ICD-10-CM Book 2026 Edition

Chapters  /  Chapter 6  /  G89-G99

Other disorders of the nervous system (G89-G99)

G89 Pain, not elsewhere classified
CodeAlso related psychological factors associated with pain (F45.42)
Excludes1 generalized pain NOS (R52)
pain disorders exclusively related to psychological factors (F45.41)
pain NOS (R52)
Excludes2 atypical face pain (G50.1)
headache syndromes (G44.-)
localized pain, unspecified type - code to pain by site, such as:
abdomen pain (R10.-)
back pain (M54.9)
breast pain (N64.4)
chest pain (R07.1-R07.9)
ear pain (H92.0-)
eye pain (H57.1)
headache (R51.9)
joint pain (M25.5-)
limb pain (M79.6-)
lumbar region pain (M54.5-)
painful urination (R30.9)
pelvic and perineal pain (R10.2-)
shoulder pain (M25.51-)
spine pain (M54.-)
throat pain (R07.0)
tongue pain (K14.6)
tooth pain (K08.8)
renal colic (N23)
migraines (G43.-)
myalgia (M79.1-)
pain from prosthetic devices, implants, and grafts (T82.84, T83.84, T84.84, T85.84-)
phantom limb syndrome with pain (G54.6)
vulvar vestibulitis (N94.810)
vulvodynia (N94.81-)
G89.0 Central pain syndrome
Déjérine-Roussy syndrome
Myelopathic pain syndrome
Thalamic pain syndrome (hyperesthetic)
G89.1 Acute pain, not elsewhere classified
G89.11 Acute pain due to trauma
G89.12 Acute post-thoracotomy pain
Post-thoracotomy pain NOS
G89.18 Other acute postprocedural pain
Postoperative pain NOS
Postprocedural pain NOS
G89.2 Chronic pain, not elsewhere classified
Excludes1 causalgia, lower limb (G57.7-)
causalgia, upper limb (G56.4-)
central pain syndrome (G89.0)
chronic pain syndrome (G89.4)
complex regional pain syndrome II, lower limb (G57.7-)
complex regional pain syndrome II, upper limb (G56.4-)
neoplasm related chronic pain (G89.3)
reflex sympathetic dystrophy (G90.5-)
G89.21 Chronic pain due to trauma
G89.22 Chronic post-thoracotomy pain
G89.28 Other chronic postprocedural pain
Other chronic postoperative pain
G89.29 Other chronic pain
G89.3 Neoplasm related pain (acute) (chronic)
Cancer associated pain
Pain due to malignancy (primary) (secondary)
Tumor associated pain
G89.4 Chronic pain syndrome
Chronic pain associated with significant psychosocial dysfunction
G90 Disorders of autonomic nervous system
Excludes1 dysfunction of the autonomic nervous system due to alcohol (G31.2)
G90.0 Idiopathic peripheral autonomic neuropathy
G90.01 Carotid sinus syncope
Carotid sinus syndrome
G90.09 Other idiopathic peripheral autonomic neuropathy
Idiopathic peripheral autonomic neuropathy NOS
G90.1 Familial dysautonomia [Riley-Day]
G90.2 Horner's syndrome
Bernard(-Horner) syndrome
Cervical sympathetic dystrophy or paralysis
G90.3 Multi-system degeneration of the autonomic nervous system
Neurogenic orthostatic hypotension [Shy-Drager]
Excludes1 orthostatic hypotension NOS (I95.1)
G90.4 Autonomic dysreflexia
UseAdditionalCode code to identify the cause, such as:
fecal impaction (K56.41)
pressure ulcer (pressure area) (L89.-)
urinary tract infection (N39.0)
G90.5 Complex regional pain syndrome I (CRPS I)
Reflex sympathetic dystrophy
Excludes1 causalgia of lower limb (G57.7-)
causalgia of upper limb (G56.4-)
complex regional pain syndrome II of lower limb (G57.7-)
complex regional pain syndrome II of upper limb (G56.4-)
G90.50 Complex regional pain syndrome I, unspecified
G90.51 Complex regional pain syndrome I of upper limb
G90.511 Complex regional pain syndrome I of right upper limb
G90.512 Complex regional pain syndrome I of left upper limb
G90.513 Complex regional pain syndrome I of upper limb, bilateral
G90.519 Complex regional pain syndrome I of unspecified upper limb
G90.52 Complex regional pain syndrome I of lower limb
G90.521 Complex regional pain syndrome I of right lower limb
G90.522 Complex regional pain syndrome I of left lower limb
G90.523 Complex regional pain syndrome I of lower limb, bilateral
G90.529 Complex regional pain syndrome I of unspecified lower limb
G90.59 Complex regional pain syndrome I of other specified site
G90.8 Other disorders of autonomic nervous system
G90.81 Serotonin syndrome
Serotonin toxicity
CodeFirst poisoning due to drug or toxin, such as:
linezolid (T36.8X- with sixth character 1-4)
monoamine oxidase inhibitors (T43.1X with sixth character 1-4)
selective serotonin and norepinephrine reuptake inhibitors [SSNRI] (T43.21 with sixth character 1-4)
selective serotonin reuptake inhibitors [SSRI] (T43.22 with sixth character 1-4)
UseAdditionalCode code for adverse effect, if applicable, to identify drug, such as:
linezolid (T36.8X5)
monoamine oxidase inhibitors (T43.1X5)
selective serotonin and norepinephrine reuptake inhibitors [SSNRI] (T43.215)
selective serotonin reuptake inhibitors [SSRI] (T43.225)
UseAdditionalCode code, if applicable, to identify:
disseminated intravascular coagulation (D65)
hypertensive crisis (I16.-)
metabolic acidosis (E87.2-)
shock, not elsewhere classified (R57.-)
toxic encephalopathy (G92.-)
ventricular tachycardia (I47.2-)
G90.89 Other disorders of autonomic nervous system
G90.9 Disorder of the autonomic nervous system, unspecified
G90.A Postural orthostatic tachycardia syndrome [POTS]
Chronic orthostatic intolerance
Postural tachycardia syndrome
G90.B LMNB1-related autosomal dominant leukodystrophy
G91 Hydrocephalus
Includes acquired hydrocephalus
Excludes1 Arnold-Chiari syndrome with hydrocephalus (Q07.-)
congenital hydrocephalus (Q03.-)
spina bifida with hydrocephalus (Q05.-)
G91.0 Communicating hydrocephalus
Secondary normal pressure hydrocephalus
G91.1 Obstructive hydrocephalus
G91.2 (Idiopathic) normal pressure hydrocephalus
Normal pressure hydrocephalus NOS
G91.3 Post-traumatic hydrocephalus, unspecified
G91.4 Hydrocephalus in diseases classified elsewhere
CodeFirst underlying condition, such as:
congenital syphilis (A50.4-)
neoplasm (C00-D49)
plasminogen deficiency (E88.02)
Excludes1 hydrocephalus due to congenital toxoplasmosis (P37.1)
nonPrimary Yes
G91.8 Other hydrocephalus
G91.9 Hydrocephalus, unspecified
G92 Toxic encephalopathy
G92.0 Immune effector cell-associated neurotoxicity syndrome
CodeFirst underlying cause such as:
complications of immune effector cellular therapy (T80.82)
CodeAlso , if applicable, associated signs and symptoms, such as:
cerebral edema (G93.6)
unspecified convulsions (R56.9)
G92.00 Immune effector cell-associated neurotoxicity syndrome, grade unspecified
ICANS, grade unspecified
G92.01 Immune effector cell-associated neurotoxicity syndrome, grade 1
ICANS, grade 1
G92.02 Immune effector cell-associated neurotoxicity syndrome, grade 2
ICANS, grade 2
G92.03 Immune effector cell-associated neurotoxicity syndrome, grade 3
ICANS, grade 3
G92.04 Immune effector cell-associated neurotoxicity syndrome, grade 4
ICANS, grade 4
G92.05 Immune effector cell-associated neurotoxicity syndrome, grade 5
ICANS, grade 5
G92.8 Other toxic encephalopathy
Toxic encephalitis
Toxic metabolic encephalopathy
CodeFirst poisoning due to drug or toxin, if applicable, (T36-T65 with fifth or sixth character 1-4)
UseAdditionalCode code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)
G92.9 Unspecified toxic encephalopathy
CodeFirst poisoning due to drug or toxin, if applicable, (T36-T65 with fifth or sixth character 1-4)
UseAdditionalCode code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)
G93 Other disorders of brain
G93.0 Cerebral cysts
Arachnoid cyst
Porencephalic cyst, acquired
Excludes1 acquired periventricular cysts of newborn (P91.1)
congenital cerebral cysts (Q04.6)
G93.1 Anoxic brain damage, not elsewhere classified
Excludes1 cerebral anoxia due to anesthesia during labor and delivery (O74.3)
cerebral anoxia due to anesthesia during the puerperium (O89.2)
neonatal anoxia (P84)
G93.2 Benign intracranial hypertension
Pseudotumor
Excludes1 hypertensive encephalopathy (I67.4)
obstructive hydrocephalus (G91.1)
G93.3 Postviral and related fatigue syndromes
UseAdditionalCode code, if applicable, for post COVID-19 condition, unspecified (U09.9)
Excludes1 chronic fatigue NOS (R53.82)
neurasthenia (F48.8)
G93.31 Postviral fatigue syndrome
G93.32 Myalgic encephalomyelitis/chronic fatigue syndrome
Chronic fatigue syndrome
ME/CFS
Myalgic encephalomyelitis
G93.39 Other post infection and related fatigue syndromes
G93.4 Other and unspecified encephalopathy
Excludes2 alcoholic encephalopathy (G31.2)
encephalopathy in diseases classified elsewhere (G94)
hypertensive encephalopathy (I67.4)
toxic (metabolic) encephalopathy (G92.8)
G93.40 Encephalopathy, unspecified
G93.41 Metabolic encephalopathy
Septic encephalopathy
G93.42 Megalencephalic leukoencephalopathy with subcortical cysts
G93.43 Leukoencephalopathy with calcifications and cysts
G93.44 Adult-onset leukodystrophy with axonal spheroids
Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia
G93.45 Developmental and epileptic encephalopathy
Early infantile epileptic encephalopathy
CodeAlso , if applicable, associated disorders such as:
developmental disorders of scholastic skills (F81.-)
developmental disorder of speech and language (F80.-)
epilepsy, by specific type (G40.-)
intellectual disabilities (F70-F79)
other neurodevelopmental disorder (F88)
pervasive developmental disorders (F84.-)
G93.49 Other encephalopathy
Encephalopathy NEC
G93.5 Compression of brain
Arnold-Chiari type 1 compression of brain
Compression of brain (stem)
Herniation of brain (stem)
Excludes1 traumatic compression of brain (S06.A-)
G93.6 Cerebral edema
Excludes1 cerebral edema due to birth injury (P11.0)
traumatic cerebral edema (S06.1-)
G93.7 Reye's syndrome
CodeFirst poisoning due to salicylates, if applicable (T39.0-, with sixth character 1-4)
UseAdditionalCode code for adverse effect due to salicylates, if applicable (T39.0-, with sixth character 5)
age Pediatric: [0-17]
G93.8 Other specified disorders of brain
G93.81 Temporal sclerosis
Hippocampal sclerosis
Mesial temporal sclerosis
G93.82 Brain death
G93.89 Other specified disorders of brain
Postradiation encephalopathy
G93.9 Disorder of brain, unspecified
G94 Other disorders of brain in diseases classified elsewhere
CodeFirst underlying disease
Excludes1 encephalopathy in congenital syphilis (A50.49)
encephalopathy in influenza (J09.X9, J10.81, J11.81)
encephalopathy in syphilis (A52.19)
hydrocephalus in diseases classified elsewhere (G91.4)
nonPrimary Yes
G95 Other and unspecified diseases of spinal cord
Excludes2 myelitis (G04.-)
G95.0 Syringomyelia and syringobulbia
G95.1 Vascular myelopathies
Excludes2 intraspinal phlebitis and thrombophlebitis, except non-pyogenic (G08)
G95.11 Acute infarction of spinal cord (embolic) (nonembolic)
Anoxia of spinal cord
Arterial thrombosis of spinal cord
G95.19 Other vascular myelopathies
Edema of spinal cord
Hematomyelia
Nonpyogenic intraspinal phlebitis and thrombophlebitis
Subacute necrotic myelopathy
G95.2 Other and unspecified cord compression
G95.20 Unspecified cord compression
G95.29 Other cord compression
G95.8 Other specified diseases of spinal cord
Excludes1 neurogenic bladder NOS (N31.9)
neurogenic bladder due to cauda equina syndrome (G83.4)
neuromuscular dysfunction of bladder without spinal cord lesion (N31.-)
G95.81 Conus medullaris syndrome
G95.89 Other specified diseases of spinal cord
Cord bladder NOS
Drug-induced myelopathy
Radiation-induced myelopathy
Excludes1 myelopathy NOS (G95.9)
G95.9 Disease of spinal cord, unspecified
Myelopathy NOS
G96 Other disorders of central nervous system
G96.0 Cerebrospinal fluid leak
CodeAlso if applicable:
intracranial hypotension (G96.81-)
Excludes1 cerebrospinal fluid leak from spinal puncture (G97.0)
G96.00 Cerebrospinal fluid leak, unspecified
CodeAlso if applicable:
head injury (S00-S09)
G96.01 Cranial cerebrospinal fluid leak, spontaneous
Otorrhea due to spontaneous cerebrospinal fluid CSF leak
Rhinorrhea due to spontaneous cerebrospinal fluid CSF leak
Spontaneous cerebrospinal fluid leak from skull base
G96.02 Spinal cerebrospinal fluid leak, spontaneous
Spontaneous cerebrospinal fluid leak from spine
G96.08 Other cranial cerebrospinal fluid leak
Postoperative cranial cerebrospinal fluid leak
Traumatic cranial cerebrospinal fluid leak
CodeAlso if applicable:
head injury (S00 - S09)
G96.09 Other spinal cerebrospinal fluid leak
Other spinal CSF leak
Postoperative spinal cerebrospinal fluid leak
Traumatic spinal cerebrospinal fluid leak
CodeAlso if applicable:
head injury (S00 - S09)
G96.1 Disorders of meninges, not elsewhere classified
G96.11 Dural tear
CodeAlso intracranial hypotension, if applicable (G96.81-)
Excludes1 accidental puncture or laceration of dura during a procedure (G97.41)
G96.12 Meningeal adhesions (cerebral) (spinal)
G96.19 Other disorders of meninges, not elsewhere classified
G96.191 Perineural cyst
Cervical nerve root cyst
Lumbar nerve root cyst
Sacral nerve root cyst
Tarlov cyst
Thoracic nerve root cyst
G96.198 Other disorders of meninges, not elsewhere classified
G96.8 Other specified disorders of central nervous system
G96.81 Intracranial hypotension
CodeAlso any associated diagnoses, such as:
Brachial amyotrophy (G54.5)
Cerebrospinal fluid leak from spine (G96.02)
Cranial nerve disorders in diseases classified elsewhere (G53)
Nerve root and compressions in diseases classified elsewhere (G55)
Nonpyogenic thrombosis of intracranial venous system (I67.6)
Nontraumatic intracerebral hemorrhage (I61.-)
Nontraumatic subdural hemorrhage (I62.0-)
Other and unspecified cord compression (G95.2-)
Other secondary parkinsonism (G21.8)
Reversible cerebrovascular vasoconstriction syndrome (I67.841)
Spinal cord herniation (G95.89)
Stroke (I63.-)
Syringomyelia (G95.0)
G96.810 Intracranial hypotension, unspecified
G96.811 Intracranial hypotension, spontaneous
G96.819 Other intracranial hypotension
G96.89 Other specified disorders of central nervous system
G96.9 Disorder of central nervous system, unspecified
G97 Intraoperative and postprocedural complications and disorders of nervous system, not elsewhere classified
Excludes2 intraoperative and postprocedural cerebrovascular infarction (I97.81-, I97.82-)
G97.0 Cerebrospinal fluid leak from spinal puncture
CodeAlso any associated diagnoses or complications, such as:
intracranial hypotension following a procedure (G97.83-G97.84)
G97.1 Other reaction to spinal and lumbar puncture
Headache due to lumbar puncture
Other reaction to spinal dural puncture
CodeAlso , if applicable, any associated headache with orthostatic component (R51.0)
G97.2 Intracranial hypotension following ventricular shunting
CodeAlso any associated diagnoses or complications
G97.3 Intraoperative hemorrhage and hematoma of a nervous system organ or structure complicating a procedure
Excludes1 intraoperative hemorrhage and hematoma of a nervous system organ or structure due to accidental puncture and laceration during a procedure (G97.4-)
G97.31 Intraoperative hemorrhage and hematoma of a nervous system organ or structure complicating a nervous system procedure
G97.32 Intraoperative hemorrhage and hematoma of a nervous system organ or structure complicating other procedure
G97.4 Accidental puncture and laceration of a nervous system organ or structure during a procedure
G97.41 Accidental puncture or laceration of dura during a procedure
Incidental (inadvertent) durotomy
CodeAlso any associated diagnoses or complications
G97.48 Accidental puncture and laceration of other nervous system organ or structure during a nervous system procedure
G97.49 Accidental puncture and laceration of other nervous system organ or structure during other procedure
G97.5 Postprocedural hemorrhage of a nervous system organ or structure following a procedure
G97.51 Postprocedural hemorrhage of a nervous system organ or structure following a nervous system procedure
G97.52 Postprocedural hemorrhage of a nervous system organ or structure following other procedure
G97.6 Postprocedural hematoma and seroma of a nervous system organ or structure following a procedure
G97.61 Postprocedural hematoma of a nervous system organ or structure following a nervous system procedure
G97.62 Postprocedural hematoma of a nervous system organ or structure following other procedure
G97.63 Postprocedural seroma of a nervous system organ or structure following a nervous system procedure
G97.64 Postprocedural seroma of a nervous system organ or structure following other procedure
G97.8 Other intraoperative and postprocedural complications and disorders of nervous system
UseAdditionalCode code to further specify disorder
G97.81 Other intraoperative complications of nervous system
G97.82 Other postprocedural complications and disorders of nervous system
G97.83 Intracranial hypotension following lumbar cerebrospinal fluid shunting
CodeAlso any associated diagnoses or complications
G97.84 Intracranial hypotension following other procedure
CodeAlso , if applicable:
accidental puncture or laceration of dura during a procedure (G97.41)
cerebrospinal fluid leak from spinal puncture (G97.0)
G98 Other disorders of nervous system not elsewhere classified
Includes nervous system disorder NOS
G98.0 Neurogenic arthritis, not elsewhere classified
Nonsyphilitic neurogenic arthropathy NEC
Nonsyphilitic neurogenic spondylopathy NEC
Excludes1 spondylopathy (in):
syringomyelia and syringobulbia (G95.0)
tabes dorsalis (A52.11)
G98.8 Other disorders of nervous system
Nervous system disorder NOS
G99 Other disorders of nervous system in diseases classified elsewhere
G99.0 Autonomic neuropathy in diseases classified elsewhere
CodeFirst underlying disease, such as:
amyloidosis (E85.-)
gout (M1A.-, M10.-)
hyperthyroidism (E05.-)
Excludes1 diabetic autonomic neuropathy (E08-E13 with .43)
nonPrimary Yes
G99.2 Myelopathy in diseases classified elsewhere
CodeFirst underlying disease, such as:
neoplasm (C00-D49)
Excludes1 myelopathy in:
intervertebral disease (M50.0-, M51.0-)
spondylosis (M47.0-, M47.1-)
nonPrimary Yes
G99.8 Other specified disorders of nervous system in diseases classified elsewhere
CodeFirst underlying disorder, such as:
amyloidosis (E85.-)
avitaminosis (E56.-)
Excludes1 nervous system involvement in:
cysticercosis (B69.0)
rubella (B06.0-)
syphilis (A52.1-)
nonPrimary Yes