Neurosurgery Coding Alert

Provider will likely use E/M, imaging to diagnose condition.  

Patients suffering from hydrocephalus are a common occurrence in a neurosurgeon’s office. And for every one of those hydrocephalic patients, a provider had to diagnose the condition.

More often than not, the person diagnosing the condition is also a neurosurgeon. That means you need to know the ins and outs of coding for services your surgeon provides to diagnose the condition.

Read on for a rundown of how the surgeon will identify hydrocephalus and the ICD-10 codes you’ll use once they reach a definitive diagnosis.

E/M Starts the Journey

The diagnostic process for hydrocephalus is a combination of evaluation and management (E/M) services and imaging studies.

The initial encounter for a patient with hydrocephalic symptoms will include a physical and neurological examination. During this exam, the surgeon will query the patient’s symptoms, which can include:

• Headaches
• Vision problems
• Difficulty walking
• Cognitive issues
• An abnormal increase in head size (infants only)

The E/M will also include a neurological exam where the surgeon tries to identify signs of dysfunctional nerves or increased intracranial pressure (ICP).

These services will almost certainly be office/outpatient (E/M) 99202 (Office or other outpatient visit for the evaluation and management of a new patient, which requires a medically appropriate history and/or examination and straightforward medical decision making. When using total time on the date of the encounter for code selection, 15 minutes must be met or exceeded.) through 99215 (Office or other outpatient visit for the evaluation and management of an established patient, which requires a medically appropriate history and/or examination and high level of medical decision making. When using total time on the date of the encounter for code selection, 40 minutes must be met or exceeded.). Be careful, though. If the E/M occurred in an inpatient setting, you’ll use the appropriate inpatient E/M code.

Infant caveat: When the surgeon is examining an infant for hydrocephalus, the E/M might also include head circumference measurements. They will also keep an eye on symptoms such as bulging fontanelles, irritability, seizures, or developmental delays.

Imaging Comes Next

When looking for the etiology of the hydrocephalus, the surgeon will need to perform some sort of imaging study. One of the most common is a computed tomography (CT) scan. This study can reveal enlarged ventricles, a sign of cerebrospinal fluid buildup.

When a patient with hydrocephalic symptoms has a CT scan, you’ll choose from the following codes:

• 70450 (Computed tomography, head or brain; without contrast material)
• 70460 (… with contrast material(s))
• 70470 (… without contrast material, followed by contrast material(s) and further sections)

The surgeon might also consider using magnetic resonance imaging (MRI), which is more detailed than a CT scan. An MRI features high-resolution brain images that can assist in the discovery of the disease’s cause: tumors, cysts, or a blockage in cerebrospinal fluid (CSF) flow.

When a patient with hydrocephalic symptoms has an MRI, you’ll choose from the following codes:

• 70551 (Magnetic resonance (eg, proton) imaging, brain (including brain stem); without contrast material)
• 70552 (… with contrast material(s))
• 70553 (… without contrast material, followed by contrast material(s) and further sequences)

Infant caveat: Diagnosing hydrocephalus in infants could include an echoencephalography, which is a type of ultrasound through the infant’s fontanelles. The surgeon can often assess hydrocephalus and spot enlarged ventricles in newborns and infants with an echoencephalogram.

When the surgeon orders this study, report 76506 (Echoencephalography, real time with image documentation (gray scale) (for determination of ventricular size, delineation of cerebral contents, and detection of fluid masses or other intracranial abnormalities), including A-mode encephalography as secondary component where indicated).

Use These ICD-10 Codes for Hydrocephalic Px

Once your surgeon has confirmed hydrocephalus, you’ll choose from the following ICD-10 codes to represent the condition (Alternate terms, if any, listed below descriptor):

• 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)
• G91.8 (Other hydrocephalus)
• G91.9 (Hydrocephalus, unspecified)

Consider This Clinical Example

An 84-year-old new patient is brought to the office by one of their children. They are concerned that over the past few years, their parent has been confused and has been losing their memory. The parent’s primary care physician suspected dementia. However, they described their father as also having trouble maintaining balance with ambulation. 

After the surgeon asks whether the patient has experienced any urinary issues, the patient’s adult child acknowledges intermittent urinary incontinence. The surgeon suspects normal-pressure hydrocephalus and orders a non-contrast MRI of the brain, which reveals enlarged ventricles and transependymal edema. The surgeon subsequently performs a high-volume therapeutic lumbar puncture and finds an opening pressure of 14 cmH₂0. A physical therapist evaluates the patient’s ability to walk before and after the lumbar puncture, and reports significantly improved gait for several hours after the lumbar puncture. The surgeon also recommends a ventriculoperitoneal shunt.

For this encounter, you’d report:

• 62223 (Creation of shunt; ventriculo-peritoneal, -pleural, other terminus) for the spinal puncture
• 70551 (Magnetic resonance (eg, proton) imaging, brain (including brain stem); without contrast material) for the MRI
• 62272 (Spinal puncture, therapeutic, for drainage of cerebrospinal fluid (by needle or catheter)) for the spinal puncture
• Modifier 51 (Multiple procedures) appended to 70551 and 62272 to indicate that multiple procedures occurred during this encounter — if the payer requires the multiple procedures modifier
• 99205 (Office or other outpatient visit for the evaluation and management of a new patient, which requires a medically appropriate history and/or examination and high level of medical decision making. When using total time on the date of the encounter for code selection, 60 minutes must be met or exceeded.) for the E/M
• Modifier 25 (Significant, separately identifiable evaluation and management service by the same physician or other qualified health care professional on the same day of the procedure or other service) appended to 99205 to show that the E/M and the other procedures were significant, separately identifiable services
• G91.2 ((Idiopathic) normal pressure hydrocephalus) appended to 62223, 70551, 62272, and 99205 to represent the patient’s hydrocephalus.

Chris Boucher, MS, CPC, Senior Development Editor, AAPC