Test-Retest Reliability and Face Validity of a Modified Neural Tissue Provocation Test in Patients with Cervicobrachial Pain Syndrome

Abstract

The Neural Tissue Provocation Test (NTPT) via median nerve is used to assess the compliance and mechanosensitivity of neural tissues in the upper limb. However, the standard requires 90° of shoulder abduction, a position that may be unsuitable for patients with cervicobrachial pain, who often present with limited range of shoulder abduction. This study, therefore, examined the test-retest reliability of pain responses to a modified testing procedure in 12 subjects with unilateral cervicobrachial pain syndrome (CBPS). The test was performed on the symptomatic and asymptomatic arm with the cervical spine in neutral position. The angles of elbow extension at the onset of pain/pain threshold (P1) and at the limitation of elbow extension due to pain/pain tolerance (P2) were measured using an external trigger and an electrogoniometer. Results showed that the onsets of P1 and P2 were sufficiently reliable across trials to warrant clinical use of this test (ICC3,1 ≥ 0.925). The elbow extension angles associated with pain threshold and pain tolerance were significantly lower in the symptomatic arm compared to the asymptomatic arm (p=0.003). In the majority of subjects, their exact symptoms were reproduced in the symptomatic arm and normal sensory responses occurred on the other side. The difference between sides in the elbow extension angle associated with pain responses, the type of pain responses, and the available elbow extension range of motion suggest that this modified version of the NTPT via median nerve has face validity for the assessment of the presence of heightened mechanosensitivity of neural tissues in patients with CBPS.