A review of nerve conduction studies in cases of suspected compression neuropathies of the upper limb.

Abstract

Entrapment neuropathies, particularly those affecting upper limbs, are common reasons for referral for nerve conduction studies (NCS). However, concordance between clinical findings and NCS findings, especially in patients being considered for intervention including decompressive surgery, has not been assessed.

We conducted a retrospective study using records from a tertiary referral centre's neurophysiology database. We aimed to establish the proportions of agreement between the suspected clinical diagnosis as defined by the referring clinician and NCS findings in the setting of an upper limb entrapment neuropathy.

Of the 571 referrals for NCS, suspected bilateral carpal tunnel syndrome was the commonest reason for referral (30.5%). In total, there was 51.5% concordance between suspected clinical diagnosis and NCS findings. Patients with NCS evidence of an entrapment neuropathy (n = 437) were more likely to be older compared to those with normal studies (54.0 +/- 15.6 years vs. 45.9 +/- 13.4 years, p < 0.001). Those with normal NCS findings were more likely to be female (72%, p = 0.001). An alternative or additional diagnosis was found in 14%.

This study raises concerns regarding the appropriateness of referral for decompressive surgery based on clinical diagnosis alone as many have an additional or alternative diagnosis as suggested by NCS findings.