Trigeminal neuralgia and persistent idiopathic facial pain

Case report: use of high-intensity laser therapy for treatment of trigeminal neuralgia

Trigeminal neuralgia represents a form of chronic facial pain that is characterized by its incapacitating nature. The current therapeutic approaches encompass pharmacological agents with carbamazepine or non-pharmacologic options including utilization of percutaneous rhizotomy, Gamma knife radiosurgery or microvascular decompression may be indicated in certain cases. While the interventions may be effective, medications have negative side effects and procedures are invasive which can pose challenges for patients with various comorbidities. High-intensity laser therapy (HILT) has demonstrated safety and efficacy for many types of chronic pain such as musculoskeletal, autoimmune and neuropathic. Herein, we demonstrate the benefits of HILT therapy in the management of trigeminal neuralgia in a 72 year-old patient with a complex history of facial surgery and radiation who had failed pharmacological treatments and denied any invasive procedures.

Functional MRI-Guided Motor Cortex and Deep Brain Stimulation for Intractable Facial Pain: A Novel, Personalized Approach in 1 Patient

BACKGROUND

Facial neuropathic pain syndromes such as trigeminal neuralgia are debilitating disorders commonly managed by medications, vascular decompression, and/or ablative procedures. In trigeminal neuralgia cases unresponsive to these interventions, trigeminal deafferentation pain syndrome (TDPS) can emerge and remain refractory to any further attempts at these conventional therapies. Deep brain stimulation (DBS) and motor cortex stimulation are 2 neuromodulatory treatments that have demonstrated efficacy in small case series of TDPS yet remain largely underutilized. In addition, functional MRI (fMRI) is a tool that can help localize central processing of evoked stimuli such as mechanically triggered facial pain. In this study, we present a case report and operative technique in a patient with TDPS who underwent fMRI to guide the operative management and placement of dual targets in the sensory thalamus and motor cortex.

OBJECTIVE

To evaluate the safety, efficacy, and outcome of a novel surgical approach for TDPS in a single patient.

METHODS

The fMRI and operative technique of unilateral DBS targeting the ventroposteromedial nucleus of the thalamus and facial motor cortex stimulator placement through a single burr hole is illustrated as well as the patient's clinical outcome.

RESULTS

In less than 1 year, the patient had near complete resolution of his facial pain with no postoperative complications.

CONCLUSION

We present the first published case of successful treatment of TDPS using simultaneous DBS of the ventroposteromedial and motor cortex stimulation. fMRI can be used as an effective imaging modality to guide neuromodulation in this complex disorder.

Pharmacological Approach to Atypical Odontalgia Patients: A Systematic Review of Case Reports

Background:

Atypical odontalgia (AO) is a poorly understood condition of orofacial pain and is often misdiagnosed. The pharmacological approach varies from case to case. This may be due to the differences in etiology, clinical symptoms, as well as comorbidities in each patient.

Objective:

This systematic review aimed at identifying and comprehending the adequate pharmacological approaches in AO management.

Methods:

In this systematic review, case reports that used pharmacological approach(es) as part of the AO management in the last 10 years (2010 to 2020) were reviewed using the PRISMA analysis guidelines. Initial screening was performed using keywords and inclusion criteria in several databases. Subsequently, further screening was carried out by checking for any duplication, followed by an assessment of the title and abstract and the entire content of the case report. All three authors were independently involved in studies selection based on the inclusion criteria, data extraction, and bias assessment.

Results:

Five hundred and ninety-five articles were identified from the initial search. The final result consisted of eleven case reports reviewed in this study. The use of antidepressants in AO management was reported in eight cases, anticonvulsants in five cases, antipsychotic in two cases, opioid analgesics in two cases, and topical analgesics in two cases.

Conclusion:

Based on this systematic review, various pharmacological agents showed adequate results as AO management. Antidepressants seemed to be the most effective ones (PROSPERO registration ID: CRD42021245918).

Leveraging high-resolution 7-tesla MRI to derive quantitative metrics for the trigeminal nerve and subnuclei of limbic structures in trigeminal neuralgia

BACKGROUND

Trigeminal Neuralgia (TN) is a chronic neurological disease that is strongly associated with neurovascular compression (NVC) of the trigeminal nerve near its root entry zone. The trigeminal nerve at the site of NVC has been extensively studied but limbic structures that are potentially involved in TN have not been adequately characterized. Specifically, the hippocampus is a stress-sensitive region which may be structurally impacted by chronic TN pain. As the center of the emotion-related network, the amygdala is closely related to stress regulation and may be associated with TN pain as well. The thalamus, which is involved in the trigeminal sensory pathway and nociception, may play a role in pain processing of TN. The objective of this study was to assess structural alterations in the trigeminal nerve and subregions of the hippocampus, amygdala, and thalamus in TN patients using ultra-high field MRI and examine quantitative differences in these structures compared with healthy controls.

METHODS

Thirteen TN patients and 13 matched controls were scanned at 7-Tesla MRI with high resolution, T1-weighted imaging. Nerve cross sectional area (CSA) was measured and an automated algorithm was used to segment hippocampal, amygdaloid, and thalamic subregions. Nerve CSA and limbic structure subnuclei volumes were compared between TN patients and controls.

RESULTS

CSA of the posterior cisternal nerve on the symptomatic side was smaller in patients (3.75 mm2) compared with side-matched controls (5.77 mm2, p = 0.006). In TN patients, basal subnucleus amygdala volume (0.347 mm3) was reduced on the symptomatic side compared with controls (0.401 mm3, p = 0.025) and the paralaminar subnucleus volume (0.04 mm3) was also reduced on the symptomatic side compared with controls (0.05 mm3, p = 0.009). The central lateral thalamic subnucleus was larger in TN patients on both the symptomatic side (0.033 mm3) and asymptomatic side (0.035 mm3), compared with the corresponding sides in controls (0.025 mm3 on both sides, p = 0.048 and p = 0.003 respectively). The inferior and lateral pulvinar thalamic subnuclei were both reduced in TN patients on the symptomatic side (0.2 mm3 and 0.17 mm3 respectively) compared to controls (0.23 mm3, p = 0.04 and 0.18 mm3, p = 0.04 respectively). No significant findings were found in the hippocampal subfields analyzed.

CONCLUSIONS

These findings, generated through a highly sensitive 7 T MRI protocol, provide compelling support for the theory that TN neurobiology is a complex amalgamation of local structural changes within the trigeminal nerve and structural alterations in subnuclei of limbic structures directly and indirectly involved in nociception and pain processing.

Stimulating GABAergic Neurons in the Nucleus Accumbens Core Alters the Trigeminal Neuropathic Pain Responses in a Rat Model of Infraorbital Nerve Injury

The nucleus accumbens core (NAcc) is an important component of brain reward circuitry, but studies have revealed its involvement in pain circuitry also. However, its effect on trigeminal neuralgia (TN) and the mechanism underlying it are yet to be fully understood. Therefore, this study aimed to examine the outcomes of optogenetic stimulation of NAcc GABAergic neurons in an animal model of TN. Animals were allocated into TN, sham, and control groups. TN was generated by infraorbital nerve constriction and the optogenetic virus was injected into the NAcc. In vivo extracellular recordings were acquired from the ventral posteromedial nucleus of the thalamus. Alterations of behavioral responses during stimulation "ON" and "OFF" conditions were evaluated. In vivo microdialysis was performed in the NAcc of TN and sham animals. During optogenetic stimulation, electrophysiological recordings revealed a reduction of both tonic and burst firing activity in TN animals, and significantly improved behavioral responses were observed as well. Microdialysis coupled with liquid chromatography/tandem mass spectrometry analysis revealed significant alterations in extracellular concentration levels of GABA, glutamate, acetylcholine, dopamine, and citrulline in NAcc upon optic stimulation. In fine, our results suggested that NAcc stimulation could modulate the transmission of trigeminal pain signals in the TN animal model.

Optogenetic stimulation of the motor cortex alleviates neuropathic pain in rats of infraorbital nerve injury with/without CGRP knock-down

BACKGROUND

Previous studies have reported that electrical stimulation of the motor cortex is effective in reducing trigeminal neuropathic pain; however, the effects of optical motor cortex stimulation remain unclear.

OBJECTIVE

The present study aimed to investigate whether optical stimulation of the primary motor cortex can modulate chronic neuropathic pain in rats with infraorbital nerve constriction injury.

METHODS

Animals were randomly divided into a trigeminal neuralgia group, a sham group, and a control group. Trigeminal neuropathic pain was generated via constriction of the infraorbital nerve and animals were treated via selective inhibition of calcitonin gene-related peptide in the trigeminal ganglion. We assessed alterations in behavioral responses in the pre-stimulation, stimulation, and post-stimulation conditions. In vivo extracellular recordings were obtained from the ventral posteromedial nucleus of the thalamus, and viral and α-CGRP expression were investigated in the primary motor cortex and trigeminal ganglion, respectively.

RESULTS

We found that optogenetic stimulation significantly improved pain behaviors in the trigeminal neuralgia animals and it provided more significant improvement with inhibited α-CGRP state than active α-CGRP state. Electrophysiological recordings revealed decreases in abnormal thalamic firing during the stimulation-on condition.

CONCLUSION

Our findings suggest that optical motor cortex stimulation can alleviate pain behaviors in a rat model of trigeminal neuropathic pain. Transmission of trigeminal pain signals can be modulated via knock-down of α-CGRP and optical motor cortex stimulation.

Microvascular decompression and radiofrequency for the treatment of trigeminal neuralgia: a meta-analysis

PURPOSE

Surgical treatments are used for trigeminal neuralgia (TN) when drug treatment fails. Surgical options can be divided into two categories: ablation (destructive) or non-ablation. Microvascular decompression (MVD) is primarily a non-ablation option, while radiofrequency thermocoagulation/rhizotomy (RF) is an ablation option. The aim of this study was to compare outcomes of MVD versus RF in the treatment of TN.

MATERIALS AND METHODS

This article evaluates the clinical results and economic effectiveness of trigeminal nerve RF and MVD for the treatment of TN. This review was conducted according to the methodological standards described in the Cochrane Handbook for Systematic Reviews of Interventions and the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement. The PubMed, Embase and Cochrane libraries were searched in January 2018. We have registered our review at the Review Registry.

RESULTS

Nine studies were included in this review. The sample size was 2163 participants. The results showed that compared with RF, MVD had a lower risk of requiring a secondary procedure. The MVD group also had a lower risk of facial numbness. There was no significant difference in postoperative medication use between the two groups. Compared to RF, MVD was more likely to increase the risk of hypacusis and hypesthesia and to decrease the risk of facial pain and dysesthesia. The total cost of MVD, including the operation, hospital stay and additional procedures, was much higher than that of RF.

CONCLUSION

MVD had a lower risk of requiring a secondary procedure and facial numbness after surgery. RF could be considered in patients who are unfit for MVD or refused invasive treatment.

Treatment of Facial Pain with I Ching Balance Acupuncture

Background: Trigeminal neuralgia (TN) is the most common cranial neuralgia in adults, with a slightly higher incidence in women than in men. This chronic pain condition affects the trigeminal nerve, also known as the 5th cranial nerve. It is one of the most deeply distributed nerves in the head. Antiseizure drugs are the main biomedical treatment of TN. However, TN is not the only source of facial pain. Background persistent idiopathic facial pain (PIFP) is also a chronic disorder, recurring daily for more than 2 hours per day over more than 3 months. PIFP occurs in the absence of a neurologic deficit. The underlying pathophysiologies of TN and PIFP are still unknown, and treatment options have not been sufficiently evaluated. Nevertheless, neuropathic mechanisms could be relevant in both TN and PIFP. Cases: A 65-year-old Caucasian female with left facial pain was diagnosed by a neurologist with TN ∼2.5 years prior to seeking acupuncture treatment. A 42-year-old Caucasian female with left and right facial pain was diagnosed by a neurologist with PIFP ∼3 years prior to commencing acupuncture treatment. The cause of facial pain was treated with 60-minute sessions of I Ching Balance Acupuncture (ICBA) twice per week. Prior to each session, the effect of the previous session was recorded carefully in the patients' files. Results: A complete dissipation of pain was achieved after 29 and 60 ICBA sessions in the TN and the PIFP patient, respectively. Conclusions: The present article is the one of the first to demonstrate the efficacy of ICBA treatment for refractory facial pain. As the present article shows, ICBA treatment affects facial pain of different types successfully. However, additional larger-scale studies are necessary to validate the efficacy of ICBA in TN and PIFP treatment.

Two Cases of Hemicrania Continua-Trigeminal Neuralgia Syndrome: Expanding the Spectrum of Trigeminal Autonomic Cephalalgia-Tic (TAC-TIC) Syndrome

BACKGROUND

Trigeminal neuralgia (TN) has been described in association with various primary headache disorders. So far, no case of TN has been reported in association with hemicrania continua (HC).

CASE REPORT

Here, we report two patients of hemicrania continua associated with TN (HC-tic syndrome). These patients had both headaches concurrently. Both patients responded to a combination of carbamazepine and indomethacin. The skipping or tapering of carbamazepine led to the recurrence of the neuralgic pain of TN. In the same way, the skipping of indomethacin resulted in the relapse of the pain, typical of HC.

CONCLUSION

With these two cases of HC-tic syndrome, we suggest that TN has a special predilection for all types of TACs. Various speculations suggest that such associations are more than a simple coincidence, and both diseases may be causally interrelated. The identification of this association is important as both disorders may need separate drugs.

Therapeutic efficacy and safety of Botulinum Toxin A Therapy in Trigeminal Neuralgia: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Several different interventions have been examined to alleviate pain and reduce frequency of trigeminal neuralgia (TN) paroxysms. However, some patients continue to have persistent or recurrent painful attacks. Using a systematic review and meta-analysis approach, we aimed to synthesize evidence from published randomized controlled trials (RCTs) regarding safety and efficacy of botulinum toxin type A (BTX-A) as a possible emerging choice of treatment for TN.

METHODS

We conducted an electronic search in 10 databases/electronic search engines to access relevant publications. All articles in all languages reporting RCTs on the efficacy and safety of BTX-A in the treatment of TN were included for systematic review and meta-analysis.

RESULTS

A total of four RCTs (n = 178) were identified for final meta-analysis. The overall effect favored BTX-A versus placebo in terms of proportion of responders (risk ratio RR = 2.87, 95 % confidence interval CI [1.76, 4.69], p <0.0001) with no significant detected heterogeneity (p = 0.31; I(2) = 4 %). Paroxysms frequency per day was significantly lower for BTX-A group (mean difference MD = -29.79, 95 % CI [-38.50,-21.08], p <0.00001) with no significant heterogeneity (p = 0.21; I(2) = 36 %).

CONCLUSION

Despite limited data, our results suggest that BTX-A may be an effective and safe treatment option for patients with TN. Further larger and well-designed RCTs are encouraged to translate these findings into better clinical outcome and better quality of life for TN patients.

Trigeminal neuralgia: unilateral episodic facial pain

Trigeminal neuralgia is a rare cause of episodic unilateral facial pain and often in the initial presentation dental causes need to be eliminated, as it frequently presents in the lower trigeminal divisions. The pain description is characteristic of electric shock-like pain that is light-touch provoked, paroxysmal, and occurring daily; the condition can go into remission for weeks or months, however. The first-line drug is either carbamazepine or oxcarbazepine and has to be started in low doses. Over 70% of patients will initially obtain immediate relief. If efficacy or tolerability becomes a problem, then referral to a secondary care specialist should be made. Magnetic resonance imaging (MRI) scans can determine if there is a symptomatic cause and whether surgery is indicated. Surgical options provide longest pain relief periods. Patients need to be given information about all treatment options so they can make a decision about treatment. This report is adapted from paineurope 2014; Issue 4, © Haymarket Medical Publications Ltd., and is presented with permission. paineurope is provided as a service to pain management by Mundipharma International, Ltd., and is distributed free of charge to health care professionals in Europe. Archival issues can be viewed via the Web site: www.paineurope.com , at which health professionals can find links to the original articles and request copies of the quarterly publication and access additional pain education and pain management resources.

Trigeminal and sphenopalatine ganglion stimulation for intractable craniofacial pain--case series and literature review

INTRODUCTION

Facial pain is often debilitating and can be characterized by a sharp, stabbing, burning, aching, and dysesthetic sensation. Specifically, trigeminal neuropathic pain (TNP), anesthesia dolorosa, and persistent idiopathic facial pain (PIFP) are difficult diseases to treat, can be quite debilitating and an effective, enduring treatment remains elusive.

METHODS

We retrospectively reviewed our early experience with stimulation involving the trigeminal and sphenopalatine ganglion stimulation for TNP, anesthesia dolorosa, and PIFP between 2010-2014 to assess the feasibility of implanting at these ganglionic sites. Seven patients received either trigeminal and/or sphenopalatine ganglion stimulation with or without peripheral nerve stimulation, having failed multiple alternative modalities of treatment. The treatments were tailored on the physical location of pain to ensure regional coverage with the stimulation.

RESULTS

Fluoroscopy or frameless stereotaxy was utilized to place the sphenopalatine and/or trigeminal ganglion stimulator. All patients were initially trialed before implantation. Trial leads implanted in the pterygopalatine fossa near the sphenopalatine ganglion were implanted via transpterygoid (lateral-medial, infrazygomatic) approach. Trial leads were implanted in the trigeminal ganglion via percutaneous Hartel approach, all of which resulted in masseter contraction. Patients who developed clinically significant pain improvement underwent implantation. The trigeminal ganglion stimulation permanent implants involved placing a grid electrode over Meckel's cave via subtemporal craniotomy, which offered a greater ability to stimulate subdivisions of the trigeminal nerve, without muscular (V3) side effects. Two of the seven overall patients did not respond well to the trial and were not implanted. Five patients reported pain relief with up to 24-month follow-up. Several of the sphenopalatine ganglion stimulation patients had pain relief without any paresthesias. There were no electrode migrations or post-surgical complications.

CONCLUSIONS

Refractory facial pain may respond positively to ganglionic forms of stimulation. It appears safe and durable to implant electrodes in the pterygopalatine fossa via a lateral transpterygoid approach. Also, implantation of an electrode grid overlying Meckel's cave appears to be a feasible alternative to the Hartel approach. Further investigation is needed to evaluate the usefulness of these approaches for various facial pain conditions.

Risk of psychiatric disorders following trigeminal neuralgia: a nationwide population-based retrospective cohort study

Background

TN is one of the most common causes of facial pain. A higher prevalence of psychiatric co-morbidities, especially depressive disorder, has been proven in patients with TN; however, a clear temporal-causal relationship between TN and specific psychiatric disorders has not been well established. We performed a nationwide population-based retrospective cohort study to explore the relationship between TN and the subsequent development of psychiatric disorders, including schizophrenia, bipolar disorder, depressive disorder, anxiety disorder, and sleep disorder.

Methods

We identified subjects who were newly diagnosed with TN between January 1, 2000 and December 31, 2010 in the Taiwan National Health Insurance Research Database. A comparison cohort was constructed for patients without TN who were matched according to age and sex. All TN and control patients were observed until diagnosed with psychiatric disorders, death, withdrawal from the National Health Institute system, or until December 31, 2010.

Results

The TN cohort consisted of 3273 patients, and the comparison cohort consisted of 13,092 matched control patients without TN. The adjusted hazard ratio (aHR) of depressive disorder, anxiety disorder and sleep disorder in subjects with TN was higher than that of the controls during the follow-up [aHR: 2.85 (95 % confidence interval: 2.11–3.85), aHR: 2.98 (95 % confidence interval: 2.12–4.18) and aHR: 2.17 (95 % confidence interval: 1.48–3.19), respectively].

Conclusions

TN might increase the risk of subsequent newly diagnosed depressive disorder, anxiety disorder, and sleep disorder, but not schizophrenia or bipolar disorder. Additional prospective studies are required to confirm these findings.

Trigeminal isolated sensory neuropathy (TISN) and FOSMN syndrome: despite a dissimilar disease course do they share common pathophysiological mechanisms?

Background

Patients presenting with bilateral trigeminal hypoesthesia may go on to have trigeminal isolated sensory neuropathy, a benign, purely trigeminal neuropathy, or facial-onset sensory motor neuronopathy (FOSMN), a malignant life-threatening condition. No diagnostic criteria can yet differentiate the two conditions at their onset. Nor is it clear whether the two diseases are distinct entities or share common pathophysiological mechanisms.

Methods

Seeking pathophysiological and diagnostic information to distinguish these two conditions at their onset, in this neurophysiological and morphometric study we neurophysiologically assessed function in myelinated and unmyelinated fibres and histologically examined supraorbital nerve biopsy specimens with optic and electron microscopy in 13 consecutive patients with recent onset trigeminal hypoesthesia and pain.

Results

The disease course distinctly differed in the 13 patients. During a mean 10 year follow-up whereas in eight patients the disease remained relatively stable, in the other five it progressed to possibly life-threatening motor disturbances and extra-trigeminal spread. From two to six years elapsed between the first sensory symptoms and the onset of motor disorders. In patients with trigeminal isolated sensory neuropathy (TISN) and in those with FOSMN neurophysiological and histological examination documented a neuronopathy manifesting with trigeminal nerve damage selectively affecting myelinated fibres, but sparing the Ia-fibre-mediated proprioceptive reflex.

Conclusions

Although no clinical diagnostic criteria can distinguish the two conditions at onset, neurophysiological and nerve-biopsy findings specify that in both disorders trigeminal nerve damage manifests as a dissociated neuronopathy affecting myelinated and sparing unmyelinated fibres, thus suggesting similar pathophysiological mechanisms.

Linear headache: a recurrent unilateral head pain circumscribed in a line-shaped area

Background

A headache circumscribed in a line-shaped area but not confined to the territory of one particular nerve had ever been described in Epicrania Fugax (EF) of which the head pain is moving and ultrashort. In a 25-month period from Feb 2012 to Mar 2014, we encountered 12 patients with a paroxysmal motionless head pain restricted in a linear trajectory. The head pain trajectory was similar to that of EF, but its all other features obviously different from those of EF. We named this distinctive but undescribed type of headache linear headache (LH).

Methods

A detailed clinical feature of the headache was obtained in all cases to differentiate with EF, trigeminal autonomic cephalalgias (TACs) and cranial neuralgia. Similarities and differences in clinical features were compared between LH and migraine.

Results

The twelve LH patients (mean age 43.9 ± 12.2) complained of a recurrent, moderate to severe, distending (n = 9), pressure-like (n = 3) or pulsating (n = 3) pain within a strictly unilateral line-shaped area. The painful line is distributed from occipital or occipitocervical region to the ipsilateral eye (n = 5), forehead (n = 6) or parietal region (n = 1). The pain line has a trajecory similar to that of EF but no characteristics of moving. The headache duration would be ranged from five minutes to three days, but usually from half day to one day in most cases (n = 8). Six patients had the accompaniment of nausea with or without vomiting, and two patients had the accompaniment of ipsilateral dizziness. The attacks could be either spontaneous (n = 10) or triggered by noise, depression and resting after physical activity (n = 1), or by stress and staying up late (n = 1). The frequency of attacks was variable. The patients had well response to flunarizine, sodium valproate and amitriptyline but not to carbamazepine or oxcarbazepine. LH is different from EF, trigeminal autonomic cephalalgias (TACs) and cranial neuralgia, but it had couple of features similar to that of migraine.

Conclusions

The clinical picture of LH might be a subtype of migraine, or represent a novel syndrome.

Lacrimal neuralgia: so far, a missing cranial neuralgia

BACKGROUND

The lacrimal nerve supplies the lacrimal gland, the lateral upper eyelid, and a small cutaneous area adjacent to the external CANTHUS . First division trigeminal neuralgia, supraorbital/supratrochlear neuralgia, and infraorbital neuralgia have been acknowledged as neuralgic causes of pain in the forehead and periorbit. However, the lacrimal nerve has never been identified as a source of facial pain. Here we report two cases of lacrimal neuralgia.

CASE REPORTS

A 66-year-old woman had continuous pain in the lateral aspect of her left superior eyelid and an adjacent area of the temple since age 64. A 33-year-old woman suffered from continuous pain in a small area next to the lateral CANTHUS of her left eye since age 25. In both patients the superoexternal edge of the orbit was tender. In addition, sensory dysfunction could be demonstrated within the painful area. Anaesthetic blockades of the lacrimal nerve with lidocaine 2% resulted in complete but short-lasting relief. Pregabalin provided a complete response in the first patient. The second patient was refractory to various oral and topical drugs and different radiofrequency procedures, but she eventually obtained partial relief with pregabalin.

CONCLUSIONS

Lacrimal neuralgia should be considered among the neuralgic causes of orbital and periorbital pain.