Neurosurgery Coding Alert

Spina bifida, congenital hydrocephalus map to more specific codes.

When you report a communicating, obstructive, idiopathic normal pressure hydrocephalus, or one due to other acquired deformity of the head in ICD-10, the good news is the choices aren't extensive.

Know the One-To-One Mapping

See the table below for the codes you will report for these conditions in ICD-9 and ICD-10.

Look to Region for Spina Bifida

When you report hydrocephalus that occurs with a spina bifida, you turn to ICD-9 code 741.00 (Spina bifida unspecified region with hydrocephalus). The term 'unspecified region' in the descriptor of 741.00 implies that the pathological lesion of a bifid spine may be located anywhere through the length of the spine. So, you report 741.00 irrrespective of the location of the bifid spine when you are reporting a hydrocephalus that occurs with a spina bifida. "With increased awareness of the influence of folate intake by women in early pregnancy, the frequency of spina bifida has significantly declined. Although the code does not specify the location of the spinal defect, most occur in the lumbar area," says Gregory Przybylski, MD, director of neurosurgery, New Jersey Neuroscience Institute, JFK Medical Center, Edison.

When ICD-10 goes into effect, you will also need to see if Chiari malformation is documented in the diagnosis that your surgeon makes. Chiari malformation is a condition wherein the cerebellar tonsils are displaced through the foramen magnum (opening in the skull base) to obstruct the flow of cerebrospinal fluid, contributing to the development of hydrocephalus.

You will need to see if Chiari malformation occurs in combination with spina bifida, hydrocephalus, or both. "Patients will often require treatment of both the hydrocephalus as well as the foramen magnum compression with ventriculoperitoneal shunting and suboccipital craniotomy. Improvement in endoscopic technology has offered the opportunity to obviate the need for shunting in some patients if successful third ventriculostomy can be achieved," says Przybylski.

Below are the four codes in ICD-10 that map to ICD-9 code 741.00:

• Q05.4 - Unspecified spina bifida with hydrocephalus
• Q07.01 - Arnold-Chiari syndrome with spina bifida
• Q07.02 - Arnold-Chiari syndrome with hydrocephalus
• Q07.03 - Arnold-Chiari syndrome with spina bifida and hydrocephalus

Document the Reason for Congenital Hydrocephalus

In ICD-9, you report code 742.3 (Congenital hydrocephalus) for congenital hydrocephalus. When reporting the same in ICD-10, you will need to make sure that your surgeon documents the underlying congenital lesion that lead to the congenital hydrocephalus. A common cause of the congenital hydrocephalus is an obstruction of the aqueduct or foramina through which the cerebrospinal fluid drains. There can be other reasons as well.

Bear in mind that the ICD-9 code 742.3 actually expands to four codes in ICD-10. Below are the codes in ICD-10 that you may appropriately select, depending upon the site of the obstruction, when reporting congenital hydrocephalus:

• Q03.0 - Malformations of aqueduct of Sylvius
• Q03.1 - Atresia of foramina of Magendie and Luschka
• Q03.8 - Other congenital hydrocephalus

"While the treatment for each of these may be the same, the purpose of ICD-10 is to provide greater diagnostic specificity in order to facilitate better outcome studies," says Przybylski.