A man with medium skin tone wearing a lab coat leans on a research laboratory bench and smiles at the camera.
For Physicians and Clinicians

How an ICD-10 Code Is Improving Care for Children With MOGAD

A Children’s Hospital Los Angeles neuroimmunologist led a three-year effort to create a diagnosis code for a rare demyelinating disorder in children.

ICD-10 codes are not the kind of thing that Jonathan Santoro, MD, learned about in medical school, or in his yearslong training to become a pediatric neurologist and neuroimmunologist. In fact, for most of his career he never spent any time thinking about them.

Then, his patients with a rare demyelinating disorder called myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) began having trouble getting vital treatments covered by their insurers.

“These treatments are crucial for preventing permanent disabilities in these patients,” says Dr. Santoro, Director of the Neuroimmunology Program at Children’s Hospital Los Angeles. “We couldn’t understand why this was happening. And it turned out that the problem was this ICD-10 code. There wasn’t one for this disease. And that’s when we knew we had to do something.”

A relatively new diagnosis

The 10th edition of the International Classification of Diseases and Related Health Problems (ICD-10) is a system used to classify all diagnoses, symptoms and procedures so that insurance companies and government entities can process claims and pay physicians and hospitals for patient care.

The system was designed chiefly by the World Health Organization, but the U.S. version is managed by the Centers for Medicare and Medicaid Services (CMS) and the National Center for Health Statistics, a federal agency that is part of the Centers for Disease Control and Prevention (CDC).

Although there are more than 150,000 of these codes covering both outpatient and inpatient care, Dr. Santoro and his team discovered that none of them were specific for MOGAD.

An inflammatory disorder of the central nervous system that disproportionately affects children, MOGAD takes different forms that affect the optic nerves, brain and spinal cord. The common thread, though, is the presence of antibodies to MOG, a protein found on the surface of myelin—the protective sheath that wraps around nerve fibers.

MOG antibodies damage this myelin coating, which causes nerve impulses to slow or stop. Depending on which nerves are affected, it can result in optic neuritis, transverse myelitis or acute disseminated encephalomyelitis (ADEM).

Commercial testing for these antibodies became widely available in 2018. That has enabled physicians to specifically diagnose which patients with optic neuritis, ADEM and transverse myelitis are positive for MOG antibodies, and which are negative.

But because testing is relatively new, no ICD-10 code had been created to match this specific diagnosis. Instead, all cases of optic neuritis, for example, were lumped together under a general optic neuritis diagnosis code. On their end, insurers couldn’t tell the difference between patients who had MOG antibodies and those who didn’t.

“That was a big problem because we treat patients differently if they have MOG antibodies,” Dr. Santoro explains. “The major difference is that the risk of relapse is much higher for patients who have the antibodies. If a relapse occurs, we need to treat it immediately, and some of these children need ongoing treatment to prevent future attacks.”

Advocating for change

It was the immune-based therapies that treat and prevent relapses in patients with MOGAD that were getting bogged down in insurance approvals, resulting in lengthy delays. Physicians instead had to prescribe steroids, which come with risks and long-term side effects.

“If you have two attacks of optic neuritis, you can lose vision in an eye. If you have two attacks of transverse myelitis, you might be in a wheelchair for the rest of your life,” Dr. Santoro says. “It was frustrating that patients weren’t able to start the appropriate treatments right away.”

To remedy this issue, he and his team worked with The MOG Project, a national patient advocacy group for individuals with MOGAD. Together, they researched the process and developed an application for the new code. Dr. Santoro submitted it as an individual physician and then worked with the American Academy of Neurology, which provided letters of support to the CDC.

The process began in Fall 2020, in the middle of the pandemic. Two years later—after one application rejection and multiple COVID-related delays—Dr. Santoro gave a virtual presentation to the CDC to advocate for the code. In March 2023, the new ICD-10 code was approved.

Although the code won’t officially be added until October, Dr. Santoro has begun using it for patients and has already seen a dramatic improvement in medication approval times for MOGAD.

“We’ve gone from an average approval time of six weeks to just two weeks,” he says. “Once the code is official, we expect things will move even faster. But already, we’re able to get patients on the right medications much more quickly. Patients feel better, families feel better, and we as doctors feel better.” 

Learn more about neuroimmunology care at Children’s Hospital Los Angeles.