Aetiology of convulsions due to stellate ganglion block: a review and report of two cases.

Stellate ganglion block is a selective sympathetic block that affects the ipsilateral head, neck, upper extremity and upper part of the thorax. Convulsions are a recognized complication of intra-arterial injection during stellate ganglion block. As central nervous system toxicity depends ultimately on the concentration of the local anaesthetics presented to the brain, the likely causative factors are discussed as well as the types of toxic symptoms and their onset times. The paper considers the aetiological factors of such convulsions resulting from stellate ganglion block in two patients.