Aphasia and hemiparesis following stellate ganglion block.

The proximity of the stellate ganglion to the arterial vessel supplying the brain creates two problems. First, the close anatomical relation of the ganglion and the arteries increases the risk of intraarterial injection. Second, cerebral toxicity occurs at much lower total doses of local anesthetic when intraarterial injections are made into arteries that directly supply the brain (1). Excitatory reactions to local anesthetic injections into the vertebral artery, as well as blindness, have been described (2), but there have been no reports of symptoms after direct carotid artery injection with local anesthetics and few reports of depressive reaction to local anesthetic toxicity. In the present case, a patient experienced a transient episode of unconsciousness, expressive aphasia, and right hemiparesis after the injection of 2 ml of 1% lidocaine into, we postulate, the carotid artery. The case was unusual because the total dose of anesthetic was far below that expected to produce a reaction and the initial signs were depressive without antecedant excitatory central nervous system symptoms or signs.