323.9 ENCEPHALITIS NOS

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Code Information

Diagnosis Code: 323.9

Short Description: Encephalitis NOS

Long Description: Unspecified causes of encephalitis, myelitis, and encephalomyelitis

Code Classification:

Diseases of the nervous system (320–359)
- Inflammatory diseases of the central nervous system (320-327)
  - 323 Encephalitis, myelitis, and encephalomyelitis
    - 323.9 Encephalitis NOS

Code Version: 2015 ICD-9-CM

Synonyms

Acute and subacute hemorrhagic leukoencephalitis
Acute ascending myelitis
Acute necrotizing myelitis
Acute non-infective transverse myelitis
Acute transverse myelitis
Acute viral transverse myelitis
Brainstem encephalitis
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy
Cerebral irritation
Encephalitis
Encephalitis associated with acquired immunodeficiency syndrome
Encephalitis, myelitis and encephalomyelitis
Encephalomyelitis
Focal encephalitis
Fungal infection of brain
Granulomatous meningoencephalitis
Granulomatous meningoencephalomyelitis
Inflammation of spinal cord due to toxin
Leukoencephalopathy
Limbic encephalitis
Meningoencephalomyelitis
Meningomyelitis
Myelitis
Myelitis associated with acquired immunodeficiency syndrome
Primary encephalitis
Rasmussen syndrome
Subacute hemorrhagic leukoencephalitis
Subacute necrotizing myelitis
Transverse myelopathy syndrome

References to Index of Diseases and Injuries

The code 323.9 has the following ICD-9-CM references to the Index of Diseases and Injuries

Encephalitis (bacterial) (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) 323.9
- acute - see also Encephalitis, viral
  - disseminated (postinfectious) NEC 136.9 [323.61]
    - postimmunization or postvaccination 323.51
  - inclusional 049.8
  - inclusion body 049.8
  - necrotizing 049.8
- arboviral, arbovirus NEC 064
- arthropod-borne (see also Encephalitis, viral, arthropod-borne) 064
- Australian X 062.4
- Bwamba fever 066.3
- California (virus) 062.5
- Central European 063.2
- Czechoslovakian 063.2
- Dawson's (inclusion body) 046.2
- diffuse sclerosing 046.2
- due to
  - actinomycosis 039.8 [323.41]
  - cat-scratch disease 078.3 [323.01]
  - human herpesvirus 6 058.21
  - human herpesvirus 7 058.29
  - human herpesvirus NEC 058.29
  - human immunodeficiency virus [HIV] disease 042 [323.01]
  - infectious mononucleosis 075 [323.01]
  - malaria (see also Malaria) 084.6 [323.2]
  - negishi virus 064
  - ornithosis 073.7 [323.01]
  - other infection classified elsewhere 136.9 [323.41]
  - prophylactic inoculation against smallpox 323.51
  - rickettsiosis (see also Rickettsiosis) 083.9 [323.1]
  - rubella 056.01
  - toxoplasmosis (acquired) 130.0
    - congenital (active) 771.2 [323.41]
  - typhus (fever) (see also Typhus) 081.9 [323.1]
  - vaccination (smallpox) 323.51
- Eastern equine 062.2
- endemic 049.8
- epidemic 049.8
- equine (acute) (infectious) (viral) 062.9
  - eastern 062.2
  - venezuelan 066.2
  - western 062.1
- Far Eastern 063.0
- following vaccination or other immunization procedure 323.51
- herpes 054.3
- human herpesvirus 6 058.21
- human herpesvirus 7 058.29
- human herpesvirus NEC 058.29
- ilheus (virus) 062.8
- inclusion body 046.2
- infectious (acute) (virus) NEC 049.8
- influenzal (see also Influenza) 487.8 [323.41]
  - lethargic 049.8
- Japanese (B type) 062.0
- La Crosse 062.5
- Langat 063.8
- late effect - see Late, effect, encephalitis
- lead 984.9 [323.71]
- lethargic (acute) (infectious) (influenzal) 049.8
- lethargica 049.8
- louping ill 063.1
- lupus 710.0 [323.81]
- lymphatica 049.0
- Mengo 049.8
- meningococcal 036.1
- mumps 072.2
- Murray Valley 062.4
- myoclonic 049.8
- Negishi virus 064
- otitic NEC 382.4 [323.41]
- parasitic NEC 123.9 [323.41]
- periaxialis (concentrica) (diffusa) 341.1
- postchickenpox 052.0
- postexanthematous NEC 057.9 [323.62]
- postimmunization 323.51
- postinfectious NEC 136.9 [323.62]
- postmeasles 055.0
- posttraumatic 323.81
- postvaccinal (smallpox) 323.51
- postvaricella 052.0
- postviral NEC 079.99 [323.62]
  - postexanthematous 057.9 [323.62]
    - specified NEC 057.8 [323.62]
- Powassan 063.8
- progressive subcortical (Binswanger's) 290.12
- Rasmussen 323.81
- Rio Bravo 049.8
- rubella 056.01
- Russian
  - autumnal 062.0
  - spring-summer type (taiga) 063.0
- saturnine 984.9 [323.71]
- Semliki Forest 062.8
- serous 048
- slow-acting virus NEC 046.8
- specified cause NEC 323.81
- St. Louis type 062.3
- subacute sclerosing 046.2
- subcorticalis chronica 290.12
- summer 062.0
- suppurative 324.0
- syphilitic 094.81
  - congenital 090.41
- tick-borne 063.9
- torula, torular 117.5 [323.41]
- toxic NEC 989.9 [323.71]
- toxoplasmic (acquired) 130.0
  - congenital (active) 771.2 [323.41]
- trichinosis 124 [323.41]
- Trypanosomiasis (see also Trypanosomiasis) 086.9 [323.2]
- tuberculous (see also Tuberculosis) 013.6
- type B (Japanese) 062.0
- type C 062.3
- van Bogaert's 046.2
- Venezuelan 066.2
- Vienna type 049.8
- viral, virus 049.9
  - arthropod-borne NEC 064
    - mosquito-borne 062.9
      - Australian X disease 062.4
      - California virus 062.5
      - Eastern equine 062.2
      - Ilheus virus 062.8
      - Japanese (B type) 062.0
      - Murray Valley 062.4
      - specified type NEC 062.8
      - St. Louis 062.3
      - type B 062.0
      - type C 062.3
      - Western equine 062.1
    - tick-borne 063.9
      - biundulant 063.2
      - Central European 063.2
      - Czechoslovakian 063.2
      - diphasic meningoencephalitis 063.2
      - Far Eastern 063.0
      - Langat 063.8
      - louping ill 063.1
      - Powassan 063.8
      - Russian spring-summer (taiga) 063.0
      - specified type NEC 063.8
    - vector unknown 064
  - slow acting NEC 046.8
  - specified type NEC 049.8
  - vaccination, prophylactic (against) V05.0
- von Economo's 049.8
- Western equine 062.1
- West Nile type 066.41

Encephalomyelitis (chronic) (granulomatous) (myalgic, benign) (see also Encephalitis) 323.9
- abortive disseminated 049.8
- acute disseminated (ADEM) (postinfectious) 136.9 [323.61]
  - infectious 136.9 [323.61]
  - noninfectious 323.81
  - postimmunization 323.51
- due to
  - cat-scratch disease 078.3 [323.01]
  - infectious mononucleosis 075 [323.01]
  - ornithosis 073.7 [323.01]
  - vaccination (any) 323.51
- equine (acute) (infectious) 062.9
  - eastern 062.2
  - venezuelan 066.2
  - western 062.1
- funicularis infectiosa 049.8
- late effect - see Late, effect, encephalitis
- Munch-Peterson's 049.8
- postchickenpox 052.0
- postimmunization 323.51
- postmeasles 055.0
- postvaccinal (smallpox) 323.51
- rubella 056.01
- specified cause NEC 323.81
- syphilitic 094.81
- West Nile 066.41

Fever 780.60
- brain 323.9
  - late effect - see category 326
- cerebral 323.9
  - late effect - see category 326

Hematomyelitis 323.9
- late effect - see category 326

Infection, infected, infective (opportunistic) 136.9
- brain (see also Encephalitis) 323.9
  - late effect - see category 326
  - membranes - (see also Meningitis) 322.9
  - septic 324.0
    - late effect - see category 326
    - meninges (see also Meningitis) 320.9
- spinal cord NEC (see also Encephalitis) 323.9
  - abscess 324.1
    - late effect - see category 326
  - late effect - see category 326
  - meninges - see Meningitis
  - streptococcal 320.2

Inflammation, inflamed, inflammatory (with exudation)
- brain (see also Encephalitis) 323.9
  - late effect - see category 326
  - membrane - see Meningitis
- cerebral (see also Encephalitis) 323.9
  - late effect - see category 326
  - membrane - see Meningitis
- spinal
  - cord (see also Encephalitis) 323.9
    - late effect - see category 326

Leukoencephalopathy (see also Encephalitis) 323.9
- acute necrotizing hemorrhagic (postinfectious) 136.9 [323.61]
  - postimmunization or postvaccinal 323.51
- arteriosclerotic 437.0
- Binswanger's 290.12
- metachromatic 330.0
- multifocal (progressive) 046.3
- progressive multifocal 046.3
- reversible, posterior 348.5

Meningoencephalitis (see also Encephalitis) 323.9
- acute NEC 048
- bacterial, purulent, pyogenic, or septic - see Meningitis
- chronic NEC 094.1
- diffuse NEC 094.1
- diphasic 063.2
- due to
  - actinomycosis 039.8 [320.7]
  - blastomycosis NEC (see also Blastomycosis) 116.0 [323.41]
  - free-living amebae 136.29
  - Listeria monocytogenes 027.0 [320.7]
  - Lyme disease 088.81 [320.7]
  - mumps 072.2
  - Naegleria (amebae) (gruberi) (organisms) 136.29
  - rubella 056.01
  - sporotrichosis 117.1 [321.1]
  - toxoplasmosis (acquired) 130.0
    - congenital (active) 771.2 [323.41]
  - Trypanosoma 086.1 [323.2]
- epidemic 036.0
- herpes 054.3
- herpetic 054.3
- H. influenzae 320.0
- infectious (acute) 048
- influenzal 320.0
- late effect - see category 326
- Listeria monocytogenes 027.0 [320.7]
- lymphocytic (serous) 049.0
- mumps 072.2
- parasitic NEC 123.9 [323.41]
- pneumococcal 320.1
- primary amebic 136.29
- rubella 056.01
- serous 048
  - lymphocytic 049.0
- specific 094.2
- staphylococcal 320.3
- streptococcal 320.2
- syphilitic 094.2
- toxic NEC 989.9 [323.71]
  - due to
    - carbon tetrachloride (vapor) 987.8 [323.71]
    - hydroxyquinoline derivatives poisoning 961.3 [323.71]
    - lead 984.9 [323.71]
    - mercury 985.0 [323.71]
    - thallium 985.8 [323.71]
- toxoplasmosis (acquired) 130.0
- trypanosomic 086.1 [323.2]
- tuberculous (see also Tuberculosis, meninges) 013.0
- virus NEC 048

Meningoencephalomyelitis (see also Meningoencephalitis) 323.9
- acute NEC 048
  - disseminated (postinfectious) 136.9 [323.61]
    - postimmunization or postvaccination 323.51
- due to
  - actinomycosis 039.8 [320.7]
  - torula 117.5 [323.41]
  - toxoplasma or toxoplasmosis (acquired) 130.0
    - congenital (active) 771.2 [323.41]
- late effect - see category 326

Meningomyelitis (see also Meningoencephalitis) 323.9
- blastomycotic NEC (see also Blastomycosis) 116.0 [323.41]
- due to
  - actinomycosis 039.8 [320.7]
  - blastomycosis (see also Blastomycosis) 116.0 [323.41]
  - Meningococcus 036.0
  - sporotrichosis 117.1 [323.41]
  - torula 117.5 [323.41]
- late effect - see category 326
- lethargic 049.8
- meningococcal 036.0
- syphilitic 094.2
- tuberculous (see also Tuberculosis, meninges) 013.0

Mesencephalitis (see also Encephalitis) 323.9
- late effect - see category 326

Myelitis (ascending) (cerebellar) (childhood) (chronic) (descending) (diffuse) (disseminated) (pressure) (progressive) (spinal cord) (subacute) (see also Encephalitis) 323.9
- acute (transverse) 341.20
  - idiopathic 341.22
  - in conditions classified elsewhere 341.21
- due to
  - other infection classified elsewhere 136.9 [323.42]
  - specified cause NEC 323.82
  - vaccination (any) 323.52
  - viral diseases classified elsewhere 323.02
- herpes simplex 054.74
- herpes zoster 053.14
- late effect - see category 326
- optic neuritis in 341.0
- postchickenpox 052.2
- postimmunization 323.52
- postinfectious 136.9 [323.63]
- postvaccinal 323.52
- postvaricella 052.2
- syphilitic (transverse) 094.89
- toxic 989.9 [323.72]
- transverse 323.82
  - acute 341.20
    - idiopathic 341.22
    - in conditions classified elsewhere 341.21
  - idiopathic 341.22
- tuberculous (see also Tuberculosis) 013.6
- virus 049.9

Parencephalitis (see also Encephalitis) 323.9
- late effect - see category 326

Phrenitis 323.9

Syringomyelitis 323.9
- late effect - see category 326

Crosswalk Information

The code 323.9 converts into the following ICD-10 code(s):

ICD-9 Code		ICD-10 Code	ICD-10 Description
323.9		G04.90	Encephalitis and encephalomyelitis, unspecified
323.9		G04.91	Myelitis, unspecified

This ICD-9 to ICD-10 data is based on the 2018 General Equivalency Mapping (GEM) files published by the Centers for Medicare & Medicaid Services (CMS) for informational purposes only. The data is not an ICD-10 conversion tool and doesn’t guarantee clinical accuracy.

Similar Codes

ICD-9 Code	ICD-9 Description
323.01	Encephalitis and encephalomyelitis in viral diseases classified elsewhere
323.02	Myelitis in viral diseases classified elsewhere
323.1	Encephalitis, myelitis, and encephalomyelitis in rickettsial diseases classified elsewhere
323.2	Encephalitis, myelitis, and encephalomyelitis in protozoal diseases classified elsewhere
323.41	Other encephalitis and encephalomyelitis due to other infections classified elsewhere
323.42	Other myelitis due to other infections classified elsewhere
323.51	Encephalitis and encephalomyelitis following immunization procedures
323.52	Myelitis following immunization procedures
323.61	Infectious acute disseminated encephalomyelitis (ADEM)
323.62	Other postinfectious encephalitis and encephalomyelitis
323.63	Postinfectious myelitis
323.71	Toxic encephalitis and encephalomyelitis
323.72	Toxic myelitis
323.81	Other causes of encephalitis and encephalomyelitis
323.82	Other causes of myelitis

This page was last updated on: 10/1/2014

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