DSM-5 diagnostic criteria for Neurocognitive disorder with Lewy bodies explained

By Rajnish Mago, MD

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DSM-5 includes diagnoses of both:

– “Major neurocognitive disorder with Lewy bodies,” and

– “Mild neurocognitive disorder with Lewy bodies.”

In addition to meeting the diagnostic criteria for major or mild neurocognitive disorder, what other diagnostic criteria must be met in order to diagnose neurocognitive disorder with Lewy bodies?

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Onset and course

Both of these must be present:

1. Very gradual (“insidious”) onset

2. Gradual progression.

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Core versus Suggestive clinical features

The clinical features suggestive of neurocognitive disorder with Lewy bodies are divided into:

– The three core diagnostic features, and

– The two suggestive diagnostic features.

Here are the five:

Core diagnostic features

1. Fluctuating cognition including marked variability in attention and alertness.

2. Recurrent, well-formed, and detailed visual hallucinations.

3. Presence of “spontaneous” parkinsonism (i.e., not due to medication side effects) that started AFTER onset of the cognitive decline.

Suggestive diagnostic features

1. Rapid eye movement sleep behavior disorder.

2. Marked sensitivity to side effects of antipsychotic medications.

All these clinical features are explained on THIS PAGE.

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Probable versus Possible diagnosis

The diagnosis of neurocognitive disorder (major or mild) with Lewy bodies can be considered to be;

–  Probable or

– Possible.

This difference between a probable diagnosis and a possible diagnosis of neurocognitive disorder with Lewy bodies is in what clinical features are present.

Probable diagnosis: Either two core features OR at least one core feature plus at least one suggestive feature.

Possible diagnosis: One core feature OR one or more suggestive features.

If you think about it, a possible diagnosis can be based on JUST ONE clinical feature from either the core features or the suggestive features.

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And, of course, the clinical picture is not better explained by another disorder.

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ICD-10 diagnostic codes

A combination of ICD-10 codes will have to be used because along with the neurocognitive disorder, we have to code for the Lewy body disease and for the behavioral disturbance. Here are the three relevant codes:

– G31.83 “Dementia with Lewy bodies”

– F02.81 “Dementia in other diseases classified elsewhere with behavioral disturbance”

– F02.80 “Dementia in other diseases classified elsewhere without behavioral disturbance”

Based on the above, DSM-5 suggests coding as follows:

– Major neurocognitive disorder with probable or possible Lewy bodies, with behavioral disturbance: code both G31.83 and F02.81.

– Major neurocognitive disorder with probable or probable Lewy bodies, without behavioral disturbance: code both G31.83 and F02.80.

What about coding for Mild neurocognitive disorder with Lewy bodies? Use G31.84. For patients with Mild neurocogitive disorder with Lewy bodies, no code is used for the behavioral disturbance.

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Related Pages

What is Lewy body dementia? 

An introduction to Neurocognitive disorder with Lewy bodies

Neurocognitive disorder with Lewy bodies: Diagnosis

Neurocognitive disorder with Lewy bodies: Treatment

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References

American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Arlington, VA, American Psychiatric Association, 2013.

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