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  2. ICD-10-CM Codes List
  3. G00–G99
  4. G89-G99
  5. Hydrocephalus (G91)

Hydrocephalus (G91)

The ICD-10 codes under G91 are used specifically to classify and document different types of hydrocephalus, a condition characterized by accumulation of cerebrospinal fluid within the brain's ventricles. These codes help healthcare providers distinguish between various forms such as communicating, obstructive, idiopathic normal pressure, post-traumatic, and hydrocephalus related to other diseases.

The ICD-10 code for hydrocephalus ranges from general to highly specific conditions. For example, G91.0 covers communicating hydrocephalus, which includes synonyms like hydrocephalus ex vacuo and cases following radiation therapy or brain injury. The code G91.1 is assigned for obstructive hydrocephalus, including obstructions due to tumors or meningitis. G91.2 refers to idiopathic normal pressure hydrocephalus, linked with symptoms like dementia. Post-traumatic cases are coded as G91.3, while hydrocephalus due to other diseases such as tuberculosis or brain malformations falls under G91.4. Other less common or unspecified types are classified under G91.8 and G91.9. Using these codes guides accurate diagnosis and treatment documentation for conditions like communicating hydrocephalus following traumatic injury or posthemorrhagic hydrocephalus.

Instructional Notations

Includes

This note appears immediately under a three character code title to further define, or give examples of, the content of the category.

  • acquired hydrocephalus

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

  • Arnold-Chiari syndrome with hydrocephalus Q07
  • congenital hydrocephalus Q03
  • spina bifida with hydrocephalus Q05

Clinical Terms

The following clinical terms provide additional context, helping users better understand the clinical background and common associations for each diagnosis listed in this section. Including related terms alongside ICD-10-CM codes supports coders, billers, and healthcare professionals in improving accuracy, enhancing documentation, and facilitating research or patient education.

Cerebrospinal Fluid Rhinorrhea

Discharge of cerebrospinal fluid through the nose. Common etiologies include trauma, neoplasms, and prior surgery, although the condition may occur spontaneously. (Otolaryngol Head Neck Surg 1997 Apr;116(4):442-9)

Dandy-Walker Syndrome

A congenital abnormality of the central nervous system marked by failure of the midline structures of the cerebellum to develop, dilation of the fourth ventricle, and upward displacement of the transverse sinuses, tentorium, and torcula. Clinical features include occipital bossing, progressive head enlargement, bulging of anterior fontanelle, papilledema, ataxia, gait disturbances, nystagmus, and intellectual compromise. (From Menkes, Textbook of Child Neurology, 5th ed, pp294-5)

Hydrocephalus

Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, INTRACRANIAL HYPERTENSION; HEADACHE; lethargy; URINARY INCONTINENCE; and ATAXIA.

Hydrocephalus, Normal Pressure

A form of compensated hydrocephalus characterized clinically by a slowly progressive gait disorder (see GAIT DISORDERS, NEUROLOGIC), progressive intellectual decline, and URINARY INCONTINENCE. Spinal fluid pressure tends to be in the high normal range. This condition may result from processes which interfere with the absorption of CSF including SUBARACHNOID HEMORRHAGE, chronic MENINGITIS, and other conditions. (From Adams et al., Principles of Neurology, 6th ed, pp631-3)

Walker-Warburg Syndrome

Rare autosomal recessive lissencephaly type 2 associated with congenital MUSCULAR DYSTROPHY and eye anomalies (e.g., RETINAL DETACHMENT; CATARACT; MICROPHTHALMOS). It is often associated with additional brain malformations such as HYDROCEPHALY and cerebellar hypoplasia and is the most severe form of the group of related syndromes (alpha-dystroglycanopathies) with common congenital abnormalities in the brain, eye and muscle development.