Home  |   Subscribe  |   Resources  |   Reprints  |   Writers' Guidelines

December 3, 2012

Coding for Hydrocephalus
For The Record
Vol. 24 No. 22 P. 26

Hydrocephalus is the buildup of cerebral spinal fluid (CSF) in the brain. CSF levels can rise if there is an imbalance between how much CSF is produced and how much is absorbed into the bloodstream. The excess fluid may increase the size of the ventricles and cause pressure on the brain, which may damage brain tissue. Hydrocephalus can occur at any age but is more common in infants and older patients.

Common causes of elevated CSF are obstruction of the normal flow of CSF between ventricles or around other spaces around the brain; poor absorption of CSF in blood vessels, probably due to the inflammation of brain tissues from disease or injury; and overproduction of CSF.

Hydrocephalus present at birth is referred to as congenital hydrocephalus and may result from abnormal development of the central nervous system, which obstructs CSF flow; bleeding in the ventricles of the brain; and inflammation of fetal brain tissue.

Symptoms of hydrocephalus vary based on a patient’s age. Common signs and symptoms of hydrocephalus in infants include a bulging or larger-than-expected soft spot on the top of the head, eyes fixed downward, vomiting, sleepiness, irritability, and seizures.

Congenital hydrocephalus is classified to ICD-9-CM code 742.3. Documentation of chronic hydrocephalus also is indexed to code 742.3. If the hydrocephalus is associated with spina bifida, assign code 741.0. A fifth-digit subclassification will be assigned to identify the region of the spine involved in the spina bifida (eg, cervical, dorsal/thoracic, lumbar).

Older Patients
Causes of hydrocephalus in older age groups include lesions or tumors of the brain or spinal cord, central nervous system infections, brain hemorrhage from stroke or head injury, and traumatic brain injury.

Symptoms in older children may include changes in personality, memory, or the ability to reason; poor attention span; changes in facial appearance; uncontrolled eye movements; impaired vision (blurred or double vision); headache; irritability; poor coordination and balance; excessive sleepiness; and loss of bladder control.

Symptoms in geriatric patients include memory loss, progressive loss of other thinking or reasoning skills, gait problems, poor coordination and balance, generally slower-than-normal movements, and loss of bladder control.

Types of Hydrocephalus
Acquired hydrocephalus may be categorized as communicating or noncommunicating. Communicating hydrocephalus is caused by a blockage of CSF after it leaves the ventricles. The fluid can still flow between the ventricles. Communicating hydrocephalus is classified to code 331.3 and includes secondary normal pressure hydrocephalus.

Noncommunicating hydrocephalus may be documented as obstructive hydrocephalus (331.4) and occurs when the flow of CSF is blocked along one or more of the narrow passages connecting the ventricles. One common cause of obstructive hydrocephalus is aqueductal stenosis. The aqueduct of Sylvius is a small passage between the third and fourth ventricles. If the narrowing is due to a congenital anomaly, this will be considered a congenital hydrocephalus (742.3). However, if it is an acquired stenosis, then assign code 331.4. Code 331.4 also includes acquired hydrocephalus not otherwise specified.

Documentation of hydrocephalus without specification of type will default to code 331.4.

Idiopathic normal pressure hydrocephalus (331.5), also documented as normal pressure hydrocephalus, results from excess CSF that affects brain function, but the fluid pressure usually is normal. It may result from a subarachnoid hemorrhage, head trauma, infection, or tumor.

Diagnosis and Treatment
To diagnose hydrocephalus, the physician will perform a thorough history and physical, and review the signs and symptoms. A neurological exam may be performed to evaluate reflexes, muscle strength/tone, balance, coordination, hearing, vision, and sensitivity to touch. In addition, the physician may order brain imaging to evaluate any fluid accumulation.

Hydrocephalus needs to be treated to improve the flow of CSF and reduce or prevent brain damage. A flexible tube called a shunt may be inserted into one of the brain ventricles and tunneled under the skin, with the other end inserted into the abdomen or heart. The shunt keeps the CSF moving in the right direction at the proper rate. The patient usually will need the shunt for his or her entire life.

A shunt inserted from the brain to the abdomen or peritoneum is classified to code 02.34, Ventricular shunt to abdominal cavity and organs, and sometimes may be documented as a ventriculoperitoneal shunt. Code 02.34 also includes ventriculocholecystostomy and ventriculoperitoneostomy.

If the shunt is inserted into a different site, assign code 02.22, Intracranial ventricular shunt or anastomosis. Code 02.22 also is assigned for ventriculostomy, a procedure that creates a hole at the bottom of the ventricle or between two ventricles to drain CSF from the brain. A ventriculostomy by an external ventricular drain is classified to code 02.21.

Coding and sequencing for hydrocephalus are dependent on the physician documentation in the medical record and application of the Official Coding Guidelines for inpatient care. Also, use specific AHA Coding Clinic for ICD-9-CM and American Medical Association CPT Assistant references to ensure complete and accurate coding.

— This information was prepared by Audrey Howard, RHIA, of 3M Consulting Services. 3M Consulting Services is a business of 3M Health Information Systems, a supplier of coding and classification systems to more than 5,000 healthcare providers. The company and its representatives do not assume any responsibility for reimbursement decisions or claims denials made by providers or payers as the result of the misuse of this coding information. More information about 3M Health Information Systems is available at www.3mhis.com or by calling 800-367-2447.


Coding for Hydrocephalus in ICD-10-CM
In ICD-10-CM, hydrocephalus is classified to category G91, with the following codes depending on the type of hydrocephalus:

• G91.0, Communicating hydrocephalus;

• G91.1, Obstructive hydrocephalus;

• G91.2, (Idiopathic) normal pressure hydrocephalus;

• G91.3, Posttraumatic hydrocephalus, unspecified;

• G91.4, Hydrocephalus in diseases classified elsewhere;

• G91.8, Other hydrocephalus; and

• G91.9, Hydrocephalus, unspecified.

As shown above, there is a code for unspecified hydrocephalus, and it will not default to obstructive hydrocephalus as it does in ICD-9-CM. In addition, there are two new codes in ICD-10-CM for posttraumatic hydrocephalus and hydrocephalus in diseases classified elsewhere. If the hydrocephalus results from another condition, sequence first the underlying cause, such as neoplasm.

For the procedure coding, a shunt is reported as a bypass in ICD-10-PCS, which is defined as “altering the route of passage of the contents of a tubular body part.” The body part value identifies the origin of the bypass or shunt, and the qualifier identifies the destination. The code assignment will be broken down as follows:

• Character 1—Section: Ventriculoperitoneal (VP) shunt falls under the Medical and Surgical section of the Procedure Coding System, value of 0.

• Character 2—Body system: The body system for this procedure is the central nervous system, value of 0.

• Character 3—Root operation: The root operation for shunt is bypass, value of 1, which is defined as “altering the route of passage of the contents of a tubular body part.”

• Character 4—Body part: The body part for this procedure is usually the cerebral ventricle, which has a character value of 6.

• Character 5—Approach: A VP shunt procedure can either be done via open approach (character value of 0) or percutaneous approach (character value of 3).

• Character 6—Device: The device used is a catheter, which is connected to a one-way valve system. The possible options include autologous tissue substitute (character value of 7), synthetic substitute (character value of J), and nonautologous tissue substitute (character value of K). The catheter is typically a synthetic substitute in this type of procedure.

• Character 7—Qualifier: The qualifier identifies the destination of the bypass or shunt. In a VP shunt, the fluid is typically drained to the peritoneal cavity, value of 6.

— AH