Lumbosacral plexopathy is an uncommon disorder of the peripheral nervous system characterized by asymmetric, weakness, and numbness in lumbosacral nerve root distributions. A 53-year-old woman experienced left lower extremity weakness and numbness after high intensity focused ultrasound (HIFU) procedure to treat uterine myoma. Electrodiagnostic study revealed left lumbosacral plexopathy. Pelvic magnetic resonance imaging showed high signal intensity in the left lumbosacral plexus. After 6 months, the symptoms did not improve. This case report illustrates the potential danger of HIFU.
