The Influence of Diabetes Mellitus on Cervical Radiculopathy Treatment Outcomes: A Pilot Study

Background

Cervical radiculopathy (CR) is a condition causing disability that is commonly treated with neural mobilization (NM) and cervical traction (CT). Diabetes mellitus (DM) has been shown to have a negative effect on the peripheral nerves by the degeneration of the axons, demyelination, and endoneurial fibrosis, which could dampen the therapeutic effect of mechanically guided interventions.

Objective

To determine if type 2 DM affects two main outcomes (Neck Disability Index [NDI] and Upper Limb Tension Test [ULTT] normalisation) for a standardised combined NM and CT programme in a population of cervical radiculopathy.

Methods

Ten patients (5 with type 2 DM and 5 without) were treated with 18 sessions of combined NM and mechanical CT for a period of six weeks. NDI and ULTT were primary outcomes, pain intensity (NRS) was a secondary outcome. The Mann-Whitney U test was employed for between group comparisons with ULTT difference by Fisher's exact test.

Results

Non-DM patients achieved a mean NDI reduction of 26.4 ± 3.1 pts vs 14.8 ± 4.2 pts in the DM group (p = 0.016; Cohen's d = 3.4). ULTT normalised in 100% of non-DM vs 0% of DM patients (p = 0.008). NRS reduction was 4.0 ± 0.7 (non-DM) vs 2.4 ± 0.5 (DM; p = 0.016).

Conclusions

DM significantly reduces functional and neurodynamic recovery after combined NM and CT in CR. The mechanotherapeutic response seems to be limited by intrinsic DPN pathology including fibrosis, microangiopathy, and impaired axoplasmic transport.