For more information, see Major and Mild Neurocognitive Disorders
A. The criteria are met for major or mild neurocognitive disorder.
B. The disorder has an insidious onset and gradual progression.
C. The disorder meets a combination of core diagnostic features and suggestive diagnostic features for either probable or possible neurocognitive disorder with Lewy bodies.
For probable major or mild neurocognitive disorder with Lewy bodies, the individual has two core features, or one suggestive feature with one or more core features.
For possible major or mild neurocognitive disorder with Lewy bodies, the individual has only one core features, or one or more suggestive features.
- Core diagnostic features:
- a. Fluctuating cognition with pronounced variations in attention and alertness.
- b. Recurrent visual hallucinations that are well formed and detailed.
- c. Spontaneous features of parkinsonism, with onset subsequent to the development of cognitive decline.
- Suggestive diagnostic features:
- a. Meets criteria for rapid eye movement sleep behavior disorder.
- b. Severe neuroleptic sensitivity.
D. The disturbance is not better explained by cerebrovascular disease, another neurodegenerative disease, the effects of a substance, or another mental, neurological, or systemic disorder.
A key differentiating feature in clinical diagnosis is the temporal sequence in which the parkinsonism and the NCD appear. For NCD due to Parkinson's disease, the individual must develop cognitive decline in the context of established Parkinson's disease; by convention, the decline should not reach the stage of major NCD until at least 1 year after Parkinson's is diagnosed. If less than a year has passed since the onset of motor symptoms, the diagnosis is NCDLB. This distinction is clearer at the major NCD level than at the mild NCD level.
The timing and sequence of parkinsonism and mild NCD may be more difficult to determine because the onset and clinical presentation can be ambiguous, and unspecified mild NCD should be diagnosed if the other core and suggestive features are absent.