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THE EDITORIAL DEBATE
Year : 2015  |  Volume : 63  |  Issue : 6  |  Page : 837-840

Trigeminal neuralgia: Therapeutic options


Institute of Neurosciences Medanta - The Medicity, Gurgaon, Haryana, India

Date of Web Publication20-Nov-2015

Correspondence Address:
Ajaya Nand Jha
Institute of Neurosciences Medanta - The Medicity, Gurgaon, Haryana
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0028-3886.170066

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How to cite this article:
Jha AN. Trigeminal neuralgia: Therapeutic options. Neurol India 2015;63:837-40

How to cite this URL:
Jha AN. Trigeminal neuralgia: Therapeutic options. Neurol India [serial online] 2015 [cited 2019 Aug 21];63:837-40. Available from: http://www.neurologyindia.com/text.asp?2015/63/6/837/170066


Trigeminal neuralgia is a condition that produces one of the most severe kinds of pain known to mankind. The discomfort of these patients is further compounded by the array of treatments available, with broadly similar efficacy and recurrence rates. It, therefore, merits a detailed look and evaluation.

Historically, trigeminal neuralgia is an ancient disease, with the first reference coming from the Greek physician, Aretaeus of Cappodocia (circa 150 AD book 1), who wrote,[1] "Where the pain does not pass this limit, but remains in half of the head. This is called Heterocrania, an illness by no means mild, even though it intermits and although it appears to be slight. For, if at any time it sets in acutely, it occasions unseemly and dreadful symptoms; spasm." Many further descriptions include those of Ibn Sina (980–1037),[2] also called by the Latin name "Avicenna," and Dr. Johannes Bausch (1605–1665),[3],[4] who was the first President and Founding Member of the German Academy of Sciences, Leopoldina (the oldest existing learned society). Unfortunately, Dr. Bausch died as a consequence of trigeminal neuralgia! He described his own symptoms that included a sharp, shooting pain in his right maxilla that came on suddenly like a bolt of lightning, varying in intensity, leaving him unable to speak or eat solid food.[5] In the fall of 1665, the pain disappeared, only to return early that same winter. The pain was so intense that it forced him to remain bedridden. He eventually died of malnutrition because his dietary intake was limited by the excruciating pain.

The credit for what is often thought of as one of the best descriptions of this disease must be given to John Fothergill,[6] who, in 1773, described it as "a painful affliction of the face" and that "the pain comes suddenly and is excruciating; it lasts but a short time…. Eating, talking or the gentlest touch of a handkerchief will sometimes bring on the pain." His description of 14 patients suffering from trigeminal neuralgia is still considered to be a classic treatise.

Trigeminal neuralgia is a common condition, with an incidence of 5.7 per 100,000 women and 2.5 per 100,000 men. The most commonly affected subjects are in the 50- to 70-year age-group.[7]

It should be emphasized that the most important part of the diagnosis is the clinical examination, which will determine whether this is trigeminal neuralgia type I or II, or other forms of atypical facial pain. Furthermore, apart from a careful elicitation of the history, there are no known laboratory or any other kind of investigations that can establish the diagnosis.

Lesions in the cerebellopontine angle such as epidermoids, or intrinsic lesions such as multiple sclerosis, can mimic this disease, in which case, the condition is categorized as secondary trigeminal neuralgia.

Classic trigeminal neuralgia responds to treatment better than the atypical varieties. The easiest way to differentiate between the classic and the atypical varieties is to distinguish between the nociceptive pain caused by local tissue injury or by any other pathology in the former, and the neuropathic pain occurring from inappropriate neural activity in the latter. The classic trigeminal neuralgia is the one that will be discussed. It is usually a sudden, stabbing, or recurrent pain in one of the branches of the fifth nerve. The pain can be excruciating and is often triggered by activities such as exposure to cold, washing, or eating. It has long been thought that local pressure at the root entry zone of the fifth nerve may in some ways be responsible for this pain. As early as in 1941, Olivecrona understood and described that "mechanical pressure along the root or at the level of the  Gasserian ganglion More Details could be the cause of trigeminal neuralgia."[8] The pioneering work of Granit, Leksell, and Skoglund demonstrated that local pressure on the nerve fibers could result in painful afferent discharges from the injured neural segment.

Walter Dandy also described this as one of the findings while performing rhizotomy for trigeminal neuralgia, but he did not expand his work in this arena to also focus on the decompression of the fifth cranial nerve. Although others have also discussed this procedure, the actual credit for popularizing microvascular decompression (MVD) goes to Peter Jannetta,[9] who, with the aid of an operating microscope, performed thousands of MVD operations, thereby making this a widely accepted surgical procedure. It should be noted that the classic form of trigeminal neuralgia, even if it responds well to medical treatment initially, usually has a progressive course after 8–10 years. The most widely accepted theory is that the site of origin of the pain lies in the transitional zone between the central myelin that is produced by oligodendrocytes and the peripheral myelin that is produced by Schwann cells. These few millimeters of the transitional point on the fifth nerve is called the "Obersteiner-Redlich zone."[10] It is thought that this zone is most prone to injuries leading to an ephaptic transmission, which causes cross-excitation and a paroxysmal facial pain. However, the matter is not that simple and straightforward, as several factors that influence the pain cannot be explained by this hypothesis. To quote an example, the effectiveness of various drugs in the remission of trigeminal neuralgia does not actually have any effect in producing vascular decompression of the V th nerve. This fact points toward the simultaneous activation of central mechanisms that may be responsible for the origin of a classic trigeminal neuralgia. In addition, anatomical studies have shown that in up to approximately 70% of cases, vascular compression has been seen in postmortem studies without the patient having any pain. Furthermore, magnetic resonance imaging (MRI) studies have shown that in 8% of cases, there is evidence of vascular impingement of the trigeminal, facial, and vestibulocochlear nerves in healthy volunteers.[11] Sunderland's study on cadavers has shown that blood vessels were present in close contact with the cranial nerves at the cerebellopontine angle, that is, at the entry/exit zone of the trigeminal and facial nerves, in varying numbers of asymptomatic individuals (approximately 70%). However, Jannetta claimed that his earlier-published studies showed no evidence of vascular compression at the root entry zone of the fifth cranial nerve in asymptomatic individuals.[9] Adams has mentioned that vascular compression of cranial nerves is so common in asymptomatic individuals that it is certainly not the cause of this disease. He claimed that MVD is effective, as it causes a slight injury to the fifth nerve.[12] There have been suggestions that vascular compression is simply one of the several factors that may be contributing to the origin of trigeminal neuralgia, owing to its presence in asymptomatic patients as well as its absence in some patients suffering from trigeminal neuralgia.

In the treatment of this dreadful disease, the first method of treatment is usually medical. The effectiveness of medical treatment was discovered accidentally while using phenytoin in 1942. While many anticonvulsants have a significant effect on this condition, their long-term usage is associated with side effects. Carbamazepine and oxcarbamazepine are usually prescribed initially as the preferredfirst choice of medications. However, owing to lack of awareness, they are often inappropriately started as well as stopped. These medicines are not to be used as painkillers but should slowly be escalated to a level where they stop the ephaptic transmission of the neuralgic pain. They should then be continued at a maintenance level for at least 6 months, and then the drug should be slowly de-escalated. The drug should not be started at a very high dose, as the patient will start having side effects. Considering the variety of surgical options available for this condition, it is obvious that none of the methods are perfect. Therefore, every attempt should be made to treat these patients with medical management before considering surgery. However, there are many patients who do not respond to medical therapy, and therefore, require alternative modes of management.

Surgical therapy can be divided into the ablative or decompressive procedures. Many factors help in determining the selection of patients into either of these groups. These include the patient's age, the comorbid factors, and the patient's own choice. The first ablative procedure was carried out in 1853 by Patruban, who divided the maxillary nerve behind the orbit by passing a tenotome along the floor of the orbit and cutting the nerve as far back as possible.[13] Also in 1983, Mullan and Lichtor introduced the technique of percutaneous balloon compression of the Gasserian ganglion. These techniques were further modified by using alcohol or glycerol, and subsequently, radiofrequency (RF) ablation was introduced by Sweet and utilized as an alternative minimally invasive treatment for trigeminal neuralgia in 1974.[14]

All these procedures have a specific advantage that they are less invasive compared with MVD. The RF ablation offers long-term pain relief (average, 6 years; range, 1–9 years), reported in 75% of patients (range, 63%–89%) after RF rhizotomy. Pain relief after glycerol rhizotomy (average, 3 years; range 0.5–5.5 years) was reported in 55% of patients (range, 22%–70%). In the case of balloon compression, pain relief was reported in 73% of patients (range, 62%–83%) at a 4-year follow-up (range, 0.5–10.7 years). The major disadvantages of RF rhizotomy include severe dysesthesia in 6%–9% of patients, corneal hypoesthesia in 1%–17% (mean, 6%), and transient motor weakness in approximately 19%.[15] After the glycerol rhizotomy, the most common complications are corneal hypoesthesia in approximately 5% (range, 0%–10%) of cases and significant dysesthesia in approximately 5% (range, 0%–13%) of patients. Although permanent motor root weakness is a major complication of balloon rhizotomy, occurring in 3% of cases (range, 0%–12%), significant dysesthesia is also common, occurring in approximately 5% (range, 0%–10.6%) of them. The most significant complication of stereotactic radiosurgery is numbness, which has been reported to occur in up to 21% of cases and is considered as bothersome or painful in 5%–10% of them. Significant dysesthesia has been reported in approximately 3.2% of patients after radiosurgery for trigeminal neuralgia. Anesthesia dolorosa, if it develops, is uncontrollable, and is often described as being a worse manifestation than the original disease.[16]

Radiosurgery has also been increasingly used for the treatment of this condition. It was initially started in patients with recurrent trigeminal neuralgia but has now also been used for those who voluntarily opt for it as the initial treatment. A better delineation of the fifth nerve using newer MRI techniques such as balanced fast-field echo (BFFE) images fused with three-dimensional time-of-flight (TOF) MR angiography and a simultaneous better visualization of the facial nerve by gadolinium-enhanced three-dimensional spoiled gradient recalled sequence are very effective for the preoperative planning. The localization of the 4-mm target is either at the root entry zone or a few millimeters proximal to the brain stem.[17] The closer the target is to the brain stem, the higher the chances of pain relief, but so are the chances of occurence of complications. This procedure has a latency period prior to achieving pain relief, which may vary from a few weeks to a few months, typically averaging approximately 2 months. It has also been seen that 5%–10% of patients may perceive an immediate relief in pain at the time of finishing treatment.

The University of Pittsburgh group have reported complete pain relief in approximately half of their cases, with approximately 82% of patients achieving some pain relief within 6–33 months after radiosurgery.[18] The reported recurrence rates vary from 5%–42%.[19] Recurrence is likely related to the incomplete effects of radiation on the targeted tissues. Maesawa et al., demonstrated that 71% of patients achieved or maintained complete or greater than 50% relief at 2 years, whereas 56% maintained the relief at 5 years. Radiosurgery has a relatively low rate (approximately 10%) of causing a sensory decline in the nerve treated.

The most commonly accepted method of surgical treatment of trigeminal neuralgia is MVD as described by Jannetta. A recent review on the results of all reports from January 2000 to June 2013 were studied, and the success rate was determined to be approximately 83.5%, with complications occurring in 1.3% of patients, facial palsy in 0.5%–2.9%, facial numbness in 9.1%, cerebrospinal fluid leak in 1.6%, and hearing deficit in 1.9%. The overall mortality rate was 0.1%.[20] MVD has, therefore, proven to be a safe and effective procedure particularly in young patients, in whom long-term facial numbness can be a problem. The incidence of recurrence should be explained to the patients and be accepted and well understood by them. The exact mechanism by which MVD is effective in bringing about relief from trigeminal neuralgia is not known, and it is assumed that removal of pressure from the vascular compression on the fifth nerve permits remyelination to occur. It has always been thought that there are no sensory changes following an MVD procedure for trigeminal neuralgia; however, electrophysiological monitoring has revealed that there are well-documented changes in sensory conduction as well.

An interesting report from Sindou has questioned the use of implants and showed that the results of MVD for trigeminal neuralgia were slightly better in a group of 60 patients in whom no implant was used and only a fifth nerve MVD had been performed. The recurrence rate in these circumstances was 4.7% compared with 10% when Teflon had been used. They, therefore, stated that Teflon offered no additional benefit.[21]

In summation, several good options exist for a medically refractory patient with trigeminal neuralgia. For a young patient, MVD is the procedure with the longest lasting and durable relief, whereas for an elderly or medically infirm patient, several ablative options or radiosurgery may be used. Additionally, ablative procedures are of value in patients with acute and extremely severe pain, as they can provide immediate relief in an outpatient setting.

Further research in this field, led by surgeons from Israel and the United States, is being conducted to unravel the DNA abnormalities linked to this dreaded disease so that the genetic basis for trigeminal neuralgia may be determined.[22]

Careful evaluation not only of the patient but also of the available options and the choice of treatment is the need of the hour. This clearly demonstrates the primacy of good clinical evaluation in decision making in clinical practice. The last words have not been written on this disease.

 
  References Top

1.
HTTP://www.drhoney.org/tn/. [Last accessed on 2015 Oct 17].  Back to cited text no. 1
    
2.
HTTP://www.drhoney.org/tn/. [Last accessed on 2015 Oct 17].  Back to cited text no. 2
    
3.
HTTP://www.drhoney.org/tn/. [Last accessed on 2015 Oct 17].  Back to cited text no. 3
    
4.
HTTP://www.drhoney.org/tn/. [Last accessed on 2015 Oct 17].  Back to cited text no. 4
    
5.
HTTP://www.drhoney.org/tn/. [Last accessed on 2015 Oct 17].  Back to cited text no. 5
    
6.
HTTP://www.drhoney.org/tn/. [Last accessed on 2015 Oct 17].  Back to cited text no. 6
    
7.
Hall GC, Carroll D, Parry D, McQuay HJ. Epidemiology and treatment of neuropathic pain: The UK primary care perspective. Pain 2006;122:156-62.  Back to cited text no. 7
    
8.
Olivecrona H. Die Trigeminusneuralgie und ihre Behandlung. Nervenarzt 1941;14:49-57.  Back to cited text no. 8
    
9.
Jannetta PJ. Arterial compression of the trigeminal nerve at the pons in patients with trigeminal neuralgia. J Neurosurg 1967;26(Suppl):159-62.  Back to cited text no. 9
    
10.
Devor M, Govrin-Lippmann R, Rappaport ZH. Mechanism of trigeminal neuralgia: An ultrastructural analysis of trigeminal root specimens obtained during microvascular decompression surgery. J Neurosurg 2002;96:532-43.  Back to cited text no. 10
    
11.
Lingawi SS. The prevalence of vascular impingement of the trigeminal, facial, and vestibulocochlear nerves in healthy volunteers. J HK Coll Radiol 2003;6:20-4.  Back to cited text no. 11
    
12.
Adams CB. Microvascular compression: An alternative view and hypothesis. J Neurosurg 1989;70:1-12.  Back to cited text no. 12
    
13.
Harris W. An analysis of 1,433 cases of paroxysmal trigeminal neuralgia (trigeminal tic) and the end results of Gasserian alcohol injection. Brain 1940;63:209-24.  Back to cited text no. 13
    
14.
Sweet WH, Wepsic JG. Controlled thermocoagulation of trigeminal ganglion and rootlets for differential destruction of pain fibres. 1. Trigeminal neuralgia. J Neurosurg 1974;40:143-56.  Back to cited text no. 14
    
15.
Taha J. Trigeminal neuralgia: Percutaneous procedures. Semin Neurosurg 2004;15:115-34.  Back to cited text no. 15
    
16.
Dellaretti M, Reyns N, Touzet G, Sarrazin T, Dubois F, Lartigau E, et al. Clinical outcomes after Gamma Knife surgery for idiopathic trigeminal neuralgia: Review of 76 consecutive cases. J Neurosurg 2008;109(Suppl):173-8.  Back to cited text no. 16
    
17.
Miller J, Acar F, Hamilton B, Burchiel K. Preoperative visualization of neurovascular anatomy in trigeminal neuralgia. J Neurosurg 2008;108:477-82.  Back to cited text no. 17
    
18.
Maesawa S, Salame C, Flickinger JC, Pirris S, Kondziolka D, Lunsford LD. Clinical outcomes after stereotactic radiosurgery for idiopathic trigeminal neuralgia. J Neurosurg 2001;94:14-20.  Back to cited text no. 18
    
19.
Eller JL, Raslan AM, Burchiel KJ. Trigeminal neuralgia: Definition and classification. Neurosurg Focus 2005;18:E3.  Back to cited text no. 19
    
20.
Xia L, Zhong J, Zhu J, Wang YN, Dou NN, Liu MX, et al. Effectiveness and safety of microvascular decompression surgery for treatment of trigeminal neuralgia: A systematic review. J Craniofac Surg 2014;25:1413-7.  Back to cited text no. 20
    
21.
Sindou M, Amrani F, Mertens P. Does microsurgical vascular decompression for trigeminal neuralgia work through a neo-compressive mechanism? Anatomical-surgical evidence for a decompressive effect. Acta Neurochir Suppl (Wien) 1991;52:127-9.  Back to cited text no. 21
    
22.
Devor M, Burchiel K, Seltzer Z. Unlocking DNA to find a cure for trigeminal neuralgia. The March 2015 Naples Science Meeting.  Back to cited text no. 22
    




 

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