Clonic hemifacial spasm, left

This code describes an involuntary, repetitive, and rhythmic contraction of muscles on the left side of the face, specifically characterized by clonic (rapidly alternating contraction and relaxation) movements. It is a neurological disorder affecting the facial nerve, leading to visible twitching or spasms.

Apply this code when documentation clearly indicates a diagnosis of hemifacial spasm affecting the left side of the face, with the specific characteristic of clonic muscle contractions. This diagnosis is typically made based on clinical observation and neurological examination.

• Ensure documentation specifies "clonic" to differentiate from other types of hemifacial spasm.
• Verify laterality (left side) is clearly documented.
• Do not confuse with blepharospasm or other facial dystonias, which have distinct ICD-10-CM codes.