De Quervein’s Syndrome Originating From an Unsuspected Source

BACKGROUND: This case report describes a patient with right-sided de Quervain’s syndrome accompanied by multiple right-sided C7 muscle weaknesses. Because the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) muscles involved in de Quervain’s syndrome share a C7 innervation, a cervical origin was suspected.

CASE PRESENTATION: The patient developed insidious pain at the base of her right thumb during gripping and grasping. This pain was replicated during Finkelstein’s test and manual muscle testing of the APL and EPB. Further assessment revealed weakness in the right sternocleidomastoid (SCM), triceps, pronator, and wrist extensor muscles. Passive intervertebral movement testing demonstrated limited right side-gliding at C6/7, despite no prior history of neck pain.

OUTCOME: Successful intervention consisted of C6/7 joint mobilization and targeted strengthening of the weak right upper extremity and SCM muscles.

DISCUSSION: Therapists should routinely assess the cervical spine when evaluating patients who present with recalcitrant upper extremity pain.