ABSTRACT
Objective: To describe the prevalence and diagnostic value of positive symptoms and provocative signs of thoracic outlet syndrome [TOS] in patients with carpal tunnel syndrome [CTS].
Methods: A total of 93 symptomatic upper extremities in 56 consecutive patients referred for clinical and electrodiagnostic evaluation of suspected CTS were studied. Each patient was asked to describe their hand symptoms with overhead positioning [TOS symptom] and at nighttime [CTS symptom]. Physical examination included five provocative TOS signs [Roos, costoclavicular, Adson, Allen, and Halstead] and three provocative CTS signs [Tinel, Phalen, and carpal tunnel compression].
Results: A total of 60 out of 93 [65 percent] upper limbs had electrodiagnostic abnormalities compatible with CTS. Of them, 29 percent had symptom aggravation with overhead arm positioning, whereas 97 percent had nocturnal symptom aggravation. Nocturnal symptom aggravation was highly sensitive but not specific for CTS, whereas symptom aggravation with overhead positioning was specific but not sensitive. The likelihood of CTS was highest when there were both symptom aggravation at nighttime and overhead hand positioning [likelihood ratio = 4.1]. In total 55 percent of limbs with CTS had at least one positive provocative TOS sign compared to 76 percent of those without CTS. However, the presence of a positive TOS sign[s] was associated with the least likelihood of having CTS [likelihood ratio from 0.62 to 0.71].
Conclusions: Hand neurologic symptom aggravation when positioned overhead is specific for CTS and nocturnal symptom aggravation is sensitive. When both are present, CTS is 4.1 times as likely as when they are not present. Positive TOS provocative tests reduce the likelihood of CTS being present.