Coma after greater occipital nerve blockade in a patient with previous posterior fossa surgery

We here report the case of a patient who previously underwent posterior fossa surgery and was later treated with greater occipital nerve blockade for unilateral facial pain. The patient went into coma immediately post-injection but made a full recovery without sequelae after intensive care treatment. Physicians should be aware of the risks of greater occipital nerve blockade after previous posterior fossa craniotomy.