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.

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.