Abnormal temperature control suggesting sympathetic dysfunction in the shoulder skin of patients with frozen shoulder

In view of the possibility that sympathetically mediated pain could be responsible for frozen shoulder symptoms we compared shoulder skin vasomotor control in 11 patients with frozen shoulder and 17 similarly aged normal subjects without shoulder pain. Using computer-assisted thermography the shoulder skin temperature was assessed before and following a 'cold challenge' which consisted of a 15 degrees C cold pack being held against the skin for 60 sec. Both prior to and immediately following the cold challenge shoulder skin temperatures tended to be lower in the patients. During a 10-min rewarming phase, however, the between-group temperature difference increased and became significant at the 0.05 level. These abnormalities of temperature control in patients clearly suggest sympathetic dysfunction in the dermatome subserving pain sensation from the affected shoulder. Whether these abnormalities are primary or secondary remains unresolved.