Diagnosis of Trigeminal Neuralgia

Trigeminal neuralgia can be clinically diagnosed based on a complete medical history and neurosensory examination of the patient. The neurologic examination should demonstrate the classic reproducible symptoms of trigeminal neuralgia by eliciting pain within the distribution of V2 or V3 branch on the affected side of the face upon minimal cutaneous stimulation of the trigger zone (ie, a localized spot on the face that produces pain when contacted).7

To identify and diagnose trigeminal neuralgia, 2 criteria must be met based on patient presentation: (1) the pain is paroxysmal and (2) the pain only affects the trigeminal nerve distribution.8 No definitive laboratory analyses currently exist for the diagnosis of trigeminal neuralgia. Magnetic resonance imaging (MRI) is considered the gold standard for confirming the diagnosis of trigeminal neuralgia and can identify neurovascular compromise from vascular compression, which is considered the most common cause of the trigeminal neuralgia.8,9

Once a diagnosis of trigeminal neuralgia is suspected or confirmed, a well-rounded multidisciplinary team approach should be utilized to address barriers to successful management and treatment, such as depression, anxiety, and sleep disorders. Additionally, patients should be given appropriate education about trigeminal neuralgia to better understand the rationale for treatment.  


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Management of Trigeminal Neuralgia

Multiple pharmacologic and surgical therapies may be used to treat trigeminal neuralgia (Table).9-11 The anticonvulsants carbamazepine and oxcarbazepine are first-line treatments for trigeminal neuralgia.3,8,9,12 Both of these medications block voltage-sensitive sodium channels, resulting in decreased neuronal firing and activity.12 Carbamazepine is the only agent indicated for the treatment of trigeminal neuralgia.

Carbamazepine is 70% effective in reducing trigeminal neuralgia pain.3,13 However, patients may experience intolerable adverse side effects, such as taste change, headaches, and dizziness that require decreasing doses to subtherapeutic levels.3 Therefore, close monitoring and follow-up of the patient are essential to care. Patients should receive counseling and education about possible side effects of treatment and should be instructed to report any adverse events to their primary care clinician.

Second-line treatments include baclofen, botulinum toxin type A, gabapentin, lamotrigine, phenytoin, and pregabalin.9 These agents can be used as monotherapy or combined with first-line therapies (ie, carbamazepine or oxcarbazepine) if necessary.3,9

If medical therapy is no longer effective or tolerable or the pain is intractable, surgical options may be considered depending on the underlying etiology.10 Surgical approaches include microvascular decompression (MVD), gamma knife radiosurgery, and percutaneous rhizotomies.9,10 MVD is consistently considered the best surgical option throughout the literature.10,11 Clinicians should educate patients on the risks and benefits of surgery to aid in the shared-decision making process.

Currently, there are no definitive lifestyle modifications or preventative measures for trigeminal neuralgia. Primary care clinicians should continue to re-evaluate their patients’ pain control, physical health, and mental health to achieve optimal therapeutic outcomes. As the clinical course of trigeminal neuralgia can be taxing on patients’ morale, depression and anxiety can develop at any point. Therefore, it is of significant importance for clinicians to recognize and treat these comorbidities as soon as possible to decrease patients’ disease burden. Ultimately, the chosen therapeutic course should be patient specific and reassessment is critical to treatment outcome.


Table. Therapies for Trigeminal Neuralgia9-11

PharmacologicSurgical
BaclofenBalloon compression
Botulinum toxin type AGamma knife radiosurgery
Carbamazepine (first-line treatment)Microvascular decompression
GabapentinPercutaneous rhizotomy
LamotrigineRadiofrequency thermocoagulation
Oxcarbazepine (first-line treatment) 
Phenytoin 
Pregabalin 

Prognosis

The prognosis of trigeminal neuralgia is highly variable, with therapeutic outcomes relying primarily on the underlying etiology of the pain. Although patients may initially respond well to medical therapy, many eventually require surgical intervention for sustained pain relief. However, surgical intervention is not always curative. Thus, to achieve optimal pain control and enhance patients’ quality of life, clinicians must educate patients on realistic expectations of treatment efficacy and disease course.

Further research is ongoing to identify the best treatment course in the hopes of providing a cure and re-establishing quality of life for patients with trigeminal neuralgia.

Conclusion

Although the clinical presentation of trigeminal neuralgia can be similar to other head and facial pain disorders, the associated reproducible neuropathic pain and paroxysmal attacks characteristic of trigeminal neuralgia provide diagnostic value. While trigeminal neuralgia is a relatively rare condition, it should be considered in the differential diagnosis of patients presenting with head or facial pain.

As a primary care clinician, it is imperative to gather a complete medical history and perform a thorough neurosensory physical examination in the differential diagnosis of trigeminal neuralgia. Magnetic resonance imaging will confirm the diagnosis of trigeminal neuralgia and evaluate possible underlying causes, allowing healthcare providers to determine the optimal therapeutic approach.

The most challenging aspect of trigeminal neuralgia treatment is maintaining pain control to improve patients’ quality of life. Patients with intractable pain may require surgical referral. Clinicians should screen and treat patients for comorbid depression and anxiety, which may negatively affect treatment efficacy and outcomes in trigeminal neuralgia.

Amber Pratt, PA-S, is a student in the Physician Assistant Program at Augusta University. Lisa Daitch, MPAS, PA-C, is an associate professor in the Physician Assistant Department of Augusta University, in Augusta, Georgia.

References

1. Melek LN, Devine M, Renton T. The psychosocial impact of orofacial pain in trigeminal neuralgia patients: a systematic review. Int J Oral Maxillofac Surg. 2018;47(7):869-878. doi: doi.org/10.1016/j.ijom.2018.02.006

2. Jones MR, Urits I, Ehrhardt KP, et al. A comprehensive review of trigeminal neuralgia. Curr Pain Headache Rep. 2019;23(10):74. doi: 10.1007/s11916-019-0810-0

3. Gambeta E, Chichorro JG, Zamponi GW. Trigeminal neuralgia: an overview from pathophysiology to pharmacological treatments [published online January 26, 2020]. Mol Pain. doi: 10.1177/1744806920901890

4. Wu T-H, Hu L-Y, Lu T, et al. Risk of psychiatric disorders following trigeminal neuralgia: a nationwide population-based retrospective cohort study. J Headache Pain. 2015;16:64. doi: 10.1186/s10194-015-0548-y

5. Chang B, Zhu W, Li S. Effects of depression and anxiety on microvascular decompression outcome for trigeminal neuralgia patients. World Neurosurg. 2019;128:e556-e561. doi: 10.1016/j.wneu.2019.04.194

6. Pihut M, Szuta M, Ferendiuk E, Zeńczak-Więckiewicz D. Differential diagnostics of pain in the course of trigeminal neuralgia and temporomandibular joint dysfunction. Biomed Res Int. 2014;2014:563786. doi:10.1155/2014/563786

7. Joffroy A, Levivier M, Massager N. Trigeminal neuralgia. pathophysiology and treatment. Acta Neurol Belg. 2001;101(1):20-25.

8. Alshukry A, Salburgo F, Jaloux L, Lavieille JP, Montava M. Trigeminal neuralgia (TN): a descriptive literature analysis on the diagnosis and management modalities. J Stomatol Oral Maxillofac Surg. 2017;118(4):251-254. doi: 10.1016/j.jormas.2017.06.010

9. Bendtsen L, Zakrzewska JM, Abbott J, et al. European Academy of Neurology guideline on trigeminal neuralgia. Eur J Neurol. 2019;26(6):831-849. doi: 10.1111/ene.13950

10. Al-Quliti KW. Update on neuropathic pain treatment for trigeminal neuralgia. The pharmacological and surgical optionsNeurosciences (Riyadh). 2015;20(2):107-114. doi: 10.17712/nsj.2015.2.20140501

11. Xia L, Zhong J, Zhu J, et al. Effectiveness and safety of microvascular decompression surgery for treatment of trigeminal neuralgia: a systematic review. J Craniofac Surg. 2014;25(4):1413-1417. doi: 10.1097/SCS.0000000000000984

12. Cheshire WP. Trigeminal neuralgia: for one nerve a multitude of treatments. Expert Rev Neurother. 2007;7(11):1565-1579. doi: 10.1586/14737175.7.11.1565

13. Wiffen PJ, Derry S, Moore RA, McQuay HJ. Carbamazepine for acute and chronic pain in adults. Cochrane Database Syst Rev. 2011;(1):CD005451. doi: 10.1002/14651858.CD005451.pub2

This article originally appeared on Clinical Advisor