Value of oxyneurography, based on near infrared spectroscopy, in the diagnosis of carpal tunnel syndrome in comparison to provocative clinical diagnostic tests and nerve conduction studies.

ABSTRACT

OBJECTIVE: Evaluation of the diagnostic utility of the oxyneurography (ONG) in diagnosing carpal tunnel syndrome (CTS). METHODS: ONG examination of the median nerve was performed in 260 patients. The results were compared with nerve conduction studies and clinical provocative tests. RESULTS: ONG index greater than or equal to 62% was found in 95.18% of the patients with no or minimal Nerve Conduction Study (NCS) changes (1-2 according to the Padua classification) but only in 1.69% of the patients with advanced NCS changes (Padua 3-6). The sensitivity and specificity of the ONG study i.e. 95.18% and 98.31%, respectively, were compared with standard clinical tests Tinel sign (61.45% and 14.69%), Phalen test (34.94% and 45.20%), reverse Phalen test (81.93% and 34.46%) and carpal compression test (91.57% and 72.32%). CONCLUSIONS: ONG index lower than 62% was indicative of CTS. ONG has higher sensitivity and specificity then other clinical tests and it is an accurate and reliable method for the diagnosis of CTS. SIGNIFICANCE: Oxyneurography is a non-invasive, fast and safe study which may play role in the diagnosis of carpal tunnel syndrome.