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

Episodic and paroxysmal disorders
(G40-G47)

G40 Epilepsy
Excludes: Landau-Kleffner syndrome ( F80.3 )
seizure (convulsive) NOS ( R56.8 )
status epilepticus ( G41.- )
Todd's paralysis ( G83.8 )
G40.0 Localization-related (focal)(partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset
Benign childhood epilepsy with centrotemporal EEG spikes
Childhood epilepsy with occipital EEG paroxysms
G40.1 Localization-related (focal)(partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures
Attacks without alteration of consciousness
Simple partial seizures developing into secondarily generalized seizures
G40.2 Localization-related (focal)(partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures
Attacks with alteration of consciousness, often with automatisms
Complex partial seizures developing into secondarily generalized seizures
G40.3 Generalized idiopathic epilepsy and epileptic syndromes
Benign:
· myoclonic epilepsy in infancy
· neonatal convulsions (familial)
Childhood absence epilepsy [pyknolepsy]
Epilepsy with grand mal seizures on awakening
Juvenile:
· absence epilepsy
· myoclonic epilepsy [impulsive petit mal]
Nonspecific epileptic seizures:
· atonic
· clonic
· myoclonic
· tonic
· tonic-clonic
G40.4 Other generalized epilepsy and epileptic syndromes
Epilepsy with:
· myoclonic absences
· myoclonic-astatic seizures
Infantile spasms
Lennox-Gastaut syndrome
Salaam attacks
Symptomatic early myoclonic encephalopathy
West's syndrome
G40.5 Special epileptic syndromes
Epilepsia partialis continua [Kozhevnikof]
Epileptic seizures related to:
· alcohol
· drugs
· hormonal changes
· sleep deprivation
· stress
Use additional external cause code (Chapter XX), if desired, to identify drug, if drug-induced.
G40.6 Grand mal seizures, unspecified (with or without petit mal)
G40.7 Petit mal, unspecified, without grand mal seizures
G40.8 Other epilepsy
Epilepsies and epileptic syndromes undetermined as to whether they are focal or generalized
G40.9 Epilepsy, unspecified
Epileptic:
· convulsions NOS
· fits NOS
· seizures NOS

G41 Status epilepticus
G41.0 Grand mal status epilepticus
Tonic-clonic status epilepticus
Excludes: epilepsia partialis continua [Kozhevnikof] ( G40.5 )
G41.1 Petit mal status epilepticus
Epileptic absence status
G41.2 Complex partial status epilepticus
G41.8 Other status epilepticus
G41.9 Status epilepticus, unspecified

G43 Migraine
Use additional external cause code (Chapter XX), if desired, to identify drug, if drug-induced.
Excludes: headache NOS ( R51 )
G43.0 Migraine without aura [common migraine]
G43.1 Migraine with aura [classical migraine]
Migraine:
· aura without headache
· basilar
· equivalents
· familial hemiplegic
· with:
  · acute-onset aura
  · prolonged aura
  · typical aura
G43.2 Status migrainosus
G43.3 Complicated migraine
G43.8 Other migraine
Ophthalmoplegic migraine
Retinal migraine
G43.9 Migraine, unspecified

G44 Other headache syndromes
Excludes: atypical facial pain ( G50.1 )
headache NOS ( R51 )
trigeminal neuralgia ( G50.0 )
G44.0 Cluster headache syndrome
Chronic paroxysmal hemicrania
Cluster headache:
· chronic
· episodic
G44.1 Vascular headache, not elsewhere classified
Vascular headache NOS
G44.2 Tension-type headache
Chronic tension-type headache
Episodic tension headache
Tension headache NOS
G44.3 Chronic post-traumatic headache
G44.4 Drug-induced headache, not elsewhere classified
Use additional external cause code (Chapter XX), if desired, to identify drug.
G44.8 Other specified headache syndromes

G45 Transient cerebral ischaemic attacks and related syndromes
Excludes: neonatal cerebral ischaemia ( P91.0 )
G45.0 Vertebro-basilar artery syndrome
G45.1 Carotid artery syndrome (hemispheric)
G45.2 Multiple and bilateral precerebral artery syndromes
G45.3 Amaurosis fugax
G45.4 Transient global amnesia
Excludes: amnesia NOS ( R41.3 )
G45.8 Other transient cerebral ischaemic attacks and related syndromes
G45.9 Transient cerebral ischaemic attack, unspecified
Spasm of cerebral artery
Transient cerebral ischaemia NOS

G46* Vascular syndromes of brain in cerebrovascular diseases ( I60-I67+ )
G46.0* Middle cerebral artery syndrome ( I66.0+ )
G46.1* Anterior cerebral artery syndrome ( I66.1+ )
G46.2* Posterior cerebral artery syndrome ( I66.2+ )
G46.3* Brain stem stroke syndrome ( I60-I67+ )
Syndrome:
· Benedikt
· Claude
· Foville
· Millard-Gubler
· Wallenberg
· Weber
G46.4* Cerebellar stroke syndrome ( I60-I67+ )
G46.5* Pure motor lacunar syndrome ( I60-I67+ )
G46.6* Pure sensory lacunar syndrome ( I60-I67+ )
G46.7* Other lacunar syndromes ( I60-I67+ )
G46.8* Other vascular syndromes of brain in cerebrovascular diseases ( I60-I67+ )

G47 Sleep disorders
Excludes: nightmares ( F51.5 )
nonorganic sleep disorders ( F51.- )
sleep terrors ( F51.4 )
sleepwalking ( F51.3 )
G47.0 Disorders of initiating and maintaining sleep [insomnias]
G47.1 Disorders of excessive somnolence [hypersomnias]
G47.2 Disorders of the sleep-wake schedule
Delayed sleep phase syndrome
Irregular sleep-wake pattern
G47.3 Sleep apnoea
Sleep apnoea:
· central
· obstructive
Excludes: pickwickian syndrome ( E66.2 )
sleep apnoea of newborn ( P28.3 )
G47.4 Narcolepsy and cataplexy
G47.8 Other sleep disorders
Kleine-Levin syndrome
G47.9 Sleep disorder, unspecified