Trigeminal Neuralgia – A Sign of DCM?

The RECODE-DCM initiative calls upon the global community of healthcare professionals working with DCM, and individuals living with DCM, to come together to solve the Top 10 Research Priorities — 10 critical questions that are relevant to the whole community.

In this blog focusing on Research Priority 2: Natural History, we will hear from Dr Robert Trager, a chiropractic physician and researcher at Connor Whole Health, University Hospitals, Cleveland.

We welcome comments from our community on our RECODE-DCM blog posts. Please share your perspectives by emailing recode@myelopathy.org — we’re listening!


Why Study This Topic?

I first became interested in degenerative cervical myelopathy (DCM), a progressive spinal cord injury caused by narrowing of the cervical spinal canal, when working as a chiropractor. As portal-of-entry clinicians in the United States, chiropractors should identify patients with DCM as early as possible to reduce delays to surgery when necessary for this condition [1]. Another reason is to maximize the safety of care, considering certain hands-on techniques should be avoided when neck pain among those with DCM [2]. However, DCM can be challenging to recognize because its symptoms vary [3]. 

Recently, research has highlighted the atypical cranial symptoms of DCM, such as facial pain and headache [3]. Particularly, several smaller studies have suggested DCM could be a trigger of trigeminal neuralgia (TN), a condition characterized by severe neuropathic facial pain [4–8]. Based on my own clinical experience and reading the literature, I was excited to look into the potential association between DCM and TN on a larger scale.

From an anatomical perspective, it’s reasonable to consider that disorders affecting the cervical spinal cord might play a role in TN. The trigeminal nerve, responsible for facial sensation, originates in the cervical spinal cord (Figure 1). Consequently, the pathway of the trigeminal nerve could be susceptible to damage due to degenerative changes of the cervical spine, similar to other nerve tracts. In addition, the cause of TN remains elusive, underscoring the importance of research aimed at identifying conditions that may contribute to this disorder [9].

close up MRI scan of a spine

Figure 1: Spinal trigeminal tract (green) and its relationship to cervical spine. The trigeminal nerve pathway begins in the spinal cord, as low as the fourth cervical vertebra [10,11]. Magnetic resonance image of a normal cervical spine adapted by Robert Trager to include the trigeminal tract, from Alghamdi et al [12], CC-BY-4.0 License.

What Was Our Study?

Our recent study examined medical records data from US adults using a national dataset [13]. We first excluded patients at high risk for developing TN such as those with multiple sclerosis and surgery on the mouth, jaw, or face. Next, we matched TN patients to control subjects without TN according to age, sex, and other comorbidities (i.e., we found similar pairs of patients). Ultimately, we compared 37,163 patients with TN to 37,163 patients without TN in a cross-sectional analysis.

What Did Our Study Find?

We found that patients with TN more often had a diagnosis of DCM compared to patients without TN (0.55% vs. 0.04%; Figure 2). This translated to an odds ratio of 12.94 – to put it simply – patients with TN had nearly 13 times the odds of having DCM compared to patients without TN [13]. This strong association implies that our findings are not easily explained by chance.

Figure 2: Prevalence of degenerative cervical myelopathy (DCM) per group after propensity matching. The trigeminal neuralgia (TN) group is shown in cyan, while the group without trigeminal neuralgia (No TN) group is pink. 95% confidence intervals are indicated by brackets. Image used from previous publication via CC BY 4.0 attribution license [13].

Why Is This Important?

Understanding the potential link between DCM and TN is crucial to improving early diagnosis and management of DCM. While our study hints that DCM is a significant risk factor for TN, being the first extensive investigation on this connection, we cannot conclude that DCM is definitively a cause of TN. We invite researchers to explore this finding further, as additional studies that reproduce our results would reinforce the association between DCM and TN.

In addition, our work draws attention to another area of investigation – could cervical spine surgery for DCM potentially alleviate TN? This notion, suggested by a small case series [5], warrants attention in larger studies. Our recent study not only shows a link between TN and DCM, potentially aiding clinicians in earlier DCM recognition, but also sheds light on the potential for DCM to trigger for TN, a disorder with poorly defined causes [9].

About The Author

Robert Trager, DC, is a chiropractic physician and researcher at Connor Whole Health, University Hospitals, of Cleveland, Ohio, in the United States. Working in an integrated setting, he primarily cares for patients with chronic pain. His research focuses on real-world outcomes related to chiropractic care and diagnosis and management of neurological and musculoskeletal disorders. He is an assistant professor at Case Western Reserve University School of Medicine in the Department of Family Medicine and Community Health, and a Master’s degree student in the Clinical Research Training Program at Duke University’s School of Medicine.

References

1. Trager RJ, Smith GA, Labak CM, Battaglia PJ, Dusek JA: Identification of Degenerative Cervical Myelopathy in the Chiropractic Office: Case Report and a Review of the Literature. Cureus. 2022, 14:. 10.7759/cureus.30508

2. Chu EC-P, Trager RJ, Lee LY-K, Niazi IK: A retrospective analysis of the incidence of severe adverse events among recipients of chiropractic spinal manipulative therapy. Sci Rep. 2023, 13:1254. 10.1038/s41598-023-28520-4

3. Munro CF, Yurac R, Moritz ZC, et al.: Targeting earlier diagnosis: What symptoms come first in Degenerative Cervical Myelopathy? PLOS ONE. 2023, 18:e0281856. 10.1371/journal.pone.0281856

4. Gotoh S, Iwasaki M, Kawabori M, Niiya Y, Mabuchi S: [A Case of Onion-Skin Hemifacial Dysesthesia Caused by Ossification of the Cervical Posterior Longitudinal Ligament]. No Shinkei Geka. 2018, 46:783–7. 10.11477/mf.1436203814

5. Francois EL, Clark NJ, Freedman BA: Facial Numbness and Paresthesias Resolved with Anterior Cervical Decompression and Fusion: A Report of 3 Cases. JBJS Case Connect. 2019, 9:e0294. 10.2106/JBJS.CC.18.00294

6. Kuraishi K, Mizuno M, Furukawa K, Suzuki H: Onion-skin Hemifacial Dysesthesia Successfully Treated with C2–4 Anterior Cervical Decompression and Fusion: A Case Report. NMC Case Rep J. 2016, 3:45–7. 10.2176/nmccrj.cr.2015-0175

7. Kawabori M, Hida K, Yano S, Iwasaki Y: [Cervicogenic headache caused by lower cervical spondylosis]. No Shinkei Geka. 2009, 37:491–5. 

8. Fredriksen TA, Salvesen R, Stolt-Nielsen A, Sjaastad O: Cervicogenic headache: long-term postoperative follow-up. Cephalalgia Int J Headache. 1999, 19:897–900. 10.1046/j.1468-2982.1999.1910897.x

9. Alper J, Shrivastava RK, Balchandani P: Is There a Magnetic Resonance Imaging-Discernible Cause for Trigeminal Neuralgia? A Structured Review. World Neurosurg. 2017, 98:89–97. 10.1016/j.wneu.2016.10.104

10. Gonella MC, Fischbein NJ, So YT: Disorders of the Trigeminal System. Semin Neurol. 2009, 29:36–44. 10.1055/s-0028-1124021

11. Vanderah T, Gould D: Cranial Nerves and Their Nuclei. In: Nolte’s The Human Brain: An Introduction to its Functional Anatomy. Elsevier: Philadelphia; 2020. 286–311.

12. Alghamdi A, Alqahtani A: Magnetic Resonance Imaging of the Cervical Spine: Frequency of Abnormal Findings with Relation to Age. Medicines. 2021, 8:77. 10.3390/medicines8120077

13. Trager RJ, Theodorou EC, Chu EC-P: Association between trigeminal neuralgia and degenerative cervical myelopathy: A cross-sectional study using US data. Neurol Clin Neurosci. 2023, n/a: 10.1111/ncn3.12787