Peripheral nerve blocks for primary and secondary headache disorders: review of current evidence and a practical approach.

Headache is prevalent, disabling, and a frequent neurological referral in the healthcare system. Clinic-based procedures have evolved in recent years to play an important role in headache medicine, with growing evidence on the safety, tolerability and efficacy of peripheral nerve blocks (PNBs). Despite novel headache therapies, PNBs are still widely used in headache services to treat primary and secondary headache disorders, including cluster headache and other trigemino-autonomic cephalalgias, migraine, occipital neuralgia, and other less frequent headache disorders. We aim to provide an update of the current evidence and a practical approach for delivering the most common PNBs used in clinical practice. We aim to describe PNBs indications, contraindications, injection locations and techniques, drug constituents, and potential pitfalls.