User Tools

Site Tools


trigeminal_neuralgia

Trigeminal neuralgia

Trigeminal neuralgia (TN), a neuropathic pain syndrome, is defined by the International Association for the Study of Pain as “a sudden and usually unilateral severe brief stabbing recurrent pain in the distribution of one or more branches of the trigeminal nerve 1).

Also known as prosopalgia, or Fothergill's disease.

The clinical association between TN and hemifacial spasm is the so-called tic douloureux.

It has been described as among the most painful conditions known to mankind.

Epidemiology

Trigeminal neuralgia is a relatively common neurosurgical pathology

The incidence of trigeminal neuralgia is 4.3 per 100,000 persons per year, with a slightly higher incidence for women (5.9 per 100,000) compared with men (3.4 per 100,000). 2)

In a majority of cases, TN symptoms begin appearing more frequently over the age of 50, although there have been cases with patients being as young as three years of age. It is more common in females than males.

One, two, or all three branches of the nerve may be affected.

10-12% of cases are bilateral (occurring on both the left and right sides of the face). Trigeminal neuralgia most commonly involves the middle branch (the maxillary nerve or V2) and lower branch (mandibular nerve or V3) of the trigeminal nerve, but the pain may be felt in the ear, eye, lips, nose, scalp, forehead, cheeks, teeth, or jaw and side of the face.

Types

Idiopathic trigeminal neuralgia.


Trigeminal neuralgia can be subdivided according to the Burchiel scheme into trigeminal neuralgia types 1, 2a, and 2b. Such classification is important because it is predictive of surgical success.

Patients with type 1 TN experience a memorable onset of symptoms often described as a “lightning-bolt of pain that came out of nowhere.” The pain, while severe, tends to last for only seconds at a time and may occur many times per day. Even though attacks become more frequent, the pain is always shock-like and never constant or dull. Although attacks often occur spontaneously, patients with type 1 TN usually report certain triggering factors such as cold wind, eating, drinking, or using a washcloth. Additionally, patients with type 1 TN tend to have spontaneous remissions of symptoms lasting days to weeks early in the course of the disease with these pain-free intervals becoming shorter and less frequent as time passes. Patients with type 1 TN have the most favorable outcomes following any treatment modality.

In contrast, patients with type 2b trigeminal neuralgia have a more insidious onset of pain. Rather than experiencing a “lightning bolt out of nowhere,” patients may initially believe that they have a tooth or sinus ache for many months before the pain is determined to be neurologic. The pain is often described as being dull, boring, constant, aching, or throbbing. Like type 1 trigeminal neuralgia, the symptoms are extremely disabling. The prognosis following surgical treatment of patients with type 2b trigeminal neuralgia is less favorable than in patients with type 1 trigeminal neuralgia. However, patients who respond favorably to anticonvulsant medication may still benefit from an operation.

Type 2a trigeminal neuralgia is the diagnosis applied to patients who have type 1 symptoms early in the disease course and transition, over time, to a more constant pain consistent with type 2b trigeminal neuralgia. The outcomes of these patients following a surgical treatment is thought to be more favorable than in patients with type 2b trigeminal neuralgia but less favorable than in patients with type 1 trigeminal neuralgia.

Pathogenesis

Clinical Features

The Visual Analog Scale (VAS) and the Barrow Neurological Institute Pain Scale (BNI-PS) are 2 of the most frequently employed patient-reported outcome (PRO) tools used by clinicians to rate pain for patients with trigeminal neuralgia (TN).

Diagnosis

Reinard et al., from the Department of Neurosurgery, Henry Ford Medical Group (HFMG), and the Wayne State University School of Medicine, Detroit, Michigan, identify racial and socioeconomic disparities in the diagnosis and treatment of trigeminal neuralgia (TN), this appeared to stem from outside HFMG from a difference in referral patterns to the neurologists and neurosurgeons 3).


Trigeminal Neuralgia can be a typical symptom in cerebellopontine angle tumours like epidermoid, especially in young patients, so all the patients with trigeminal neuralgia should be investigated for lesion in cerebellopontine region 4).

Magnetic resonance imaging (MRI) can be helpful in visualizing neurovascular conflict (NVC) of the trigeminal nerve, but the relationship between these two events is controversial.

Treatment

Recurrence

Trigeminal neuralgia (TN) recurring after surgery can be difficult to treat. Treatment algorithms have not been standardized or universally accepted.

The records of 22 patients (13 M and 9 F) suffering recurrent TN after one (2 gamma knife surgery, 5 percutaneous radiofrequency rhizotomy, 6 percutaneous retrogasserian glycerol rhizotomy, 3 microvascular decompression) or more (6 patients) procedures were reviewed. Seven patients had TN related to multiple sclerosis (MS). Mean follow-up was 51.81 ± 26.63 months. 81.81 % of patients reported an acute pain relief. No major complication was observed after PBC. Eight patients (36.36 %) experienced pain recurrence and underwent one (five patients) or more (three patients) PBC. At the last follow-up, we obtained an excellent outcome (BNI I-II) in 16 patients out of 22 (72.72 %) and a good outcome (BNI III) in the remaining six. No patients had an uncontrolled pain. The lack of history of MS (p = 0.0174), the pear-like shape of the balloon at the operation (p = 0.0234) and a compression time <5 min (p < 0.05) were associated to higher pain-free survival. Considering these results PBC could be considered a useful technique for patients whose pain recurs after other procedures 5).

Although no procedure is best for all patients, posterior fossa exploration PFE gives the operating surgeon the option of performing either a nondestructive (microvascular decompression) or destructive (partial sensory rhizotomy) procedure and is associated with better facial pain outcomes for this difficult patient group 6).

Complications

The study of Montano et al., shows no differences in the short term results among different procedures for TN in MS patients. Each technique demonstrate advantages and limits in terms of long term pain, recurrence rate and complication rate. Each patient should be accurately informed on pros and cons of each procedure in order to be involved in the most appropriate choice 7).

Mortality

Mortality rates for MVD (0.22%), rhizotomy (0.42%), and SRS (0.12%) were low 8).

Case series

2016

Forty-three patients with trigeminal neuralgia were recruited, and diffusion tensor imaging was performed before radiofrequency rhizotomy. By selecting the cisternal segment of the trigeminal nerve manually, they measured the volume of trigeminal nerve, fractional anisotropy, apparent diffusion coefficient, axial diffusivity, and radial diffusivity. The apparent diffusion coefficient and mean value of fractional anisotropy, axial diffusivity, and radial diffusivity were compared between the affected and normal side in the same patient, and were correlated with pre-rhizotomy and post-rhizotomy visual analogue scale pain scores. The results showed the affected side had significantly decreased fractional anisotropy, increased apparent diffusion coefficient and radial diffusivity, and no significant change of axial diffusivity. The volume of the trigeminal nerve on affected side was also significantly smaller. There was a trend of fractional anisotropy reduction and visual analogue scale pain score reduction (P = 0.072). The results suggest that demyelination without axonal injury, and decreased size of the trigeminal nerve, are the microstructural abnormalities of the trigeminal nerve in patients with trigeminal neuralgia caused by neurovascular compression. The application of diffusion tensor imaging in understanding the pathophysiology of trigeminal neuralgia, and predicting the treatment effect has potential and warrants further study 9).


Between January 2003 and December 2013, 360 patients with idiopathic TN and 39 patients with tumor-related TN who had undergone microsurgery were retrospectively studied. Kaplan-Meier survival curves were generated and compared by Log-rank test, and the possible prognostic factors were analyzed by the Cox proportional-hazards regression.

Patients with tumor-related TN exhibited a younger age of pain onset (46.28 ± 18.18y vs. 53.03 ± 11.90y, p = .006), a briefer symptom duration (3.20 ± 4.38y vs. 7.01 ± 6.04y, p = .000), and much more preoperative neuropathic deficits (61.54 vs. 24.17, p = .000), as compared with patients with idiopathic TN. Using Kaplan-Meier analysis, we found microsurgery was effective in 72.3% of patients with idiopathic TN, and in 86.4% of cases with tumor-related TN at six years follow-up postoperatively. Prognostic analysis suggested that a clear-cut neurovascular compression in patients with idiopathic TN (HR = 3.098, 95%CI: 1.800-5.311; p = .000) and total tumor removal in patients with tumor secondary TN (HR = 7.662, 95%CI: 0.098-36.574; p = .044) were positively correlated with excellent long-term outcomes.

The occurrences of TN at younger age, a shorter duration and preponderance of preclinical neuropathic symptoms are the characteristics of TN patients secondary to intracranial tumor, in contrast to patients with TN caused by a compressed vessel. Microsurgery is an effective and safe treatment modality for TN regardless of the disease etiology, the involvement of a clear-cut vascular offender and total tumor resection are the most important predictors of excellent outcome for microsurgery in idiopathic and tumor-related TN patients, respectively 10)

1)
Garg RK, Malhotra HS, Verma R. Trigeminal neuralgia. J Indian Med Assoc. 2011;109:631–636.
2)
Obermann M, Katsarava Z. Update on trigeminal neuralgia. Expert Rev Neurother. 2009 Mar;9(3):323-9. doi: 10.1586/14737175.9.3.323. Review. PubMed PMID: 19271941.
3)
Reinard K, Nerenz DR, Basheer A, Tahir R, Jelsema T, Schultz L, Malik G, Air EL, Schwalb JM. Racial disparities in the diagnosis and management of trigeminal neuralgia. J Neurosurg. 2017 Feb;126(2):368-374. doi: 10.3171/2015.11.JNS151177. PubMed PMID: 26967783.
4)
Khan Afridi EA, Khan SA, Qureshi WU, Bhatti SN, Muhammad G, Mahmood S, Rehman A. Frequency of cerebellopontine angle tumours in patients with trigeminal neuralgia. . J Ayub Med Coll Abbottabad. 2014 Jul-Sep;26(3):331-3. PubMed PMID: 25671940.
5)
Montano N, Papacci F, Cioni B, Di Bonaventura R, Meglio M. The role of percutaneous balloon compression in the treatment of trigeminal neuralgia recurring after other surgical procedures. Acta Neurol Belg. 2014 Mar;114(1):59-64. doi: 10.1007/s13760-013-0263-x. Epub 2013 Dec 12. PubMed PMID: 24338759.
6)
Pollock BE, Stein KJ. Surgical management of trigeminal neuralgia patients with recurrent or persistent pain despite three or more prior operations. World Neurosurg. 2010 May;73(5):523-8. doi: 10.1016/j.wneu.2010.01.027. PubMed PMID: 20920937.
7)
Montano N, Papacci F, Cioni B, Di Bonaventura R, Meglio M. What is the best treatment of drug-resistant trigeminal neuralgia in patients affected by multiple sclerosis? A literature analysis of surgical procedures. Clin Neurol Neurosurg. 2013 May;115(5):567-72. doi: 10.1016/j.clineuro.2012.07.011. Epub 2012 Jul 26. Review. PubMed PMID: 22840414.
8)
Wang DD, Ouyang D, Englot DJ, Rolston JD, Molinaro AM, Ward M, Chang EF. Trends in surgical treatment for trigeminal neuralgia in the United States of America from 1988 to 2008. J Clin Neurosci. 2013 Nov;20(11):1538-45. doi: 10.1016/j.jocn.2012.12.026. Epub 2013 Aug 7. PubMed PMID: 23932422.
9)
Chen ST, Yang JT, Yeh MY, Weng HH, Chen CF, Tsai YH. Using Diffusion Tensor Imaging to Evaluate Microstructural Changes and Outcomes after Radiofrequency Rhizotomy of Trigeminal Nerves in Patients with Trigeminal Neuralgia. PLoS One. 2016 Dec 20;11(12):e0167584. doi: 10.1371/journal.pone.0167584. PubMed PMID: 27997548.
10)
Wei Y, Zhao W, Pu C, Li N, Cai Y, Shang H, Yang W. Clinical features and long-term surgical outcomes in 39 patients withtumor-related trigeminal neuralgia compared with 360 patients with idiopathic trigeminal neuralgia. Br J Neurosurg. 2016 Sep 20:1-6. [Epub ahead of print] PubMed PMID: 27648861.
trigeminal_neuralgia.txt · Last modified: 2018/01/22 12:40 by administrador