Association of the area of sensory disturbance with the area of suprascapular nerve palsy

Purpose. To determine the association of the area of sensory disturbance with the area of suprascapular nerve (SSN) palsy in healthy volunteers and patients with SSN palsy. Methods. Five male and one female and healthy volunteers aged 23 to 44 (mean age, 32.2) years underwent an experiment of distal and proximal SSN block (at the spinoglenoid notch and suprascapular notch, respectively). A pinprick test was performed to determine pain sensation and the area of sensory disturbance. In addition, records of 21 male and 19 female patients aged 21 to 75 (mean, 54.1) years who underwent arthroscopic SSN release for SSN palsy were reviewed. The same pinprick test was performed. Results. After distal SSN block, 5 volunteers had a sensory deficit in the area below the scapular spine only, and one had no sensory deficit. After proximal SSN block, the sensory deficit spread to both lateral and medial sides above and below the scapular spine. In the 40 patients with SSN palsy, only 5 (12.5%) patients exhibited no sensory deficit above the scapular spine; 4 of them had ganglion cysts and one had entrapment of the nerve at the spinoglenoid notch. In 30 patients with palsy at the suprascapular notch, all had sensory deficit in the lateral side above the scapular spine. In 5 patients with ganglion and one patient with palsy at the spinoglenoid notch, sensory deficit was noted below (and not above) the scapular spine in all patients except for one. Conclusion. The area of sensory disturbance is associated with the area of SSN palsy.