Neurology & Pain Management Coding Alert

There’s now a code set for KCNQ2-related epilepsy patients.

ICD-10 has released its list of new, revised, and deleted codes for 2025.

Impact: Code sets have been expanded for epilepsy and disc degeneration, among others. You’ll want to know the changes before they take effect on October 1, 2024, so you can hit the ground running when the new codes are released.

Here’s a look at how the changes will affect your practice.

ICD-10 Reveals New Epilepsy Group

There will be a whole new set of epilepsy codes in the G40.8- (Other encephalitis, myelitis and encephalomyelitis) section of ICD-10. The new codes are:

• G40.84- (KCNQ2-related epilepsy)
• G40.841 (KCNQ2-related epilepsy, not intractable, with status epilepticus)
• G40.842 (KCNQ2-related epilepsy, not intractable, without status epilepticus)
• G40.843 (KCNQ2-related epilepsy, intractable, with status epilepticus)
• G40.844 (KCNQ2-related epilepsy, intractable, without status epilepticus)

Condition description: KCNQ2-related epilepsy results from mutations in the KCNQ2 gene, which regulates neuronal excitability. This condition is able to manifest itself as various epilepsy types. Symptoms of KCNQ-2-related epilepsy include developmental delays, intellectual disability, and movement disorders.

For patients suffering KCNQ-related epilepsy, the seizures usually start in the first days or weeks of their lives. The seizures they suffer vary, but are often tonic or tonic-clonic seizures. KCNQ2-related epilepsy is typically diagnosed via genetic testing to identify the KCNQ2 gene. There is no cure for KCNQ2-related epilepsy, treatment often includes anti-seizure medications, ketogenic diet, or specialized therapies.

Several Codes Converted to Parents

There are also several currently existing ICD-10 codes that were converted to “parent” codes, which will spawn new codes that are under the parent code’s heading.

Example: One of the codes that ICD-10 converted to parent was G90.8 (Other disorders of autonomic nervous system). Starting on October 1, the code will expand to require a 5th character (G90.8-). The new codes beneath G90.8- (the “children”) are:

• G90.81 (Serotonin syndrome)
• G90.89 (Other disorders of autonomic nervous system)

Impact: This move gives a specific ICD-10 code to serotonin syndrome, which you would code as G90.8 currently. Serotonin syndrome is a potentially serious condition that occurs when there’s an excess buildup of serotonin in the central nervous system. The buildup often occurs because of certain medications the patient is taking, drug interactions, or overdose of serotonergic medication.

Another code that will covert to parent in October is M51.36 (Other intervertebral disc degeneration, lumbar region). When the code becomes M51.36-, these will be your 6th character options:

• M51.360 (Other intervertebral disc degeneration, lumbar region with discogenic back pain only)
• M51.361 (Other intervertebral disc degeneration, lumbar region with lower extremity pain only)
• M51.362 (Other intervertebral disc degeneration, lumbar region with discogenic back pain and lower extremity pain)
• M51.369 (Other intervertebral disc degeneration, lumbar region without mention of lumbar back pain or lower extremity pain)

Impact: This move will make M51.36 a code set that includes descriptions indicating the absence/presence of lower extremity pain, discogenic back pain, and lumbar back pain.