Right-sided Suprascapular Neuropathy Due to Compression by Paralabral Cyst at the Spinoglenoid Notch: A Case Study

Case Diagnosis: Right-sided suprascapular neuropathy secondary to compression by paralabral cyst located at the spinoglenoid notch.

Case Description: Mr. X is a 40-year-old male who presented to the office due to progressive right arm weakness and pain for the past 6-8 months. Patient reports having difficulty lifting more than a few pounds with his right arm. He denies any trauma. He works as a firefighter and notes difficulty performing tasks at work. Patient obtained MRI of his right shoulder and was found to have a large paralabral cyst alongside the posterior labrum extending into the spinoglenoid notch with compression of the suprascapular nerve. He presented to the outpatient clinic for electromyography and nerve conduction studies to evaluate for suprascapular neuropathy versus radiculopathy.

Discussion: Suprascapular neuropathy involves compression of the suprascapular nerve, which innervates the supraspinatus and infraspinatus muscles in the shoulder. A paralabral cyst is a fluid-filled sac that can compress the suprascapular nerve. Electromyogram showed abnormal activity solely in the right infraspinatus muscle, indicating suprascapular neuropathy distal to the supraspinatus. MRI revealed a large paralabral cyst extending into the spinoglenoid notch, causing the compression. Treatment options include conservative measures or surgical removal of the cyst.

Setting: Outpatient Rehabilitation Clinic

Assessment/Results: Positive sharp waves and decreased recruitment are seen with needle evaluation of right infraspinatus muscle. No abnormalities seen when testing other muscles of right upper extremity or right cervical paraspinal musculature, including the supraspinatus. Therefore, electrodiagnostic evidence of right sided suprascapular neuropathy at the spinoglenoid notch is seen, consistent with noted paralabral cyst extending into the spinoglenoid notch.

Conclusion: In conclusion, suprascapular neuropathy caused by a paralabral cyst is a rare but possible cause of shoulder weakness and pain, as it can compress the suprascapular nerve. Proper diagnosis through electromyogram and MRI imaging is important for appropriate management.