F02 — Dementia in other diseases classified elsewhere

What is this category?

F02 groups dementia syndromes for which a specific causative disease, other than primary degenerative Alzheimer's disease or cerebrovascular disease, has been identified. The cognitive picture can vary considerably depending on the underlying disease, but the classification logic is the same throughout: a named disease process is present and is judged to be causing the dementia.

Core diagnostic concept

The classification question F02 answers is not "what does the cognitive profile look like?" but "is there a specific, identified disease — other than Alzheimer's or cerebrovascular disease — that is known to cause dementia and is present in this person?" The category exists precisely because dementia is a syndrome that many different diseases can produce, and naming the underlying disease is central to management, unlike in F00 or F01.

Key diagnostic features

A specific identified causative disease

A named condition — such as Parkinson's disease, Huntington's disease, Pick's disease, Creutzfeldt-Jakob disease, or HIV disease — is present and judged responsible for the dementia.

A dementia syndrome meeting the general criteria

Multi-domain cognitive decline with preserved consciousness, as in F00, but attributed to the named disease rather than to Alzheimer's or cerebrovascular disease.

A disease-characteristic pattern, where recognised

Some underlying diseases produce a relatively characteristic cognitive or motor pattern (for example, prominent early motor and behavioural change in Huntington's disease), which can support the classification.

Temporal and clinical plausibility

The onset and course of the cognitive decline should be plausible for the named disease, not simply coincidental.

How to weigh evidence

These learning labels are teaching aids, not official ICD-10 terminology (see Sources and Method).

• supports A confirmed diagnosis of Parkinson's disease for several years, with a subsequent gradual decline in attention, visuospatial ability and executive function.
• consistent not decisive A family history of a neurological condition, without a confirmed diagnosis in this person.
• raises alternative No other disease identified at all, with a gradual, isolated cognitive decline otherwise typical of Alzheimer's disease.
• contradicts or weakens The named disease is present but has no plausible link to cognition (for example, a skin condition with no known cognitive effect).
• missing and necessary to ask Whether a specific causative diagnosis has actually been confirmed, or is only suspected.

Duration and course

Minimum duration: Varies by underlying disease; general dementia criteria (sustained, multi-domain decline with clear consciousness) still apply.

Course: Course often follows the trajectory of the underlying disease — for example, a stepped decline in some conditions, or a more rapidly progressive course in others such as Creutzfeldt-Jakob disease.

Included presentations

• Dementia in confirmed Parkinson's disease, once cognitive decline meets general dementia criteria.
• Dementia in Huntington's disease, often alongside characteristic motor and behavioural change.
• Dementia in HIV disease or another confirmed systemic or neurological condition with a recognised link to cognitive decline.

Exclusions and distinguishing presentations

Worked example — checking for a genuine causal link

A 63-year-old man with a confirmed eight-year history of Parkinson's disease has, over the past year, developed increasing difficulty with planning, visuospatial tasks (getting lost in familiar places), and fluctuating attention, alongside occasional visual hallucinations. His movement symptoms remain stable on current treatment.

1. Step 1 — Confirm the underlying disease: Parkinson's disease is a confirmed, long-standing diagnosis, not merely suspected.
2. Step 2 — Confirm the dementia syndrome: decline spans planning, visuospatial ability and attention, meeting general multi-domain dementia criteria.
3. Step 3 — Check plausibility: cognitive decline emerging years into an established Parkinson's disease course, with visual hallucinations, is a recognised and plausible pattern for this disease.
4. Step 4 — Check for a better alternative: no vascular events or risk-factor history are described, weakening F01; no acute fluctuating confusional presentation is described at a single time point, weakening F05, though ongoing fluctuating attention should still be monitored.
5. Conclusion — The presentation is best classified as F02, supported by a confirmed causative disease with a plausible temporal and clinical link to the dementia syndrome.

Interactive practice

• Type A A confirmed diagnosis, and now this Recognition / application · Foundation

Retrieval prompts

Try answering each of these from memory before revealing where to check. Nothing you think or type here is sent or saved anywhere.

1. Without looking back at the page, state the one thing that must be confirmed, not just suspected, before classifying dementia as F02.

   Reveal answer location

   Check Duration and course, Diagnostic boundary, or the rapid revision card below — the cue you need is one of those, in this category's own already-authored wording.

   I recalled this I need to review this

These self-checks are a personal study aid only, visible to you on this page for this visit — they are not stored and do not affect your mastery dimensions.

Related glossary terms

• Dementia

  A syndrome, usually of chronic or progressive course, in which there is decline in memory and at least one other cognitive domain (such as language, planning or judgement) severe enough to impair everyday functioning, occurring with clear consciousness. Dementia is a syndrome that can arise from several different underlying diseases, not a single diagnosis.

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• Cognitive domain

  A distinct area of mental functioning that can be separately assessed, such as memory, language, attention, planning/executive function, or visuospatial ability. Classifying organic mental disorders often depends on which domain(s) are affected and whether the pattern is isolated or multi-domain.

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