Several serum pro-inflammatory cytokines were raised in people with WADII. So inflammation can be detected systemically. x.com/AnninaBSchmi...

Magnetic resonance imaging T2 signal ratio was increased in the C5 root of the brachial plexus and the C5-C8 dorsal root ganglia in WADII participants compared with healthy controls. We did not find changes in the distal median nerve trunk.

We also took skin biopsies. Intraepidermal nerve fibre densities at the index finger were not significantly different between groups. However, dermal myelinated nerve bundles at the index finger were reduced 6-months post-injury in participants with WADII compared to controls.

Intriguingly, these functional changes were accompanied by elevated serum neurofilament light chain levels (a marker for axonal damage) acutely after whiplash. This normalised 6 months later. This suggests there is actual structural damage to axons in some people with WADII.

QST demonstrated significantly reduced thermal and mechanical detection thresholds in acute WADII compared to controls, some of which persisted at 6 months.

Within 4 weeks of injury, 65% of people with WADII had neuropathic pain which persisted in 32% 6-months post-injury.