9 Delayed-Onset MVA Injuries (Pt. 1)

These injuries share many common symptoms with those frequently found in motor-vehicle accidents. This article focuses on nine severe injuries that are generally not diagnosable until the third to fourth week following the date of injury, including how to diagnose these severe injuries. The discovery of any of these injuries early can make a significant difference in the case outcome. (Note: This is not an all-inclusive list of delayed MVA injuries.)

1. Traumatic Subdural Hematoma

Traumatic subdural hematomas (tSDH) can occur in MVAs due to the effects of rapid acceleration and deceleration on the head, resulting in this severe traumatic brain injury (TBI). The injury occurs when collision forces cause a shearing injury to the brain's bridging veins. Bleeding occurs and collects between the dura and arachnoid matter. The bridging veins are under relatively low pressure, allowing blood to accumulate slowly sometimes over several weeks.

Symptoms are often also delayed and may mimic a cervicogenic headache or headache associated with concussion initially. The tSDH represents a severe closed-head injury that may develop even without direct head contact.^1-3

Patient Symptoms: The initial symptoms associated with a tSDH often include a loss of consciousness (LOC) history, headache, vomiting, drowsiness, mild to moderate ataxia, confusion and cognitive dysfunction consistent with a  mTBI case in the early stages of recovery.^2-4

Clinical Pearls: A detailed patient history noting a LOC that has occurred as a result of the MVA is important. Observing the patient's gait for ataxia each time they present to the office as they walk to the exam room can provide useful information. Advising at-home family/ friends to be aware of gait abnormalities can benefit the clinicians clinical decision-making.

The initial physical examination including neurological testing can provide clues. Questions should include elements that detail cognitive ability.

Fixed and dilated pupils are indicative of closed head injuries. Worsening headache, ataxia, declining level of consciousness and cognitive impairment would indicate MRI evaluation to rule in/out tSDH and other closed head injuries.

A Glasgow Coma Scale (GCS) taken initially that decreases by two points on weekly testing suggests ED referral.^1-3

References

• Foreman S, Croft C. Whiplash Injuries: The Cervical Acceleration/Deceleration Syndrome, 3^rd Edition. Philadelphia: Lippincott Williams & Wilkins, 2002: pp. 429-431.

1. Evans R. Neurology and Trauma. Oxford University Press, Inc., 2006: pp. 34-36.
2. Dave S, Tichauer M. “Seven Potentially Devastating Traumatic Brain Injuries.” Medscape, Sept. 5, 2024. Last reviewed at http://reference.medscape.com/slideshow/traumatic-brain-injuries.
3. Rumbolt Z. Clinical Imaging of Spinal Trauma. Cambridge, UK: Cambridge University Press, 2018: p. 79.

2. Stroke Due to MVA

Stroke following a MVA is a severe, but rare outcome of the injury. Hyperextension with rotation or blunt-force trauma to the cervical spine at impact can cause traction on the fixed vertebral artery at C1-2 and at C6, causing vertebral artery injury (VAI).¹ The VAI may initially remain asymptomatic due to the collateral vertebral artery circulation according to Evans.² A VAI is severe and has a stroke rate of 24% and mortality of 8%.³

Patient Symptoms: The first 24 hours post-injury are the most cautionary. The symptoms may mimic typical whiplash injuries.¹

Typical signs and symptoms are similar for patients experiencing a VAI and those with CAD/ whiplash injuries. These symptoms include, but are not limited to the following: headache, neck pain, dizziness, diplopia, dysarthria, diminished pupillary light reflex, nystagmus, blurred vision, epistaxis, nausea and impaired sensation to the face. However, the VAI patient and MVA patient do not have to have all of the above symptoms to meet the diagnosis criteria. The VAI patient may have no other symptoms than neck pain.^1-3

Clinical Pearls: If you see MVA patients on the day of an accident, know that the first day is the primary day for the patient to have a stroke. A patient history outlining body position(s) at impact can be predictive of a possible VAI injury.

I know of two cases that occurred in our clinic group over 11 months. In my case, the patient succumbed to his injuries on his initial visit on the day of the accident. He had a drop attack  after just entering the examination room. He died while being transported by EMS to the ER.

The most important clinical advice is to simply be aware of the symptoms and the potential for VAI injuries, which may take days to weeks to develop before resulting in the stroke injury.

Referral and transportation to the emergency department of your local hospital are prudent steps when your clinical suspicions suggest you have a potential VAI injury in the office.

References

1. Freiheit T. “Stroke and the Motor-Vehicle Accident: Clinical Safeguards.” Dynamic Chiropractic, April 2024. Read Here
2. Evans R. Neurology and Trauma. Oxford University Press, Inc., 2006: pp. 167-176.
3. deSousa, R. Crocker, M, et al. Blunt traumatic vertebral artery injury: a clinical review. Euro Spine J, September 2011;20(9):1405-1416.

3. Traumatic Central Disc Herniation

Acute traumatic central disc herniations (DH) are not uncommon. A central disc herniation (CDH) involves tissue damage to the center of the posterior annulus and creates a sprain injury (sub failure) of the posterior longitudinal ligament (PLL), allowing the central disc to herniate as a result of the effects of acceleration, deceleration and shear.^1-3

Protective muscle spasm around  the CDH can be difficult to differentiate from healing strain at an early stage of healing. A CDH may produce little or no persisting radicular symptoms due to the absence of direct physical compression of the dorsal root ganglion (DRG).^4-5 The CDH is primarily a protrusion-type herniation.

Spinal cord injury (SCI) can occur from a large central disc herniation resulting in paresis, pain and temperature loss.^6-10

Patient Symptoms: Neck and back pain, headache, and paresthesias are common CDH symptoms that are also frequently experienced by patients suffering from  strain/sprain injuries following a whiplash injury.^11-13

Clinical Pearls: Neck pain and headache may begin to manifest or even increase in the third week of recovery with a CDH.⁶

Hyperesthesia may be noted with the  pinwheel examination at a 3-4-week follow-up progress examination without patient identification of a paresthesia sensation. Continuing pinwheel examinations into the eighth week of recovery can be helpful in uncovering the CDH.^14-15

The  CDH herniates posteriorly and may cause  limited cervical or lumbar extension due to antalgia.¹⁶

A follow-up/ dynamic X-ray (XR) evaluation finding a 2 mm or greater anterior translation of any cervical segment on the lateral cervical neutral (LCN) or flexion projection indicates a CDH.^17-18

In the lumbar spine, the flexion-distraction test (FDT) may now be positive and elicit pain at the location of a CDH 3-4-weeks post-accident.¹⁹

The heel drop test and other orthopedic tests may, while not technically positive, elicit pain in the thoracic or lumbar spine after muscle guarding is diminished in the 3-4 week range, suggesting a CDH.²⁰

Historically, 88% of herniated discs have been traumatic central disc herniations in our practice. Only 12% have persistent extremity paresthesias that are more common with extruded or sequestere  disc herniations due to DRG compression confirmed on MRI.

Author's Note: Because of the possibility of delayed injuries, any person involved in a motor-vehicle accident should have at least an initial post-accident examination, and follow-up examinations at two and four weeks to clear the spine of injury.

References

1. Guiliano V, et al. The use of flexion and extension MR in the evaluation of cervical spine trauma: initial experience in 100 trauma patients compared with 100 normal subjects. Emerg Radiol, 2002 Nov;9(5):249-53.
2. White A, Punjabi M. Clinical Biomechanics of the Spine. Philadelphia: J. B. Lippincott Company, 1978: p. 214.
3. Evans R. Neurology and Trauma. Oxford University Press, Inc., 2006: p. 85.
4. Croft A. “Revisiting the Neurological Examination.” Dynamic Chiropractic, May 1, 2014.
5. Amaya F, et al. Periganglionic inflammation elicits a distally radiating pain hypersensitivity by promoting Cox-2 induction in the dorsal root ganglia. Pain, 2009 Mar;142(1-2):59-67.
6. Foreman S, Croft C. Whiplash Injuries: The Cervical Acceleration/Deceleration Syndrome, 2^nd Edition. Philadelphia: Lippincott Williams & Wilkins, 2002: pp. 53-54.
7. Pearl N, Dubensky L. Anterior Cord Syndrome. Treasure Island, FL: StatPearls, 2023.
8. D'Souza R. Anterior Cord Syndrome. Physiopedia.com.
9. Dai L, et al. Central cord injury complicating acute cervical disc herniation in trauma. Spine, 2000 Feb 1;25(3):331-5.
10. Pogio J. Neurogenic Bowel Dysfunction. Medscape.com, Feb. 10, 2023.
11. Foreman S, Croft C. Whiplash Injuries: The Cervical Acceleration/Deceleration Syndrome, 3^rd Edition. Philadelphia: Lippincott Williams & Wilkins, 2002: p 61.
12. Evans R. Neurology and Trauma. Oxford University Press, Inc., 2006: pp. 426-434.
13. Foreman S, Croft C. Whiplash Injuries: The Cervical Acceleration/Deceleration Syndrome, 3rd Edition. Philadelphia: Lippincott Williams & Wilkins, 2002: pp.131-132.
14. Schlauderaff A, Cockroft KM. Central Cord Syndrome. American Association of Neurological Surgeons. Read Here
15. Amaya F, et al. Periganglionic inflammation elicits a distally radiating pain hypersensitivity by promoting Cox-2 induction in the dorsal root ganglia. Pain, 2009 Mar;142(1-2):59-67.
16. “Herniated Disc: The Difference Between Bulging and Herniated Disc.” Miami Neuroscience Center. Read Here
17. Tominaga Y, et al. Neck ligament strength is decreased following whiplash trauma. BMC Musculoskel Disord, 2006;7(103):8.
18. Freiheit T. “Diagnosing Acute Disc Herniation With the Follow-Up X-Ray (Pt.1).” Dynamic Chiropractic, May 2022. Read Here
19. Freiheit T. “The Flexion-Distraction Test: A New Way to Discover Hidden Thoracic and Lumbar MVC Trauma.” Dynamic Chiropractic, March 2023. Read Here
20. Advanced Physical Therapy Education Institute. www.aptei.ca/library-article/the-heel-drop-test/