AUTOMOBILE INJURIES AND CENTRAL SENSITISATION

Automobile Injuries and Central Sensitisation

Introduction

Automobile accidents are one of the leading causes of death, being responsible for approximately 1.3 million deaths worldwide per annum. Not all automobile accidents are fatal; many cause physical injuries of varying degrees of severity, which effects often last a lifetime.

Besides altering the normal physiological mechanisms of an individual, being involved in an accident affects the psychological, emotional, and physical state of an individual. Automobile accidents including those that involve whiplash injuries are associated with the onset of central sensitivity, characterised by a lowered pain threshold and hyperalgesia (increased sensitivity and extreme response to pain). Chiropratic care from Clinic 27 could help deal with this pain. 

What Is Central Sensitisation?

Central sensitisation presents as hypersensitivity to painful stimuli that includes dynamic tactile allodynia (extreme sensitivity to touch), pressure hyperalgesia, after-sensations, or secondary punctuate, often accompanied by enhanced temporal summation. The underlying mechanism is the amplification of synaptic transmission and signalling between neurons within the central nervous system manifesting as pain hypersensitivity. Central amplification involves increased synaptic efficacy concerning pain signals and reduced inhibition of pain resulting in an exaggerated response to noxious stimuli.

Approximately 50% of the individuals presenting with central sensitisation have a genetic predisposition to the onset of this phenomenon. Central sensitisation can be induced in a variety of ways including electrical stimulation, hypertonic saline, heat burn, UV burn, and chemicals serving as noxious stimuli. These factors activate the nociceptors (sensory receptors for painful stimuli) and induce neuroplasticity resulting in the occurrence of central sensitisation.

How does automobile injury cause Central Sensitisation?

Whiplash injuries are a common occurrence in automobile accidents, particularly rear-end car accidents. Whiplash involves rapid back and forth movement that injures the neck. The injured structures include neurovasculature, vertebrae and intervertebral discs, muscles, and soft tissues. Whiplash injuries manifest as chronic pain syndrome and significantly affect the work capacity and productivity of an individual.

While patients with whiplash experience hyperalgesia (an abnormally heightened sensitivity to pain) in injured areas, hyperalgesia is also reported away from the trauma site, indicating the association between central sensitisation and automobile injuries.

People suffering from whiplash injury in automobile accidents and subsequent development of central sensitisation tend to suffer from pain in the neck, head, and lower limb along with a limited range of movement. However, central sensitisation causes the development of tender or pain points other than the areas undergone direct trauma. These tender points serve as referred pain sites.

Tissue damage from automobile accidents increases the responsiveness of neurons in the spinal cord to peripheral stimulation. Peripheral neurons activate a larger number of central nervous system neurons, expanding the receptive field, and inducing hyperalgesia in those areas that are not directly involved in the injury such as the contralateral limb. The pain-causing lesions in the deep tissues of the neck are responsible for maintaining a constant state of central sensitisation. While local anaesthesia may decrease the intensity of pain to some extent, it has no significant effect on central sensitisation and pain hypersensitivity to peripheral stimulation.

Psychological distress following automobile accidents can also contribute to a reduced pain threshold and hyperalgesia. Psychological distress mediates central sensitisation by altering the nerve transmission along descending pain inhibition pathways.  

What happens immediately after an automobile injury?

The muscles of your neck can be stretched or torn immediately after an automobile injury. Pain and stiffness are signs and symptoms of trauma to the ligaments and muscles of your neck. The body’s response to injury is to restrict movement and heal the injury by sending white blood cells called leukocytes to the injured area. Your body will then begin repairing the injured area by laying down scar tissue. The problem with scar tissue is that each joint in your neck has fairly limited motion, and scar tissue reduces that motion even more. If you don’t receive treatment early, you could end up with permanent limited mobility, chronic pain and spinal degeneration.

Early intervention / treatment by a chiropractor helps prevent spinal degeneration by hindering the development of scar tissue and increasing movement of the injured area.

Chiropractic Care For Central Sensitisation

Chiropractors treat musculoskeletal, neurologic, and combined disorders based on spinal manipulation techniques. Altered sensory input during chiropractic spinal adjustments leads to alterations in pain perception, thus forming the basis for treatment and management of central sensitisation. Chiropractic spinal adjustments also improve the transmission of pain inhibition signals along the cortico-limbic-brainstem pathways.

Standard chiropractic techniques employed to combat central sensitisation involve the application of high-velocity and low-amplitude thrusts to the spinal and pelvic joints, depending on the clinical evaluation of joint dysfunction. Chiropractors may also opt for sham intervention (or placebo intervention – an important scientific control) which involves active and passive movements of the head, spine, and body of the patient.

In some cases, chiropractic spinal adjustments can restore the normal pain facilitatory and inhibitor pathways. Regarding pain transmission, chiropractic spinal adjustment is known for influencing C fibres more significantly than A-delta fibres. However, chiropractic intervention does not influence pain habituation mechanisms as seen in sham intervention. Chiropractic spinal adjustment alleviates pain by altering the central processing mechanisms of pain.

Chiropractic care also caters to the psychological and musculoskeletal factors associated with automobile accidents, as it treats musculoskeletal abnormalities and improves the psychological state of the affected individual, thereby eliminating many of the factors that could exacerbate central sensitisation.

Conclusion

Central sensitisation in individuals involved in automobile accidents is largely responsible for the deterioration of quality of life and reduced work performance. These patients suffer from hyperalgesia, dynamic tactile allodynia, and limited range of movement. Chiropractic adjustments of the spine modulate the pain inhibition pathways and assists in the restoration of the normal function of pain processing pathways. Chiropractic care recipients report an improved range of movement, quality of life, and most importantly, reduction in pain.

Call Clinic 27 today and allow one of our chiropractors to put you on the path to recovery from whiplash and central sensitisation.

References:

  1. https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC3268359/
  2. https://pubmed.ncbi.nlm.nih.gov/11783810/
  3. https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC6502880/

 

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