Delayed-onset post-craniotomy headache responsive to botulinum toxin A: a case series.

ABSTRACT

We report here the case of four patients presenting with delayed-onset temporal pain after pterional craniotomy. They reported similar symptoms attacks of pain over the temporal region, ipsilateral to the operative site, irradiating around the eye and lasting from 10 min to 1 h. All patients had hypertrophy of at least one part of the temporalis muscle. All responded dramatically to botulinum toxin A injection (25 to 50 Botox® units) into the temporalis muscle. We suggest that the headaches were caused by aberrant nerve regeneration following surgical injury to the frontal branch of the facial nerve.