©
Freepik
The Neuromusculoskeletal Health and Science Lab have just published two linked papers in the journals Brain and Pain. Both papers looked at nerve pathology in relation to Whiplash-Associated disorders (WAD).
WAD following road traffic accidents affect millions of people globally each year. Sadly, up to 50% develop persistent pain. To date, no clear structural pathology has been identified that could explain why people do not recover. This often leaves people with WAD stigmatised.
Researchers investigated whether nerve pathology may contribute to symptoms in people with WAD. They followed a group of 129 people who had recently sustained a whiplash injury, comparing them to healthy individuals.
The research published in Brain found that two thirds of participants with Whiplash Associated Disorder Grade II (WADII) – the most common type of whiplash – suffered neuropathic (nerve) pain. WADII is most commonly associated with musculoskeletal symptoms, and is traditionally not considered to involve nerve injury. However, the study showed that nerve pain was present in 65% of the cohort with WADII within four weeks of injury, and 32% were still experiencing this six months after injury. Many participants had reduced ability to sense temperature, vibration, and light touch, with deficits in warm sensation and mechanical sensation persisting after six months, suggesting ongoing nerve dysfunction. Of note, the researchers found evidence of structural nerve damage in the blood and skin: A protein linked to nerve damage (neurofilament light chain) was elevated in people shortly after whiplash injury compared to healthy people. Skin biopsies were comparable in the acute stage, but showed reduced density of sensory nerve fibres 6 months after injury in patients versus healthy participants.
Joel Fundaun from NDCN was co-lead author on the paper, Professor Annina Schmid was senior author, Soraya Koushesh, Macaraena Tejos-Bravo and Georgios Baskozos were also co-authors from NDCN.
The second paper in Pain, which was co-authored by Joel Fundaun, Soraya Koushesh and Professor Annina Schmid from NDCN, looked at the presence of neuroinflammation in participants with WADII using MRI and blood markers. MRI scans showed increased signal in some roots of the brachial plexus and dorsal root ganglia, suggesting neuroinflammation in these regions. Patients also had raised inflammatory markers in the blood shortly after injury.
These findings challenge the idea that WAD is purely a musculoskeletal problem. Instead, they suggest that in many people, mild nerve injury and neuroinflammation may contribute to symptoms. This research highlights the need for better diagnostic tests and potentially more targeted treatments for those people with nerve involvement after whiplash injury.
Professor of Pain Neurosciences Annina Schmid said:
“Our findings of nerve pathology in some patients following whiplash injury challenge the traditional view that this is solely a musculoskeletal condition. We hope these insights will prompt a reassessment of this often-stigmatized condition."