What is the ICD-10 (International Classification of Diseases, 10th Revision) code for a patient with brachial radial muscle atrophy or suspected atrophy?

ICD-10 Coding for Brachial Radial Muscle Atrophy

For brachial radial muscle atrophy or suspected atrophy, use ICD-10 code G54.0 (Brachial plexus disorders) as the primary diagnostic code, as this captures the anatomical location and neurological nature of the condition. 1

Primary Code Selection

• G54.0 is the appropriate ICD-10 code for brachial plexus disorders, which encompasses brachial plexopathy and associated muscle atrophy in the distribution of the brachial plexus (C5-T1 nerve roots). 1

• The term "brachial radial muscle atrophy" refers to muscle wasting in the distribution of nerves arising from the brachial plexus, particularly affecting muscles innervated by the radial nerve and other brachial plexus branches. 2, 3

Additional Coding Considerations

• If the muscle atrophy is confirmed rather than suspected, you may also consider adding M62.50 (Muscle wasting and atrophy, not elsewhere classified, unspecified site) or M62.521 (Muscle wasting and atrophy, not elsewhere classified, right upper arm) / M62.522 (left upper arm) as secondary codes to capture the specific manifestation. 4

• For suspected cases where the diagnosis is not yet confirmed, the primary code G54.0 remains appropriate, as ICD-10 allows coding of signs and symptoms when a definitive diagnosis has not been established. 5

Etiology-Specific Coding

• If the atrophy is due to neuralgic amyotrophy (Parsonage-Turner syndrome), which commonly affects the brachial plexus and can present with radial nerve involvement and muscle atrophy, G54.5 (Neuralgic amyotrophy) would be more specific. 2, 3

• If there is a traumatic cause, consider codes from the S14 series (Injury of nerves and spinal cord at neck level) with appropriate seventh character extensions for encounter type (A for initial, D for subsequent, S for sequela). 4, 6

• For radiation-induced plexopathy, use G54.0 with an additional code for the radiation effect if applicable. 2

Laterality Documentation

• ICD-10 emphasizes laterality specification. Ensure documentation clearly indicates whether the condition affects the right (dominant/nondominant) or left (dominant/nondominant) upper extremity, as this may influence code selection for secondary manifestation codes. 4, 6

Common Pitfalls

• Avoid using radiculopathy codes (M54 series) when the clinical presentation involves multiple nerve distributions consistent with plexopathy rather than single nerve root involvement. 1

• Do not use peripheral nerve disorder codes (G56 series for upper limb mononeuropathies) unless the atrophy is isolated to a single peripheral nerve distribution rather than a plexus pattern. 3

• Ensure your documentation supports the code selection by including clinical findings such as weakness, sensory loss, and reflex changes in the C5-T1 distribution, as well as any electrodiagnostic study results confirming plexopathy. 1

Validation Recommendation

• Given the complexity of ICD-10 code translation and the 14% increase in codes compared to ICD-9, verify your selected codes using the most current ICD-10-CM manual or electronic coding resources, as approximately 3% of codes have been relocated since initial implementation. 4, 7