9 Delayed-Onset MVA Injuries (Pt. 2)

Editor’s Note: Part 1 of this web-exclusive article appeared in the January 2025 issue.

---

4. Traumatic Schmorl’s Nodes

Schmorl's nodes (SN) are generally considered a chronic finding of a past trauma as seen on plain film XR, MRI and CT.¹ The SN occurs when a central disc protrudes into the endplate and then moves into the adjacent vertebra marrow.^1-2 The SN heals with a visible thin rim of sclerosis eventually seen on imaging.²

Schmorl's node low back pain symptoms may be similar to other MVA related injury (e.g., strain, sprain) symptoms in the early stages of recovery.³

The discovery of a traumatic SN marks the onset of the original pathology. The condition may be visualized well into the future as SN patients suffer with chronic low back pain historically.¹ The traumatic SN results from sudden axial loading, frequently seen with motorcycle MVAs.⁴ Axial loading can also occur when vehicle height is suddenly changed when the colliding vehicle “submarines” or depresses the patient's vehicle at impact.^5-6

Patient Symptoms: Immediate and severe pain at the location of the traumatic SN is common with this injury.^1,7 Deep and intense pain that may be increasing.^1,8 The T10-L1 vertebral levels are most commonly injured.⁷ Radicular symptoms are absent unless there are additional traumatic intervertebral disc injuries with DRG adjacent to the traumatic SN.^1,7

Clinical Pearls: The patient's history provides insight into the details of the patient's accident details (e.g., motorcycle MVA) or a patient's account of the sensation of rise or fall at the time of impact that may produce axial loading of the spine.^1,5

Examination: Range-of-motion testing of flexion and extension may produce intense pain without radicular symptoms. The Flexion Distraction Test (FDT) will yield pain at the traumatic SN level as protective muscle spasms diminish in the 3-4 weeks of recovery.⁸

A plain-film examination of the region may detect an SN that has no rim of sclerosis suggestive of an acute traumatic SN.² Several weeks may pass before enough sclerosis forms to be visualized on plain-film XR.² Incorrect film exposure could cloud the diagnosis. MRI is the preferred imaging method to identify the traumatic SN.^1-2

References

1. Kyere KA, et al. Schmorl's nodes. Eur Spine J, 2012 Nov;21(11):2115-21.
2. Amini B, et al. Schmorl nodes. Reference article, Radiopaedia.org: https://doi.org/10.53347/rID-2026.
3. Evans R. Neurology and Trauma. Oxford University Press, Inc., 2006: pp.425-431.
4. Fahey V, et al. The pathogenesis of Schmorl's nodes in relation to acute trauma. An autopsy study. Spine, 1998 Nov 1;23(21):2272-5.
5. https://en.wikipedia.org/w/index.php?title=Bumper_(car)&oldid=1243297380
6. NHTSA Report Number DOT HS 807 702, An Evaluation of Bumper Standard-As Modified in 1982.Heist G et al. Last retrieved at [url=https://en.wikipedia.org/wiki/National_Highway_Traffic_Safety_Administration]https://en.wikipedia.org/wiki/National_Highway_Traffic_Safety_Administration[/url]
7. Hernandez A. “Schmorl's Nodes, What Is It. Symptoms, Management, and More.” https://www.osmosis.org/answers/schmorls-node
8. Freiheit T. “The Flexion-Distraction Test: A New Way to Discover Hidden Thoracic and Lumbar MVC Trauma.” Dynamic Chiropractic, March 2023. Read Here

5. Post-Concussion Syndrome

Post-concussion syndrome (PCS) is a neuropsychological condition resulting from a mTBI that may or may not have resulted in a loss of consciousness (LOC) at the time of the initial concussion.^1-2 Grading of an mTBI is mild, moderate and severe. The most mild of the TBI injuries may go unreported or even undiagnosed until much later in the progression of the injury.¹

The epidemiology of head trauma in the United States alone is staggering. Motor vehicle accidents (MVA) account for the largest proportion of mTBI injuries at 45% of the study group.¹ The in-office rate of objective evidence (e.g., MRI) of PCS has averaged 19% when utilizing the information below.

The neuropathology of PCS occurs when an acceleration/deceleration force at impact causes a shearing effect on the the axons at the gray and white matter interface that can result in intraparenchymal hemorrhages denoting diffuse axonal injury (DAI).^1-3 The psychological impact of PCS is based on the breadth of symptoms associated with the condition.

Patient Symptoms: Continued symptoms from a diagnosed or undiagnosed concussion may include lightheadedness, vertigo/dizziness, headache and drowsiness.

Additionally, neck pain, photophobia, phonophobia, tinnitus, impaired memory, diminished concentration, impaired comprehension, forgetfulness, impaired logical thought, difficulty with new or abstract concepts, insomnia, irritability, increased fatigability, apathy, anger outbursts, mood swings, depression, loss of libido, and personality changes are attributable to PCS.²

Clinical Pearls: A simple review of the symptoms above with the patient and any person who comes in contact with the individual is extremely beneficial. A patient may be reluctant to share some important details that a spouse or close relative or friend may advance.

MRI is the preferred imaging method to observe white matter hyperintensities (WMH) signifying DAI. Up to 20% of DAI lesions are not visible on initial CT evaluation following EMS transport to the ED. While not a criteria of PCS, a loss of consciousness (LOC) at the time of mTBI will present DAI findings.³ A good patient history is essential particularly if any patient/staff language barriers exist in the office.

References

1. Evans R. Neurology and Trauma. Oxford University Press, Inc., 2006: pp. 95-100.
2. Foreman S, Croft C. Whiplash Injuries: The Cervical Acceleration/Deceleration Syndrome, 3^rd Edition. Philadelphia: Lippincott Williams & Wilkins, 2002: pp. 371-376.
3. Dave S, et al. “Seven Potentially Devastating Traumatic Brain Injuries.” Medscape, Sept. 5, 2024: https://reference.medscape.com/slideshow/traumatic-brain-injuries.

6. Posttraummatic Syrinx

A posttraumatic syringomyelia (PTS) is a fluid-filled cavity that develops slowly following a spinal cord injury (SCI). However, the PTS can also develop without a spinal cord injury.¹ The exact pathophysiology of the injury is not completely agreed upon. The PTS is often a devastating injury that can develop following an MVA.^1-2

Long-term improvement occurs in less than 50% of patients diagnosed with the injury.³ Progressive neurological deficits occur as the cyst enlarges. The PTS generally develops symptoms as early as one month following the MVA, but can start years later.²

The contributing factors that lead to the initial cavity formation include dissolution of a spinal cord intraparenchymal hematoma, ischemia due to a tethering, arterial or venous obstruction or release of intracellular lysosomal enzymes and excitatory amino acids. Cord compression due to disc herniation or ligamentous injury resulting in vertebral slippage may also lead to the syrinx onset.² Blockage of normal spinal CSF flow dynamics is an important factor in the generation of the PTS.¹

Patient Symptoms: Patients generally present with whiplash symptoms following an MVC. Symptoms develop as the syrinx grows. The pain is neuropathic and can include aching, burning, and stabbing. A cough, sneeze or bowel strain may produce an electrical or shock-like sensation at the lesion site. Patients will note a loss of pain and temperature, but maintain touch and pressure. Tenderness that feels like a bruise over the area of injury without visualization of a bruise is common.^1-2

Patients may note weakness, numbness, hyperhidrosis, muscular spasticity and Horner syndrome.^1-2

Respiratory insufficiency may eventually develop and even be a cause of death if the PTS expands and destroys vital neural pathways in the brainstem respiratory centers.^1-2

Clinical Pearls: A cervical kyphosis noted on the lateral cervical neutral imaging, evidence of spinal instability noted on follow-up X-ray and/or disc herniation may precipitate a PTS. Spinal instability has been linked to PTS development.¹

New pain at a level that was otherwise improving, particularly in the cervical spine, upper thoracic spine and thoracolumbar area, should be evaluated to rule out PTS.¹

MRI is the preferred imaging modality. A PTS found on MRI should be re-imaged with gadolinium contrast to determine if the syrinx is expanding. The contrast medium will highlight a progressive PTS.⁴

The Flexion Distraction Test (FDT) will yield a positive pain response at the site of the PTS. MRI follow-up of any FDT positive finding is always recommended.⁵

Historically, I have identified nine syrinx patients involved in MVAs. Seven of the cases were male and had no evidence of progressive or expanding syrinx on contrast MRI retest. These cases were identified in the third week post-injury when MRIs were ordered after identifying one or more 2 mm vertebral anterolisthesis on follow-up X-ray.

Progressive PTS were found in the two remaining cases. Both were female patients, identified initially with a positive FDT test in the third week post-injury. MRI testing was performed due to the positive FDT and then retested with contrast demonstrating progressive PTS.^2,5

One patient, with PTS at L1, recovered with surgery. The second patient with the progressive PTS at T2 died due to respiratory failure four months following the injury. Medication and shunting failed to stop the progression

The discovery of a progressive PTS must be referred to emergency department personnel immediately. Expedited care by trained spine trauma physicians is essential for the progressive PTS patient to have the best possible outcome of this potentially devastating injury.

References

1. Goetz Ll, et al. Posttraumatic Syringomyelia. StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2024 Jan-.
2. Goetz LL, chief editor. Posttraumatic Syringomyelia. Medscape, May 16, 2024: https://emedicine.medscape.com/article/322348-overview.
3. Brodbelt AR, et al. Post-traumatic syringomyelia: a review. J Clin Neurosci, 2003;10(4):401-408.
4. Schwartz E, et al. Posttraumatic syringomyelia: pathogenesis, imaging and treatment. Am J Radiol, 1999 Aug;173.
5. Freiheit T. “The Flexion-Distraction Test: A New Way to Discover Hidden Thoracic and Lumbar MVC Trauma.” Dynamic Chiropractic, March 2023.
6. Freiheit T. “Diagnosing Acute Disc Herniation With the Follow-Up X-Ray (Pt.1).” Dynamic Chiropractic, May 2022. Read Here