Trapezius Palsy Resulting from Accessory Nerve Injury after Cervical Lymph Node Biopsy Dramatically Improved with Conservative Treatment

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Background: Iatrogenic injuries to the spinal accessory nerve (SAN) are not uncommon during cervical lymph node biopsy. Many operative treatments for SAN injury in the posterior cervical triangle have been reported, but there are no guidelines regarding the choice between operative and nonoperative treatments. Because it is believed that the nerve seldom spontaneously regenerates, some articles suggest surgical intervention within 3 months from the nerve injury to achieve good postoperative results. However, we experienced a case of spontaneous accessory nerve recovery more than 3 months after accessory nerve injury. It is necessary to carefully exclude similar patients from unnecessary surgery. Case: A 41-year-old woman underwent cervical lymph node biopsy at an otolaryngology clinic. She experienced pain across her neck and weakness of the shoulder in abduction just after the biopsy. Three months after the biopsy, her symptoms persisted and she was referred to our hospital for surgical treatment. On careful examination, we detected signs of accessory nerve regeneration. Consequently, we prescribed physical therapy and a rehabilitation program, including active and passive range-of-motion exercises of the shoulder and muscle strengthening exercises. Six months after the injury, there was a dramatic improvement of the trapezius muscle function and the patient became pain free. Discussion: When the biopsy incision is more than one finger’s breadth away from the normal course of the SAN, and when Tinel-like signs advance along the trapezius muscle over time, spontaneous SAN recovery can be anticipated.