Cervical Plexus Block (CPB) in Whiplash Associated Disorder (WAD)

Whiplash is the most common injury associated with motor vehicle accidents and a major cause of disability and litigation. An acute whiplash injury follows sudden or excessive hyperextension, hyper flexion, or rotation of the neck affecting the soft tissues. It typically results from rear-end or side-impact motor vehicle collisions. Patients commonly present with pain and stiffness in the neck, headache, and upper backache. Chronic whiplash syndrome is characterized by symptoms of neck pain that persist for more than 3 months (1, 2). With over half a million people making whiplash injury claims per annum in the UK, it has a major impact on the healthcare and legal systems and also the economy. Over 40% of patients with whiplash injury report chronic neck pain and this is often refractory to conservative management (pain relief medications, physiotherapy). Current treatment involves burning the small nerves that supply the joints (facet joints) in the neck. Although they provide pain relief that can last 6-9 months, the nerves re-grow and the treatment has to be repeated. This treatment is a complex procedure that requires extensive training and has the potential to cause serious harm. There is new evidence to show that the pain in whiplash injury could be due to an impaired function of the neck muscles arising from whiplash trauma. Current treatment for this condition is injection of numbing medicine or steroids directly into the muscle. Although this treatment is safer than burning the facet nerves, it provides short-term relief.

The investigators have shown that a novel treatment targeting the nerves that supply the muscles in the neck can provide durable relief in patients with chronic neck pain. The medication is injected into a specific area (plane) in the neck of the patient and is called cervical plexus block (CPB). The investigators currently offer CBP treatment as a standard treatment in the management of patients with chronic neck pain arising from whiplash injury. There are two types of CPB: CPB with numbing medicine (CPB-LA) and CPB with steroid.

Aim of the study is to evaluate the effectiveness of two types of Cervical Plexus Block (CPB) treatment in reducing pain at three months in patients with refractory chronic neck pain from whiplash injury

Methods: The proposed study is a prospective, observational pilot study that will be conducted at Leicester General Hospital over 36 months. Potential participants will be given an information sheet by the clinical team when they are seen in the outpatient clinic. The participants will have 24 hours to read the information sheet. Thereafter, the research team will approach the potential participant to obtain informed consent. After providing written consent, adult patients with chronic neck pain from whiplash injury will receive ultrasound guided CPB-LA in the theatre. If treatment provides >30% relief at 3 months, they will be re-assessed at six months and CPB-LAi will be repeated as per waiting list. If at 3 months, the pain returns to the baseline, CPB with steroid will be performed. If CPB with steroid does not provide any benefit, the participants will receive a rescue treatment (trigger point injection) within three months. Participants will be asked to complete questionnaires on pain scores and mood. Participation in the study will end at 9 months following the first CPB treatment on completion of relevant questionnaires.