis is probable when:

Two or more core clinical features are present

OR

Only one core clinical feature is present but with one or more indicative biomarkers.

Diagnosis is possible when:

Only one core clinical feature (with no biomarkers)

One or more indicative biomarkers are present without core clinical features.

*We continue to recommend the existing 1-year rule between the onset of dementia and parkinsonism.