1. G31 Other degenerative diseases of nervous system, not elsewhere classified

    Use additional code, if applicable, for codes G31.0-G31.83, G31.85-G31.9, to identify:
    dementia with anxiety (F02.84, F02.A4, F02.B4, F02.C4)
    dementia with behavioral disturbance (F02.81-, F02.A1-, F02.B1-, F02.C1-)
    dementia with mood disturbance (F02.83, F02.A3, F02.B3, F02.C3)
    dementia with psychotic disturbance (F02.82, F02.A2, F02.B2, F02.C2)
    dementia without behavioral disturbance (F02.80, F02.A0, F02.B0, F02.C0)
    mild neurocognitive disorder due to known physiological condition (F06.7-)

    Excludes2

    1. G31.0 Frontotemporal dementia

      1. G31.01 Pick's disease

        Inclusion term(s):

        • Primary progressive aphasia
        • Progressive isolated aphasia
      2. G31.09 Other frontotemporal neurocognitive disorder

        Inclusion term(s):

        • Frontal dementia
    2. G31.1 Senile degeneration of brain, not elsewhere classified

    3. G31.2 Degeneration of nervous system due to alcohol

      Inclusion term(s):

      • Alcoholic cerebellar ataxia
      • Alcoholic cerebellar degeneration
      • Alcoholic cerebral degeneration
      • Alcoholic encephalopathy
      • Dysfunction of the autonomic nervous system due to alcohol
    4. G31.8 Other specified degenerative diseases of nervous system

      1. G31.80 Leukodystrophy, unspecified

      2. G31.81 Alpers disease

        Inclusion term(s):

        • Grey-matter degeneration
      3. G31.82 Leigh's disease

        Inclusion term(s):

        • Subacute necrotizing encephalopathy
      4. G31.83 Neurocognitive disorder with Lewy bodies

        Inclusion term(s):

        • Lewy body dementia
        • Lewy body disease
      5. G31.84 Mild cognitive impairment of uncertain or unknown etiology

        Inclusion term(s):

        • Mild cognitive disorder NOS
        • Mild neurocognitive disorder of uncertain or unknown etiology
      6. G31.85 Corticobasal degeneration

      7. G31.86 Alexander disease

      8. G31.89 Other specified degenerative diseases of nervous system

    5. G31.9 Degenerative disease of nervous system, unspecified

Abbreviations used here:

NEC Not elsewhere classifiable
This abbreviation in the Tabular List represents “other specified”. When a specific code is not available for a condition, the Tabular List includes an NEC entry under a code to identify the code as the “other specified” code.

NOS Not otherwise specified
This abbreviation is the equivalent of unspecified.