J Manipulative Physiol Ther. 1997 Sep; 20(7): 476-81.

Thermal asymmetry of the upper extremity in scalenus anticus syndrome, leg-length inequality and response to chiropractic adjustment.

Knutson GA.

OBJECTIVE: To describe a case of a vasomotor, vascular form of thoracic outlet syndrome that causes upper extremity thermal asymmetry, and to discuss a single subject case study (N-of-1) comparing the correlation of a subjective test for putative atlas vertebral subluxation complex (supine leg-length inequality) with a single blinded objective measurement [temperature differential (delta degree T)] on the dorsum of the hands. CLINICAL FEATURES: A 71-yr-old woman with a cold, painful right hand and chronic neck pain sought chiropractic evaluation. There was a left head tilt and muscular hypertonicity with fibrous bands in the opposite scalenes and sternocleidomastoid. Thermographic examination revealed a large temperature differential (12 degrees F) between the dorsum of the right and left hands, with the superficial veins on the dorsum of the cold hand collapsed. Thoracic outlet provocation tests were negative. A left-side leg-length inequality potentially indicative of putative upper cervical subluxation was also noted. A diagnosis of presumptive thoracic outlet syndrome with vasomotor vascular complications subsequent to altered cervical biomechanics was made. INTERVENTION AND OUTCOME: Treatment was limited to chiropractic, upper cervical, vectored, linear adjustment of the atlas vertebra. Temperature differential between the hands improved significantly after individual atlas adjustment(s) and in the long term. CONCLUSION: Scalenus anticus syndrome and upper extremity thermal asymmetry may result from altered cervical biomechanics caused by atlas vertebral subluxation complex. Furthermore, the supine leg check may be of value in determining the necessity of atlas adjustment.