Is continuing Ajovy (fremanezumab) every 3 months and removing the Lumbar Puncture (LP) shunt medically necessary for a patient with Benign Intracranial Hypertension (G93.2) and a history of migraines?

Medical Necessity Assessment: Fremanezumab (Ajovy) Continuation and LP Shunt Removal in Benign Intracranial Hypertension

Direct Recommendation

Continuing Ajovy (fremanezumab) every 3 months is NOT medically indicated for this patient with benign intracranial hypertension (IIH), as fremanezumab is FDA-approved exclusively for migraine prevention and has no established role in treating IIH or its associated headaches. 1 Removing the LP shunt may be appropriate if papilloedema has resolved and intracranial pressure has normalized, but this decision requires objective documentation of ICP normalization through lumbar puncture measurements. 2, 3

Analysis of Medical Necessity

Fremanezumab (Ajovy) Continuation

Fremanezumab is NOT standard of care for IIH-related headaches:

• The FDA indication for fremanezumab is strictly limited to "preventive treatment of migraine in adults" - it has no approved indication for IIH or secondary headaches from elevated intracranial pressure 1

• The clinical trials for fremanezumab specifically excluded patients with significant neurological conditions and were conducted only in patients with primary migraine disorders (episodic migraine with <15 headache days/month or chronic migraine with ≥15 headache days/month) 1

• The patient's current presentation of "daily headaches with nausea that are unchanged" despite being on Ajovy demonstrates lack of therapeutic benefit, which argues against medical necessity 1

Critical clinical context that contradicts fremanezumab use:

• The patient's history indicates the previous migraine overuse headaches have resolved, suggesting the primary issue requiring treatment has already improved 3

• The clinical note describes headaches that worsen with "prolonged standing, suggestive of a low pressure component" - this is the opposite pathophysiology from IIH (which involves elevated pressure) and suggests possible CSF hypotension, potentially from the LP shunt 2

• IIH consensus guidelines clearly state that migraine preventatives should only be considered in patients where "the ICP is settling" and "papilloedema has resolved (IIH in ocular remission)" - there is no documentation in this case that papilloedema has resolved or that ICP has normalized 2, 3

LP Shunt Removal

Shunt removal may be medically appropriate under specific conditions:

• IIH guidelines recommend that once papilloedema has resolved, the underlying elevated ICP typically normalizes, and CSF diversion procedures may no longer be necessary 2, 3

• However, objective documentation is essential: lumbar puncture should be performed to confirm that opening pressure has normalized (≤25 cm CSF) before considering shunt removal 2

• The clinical description of headaches worsening with standing suggests possible iatrogenic low-pressure headaches from CSF over-drainage, which occurs in 28% of patients with CSF shunts and would support shunt removal 2, 3

• Guidelines specifically warn that "CSF diversion is generally not recommended as a treatment for headache alone in IIH" since 68% continue having headaches at 6 months and 79% at 2 years post-shunt 2, 3

Standard of Care for IIH-Related Headaches

The evidence-based approach for headache management in IIH follows this hierarchy:

1. First-line: Optimize ICP control - Acetazolamide (250-500mg twice daily, titrating to maximum 4g daily) or topiramate (starting 25mg, escalating to 50mg twice daily) are the standard medical treatments for IIH, not CGRP antibodies 3, 4

2. Acute headache management - Short-term NSAIDs, paracetamol, or indomethacin (which specifically reduces ICP) are appropriate for acute symptom relief 3

3. Migraine-specific therapy only after ICP normalization - Migraine preventatives like topiramate, candesartan, or venlafaxine should only be initiated once papilloedema has resolved and the patient is in "IIH ocular remission" 2, 3

4. Limit acute medication use - Triptans may be used for true migrainous attacks but must be limited to ≤2 days/week or ≤10 days/month to prevent medication overuse headache 2, 3

Critical Pitfalls in This Case

Several red flags indicate inappropriate treatment:

• Using a migraine-specific preventative (fremanezumab) for what appears to be secondary headache from IIH without documented resolution of the underlying pathology 2, 3

• No documentation of current papilloedema status, visual field testing, or recent ICP measurements to guide treatment decisions 2, 4

• The patient's resolved medication overuse headaches suggest the primary treatable condition has improved, yet a costly biologic therapy is being continued without demonstrated benefit 3

• The clinical picture of positional headaches worsening with standing strongly suggests CSF hypotension from shunt over-drainage rather than persistent elevated ICP requiring ongoing migraine prevention 2, 3

Required Documentation for Medical Necessity

To justify any ongoing preventive therapy, the following must be documented:

• Current ophthalmologic examination with fundoscopy documenting papilloedema grade 2, 4
• Recent visual field testing to assess for progressive visual loss 2, 4
• Lumbar puncture with opening pressure measurement to confirm current ICP status 2, 4
• Headache diary documenting frequency, characteristics, and relationship to position 2, 3
• Documentation that headaches have migrainous features (unilateral, pulsating, photophobia, phonophobia) rather than being purely pressure-related 2, 3

Conclusion on Medical Necessity

Fremanezumab continuation is NOT medically necessary or standard of care because: (1) it is not FDA-approved for IIH, (2) it is not recommended in evidence-based IIH guidelines, (3) the patient shows no therapeutic benefit after prolonged use, and (4) the clinical presentation suggests CSF hypotension rather than migraine as the primary problem 2, 3, 1. This represents off-label use without supporting evidence and should be discontinued. 2, 3

LP shunt removal may be medically appropriate if objective testing confirms normalized ICP and resolution of papilloedema, particularly given the clinical suggestion of low-pressure headaches 2, 3, 4. However, this decision requires proper pre-procedural assessment including lumbar puncture to document opening pressure 2, 4.