6D85.6

ICD-11 MMS 2026-01

Dementia due to normal pressure hydrocephalus

Description

Dementia due to normal pressure hydrocephalus results from excess accumulation of cerebrospinal fluid in the brain as a result of idiopathic, non-obstructive causes but can also be secondary to haemorrhage, infection or inflammation. Progression is gradual but intervention (e.g., shunt) may result in improvement of symptoms, especially if administered earlier in the course of the condition. Typically, cognitive impairments include reduced processing speed and deficits in executive functioning and attention. These symptoms are also typically accompanied by gait abnormalities and urinary incontinence. Brain imaging to reveal ventricular volume and characterize brain displacement is often necessary to confirm the diagnosis.

Coding note

This category should never be used in primary tabulation. The codes are provided for use as supplementary or additional codes when it is desired to identify the presence of dementia in diseases classified elsewhere. When dementia is due to multiple aetiologies, code all that apply.

Coding note from above levels

This category should only be used for primary tabulation, if the aetiology of the dementia is unknown. If the aetiology of the dementia is known code to the aetiology of the dementia for primary tabulation. When dementia is due to multiple aetiologies, code all that apply.

Index terms

  • Dementia due to normal pressure hydrocephalus

Exclusions from above levels

  • 6A00 – Disorders of intellectual development
  • 6D70 – Delirium
  • http://id.who.int/icd/entity/1516623224 – Neurodevelopmental disorders
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  • MB20.0 – Stupor
  • MB20.1 – Coma
  • MG2A – Ageing associated decline in intrinsic capacity
  • QE62 – Uncomplicated bereavement
  • QE84 – Acute stress reaction

Sibling codes

  • 6D85.0 – Dementia due to Parkinson disease
  • 6D85.1 – Dementia due to Huntington disease
  • 6D85.2 – Dementia due to exposure to heavy metals or other toxins
  • 6D85.3 – Dementia due to human immunodeficiency virus
  • 6D85.4 – Dementia due to multiple sclerosis
  • 6D85.5 – Dementia due to prion disease
  • 6D85.7 – Dementia due to injury to the head
  • 6D85.8 – Dementia due to pellagra
  • 6D85.9 – Dementia due to Down syndrome
  • 6D85.Y – Dementia due to other specified diseases classified elsewhere

Foundation entity

Dementia due to normal pressure hydrocephalus – http://id.who.int/icd/entity/1129134415

Allowed postcoordination axes

Part of: 6D85: Dementia due to diseases classified elsewhere › 06: Mental, behavioural or neurodevelopmental disorders