Chapter VI
Diseases of the nervous system
(G00-G99)

Other disorders of the nervous system
(G90-G99)

G90 Disorders of autonomic nervous system
Excludes: dysfunction of autonomic nervous system due to alcohol ( G31.2 )
G90.0 Idiopathic peripheral autonomic neuropathy
Carotid sinus syncope
G90.1 Familial dysautonomia [Riley-Day]
G90.2 Horner's syndrome
Bernard(-Horner) syndrome
G90.3 Multi-system degeneration
Neurogenic orthostatic hypotension [Shy-Drager]
Excludes: orthostatic hypotension NOS ( I95.1 )
G90.4 Autonomic dysreflexia
G90.8 Other disorders of autonomic nervous system
G90.9 Disorder of autonomic nervous system, unspecified

G91 Hydrocephalus
Includes: acquired hydrocephalus
Excludes: hydrocephalus:
· congenital ( Q03.- )
· due to congenital toxoplasmosis ( P37.1 )
G91.0 Communicating hydrocephalus
G91.1 Obstructive hydrocephalus
G91.2 Normal-pressure hydrocephalus
G91.3 Post-traumatic hydrocephalus, unspecified
G91.8 Other hydrocephalus
G91.9 Hydrocephalus, unspecified

G92 Toxic encephalopathy
Use additional external cause code (Chapter XX), if desired, to identify toxic agent.

G93 Other disorders of brain
G93.0 Cerebral cysts
Arachnoid cyst
Porencephalic cyst, acquired
Excludes: acquired periventricular cysts of newborn ( P91.1 )
congenital cerebral cysts ( Q04.6 )
G93.1 Anoxic brain damage, not elsewhere classified
Excludes: complicating:
· abortion or ectopic or molar pregnancy ( O00-O07 , O08.8 )
· pregnancy, labour or delivery ( O29.2 , O74.3 , O89.2 )
· surgical and medical care ( T80-T88 )
neonatal anoxia ( P21.9 )
G93.2 Benign intracranial hypertension
Excludes: hypertensive encephalopathy ( I67.4 )
G93.3 Postviral fatigue syndrome
Benign myalgic encephalomyelitis
G93.4 Encephalopathy, unspecified
Excludes: encephalopathy:
· alcoholic ( G31.2 )
· toxic ( G92 )
G93.5 Compression of brain
Compression
Herniation
}
}
of brain (stem)
Excludes: traumatic compression of brain (diffuse) ( S06.2 )
· focal ( S06.3 )
G93.6 Cerebral oedema
Excludes: cerebral oedema:
· due to birth injury ( P11.0 )
· traumatic ( S06.1 )
G93.7 Reye's syndrome
Use additional external cause code (Chapter XX), if desired, to identify cause.
G93.8 Other specified disorders of brain
Postradiation encephalopathy
Use additional external cause code (Chapter XX), if desired, to identify cause.
G93.9 Disorder of brain, unspecified

G94* Other disorders of brain in diseases classified elsewhere
G94.0* Hydrocephalus in infectious and parasitic diseases classified elsewhere ( A00-B99+ )
G94.1* Hydrocephalus in neoplastic disease ( C00-D48+ )
G94.2* Hydrocephalus in other diseases classified elsewhere
G94.8* Other specified disorders of brain in diseases classified elsewhere

G95 Other diseases of spinal cord
Excludes: myelitis ( G04.- )
G95.0 Syringomyelia and syringobulbia
G95.1 Vascular myelopathies
Acute infarction of spinal cord (embolic)(nonembolic)
Arterial thrombosis of spinal cord
Haematomyelia
Nonpyogenic intraspinal phlebitis and thrombophlebitis
Oedema of spinal cord
Subacute necrotic myelopathy
Excludes: intraspinal phlebitis and thrombophlebitis, except non-pyogenic ( G08 )
G95.2 Cord compression, unspecified
G95.8 Other specified diseases of spinal cord
Cord bladder NOS
Myelopathy:
· drug-induced
· radiation-induced
Use additional external cause code (Chapter XX), if desired, to identify external agent.
Excludes: neurogenic bladder:
· NOS ( N31.9 )
· due to cauda equina syndrome ( G83.4 )
neuromuscular dysfunction of bladder without mention of spinal cord lesion ( N31.- )
G95.9 Disease of spinal cord, unspecified
Myelopathy NOS

G96 Other disorders of central nervous system
G96.0 Cerebrospinal fluid leak
Excludes: from spinal puncture ( G97.0 )
G96.1 Disorders of meninges, not elsewhere classified
Meningeal adhesions (cerebral)(spinal)
G96.8 Other specified disorders of central nervous system
G96.9 Disorder of central nervous system, unspecified

G97 Postprocedural disorders of nervous system, not elsewhere classified
G97.0 Cerebrospinal fluid leak from spinal puncture
G97.1 Other reaction to spinal and lumbar puncture
G97.2 Intracranial hypotension following ventricular shunting
G97.8 Other postprocedural disorders of nervous system
G97.9 Postprocedural disorder of nervous system, unspecified

G98 Other disorders of nervous system, not elsewhere classified
Nervous system disorder NOS

G99* Other disorders of nervous system in diseases classified elsewhere
G99.0* Autonomic neuropathy in endocrine and metabolic diseases
Amyloid autonomic neuropathy ( E85.-+ )
Diabetic autonomic neuropathy ( E10-E14+ with common fourth character .4)
G99.1* Other disorders of autonomic nervous system in other diseases classified elsewhere
G99.2* Myelopathy in diseases classified elsewhere
Anterior spinal and vertebral artery compression syndromes ( M47.0+ )
Myelopathy in:
· intervertebral disc disorders ( M50.0+ , M51.0+ )
· neoplastic disease ( C00-D48+ )
· spondylosis ( M47.-+ )
G99.8* Other specified disorders of nervous system in diseases classified elsewhere