From Pinosky ML, Fishman RL, Reeves St et al. the effect of bupivacaine skull block on the hemodynamic response to craniotomy. Anesth Analg 1996; 83:1256-1261.
After induction of anesthesia, baseline hemodynamic variables were recorded and the skull block was performed 5 min before head pinning. The supraorbital and supratrochlear nerves were blocked with 2 mL of solution as they emerged from the orbit with a 23-gauge needle introduced above the eyebrow perpendicular to the skin. The auriculotemporal nerves were blocked bilaterally with 5 mL of solution injected 1.5 cm anterior to the ear at the level of the tragus; the needle was introduced perpendicular to the skin and infiltration was made deep to the fascia and superficially as the needle was withdrawn. The postauricular branches of the greater auricular nerves were blocked with 2 mL of solution between skin and bone, 1.5 cm posterior to the ear at the level of the tragus (Figure 1). The greater, lesser, and third occipital nerves were blocked with 5 mL of solution using a 22-gauge spinal needle, with infiltration along the superior nuchal line, approximately halfway between the occipital protuberance and the mastoid process (Figure 2).