1626 - Brachial Plexopathy as a Post-Surgical Complication of Thyroidectomy and Neck Dissection

A 39-year-old male presented with left shoulder pain and weakness after a total thyroidectomy and left selective neck dissection. Symptom onset was immediately following the surgery. Physical exam revealed significantly decreased external rotation strength and lateral scapular winging. Electrodiagnostic studies showed reduced amplitude and area of the left suprascapular nerve and abnormal spontaneous activity in the left infraspinatus and rhomboids muscles. These findings suggest a high upper trunk brachial plexopathy.

Case Description:

Following a total thyroidectomy and left selective neck dissection for papillary thyroid cancer, the patient awoke with 10/10 bilateral shoulder pain. While the pain improved, he was left with residual left shoulder weakness and pain with activity, particularly during external rotation and overhead movements. A physically active individual, he experienced significant functional limitations. Exam showed lateral scapular winging and notable loss of left shoulder external rotation strength. He was referred to physical therapy and for an EMG study to determine the cause of his symptoms.

Discussions:

This case illustrates a rare but important complication of thyroidectomy and neck dissection: a high upper trunk brachial plexopathy. The immediate onset of symptoms post-surgery, along with the specific location of pain and weakness, strongly suggests a direct surgical injury to the brachial plexus. Although spinal accessory nerve injury is a known risk, electrodiagnostic findings of involvement of the suprascapular nerve and rhomboids indicate a more extensive injury. The presence of reinnervation signs on the EMG suggests a good prognosis for recovery.

Conclusions:

High upper trunk brachial plexopathy can be a direct result of thyroidectomy with neck dissection. This case highlights the value of a thorough physical examination and the use of electrodiagnostic studies for diagnosing post-operative neurological injuries. The presence of reinnervation on EMG indicates a positive outlook for recovery. Early diagnosis and prompt physical therapy are critical for optimizing a patient's functional outcome.