Conservative Management of Median Nerve Brachial Plexopathy after Microwave-based MiraDry Treatment for Axillary Hyperhidrosis

Axillary hyperhidrosis is characterized by excessive sweating of the armpits, which can significantly affect quality of life. A new microwave-based therapy, MiraDry (Miramar labs, Sunnyvale, Calif.), is a promising minimally-invasive treatment option. We report a case of unilateral brachial plexus thermal injury in a thin 19-year-old man treated for axillary hyperhidrosis with the MiraDry system. He initially experienced swelling and pain in the left hand and was prescribed 1 week of methylprednisolone. He then presented 1 week later with induration and swelling of bilateral axillae with swelling of left thumb, left index, and left long fingers, decreased sensation in median nerve distribution of the left hand, and the inability to flex the left index finger DIP joint. EMG showed absent median nerve motor and sensory function, consistent with median nerve plexopathy. He was conservatively managed with close observation and regular occupational hand therapy appointments. At his 12-month follow-up, there was complete return of left pronator teres strength, thumb flexion, and index finger flexion. Decreased sensation remained at the tip of the left index finger. We report the case of median nerve palsy after MiraDry therapy for axillary hyperhidrosis in a thin young man. We recommend using low-energy settings and pre-procedural ultrasound for young, thin patients because of the more superficial course of the brachial plexus within the axilla.