🤕 Chronic Migraine Botulinum Toxin Protocol Simulator

Chronic Migraine — The 15-Day Threshold

Fifteen or more headache days a month defines chronic migraine.

• 15+: Chronic Migraine Threshold (headache days / month)
• 8: Episodic vs Chronic Cutoff (migraine days / month)
• 1–2%: Global Prevalence (of adults)
• #2: Disability Ranking (leading cause worldwide)

Defining chronic migraine

Fifteen-plus headache days monthly, eight migrainous, for three months.

Why prevention matters

Frequent attacks drive disability, medication overuse, and lost function.

PREEMPT Protocol — 31 Fixed Injection Sites

155 units of onabotulinumtoxinA delivered across seven muscle groups.

• 31: Total Injections (fixed sites)
• 7: Muscle Groups (head and neck)
• 155U: Total Dose (onabotulinumtoxinA)
• 12 wks: Session Interval (repeat cycle)

Seven muscle groups

Frontalis, corrugator, procerus, temporalis, occipitalis, cervical, trapezius.

Fixed-site, fixed-dose design

Every session repeats the same 31 sites, same 5U-per-site dose.

Toxin Binds Nerve Terminals — SNAP-25 Cleavage

Botulinum toxin cleaves SNAP-25, blocking acetylcholine vesicle fusion.

• SNAP-25: Target Protein (SNARE complex)
• Cleaves: Mechanism (blocks ACh release)
• 1–2 wks: Onset (clinical effect)
• ~12 wks: Duration (per session)

SNARE complex disruption

Cleaved SNAP-25 stops vesicles from docking and releasing acetylcholine.

Beyond acetylcholine

Toxin also blocks peripheral release of pain neuropeptides like CGRP.

Peripheral Sensitization Reduced

Blocked terminals lower nociceptive input into the trigeminal system.

• ↓: Nociceptor Signaling (peripheral sensitization)
• ↓: Central Sensitization (downstream effect)
• Calmed: Trigeminovascular System (less activation)
• Reduced: CGRP Release (neuropeptide signaling)

Peripheral to central

Less peripheral firing gradually quiets central trigeminal sensitization.

A cumulative effect

Sensitization drops further with each repeated 12-week cycle.

Reduced Headache Days — Cumulative Benefit

Two to three cycles compound the drop in monthly headache days.

• -8.4: PREEMPT Trial Reduction (headache days / month)
• ~70%: Responder Rate (≥50% improvement)
• 2–3: Cycles To Full Effect (12-week cycles)
• 2010: FDA Approval (chronic migraine indication)

Cumulative cycle effect

Each cycle builds on the last — benefit grows through cycle three.

Adherence matters

Skipping sites or delaying sessions blunts the cumulative benefit.