Some cases will be eligible, but not all. The NICE guidance states:
Botulinum toxin type A is recommended as an option for the prophylaxis of headaches in adults with chronic migraine (defined as headaches on at least 15 days per month of which at least 8 days are with migraine):
- that has not responded to at least three prior pharmacological prophylaxis therapies and
- whose condition is appropriately managed for medication overuse.
In addition, availability of the service varies regionally.