Severe brachial plexopathy after an ultrasound-guided single-injection nerve block for total shoulder arthroplasty in a patient with multiple sclerosis.

DESPITE the known benefits of regional anesthesia for patients undergoing joint arthroplasty, the performance of peripheral nerve blocks in patients with multiple sclerosis (MS) remains controversial. MS has traditionally been described as an isolated disease of the central nervous system, without involvement of the peripheral nerves, and peripheral nerve blockade has been suggested to be safe. However, careful review of the literature suggests that MS may also be associated with involvement of the peripheral nervous system, challenging traditional teachings. There is a paucity of evidence with regard to safety in using peripheral nerve regional anesthesia in these patients. This makes it difficult to provide adequate "informed consent" to these patients. This case report describes a patient with MS who sustained a severe brachial plexopathy after a total shoulder arthroplasty during combined general anesthesia and interscalene nerve block.