Peripheral streptomycin/lidocaine injections versus lidocaine alone in the treatment of idiopathic trigeminal neuralgia. A double blind controlled trial

Local Ulceration following Peripheral Neurolysis with Absolute Alcohol in Patients with Drug-Refractory Trigeminal Neuralgia: A Series of Four Cases

A significant number of patients with trigeminal neuralgia (TGN) are refractory to first-line drugs and require interruption of the pain pathway by various percutaneous procedures. One such percutaneous technique involves an injection of absolute alcohol (AA) into the peripheral branches of the trigeminal nerve. This procedure is useful in elderly and medically compromised drug-refractory cases of TGN who are not interested in undergoing open neurosurgery. Peripheral neurolysis with AA is easy, quick, and safe. It may be carried out in the outpatient department; however, its use is not free from complications. Here, we report four such patients who were complicated with local necrosis and ulceration following administration of AA. The most probable attributable etiologies are sympathetic nerve involvement, intravascular injection of alcohol, vascular spasm of the terminal arteries, distal micro-emboli effect, and faulty technique, including repeated injections.

Pharmacologic Management of Neuropathic Pain

This article aims to provide the practitioner with therapeutic options to treat a broad spectrum of acute and chronic orofacial pain syndromes. The focus will be nonsurgical that the oral health care physician can implement to treat this population of patients. The World Health Organization estimated that more than 1 in every 3 people suffers from acute or chronic pain. This article is primarily devoted to medication management once the diagnosis of neuropathic pain, a true trigeminal neuralgia, or a variant of trigeminal neuralgia often referred to as traumatic neuropathic pain or traumatic trigeminal neuralgia.

Treatment Outcomes in Trigeminal Neuralgia-A Systematic Review of Domains, Dimensions and Measures

BACKGROUND

Trigeminal neuralgia (TN) is a painful disorder characterized by sudden electric shock-like pain. It is a rare condition for which multiple treatments are available, including medical and surgical. The best treatment option is yet to be defined, and this is related to the lack of definition in the treatment outcomes and outcome measures. The aim of this systematic review was to summarize all the outcomes and outcomes measures that have been published to date and highlight variability in their use.

METHODS

We have conducted a literature search using a wide range of databases (1946-2019 for medical and 2008-2019 for surgical treatment), for all intervention studies in TN. Four hundred and sixty-seven studies were selected for data extraction on TN classification, data collection method, intervention, and treatment outcomes mapped to the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT guidelines).

RESULTS

Most studies collected data on pain (n = 459) and side effects (n = 386) domains; however, very few collected data on the impact of treatment on physical (n = 46) and emotional functioning (n = 17) and on patient satisfaction (n = 35). There was high variability on outcome measures used for pain relief (n = 10), pain intensity (n = 9), and frequency of pain episodes (n = 3).

CONCLUSIONS

A clear definition of what are the important outcomes for patients with TN is essential. The choice of standardized outcome measures allowing for consistent reporting in TN treatment will allow for comparison of studies and facilitate treatment choice for patients and clinicians thus, improving health outcomes and reducing health care cost.

A systematic review of rescue analgesic strategies in acute exacerbations of primary trigeminal neuralgia

BACKGROUND

Trigeminal neuralgia (TN) can have a significant impact on wellbeing and quality of life. Limited data exist for treatments that improve TN pain acutely, within 24 h of administration. This systematic review aims to identify effective treatments that acutely relieve TN exacerbations.

METHODS

We searched Medline and Cochrane Central Register of Controlled Trials (CENTRAL) for relevant English language publications. The reference list for all articles was searched for other relevant publications. All studies that satisfied the following PICO criteria were included: (i) Population-adults with acute exacerbation of primary TN symptoms; (ii) Intervention-any medication or intervention with the primary goal of pain relief within 24 h; (iii) Comparator-usual medical care, placebo, sham or active treatment; (iv) Outcome-more than 50% reduction in pain intensity within 24 h of administration.

RESULTS

Of 431 studies, 17 studies were identified that reported immediate results of acute treatment in TN. The evidence suggests that the following interventions may be beneficial: local anaesthetic, mainly lidocaine (ophthalmic, nasal or oral mucosa, trigger point injection, i.v. infusion, nerve block); anticonvulsant, phenytoin or fosphenytoin (i.v. infusion); serotonin agonist, sumatriptan (s.c. injection, nasal). Other referenced interventions with very limited evidence include N-methyl-d-aspartate receptor antagonist (magnesium sulphate infusion) and botulinum toxin (trigger point injection).

CONCLUSIONS

Several treatment options exist that may provide fast and safe relief of TN. Future studies should report on outcomes within 24 h to improve knowledge of the acute analgesic TN treatments.

Orofacial Pain: Pharmacologic Paradigms for Therapeutic Intervention

Pain is a universal experience with profound effects on the physiology, psychology, and sociology of the population. Orofacial pain (OFP) conditions are especially prevalent and can be severely debilitating to a patient's health-related quality of life. Evidence-based clinical trials suggest that pharmacologic therapy may significantly improve patient outcomes either alone or when used as part of a comprehensive treatment plan for OFP. The aim of this article is to provide therapeutic options from a pharmacologic perspective to treat a broad spectrum of OFP. Clinical-based systemic and topical applied pharmaceutical approaches are presented to treat the most common OFP syndromes.

Streptomycin-lidocaine injections for the treatment of postherpetic neuralgia: Report of three cases with literature review

The sudden, stabbing, paroxysmal pain of neuralgia is the fiercest agony that a patient may experience in his life. Many varied medical treatments and surgical procedures have been suggested in the literature for neuralgic pain. Most of the patients fail to respond to medical treatments or succumb to complications of total anesthesia owing to surgical procedures. Herein, we tried a new treatment modality in patients suffering from postherpetic neuralgia with appreciable success in all the three cases that are presented in this paper. Streptomycin sulfate dissolved in 2% lidocaine solution was deposited at the peripheral branches on the involved nerves targeting the trigger zones, given weekly once for a maximum of 6 week period and continued once in 2 weeks if symptoms persisted. All patients were followed-up for 1 year and there was a marked improvement on follow-up.

Non-antiepileptic drugs for trigeminal neuralgia

BACKGROUND

Trigeminal neuralgia was defined by the International Association for the Study of Pain as a sudden, usually unilateral, severe, brief, stabbing recurrent pain in the distribution of one or more branches of the fifth cranial nerve. Standard treatment is with anti-epileptic drugs. Non-antiepileptic drugs have been used in the management of trigeminal neuralgia since the 1970s. This is an update of a review first published in 2006 and previously updated in 2011.

OBJECTIVES

To systematically review the efficacy and tolerability of non-antiepileptic drugs for trigeminal neuralgia.

SEARCH METHODS

On 20 May 2013, for this updated review, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL (2013, Issue 4), MEDLINE (January 1966 to May 2013), EMBASE (January 1980 to May 2013), LILACS (January 1982 to May 2013) and the Chinese Biomedical Retrieval System (1978 to May 2013). We searched clinical trials registries for ongoing trials.

SELECTION CRITERIA

We included double-blind, randomised controlled trials in which the active drug was used either alone or in combination with other non-antiepileptic drugs for at least two weeks.

DATA COLLECTION AND ANALYSIS

Two authors decided which trials fitted the inclusion criteria and independently graded risk of bias. We assessed the quality of the evidence according to the GRADE criteria for this update.

MAIN RESULTS

In this 2013 update, we updated the searches, but identified only two new ongoing studies. The review includes four trials involving 139 participants. The primary outcome measure in each was pain relief. Three trials compared one of the oral non-antiepileptic drugs tizanidine, tocainide or pimozide with carbamazepine. The quality of evidence for all outcomes for which data were available was low. In a trial of tizanidine involving 12 participants (one dropped out due to unrelated disease), one of five participants treated with tizanidine and four of six treated with carbamazepine improved (risk ratio (RR) 0.30, 95% confidence interval (CI) 0.05 to 1.89). Few side effects were noted with tizanidine. For pimozide, there was evidence of greater efficacy than carbamazepine at six weeks. Up to 83% of participants reported adverse effects but these did not lead to withdrawal; the report did not provide comparable data for carbamazepine. Limited data meant that we could not assess the effects of tocainide; however, data from non-randomised studies (not included in this review) indicate that serious haematological adverse events can occur. A trial involving 47 participants compared 0.5% proparacaine hydrochloride eyedrops with placebo but did not show any significant benefits, again according to low-quality evidence. The report did not mention adverse events. The proparacaine trial was at low risk of bias; the other trials were at unclear risk of bias overall.

AUTHORS' CONCLUSIONS

There is low-quality evidence that the effect of tizanidine is not significantly different than that of carbamazepine in treating trigeminal neuralgia. Pimozide is more effective than carbamazepine, although the evidence is of low quality and the data did not allow comparison of adverse event rates. There is also low-quality evidence that 0.5% proparacaine hydrochloride eye drops have no benefit over placebo. Limitations in the data for tocainide prevent any conclusions being drawn. There is insufficient evidence from randomised controlled trials to show significant benefit from non-antiepileptic drugs in trigeminal neuralgia. More research is needed.

Combination pharmacotherapy for the treatment of neuropathic pain in adults

BACKGROUND

Pharmacotherapy remains an important modality for the treatment of neuropathic pain. However, as monotherapy current drugs are associated with limited efficacy and dose-related side effects. Combining two or more different drugs may improve analgesic efficacy and, in some situations, reduce overall side effects (e.g. if synergistic interactions allow for dose reductions of combined drugs).

OBJECTIVES

This review evaluated the efficacy, tolerability and safety of various drug combinations for the treatment of neuropathic pain.

SEARCH METHODS

We identified randomised controlled trials (RCTs) of various drug combinations for neuropathic pain from CENTRAL, MEDLINE, EMBASE and handsearches of other reviews and trial registries. The most recent search was performed on 9 April 2012.

SELECTION CRITERIA

Double-blind, randomised studies comparing combinations of two or more drugs (systemic or topical) to placebo and/or at least one other comparator for the treatment of neuropathic pain.

DATA COLLECTION AND ANALYSIS

Data extracted from each study included: proportion of participants a) reporting ≥ 30% pain reduction from baseline OR ≥ moderate pain relief OR ≥ moderate global improvement; b) dropping out of the trial due to treatment-emergent adverse effects; c) reporting each specific adverse effect (e.g. sedation, dizziness) of ≥ moderate severity. The primary comparison of interest was between study drug(s) and one or both single-agent comparators. We combined studies if they evaluated the same drug class combination at roughly similar doses and durations of treatment. We used RevMan 5 to analyse data for binary outcomes.

MAIN RESULTS

We identified 21 eligible studies: four (578 participants) evaluated the combination of an opioid with gabapentin or pregabalin; two (77 participants) evaluated an opioid with a tricyclic antidepressant; one (56 participants) of gabapentin and nortriptyline; one (120 participants) of gabapentin and alpha-lipoic acid, three (90 participants) of fluphenazine with a tricyclic antidepressant; three (90 participants) of an N-methyl-D-aspartate (NMDA) blocker with an agent from a different drug class; five (604 participants) of various topical medications; one (313 participants) of tramadol with acetaminophen; and another one (44 participants) of a cholecystokinin blocker (L-365,260) with morphine. The majority of combinations evaluated to date involve drugs, each of which share some element of central nervous system (CNS) depression (e.g. sedation, cognitive dysfunction). This aspect of side effect overlap between the combined agents was often reflected in similar or higher dropout rates for the combination and may thus substantially limit the utility of such drug combinations. Meta-analysis was possible for only one comparison of only one combination, i.e. gabapentin + opioid versus gabapentin alone. This meta-analysis involving 386 participants from two studies demonstrated modest, yet statistically significant, superiority of a gabapentin + opioid combination over gabapentin alone. However, this combination also produced significantly more frequent side effect-related trial dropouts compared to gabapentin alone.

AUTHORS' CONCLUSIONS

Multiple, good-quality studies demonstrate superior efficacy of two-drug combinations. However, the number of available studies for any one specific combination, as well as other study factors (e.g. limited trial size and duration), preclude the recommendation of any one specific drug combination for neuropathic pain. Demonstration of combination benefits by several studies together with reports of widespread clinical polypharmacy for neuropathic pain surely provide a rationale for additional future rigorous evaluations. In order to properly identify specific drug combinations which provide superior efficacy and/or safety, we recommend that future neuropathic pain studies of two-drug combinations include comparisons with placebo and both single-agent components. Given the apparent adverse impact of combining agents with similar adverse effect profiles (e.g. CNS depression), the anticipated development and availability of non-sedating neuropathic pain agents could lead to the identification of more favourable analgesic drug combinations in which side effects are not compounded.

Neurosurgical interventions for the treatment of classical trigeminal neuralgia

BACKGROUND

Surgical interventions are used for trigeminal neuralgia when drug treatment fails. Surgical treatments divide into two main categories, ablative (destructive) or non-ablative. These treatments can be done at three different sites: peripherally, at the Gasserian ganglion level, and within the posterior fossa of the skull.

OBJECTIVES

To assess the efficacy of neurosurgical interventions for classical trigeminal neuralgia in terms of pain relief, quality of life and any harms. To determine if there are defined subgroups of patients more likely to benefit.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Specialized Register, (13 May 2010), CENTRAL (issue 2, 2010 part of the Cochrane Library), Health Technology Assessment (HTA) Database, NHS Economic Evaluation Database (NHSEED) and Database of Abstracts of Reviews of Effects (DARE) (issue 4, 2010 (HTA, NHSEED and DARE are part of the Cochrane Library)), MEDLINE (January 1966 to May 2010) and EMBASE (January 1980 to May 2010) with no language exclusion.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised controlled trials of neurosurgical interventions used in the treatment of classical trigeminal neuralgia.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted authors for clarification and missing information whenever possible.

MAIN RESULTS

Eleven studies involving 496 participants met some of the inclusion criteria stated in the protocol. One hundred and eighty patients in five studies had peripheral interventions, 229 patients in five studies had percutaneous interventions applied to the Gasserian ganglion, and 87 patients in one study underwent two modalities of stereotactic radiosurgery (Gamma Knife) treatment. No studies addressing microvascular decompression (which is the only non-ablative procedure) met the inclusion criteria. All but two of the identified studies had a high to medium risk of bias because of either missing data or methodological inconsistency. It was not possible to undertake meta-analysis because of differences in the intervention modalities and variable outcome measures. Three studies had sufficient outcome data for analysis. One trial, which involved 40 participants, compared two techniques of radiofrequency thermocoagulation (RFT) of the Gasserian ganglion at six months. Pulsed RFT resulted in return of pain in all participants by three months. When this group were converted to conventional (continuous) treatment these participants achieved pain control comparable to the group that had received conventional treatment from the outset. Sensory changes were common in the continuous treatment group. In another trial, of 87 participants, investigators compared radiation treatment to the trigeminal nerve at one or two isocentres in the posterior fossa. There were insufficient data to determine if one technique was superior to another. Two isocentres increased the incidence of sensory loss. Increased age and prior surgery were predictors for poorer pain relief. Relapses were nonsignificantly reduced with two isocentres (risk ratio (RR) 0.72, 95% confidence intervaI (CI) 0.30 to 1.71). A third study compared two techniques for RFT in 54 participants for 10 to 54 months. Both techniques produced pain relief (not significantly in favour of neuronavigation (RR 0.70, 95% CI 0.46 to 1.04) but relief was more sustained and side effects fewer if a neuronavigation system was used. The remaining eight studies did not report outcomes as predetermined in our protocol.

AUTHORS' CONCLUSIONS

There is very low quality evidence for the efficacy of most neurosurgical procedures for trigeminal neuralgia because of the poor quality of the trials. All procedures produced variable pain relief, but many resulted in sensory side effects. There were no studies of microvascular decompression which observational data suggests gives the longest pain relief. There is little evidence to help comparative decision making about the best surgical procedure. Well designed studies are urgently needed.

Treatment of trigeminal neuralgia with bupivacaine HCL using a temporary epidural catheter and pain pump: preliminary study

OBJECTIVES

Trigeminal neuralgia (TN) is a rare form of neuropathic facial pain characterised by severe paroxysmal pain in the face. The treatment for trigeminal neuropathic pain disorder continues to be a major therapeutic challenge, as relief provided by medical therapy generally decreases over time. When medical therapy fails either due to poor or diminishing responses to drugs or to unacceptable side effects, peripheral intervention or surgical management of TN should be considered.

STUDY DESIGN

Fourteen patients (eight men and six women) who were not responsive to further medical treatment and who were diagnosed with TN previously at other health centres were selected for treatment. For this purpose, the affected nerve was infused with 60 mL (1 mL h(-1)) of 0.5% bupivacaine HCl with a pain pump via an temporary epidural catheter. Patient's visual analogue scores (VAS) were recorded on the fifth preoperative day and on postoperative day 5, 2 weeks, 1, 3, 6 and 9 months.

RESULTS

There was a significant difference between mean preoperative and postoperative VAS value at day 5, 2 weeks, 1, 3, 6 and at the end of 9 months ((68.85 ± 1.43) (13.57 ± 6.68) (11.43 ± 6.70) (14.29 ± 6.52) (20.71 ± 6.41) (20.71 ± 6.41) and (21.43 ± 6.10) respectively; ∗P<0.05). Two of 14 patients did not show any pain relief.

CONCLUSIONS

Continuous administration of 60 mL of 0.5% bupivacaine HCl at 1 mL h(-1) with a pain pump and epidural catheter can be used as a transition treatment for patients with side effects from high-dose antiepileptic drugs and for patients awaiting neurosurgery or individuals who refuse cranial surgery. It should not be considered as an alternative treatment of neurosurgical approaches, such as MVD, which has a definite long-lasting results.

Local anesthetic blockade of peripheral nerves for treatment of neuralgias: systematic analysis

BACKGROUND

Nerve blocks with local anesthetics have been used in the diagnosis and treatment of neuralgias. Usually these blocks were administered in combination with corticosteroids and other drugs that can be effective by themselves. Although lasting benefits from nerve blocks in neuralgias have long been described, definitive evidence is lacking. We had the following objectives in this systematic review: to analyze the evidence behind the practice of peripheral nerve blockade with local anesthetics in patients with neuralgias and radicular pain syndromes; to assess the duration of pain relief after conduction block resolution; and to evaluate the effectiveness of the treatment of these syndromes with a series of blocks.

METHODS

We searched Medline, Embase, narrative reviews, and book chapters. Only articles published in English were collected. The list of 3347 identified articles was reduced to 39 articles that were read entirely, 12 of which met inclusion criteria.

RESULTS

Twelve included articles were analyzed. Each can be classified as a single case report or case series; there were no controlled studies among them. Nine reports assessed a single block outcome; all recorded pain relief beyond the duration of conduction blockade. Those 9 reports represented a total of 69 patients, 30 of whom had complete pain relief and 10 had relief ≥50%. Seven reports with the assessment of continuous pain ≥1 week after a single block reported complete or profound pain relief in 11 of 17 patients. All 3 reports with the assessment of a series of blocks in a large number of patients (total of 270) reported overall positive results.

CONCLUSION

Because all reviewed articles were only single case reports or case series, no reliable conclusion could be drawn concerning the effectiveness of nerve blocks with local anesthetics in neuralgia. However, 2 features of the analyzed reports-the large magnitude of the effect and the high consistency of the reported outcome-indicate that future research efforts are warranted.

Anatomic study of the infraorbital foramen for radiofrequency neurotomy of the infraorbital nerve

OBJECTIVE

To examine the anatomy of the infraorbital canal and foramen and the angles at which a radiofrequency probe must be directed to enter the infraorbital foramen and canal, as a guide to performing radiofrequency ablation of the infraorbital nerve in patients with relative or absolute contraindications to lesions of the trigeminal ganglion or posterior root.

METHODS

Eleven cadaveric skulls were studied. The infraorbital nerve, after passing through the infraorbital foramen, enters the infraorbital canal and groove in the floor of the orbit before reaching the foramen rotundum. Small probes were placed through the foramen into the infraorbital canal, and pictures were taken in the anteroposterior and sagittal planes. The pictures were analyzed using the ImageTool program (University of Texas Health Science Center, San Antonio, TX) to calculate the anteroposterior and sagittal angles of the probe. The distances of the foramen from the midline, lateral edge of the anterior nasal aperture, and inferior orbital rim were examined.

RESULTS

A probe introduced through the cheek from below and medial to the foramen and directed upward and laterally at an angle of approximately 22 degrees in the coronal plane and 120 degrees in the sagittal plane toward a point approximately 26 mm from the midline and 8 mm below the inferior orbital rim will penetrate the infraorbital foramen for placement of the probe's tip in the infraorbital canal.

CONCLUSION

The coordinates for placement of the radiofrequency probe through the infraorbital foramen and into the infraorbital canal are reviewed, along with a discussion of pitfalls in radiofrequency ablation of the nerve.

AAN-EFNS guidelines on trigeminal neuralgia management

Several issues regarding diagnosis, pharmacological treatment, and surgical treatment of trigeminal neuralgia (TN) are still unsettled. The American Academy of Neurology and the European Federation of Neurological Societies launched a joint Task Force to prepare general guidelines for the management of this condition. After systematic review of the literature the Task Force came to a series of evidence-based recommendations. In patients with TN MRI may be considered to identify patients with structural causes. The presence of trigeminal sensory deficits, bilateral involvement, and abnormal trigeminal reflexes should be considered useful to disclose symptomatic TN, whereas younger age of onset, involvement of the first division, unresponsiveness to treatment and abnormal trigeminal evoked potentials are not useful in distinguishing symptomatic from classic TN. Carbamazepine (stronger evidence) or oxcarbazepine (better tolerability) should be offered as first-line treatment for pain control. For patients with TN refractory to medical therapy early surgical therapy may be considered. Gasserian ganglion percutaneous techniques, gamma knife and microvascular decompression may be considered. Microvascular decompression may be considered over other surgical techniques to provide the longest duration of pain freedom. The role of surgery versus pharmacotherapy in the management of TN in patients with multiple sclerosis remains uncertain.

Operative treatment of trigeminal neuralgia: review of current techniques

Surgical approaches to pain management are performed when medication cannot control pain or patients cannot tolerate the adverse effects of the medication. Microvascular decompression (MVD) is generally performed when the patient is healthy and relatively young. Partial sensory rhizotomy is performed in addition to, or instead of MVD, in patients in whom significant compression of the trigeminal sensory root does not exist or in whom MVD is technically not feasible. Three percutaneous ablative procedures and gamma knife radiosurgery (GKS) are also performed when MVD cannot be performed. The result of MVD is superior to that of the 3 ablative procedures. GKS is inferior to the 3 ablative procedures in terms of initial pain relief and recurrence, but superior in terms of complications. Peripheral procedures are usually performed in patients not suitable for or not wishing to have other procedures. However, no strict rules exist and each patient should be evaluated individually.

Evidence-based approach to the medical management of trigeminal neuralgia

Classical trigeminal neuralgia (TN) is a rare neuropathic pain with distinct diagnostic criteria. The aim of this review is to provide recommendations for medical management based on current evidence and provide some pointers on the conduct of future trials. A review of the literature identified four systematic reviews, of which one was a meta-analysis and 18 randomized controlled trials (RCT) on medical management of trigeminal neuralgia. The evidence suggests that carbamazepine is still the first line drug for medical management, but this should be changed to oxcarbazepine if there is poor efficacy and an unacceptable side effect profile. Combination of carbamazepine with lamotrigine or baclofen is the second line treatment when monotherapy fails, but the evidence is weak. An early neurosurgical opinion should be sought when a patient has a neurovascular contact of the trigeminal nerve, poor efficacy and tolerability of drug treatment and no remission periods. Many of the new antiepileptic drugs need to be evaluated in RCTs with innovative designs and robust outcome measures.

Management of neuropathic orofacial pain

Current management of painful trigeminal neuropathies relies on pharmacological (topical and systemic), surgical, and complementary modalities. There is, however, a lack of quality research relating to the effectiveness of these modalities. In this review we analyze the available data that relates to the therapy of trigeminal neuralgia, postherpetic neuralgia, and posttraumatic neuropathies and provide clinical guidelines. The review focuses on medical management, as well as surgical and other interventions for painful neuropathies.

Drug therapy of trigeminal neuralgia

Trigeminal neuralgia is a chronic pain syndrome of still unestablished origin. Its diagnosis depends on clinical grounds. Drug therapy initially helps a great majority of patients. The choice of drugs is quite large, but truly effective compounds with a tolerable side effect profile remain few. Carbamazepine (or oxcarbazepine) and lamotrigine appear to be the most effective, followed by baclofen. Several patients require further nonpharmacological treatment for which no evidence-based recommendation is possible. In the future, neuromodulation may be brought to bear, as in other chronic pain syndromes.

Trigeminal neuralgia: current treatments and future developments

Trigeminal neuralgia is a rare condition in which patients experience brief, unilateral recurrent episodes of sharp paroxysms of pain that can occur spontaneously or be induced by physical triggers. Although current pharmacotherapy allows most patients at least some degree of comfort, there remains a substantial number who do not have adequate pain management. This can arise as a consequence of the disorder proving to be refractory to drug treatment in an individual, or the manifestation of drug-related side effects at therapeutic doses. When this occurs, the only treatment option is a surgical procedure, which may vary in its level of invasiveness and effect. Therefore, there is a substantial need for new antineuralgic drugs. The aim of this review is to highlight the current pharmacotherapies and those emerging drug treatments which will invariably enhance the treatment options of patients with trigeminal neuralgia.

Quality of reporting in evaluations of surgical treatment of trigeminal neuralgia: recommendations for future reports

OBJECTIVE

There are numerous reports on the surgical treatment of trigeminal neuralgia, but the studies do not use uniform outcome measures, which makes it difficult for patients and clinicians to determine which treatment may be most appropriate. The objectives of this study were to set quality criteria and standards for outcome reporting for the surgical treatment of trigeminal neuralgia (on the basis of international expert opinion), to identify and assess all studies of the surgical treatment of trigeminal neuralgia and evaluate the studies against those criteria, and to provide recommendations for submitting reports on the outcomes of surgical treatment of trigeminal neuralgia.

METHODS

The types of data that 11 neurosurgeons and 2 neurologists considered essential for articles reporting the outcomes of surgical treatment of trigeminal neuralgia were the quality criteria used by the two authors. Standards were established in terms of the minimal number and type of criteria that studies should meet to allow their use in a potential systematic review of pain outcomes of surgical treatment of trigeminal neuralgia. Studies were identified in MEDLINE searches and from other sources and were independently scored against those criteria by the two authors. The reproducibility of the method was checked with assessments of inter- and intra-rater reliability. A checklist for the reporting of studies was formulated.

RESULTS

A total of 281 studies were identified, of which 222 were scored. Seventy-one (32%) of the studies reached the minimal set standards, but only 28 (13%) could be used for assessment of pain outcomes, because they included actuarial analyses. There was good agreement between the two authors in the scoring of the studies, although some criteria required stricter definitions. A checklist for the reporting of future studies on the surgical treatment of trigeminal neuralgia was proposed.

CONCLUSION

When assessed against the proposed criteria and standards, the quality of reporting was generally poor. The methods for reporting surgical outcomes for trigeminal neuralgia were not uniform; therefore, the comparability of results and techniques was low. Data should be collected and reported in a standardized way. A protocol for data collection and reporting on the surgical treatment of trigeminal neuralgia has been proposed. Further research is needed to evaluate this tool.

Use of streptomycin-lidocaine injections in the treatment of the cluster-tic syndrome. Clinical perspectives and a case report

Trigeminal neuralgia and cluster headache syndrome are complex pain conditions of the craniofacial region. Both diseases can coexist in the same patient, comprising the cluster-tic syndrome. This article reviews the literature on this condition and reports a new case who responded well to peripheral streptomycin-lidocaine injections.

Relationship of the infraorbital nerve and vessels in the pathogenesis of idiopathic trigeminal neuralgia: a theoretical discussion and cadaveric study

Many etiologies have been postulated to explain the pathogenesis of Trigeminal Neuralgia (TN). Most theories focus on a demyelinating process resulting in ephaptic transmission and recruitment of small pain fibers or a restrictive relationship of the superior cerebellar arteries and the trigeminal nerve roots at the level of the pons which may lead to demyelination. It is postulated that vasodilation or constriction of these vessels in a confined bony canal can create localized regions of demyelination and restrictive relationships creating painful stimuli. It is the purpose of this study to grossly investigate the relationship of the infraorbital nerve and vessels passing through the infraorbital canal to discuss whether their relationship may play a role in the pathogenesis of idiopathic TN. Patterns of relationship have been elucidated and will be described. This preliminary gross anatomical study should set the framework from which to base further microscopic and clinical studies.

Complications associated with peripheral alcohol injections in the management of trigeminal neuralgia

A retrospective study was carried out on 82 patients whose symptoms of trigeminal neuralgia were controlled by repeated peripheral alcohol nerve blocks in order to assess the associated complications. Peripheral alcohol nerve blocks were invariably associated with swelling and discomfort lasting several days. Significant complications occurred in 3 out of 413 nerve blocks administered over a 20-year period.

Peripheral trigeminal nerve surgery for patients with atypical facial pain

Atypical facial pain (AFP) is characterized by a constant, poorly defined anatomically aching pain, lacking the paroxysmal quality, trigger point activation, and well-defined anatomical distribution of trigeminal neuralgia. This study examines a set of AFP patients with respect to their responses to external decompression (4 patients) and neurectomy (11 patients). Criteria for trigeminal nerve exploration were: failure of non-operative treatments, the ability to control pain temporarily with local anesthetic nerve blocks, and pain generally located within the anatomical distribution of the affected nerve. Decision as whether to perform an external decompression or neurectomy was based on gross anatomical findings during exploration. A retrospective interview was conducted to evaluate the effects of the chosen procedure in regard to subjective level of pain, freedom from restrictions placed on activities of daily living, and past medical history, including history of the facial pain. The neurectomy procedure (p = 0.022), medical history of autoimmune disease (p = 0.004), and preoperative pain distribution on the left side (p = 0.042), were all found to have a positive effect on outcome. History of psychiatric treatment (p = 0.055) and preoperative affected activities of daily living (p = 0.026) significantly adversely affected the outcome.

Peripheral surgical techniques for the management of trigeminal neuralgia--alcohol and glycerol injections

Trigeminal neuralgia remains a difficult condition to manage. Surgery aimed at peripheral nerve branches continues to be used extensively by oral and maxillofacial surgeons. The efficacy of 68 peripheral alcohol injections (retrospective study) and 22 peripheral glycerol injections (prospective study) were assessed in comparison with peripheral cryotherapy. The results indicate that the median time for total pain control after the first alcohol block was 13 months. When individual branches were assessed it was 13 months for the infra-orbital nerve and 19 months for the inferior alveolar nerve. These results compare with the published results on cryotherapy. The results for glycerol were disappointing with a mean time of pain relief of 7 months. The results suggest that peripheral alcohol nerve blocks do still have a role to play in the management of trigeminal neuralgia, particularly in the elderly, medically compromised and those unwilling to undergo more extensive surgery. They also provide a means of temporary relief.

The effect of single-application topical ophthalmic anesthesia in patients with trigeminal neuralgia. A randomized double-blind placebo-controlled trial

To evaluate the reported benefit of ipsilateral single-application ophthalmic anesthetic eyedrops in patients with typical trigeminal neuralgia, a randomized double-blind placebo-controlled trial was performed. Forty-seven patients were randomly assigned to receive two drops of either proparacaine (25 cases) or saline placebo (22 cases). The experimental and placebo groups were equivalent in regard to patient age, distribution of trigeminal neuralgia pain, duration of pain, current medication regimens, and number of prior procedures performed. Pain response was assessed at 3, 10, and 30 days after instillation using two pain rating scales and a measure of pain frequency. Treatment failure was defined in advance as any of the following: a lack of clinical response, the need for an increase in medication, or the need for surgery. No significant difference in outcomes was found between the two groups either when using a verbal pain rating scale (p = 0.24) or when comparing overall pain status (unchanged, improved throughout the study period, or temporarily improved) (p = 0.98). No difference in the frequency of trigeminal neuralgia attacks between the two treatment groups (scaled within five levels of pain frequency) was detected (p = 0.09). During follow-up monitoring, 11 patients in the test drug group and 14 in the placebo group required surgery because of persistent pain (p = 0.24). The results of this study indicate that single-application topical ophthalmic anesthesia reduces neither the severity nor the frequency of pain in comparison to placebo administration. Although a simple and safe treatment, the single application of topical ophthalmic eyedrops provides no short- or long-term benefit to patients with trigeminal neuralgia.

The effects of streptomycin on autotomy

Thirty-six rats with sciatic nerve transections and autotomy scores 1-2 were divided into 3 groups. Two groups were re-operated and injected with streptomycin sulphate or saline into the polyethylene tube around the neuroma. In the third group, streptomycin was injected at the sciatic nerve, extraneurally, proximal to the tube. Streptomycin injected into the polyethylene tube suppressed autotomy scores during the entire postinjection period. At the eighth postinjection week, none of the rats from this group reached the maximal autotomy score.

Trigeminal neuralgia--treatment of the third division by radiologically controlled cryoblockade of the inferior dental nerve at the mandibular lingula: a study of 31 cases

Cryoblockade of the peripheral nerve affected by trigeminal neuralgia is an established technique for treatment. Freezing the inferior dental nerve using C-arm image-intensification control, and a nerve stimulator to guide the slim Spembly Lloyd probe, offers an additional technique for treatment of a small number of patients with trigeminal neuralgia. This paper reports the results of 31 cryoblockades of the inferior dental nerve in 11 patients.