Typically the course of the NCD progresses in a manner that is commensurate with progres- sion of the underlying medical disorder. In circumstances where the medical disorder is treat- able (e.g., hypothyroidism), the neurocognitive deficit may improve or at least not progress.
When the medical condition has a deteriorative course (e.g., secondary progressive multiple sclerosis), the neurocognitive deficits will progress along with the temporal course of illness.
pend on the nature and severity of the medical condition.
Other major or mild neurocognitive disorder. The presence of an attributable medical condition does not entirely exclude the possibility of another major or mild NCD. If cog- nitive deficits persist following successful treatment of an associated medical condition, then another etiology may be responsible for the cognitive decline.
Due to Multiple Etiologies
A. The criteria are met for major or mild neurocognitive disorder.
B. There is evidence from the history. physical examination, or laboratory findings that the neurocognitive disorder is the pathophysiological consequence of more than one etio- logical process, excluding substances (e.g., neurocognitive disorder due to Alzhei- mer’s disease with subsequent development of vascular neurocognitive disorder).
Note: Please refer to the diagnostic criteria for the various neurocognitive disorders due to specific medical conditions for guidance on establishing the particular etiologies.
C. The cognitive deficits are not better explained by another mental disorder and do not occur exclusively during the course of a delirium.
Coding note: For major neurocognitive disorder due to multiple etiologies, with behavioral disturbance, code 294.11 (F02.81); for major neurocognitive disorder due to multiple etiolo- gies, without behavioral disturbance, code 294.10 (F02.80). All of the etiological medical conditions (with the exception of vascular disease) should be coded and listed separately immediately before major neurocognitive disorder due to multiple etiologies (e.g., 331.0 [630.9] Alzheimer’s disease; 331.82 [631.83] Lewy body disease; 294.11 [F02.81] major neurocognitive disorder due to multiple etiologies, with behavioral disturbance).
When a cerebrovascular etiology is contributing to the neurocognitive disorder, the diagno- sis of vascular neurocognitive disorder should be listed in addition to major neurocognitive disorder due to multiple etiologies. For example, for a presentation of major neurocognitive disorder due to both Alzheimer's disease and vascular disease, with behavioral disturbance, code the following: 331.0 (630.9) Alzheimer’s disease; 294.11 (F02.81) major neurocogni- tive disorder due to multiple etiologies, with behavioral disturbance; 290.40 (F01.51) major vascular neurocognitive disorder, with behavioral disturbance.
For mild neurocognitive disorder due to multiple etiologies, code 331.83 (631.84). (Note:
Do not use the additional codes for the etiologies. Behavioral disturbance cannot be coded but should still be indicated in writing.)
This category is included to cover the clinical presentation of a neurocognitive disorder (NCD) development of the NCD. In addition to evidence indicative of the presence of multiple med- ical conditions that are known to cause NCD (i.e., findings from the history and physical ex- amination, and laboratory findings), it may be helpful to refer to the diagnostic criteria and text for the various medical etiologies (e.g., NCD due to Parkinson’s disease) for more information on establishing the etiological connection for that particular medical condition.
799.59 (R41.9)