Medical Necessity Assessment for Vyepti in Spasmodic Torticollis
Vyepti (eptinezumab) 300 mg every 3 months for 4 visits does NOT meet medical necessity for spasmodic torticollis (G24.3), as this medication is FDA-approved exclusively for migraine prevention and has no established role in the treatment of cervical dystonia.
Indication Mismatch
Vyepti is a CGRP (calcitonin gene-related peptide) antagonist specifically approved for the prevention of episodic or chronic migraine, not for movement disorders or dystonia 1.
The 2024 VA/DoD Headache Guidelines suggest intravenous eptinezumab (Vyepti) for migraine prevention, with demonstrated reduction in mean monthly migraine days, particularly at the 300 mg dose 1.
Spasmodic torticollis (cervical dystonia, G24.3) is a focal dystonia characterized by involuntary neck muscle contractions causing abnormal head positioning—a completely different pathophysiology from migraine 1.
Evidence-Based Treatment for Spasmodic Torticollis
Botulinum toxin injections are the established first-line treatment for spasmodic torticollis, with strong guideline support and extensive clinical evidence:
The American Academy of Otolaryngology-Head and Neck Surgery guidelines recommend botulinum toxin injections for treatment of spasmodic dysphonia and other focal dystonias (Grade B evidence), with preponderance of benefit over harm 1.
Botulinum toxin provides symptom control for 3-6 months by causing transient flaccid paralysis of affected muscles through inhibition of acetylcholine release 1.
Clinical Evidence for Botulinum Toxin in Cervical Dystonia
In a long-term follow-up study of 37 patients with spasmodic torticollis receiving repeated botulinum toxin injections, 86% experienced significant improvement in posture and 84% had pain relief 2.
A review of 107 patients receiving 510 injection treatments showed that 95% reported considerable benefit, with 76% achieving moderate or excellent improvement 3.
Treatment efficacy is maintained with repeated injections every 3-4 months, with optimal doses between 200-400 mouse units per muscle 4, 2.
Botulinum toxin was rated subjectively as the best therapy by patients with spasmodic torticollis (median rating: 2 = good effect), significantly superior to all other treatment modalities 5.
Adverse effects are generally mild and transient, with dysphagia occurring in 44% of treatments but severe in only 2% 3.
Critical Pitfalls
Using a migraine-specific medication for a movement disorder represents off-label use without any supporting evidence and would not be considered standard of care.
There is no mechanistic rationale for CGRP antagonism in cervical dystonia, as the pathophysiology involves basal ganglia dysfunction and abnormal motor control, not trigeminovascular activation.
The requested dosing schedule (every 3 months for 4 visits) aligns with migraine prevention protocols, not dystonia management, further confirming the indication mismatch.
Appropriate Treatment Pathway
For this 38-year-old female with spasmodic torticollis, medical necessity would be met for:
Botulinum toxin type A injections into affected neck muscles (sternocleidomastoid, trapezius, splenius capitis) every 3-4 months 4, 2, 3, 6.
Injection into two or more involved neck muscles is more effective than single-muscle injection 3.
Treatment should be performed by a clinician experienced in identifying dystonic muscles and administering botulinum toxin for movement disorders 1.