Facial pain: clinical differential diagnosis

Modern Approaches to the Treatment of Acute Facial Pain

PURPOSE OF REVIEW

Acute facial pain presents a complex challenge in medical practice, requiring a comprehensive and interdisciplinary approach to its management. This narrative review explores the contemporary landscape of treating acute facial pain, delving into pharmacological, non-pharmacological, and advanced interventions. The significance of tailored treatment strategies, rooted in the diverse etiologies of facial pain, such as dental infections, trigeminal neuralgia, temporomandibular joint disorders, sinusitis, or neurological conditions like migraines or cluster headaches, is underscored. We particularly emphasize recent advances in treating trigeminal neuralgia, elucidating current treatment concepts in managing this particular acute facial pain.

RECENT FINDINGS

Recent research sheds light on various treatment modalities for acute facial pain. Pharmacotherapy ranges from traditional NSAIDs and analgesics to anticonvulsants and antidepressants. Non-pharmacological interventions, including physical therapy and psychological approaches, play pivotal roles. Advanced interventions, such as nerve blocks and surgical procedures, are considered in cases of treatment resistance. Moreover, we explore innovative technologies like neuromodulation techniques and personalized medicine, offering promising avenues for optimizing treatment outcomes in acute facial pain management. Modern management of acute facial pain requires a nuanced and patient-centric approach. Tailoring treatment strategies to the individual's underlying condition is paramount. While pharmacotherapy remains a cornerstone, the integration of non-pharmacological interventions is essential for comprehensive care. Advanced interventions should be reserved for cases where conservative measures prove inadequate. Furthermore, leveraging innovative technologies and personalized medicine holds promise for enhancing treatment efficacy. Ultimately, a holistic approach that considers the diverse needs of patients is crucial for effectively addressing acute facial pain.

Orofacial Migraine and Other Idiopathic Non-Dental Facial Pain Syndromes: A Clinical Survey of a Social Orofacial Patient Group

Background: Orofacial pain syndromes (OFPs) are a heterogeneous group of syndromes mainly characterized by painful attacks localized in facial and oral structures. According to the International Classification of Orofacial Pain (ICOP), the last three groups (non-dental facial pain, NDFP) are cranial neuralgias, facial pain syndromes resembling primary headache syndromes, and idiopathic orofacial pain. These are often clinical challenges because the symptoms may be similar or common among different disorders. The diagnostic efforts often induce a complex diagnostic algorithm and lead to several imaging studies or specialized tests, which are not always necessary. The aim of this study was to describe the encountered difficulties by these patients during the diagnostic-therapeutic course. Methods: This study was based on the responses to a survey questionnaire, administered to an Italian Facebook Orofacial Patient Group, searching for pain characteristics and diagnostic-therapeutic care courses. The questionnaire was filled out by patients affected by orofacial pain, who were 18 years and older, using a free online tool available on tablets, smartphones, and computers. Results: The sample was composed of 320 subjects (244F/76M), subdivided by age range (18-35 ys: 17.2%; 36-55 ys: 55.0%; >55 ys 27.8%). Most of the patients were affected by OFP for more than 3 years The sample presented one OFP diagnosis in 60% of cases, more than one in 36.2% of cases, and 3.8% not classified. Trigeminal neuralgia is more represented, followed by cluster headaches and migraines. About 70% had no pain remission, showing persisting background pain (VAS median = 7); autonomic cranial signs during a pain attack ranged between 45 and 65%. About 70% of the subjects consulted at least two different specialists. Almost all received drug treatment, about 25% received four to nine drug treatments, 40% remained unsatisfied, and almost 50% received no pharmacological treatment, together with drug therapy. Conclusion: To the authors' knowledge, this is the first study on an OFP population not selected by a third-level specialized center. The authors believe this represents a realistic perspective of what orofacial pain subjects suffer during their diagnostic-therapeutic course and the medical approach often results in unsatisfactory outcomes.

Visual disorders and mal de debarquement syndrome: a potential comorbidity questionnaire-based study

Aim: Mal de debarquement syndrome (MdDS) is a neurological condition characterized by a constant sensation of self-motion; onset may be motion-triggered (MT) or non-motion-triggered/spontaneous (NMT/SO). People with MdDS experience similar symptoms to those with vertical heterophoria, a subset of binocular visual dysfunction. Hence, we aimed to explore potential visual symptom overlaps. Methods: MdDS patients (n = 196) and controls (n = 197) completed a visual health questionnaire. Results: Compared with controls, the MdDS group demonstrated higher visual disorder scores and visual complaints. NMT/SO participants reported unique visual symptoms and a higher prevalence of mild traumatic brain injury. Conclusion: Our findings suggest visual disorders may coexist with MdDS, particularly the NMT/SO subtype. The difference in visual dysfunction frequency and medical histories between subtypes, warrants further investigation into differing pathophysiological mechanisms.

Orofacial pain disorders: An overview and diagnostic approach

Background:

Non-dental orofacial pain disorders are not uncommon, but idiopathic or primary facial pain syndromes are rare. Inadequate recognition of these disorders usually leads to unsatisfactory and unmet treatment needs.

Methods:

We conducted a narrative review with a literature search in PubMed until December 2021, focusing on current guidelines and the recently published International Classification of Orofacial Pain (ICOP).

Results:

In this paper, we provide an updated overview of the common orofacial pain disorders following the ICOP, covering the classification, epidemiology, pathophysiology, clinical approaches, and treatment options. Additionally, we propose a pragmatic approach focusing on the attack duration to improve distinguishing orofacial disorders.

Conclusion:

The introduction of ICOP offers the opportunity to better coordinate and concentrate scientific efforts, which lays the foundation for the identification of the disease mechanism of facial pain disorders and the optimization of the currently still insufficient therapeutic strategies.

Is this really trigeminal neuralgia? Diagnostic re-evaluation of patients referred for neurosurgery

OBJECTIVES

Patients with facial pain are sometimes referred for neurosurgical treatment with a poorly documented diagnosis of trigeminal neuralgia. In such cases, neurosurgery will usually not be helpful. We conducted a re-evaluation of the diagnosis in patients referred for neurosurgical treatment of presumed trigeminal neuralgia. Our objective was to find out why and how often misdiagnosis occurred.

METHODS

A retrospective study was done in consecutive first-time patients referred for trigeminal neuralgia to our outpatient clinic in 2019. We used five ICHD-3-based clinical criteria to verify or exclude the diagnosis. In patients where trigeminal neuralgia was excluded, we established a diagnosis for their facial pain based upon medical history and a physical examination by a neurosurgeon - often supplemented with examination by an oral surgeon.

RESULTS

Thirty-eight patients were referred for presumed trigeminal neuralgia. Only 17 of them fulfilled the five criteria and were diagnosed with trigeminal neuralgia. In 20 of the remaining 21 patients trigeminal neuralgia could be clearly excluded, while one of the patients had a periodontitis closely mimicking trigeminal neuralgia. In 14 of the 21 patients we diagnosed temporomandibular dysfunction or dental conditions. MRI scans had detected low-grade neurovascular contacts in 13 of the 21 patients, a finding that was clearly overestimated by the referring neurologists in seven patients.

CONCLUSIONS

Overdiagnosis of trigeminal neuralgia was common in patients referred for neurosurgery, mostly due to insufficient clinical evaluation combined with an overestimation of MRI-detected NVCs. The clinical diagnosis should be critically re-evaluated before recommending neurosurgery to patients referred for presumed trigeminal neuralgia.

Facial Pain: A Comprehensive Review and Proposal for a Pragmatic Diagnostic Approach

BACKGROUND

Facial pain, alone or combined with other symptoms, is a frequent complaint. Moreover, it is a symptom situated at, more than any other pain condition, a crosspoint where several disciplines meet, for example, dentists; manual therapists; ophthalmologists; psychologists; and ear-nose-throat, pain, and internal medicine physicians besides neurologists and neurosurgeons. Recently, a new version of the most widely used classification system among neurologists for headache and facial pain, the International Classification of Headache Disorders, has been published.

OBJECTIVE

The aims of this study were to provide an overview of the most prevalent etiologies of facial pain and to provide a generic framework for the neurologist on how to manage patients presenting with facial pain.

METHODS

An overview of the different etiologies of facial pain is provided from the viewpoint of the respective clinical specialties that are confronted with facial pain. Key message: Caregivers should "think outside their own box" and refer to other disciplines when indicated. If not, a correct diagnosis can be delayed and unnecessary treatments might be given. The presented framework is aimed at excluding life- or organ-threatening diseases, providing several clinical clues and indications for technical investigations, and ultimately leading to the correct diagnosis and/or referral to other disciplines.

Orofacial neuralgia associated with a middle cerebral artery aneurysm

Chronic orofacial pain of neuropathic origin can present diagnostic and management dilemmas to dental practitioners and also affects the patient's quality of life. Intracranial aneurysms are a potential cause of stroke (e.g. sub-arachnoid haemorrhage) that is usually associated with, high rates of mortality and morbidity. A patient who had been previously managed for symptoms of temporomandibular joint disorder (TMD) presented with sharp, shooting pain of moderate intensity. It was precipitated by swallowing, and radiated to the right throat, posterior border of the mandible, ear and temporomandibular joint. Clinical and radiological investigations ruled out odontogenic pain, TMD and other more common types of facial pain. Magnetic resonance imaging revealed a 7 × 6 mm aneurysm in the right middle cerebral artery (MCA) which was subsequently surgically clipped. Interestingly, the facial pain resolved after this procedure. Compression of the insular region of the brain innervated by the trigeminal, glossopharyngeal and vagus nerves provides a plausible explanation for the pain reported. To our knowledge, this is the first case of facial neuralgia associated with an aneurysm in the MCA which emphasizes the importance of a multidisciplinary approach in the diagnosis and management of unusual cases of chronic orofacial pain.

Guidelines for radiographic imaging of cranial neuropathies

Disruption of the complex pathways of the 12 cranial nerves can occur at any site along their course, and many, varied pathologic processes may initially manifest as dysfunction and neuropathy. Radiographic imaging (computed topography or magnetic resonance imaging) is frequently used to evaluate cranial neuropathies; however, indications for imaging and imaging method of choice vary considerably between the cranial nerves. The purpose of this review is to provide an analysis of the diagnostic yield and the most clinically appropriate means to evaluate cranial neuropathies using radiographic imaging. Using the PubMed MEDLINE NCBI database, a total of 49,079 articles' results were retrieved on September 20, 2014. Scholarly articles that discuss the etiology, incidence, and use of imaging in the context of evaluation and diagnostic yield of the 12 cranial nerves were evaluated for the purposes of this review. We combined primary research, guidelines, and best practice recommendations to create a practical framework for the radiographic evaluation of cranial neuropathies.

Cheek Numbness Caused by Perineural Tumor Invasion of the Infraorbital Nerve: A Review of 3 Diagnostically Challenging Cases

BACKGROUND Facial pain and numbness are common symptoms with a variety of causes; rarely, it is an initial sign of perineural infiltration of malignant tumors. CASE REPORT Here, we report 3 challenging cases, all presenting with pain and numbness of the cheek as the primary symptoms. Upon referral, there were neither signs of severe illness nor information about previous malignant diseases, while the diagnostic work-ups revealed additional involvement of the facial nerve in 2 of the cases. Surgical removal of the perineural tissue around the infraorbital nerve revealed perineural invasion by a squamous carcinoma. A more thorough review of their medical histories revealed that all 3 of the patients had had previous facial skin cancer. CONCLUSIONS Numbness or pain in the cheek may represent perineural invasion of a facial cutaneous carcinoma. This review of 3 cases addresses the necessity of identifying previous incidences of skin cancer in the medical history.

A Rare Case of Glossopharyngeal Neuralgia due to Neurovascular Conflict

In the context of painful cranial neuropathies, a very rare cause is represented by the irritation of the glossopharyngeal nerve due to various aetiologic factors. Here, we present a case of neuralgia of the ninth right cranial nerve due to a compression of its nerve root upon the kinking of the homolateral vertebral artery, resulting in a disabling clinical overview for the patient. Our objective was to focus the reader's attention on the clinical manifestation, which alone could lead to an immediate diagnosis. The imaging and laboratory studies proved to be fundamental in diagnosing the causes, yet the knowledge of the symptoms and the signs of this rare clinical entity can prevent misdiagnosis, mismanagement and consequent economic expenditure as occurred in the case described here.

How and when to refer patients diagnosed with secondary headache and other craniofacial pain in the Emergency Department and Primary Care: Recommendations of the Spanish Society of Neurology's Headache Study Group

INTRODUCTION

When secondary headache is suspected and the patient is referred to the emergency department or to the outpatient neurology clinic, it is important to know which are the appropriate complementary examinations to perform and the suitable referral pathway for patients to follow. In order to establish recommendations on this matter, the Spanish Society of Neurology's Headache Study Group (GECSEN) has decided to issue a series of agreed recommendations constituting a referral protocol for patients with headache and/or craniofacial neuralgias.

DEVELOPMENT

Young neurologists with an interest and experience in headache were invited to draft a series of practical guidelines in collaboration with GECSEN's Executive Committee. For practical reasons, the document was divided into 2 articles: the first focuses on primary headaches and craniofacial neuralgias and this second article on secondary headaches and other craniofacial pain. In order for the recommendations to be helpful for daily practice, they follow a practical approach, with tables summarising referral criteria, examinations to be performed, and referral to other specialists.

CONCLUSIONS

We hope to offer a guide and tools to improve decision-making regarding patients with headache, identifying complementary tests to prioritise and referral pathways to be followed, in order to avoid duplicated consultations and delayed diagnosis and treatment.

Sialolithiasis of an Accessory Parotid Gland Causing Mid-Cheek Pain

A 52-year-old woman presented with a slightly painful swelling of the right cheek area without postprandial aggravation of the symptom last 1 week. On physical examination, an approximately 1.5 cm sized firm, slightly tender mass was palpated on the right mid-cheek region, and she did not show any abnormal findings on neurologic examination. Computed tomography showed a well-enhanced lesion with low density of internal portion in right cheek area, and tiny calcification was noted within internal low-density portion of cheek mass. These findings suggested sialolithiasis of an accessory parotid gland with duct dilatation. Mid-cheek pain with conservative medical treatment was resolved and has not occurred during 1 year follow-up.

Side-locked headaches: an algorithm-based approach

The differential diagnosis of strictly unilateral hemicranial pain includes a large number of primary and secondary headaches and cranial neuropathies. It may arise from both intracranial and extracranial structures such as cranium, neck, vessels, eyes, ears, nose, sinuses, teeth, mouth, and the other facial or cervical structure. Available data suggest that about two-third patients with side-locked headache visiting neurology or headache clinics have primary headaches. Other one-third will have either secondary headaches or neuralgias. Many of these hemicranial pain syndromes have overlapping presentations. Primary headache disorders may spread to involve the face and / or neck. Even various intracranial and extracranial pathologies may have similar overlapping presentations. Patients may present to a variety of clinicians, including headache experts, dentists, otolaryngologists, ophthalmologist, psychiatrists, and physiotherapists. Unfortunately, there is not uniform approach for such patients and diagnostic ambiguity is frequently encountered in clinical practice.

Herein, we review the differential diagnoses of side-locked headaches and provide an algorithm based approach for patients presenting with side-locked headaches. Side-locked headache is itself a red flag. So, the first priority should be to rule out secondary headaches. A comprehensive history and thorough examinations will help one to formulate an algorithm to rule out or confirm secondary side-locked headaches. The diagnoses of most secondary side-locked headaches are largely investigations dependent. Therefore, each suspected secondary headache should be subjected for appropriate investigations or referral. The diagnostic approach of primary side-locked headache starts once one rule out all the possible secondary headaches. We have discussed an algorithmic approach for both secondary and primary side-locked headaches.

Increased risk of trigeminal neuralgia in patients with migraine: A nationwide population-based study

Objectives The objectives of this article are to evaluate the association between migraine and trigeminal neuralgia and to investigate the effects of age, sex, migraine subtype, and comorbid risk factors on trigeminal neuralgia development. Methods This population-based cohort study was conducted using data from Taiwan's National Health Insurance Research Database. Individuals aged ≥ 20 years with neurologist-diagnosed migraine between 2005 and 2009 were included. A non-headache age-, sex-, and propensity score-matched control cohort was selected for comparison. All participants were followed until the end of 2010, death, or the occurrence of trigeminal neuralgia. Cox proportional hazards regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for comparison of the risk of trigeminal neuralgia between groups. Results Both cohorts ( n = 137,529 each) were followed for a mean of 3.1 years. During the follow-up period, 575 patients (421,581 person-years) in the migraine cohort and 88 matched controls (438,712 person-years) were newly diagnosed with trigeminal neuralgia (incidence rates, 136.39 and 20.06/100,000 person-years, respectively). The HR for trigeminal neuralgia was 6.72 (95% CI, 5.37-8.41; p < 0.001). The association between migraine and trigeminal neuralgia remained significant in sensitivity analyses. Among migraine subtypes, patients with migraine with aura were at greater risk of trigeminal neuralgia development. No other significant interaction was identified in subgroup analyses. Conclusions Migraine is a previously unidentified risk factor for trigeminal neuralgia. The association between these conditions suggests a linked underlying mechanism, which is worthy of further exploration.

Pontine Infarct Presenting with Atypical Dental Pain: A Case Report

Orofacial pain' most commonly occurs due to dental causes like caries, gingivitis or periodontitis. Other common causes of 'orofacial pain' are sinusitis, temporomandibular joint(TMJ) dysfunction, otitis externa, tension headache and migraine. In some patients, the etiology of 'orofacial pain' remains undetected despite optimal evaluation. A few patients in the practice of clinical dentistry presents with dental pain without any identifiable dental etiology. Such patients are classified under the category of 'atypical odontalgia'. 'Atypical odontalgia' is reported to be prevalent in 2.1% of the individuals. 'Atypical orofacial pain' and 'atypical odontalgia' can result from the neurological diseases like multiple sclerosis, trigeminal neuralgia and herpes infection. Trigeminal neuralgia has been frequently documented as a cause of 'atypical orofacial pain' and 'atypical odontalgia'. There are a few isolated case reports of acute pontine stroke resulting in 'atypical orofacial pain' and 'atypical odontalgia'. However, pontine stroke as a cause of atypical odontalgia is limited to only a few cases, hence prevalence is not established. This case is one, where a patient presented with acute onset atypical dental pain with no identifiable dental etiology, further diagnosed as an acute pontine infarct on neuroimaging. A 40 years old male presented with acute onset, diffuse teeth pain on right side. Dental examination was normal. Magnetic resonance imaging(MRI) of the brain had an acute infarct in right pons near the trigeminal root entry zone(REZ). Pontine infarct presenting with dental pain as a manifestation of trigeminal neuropathy, has rarely been reported previously. This stresses on the importance of neuroradiology in evaluation of atypical cases of dental pain.

Geniculate neuralgia: a systematic review

OBJECTIVE

To systematically summarise the peer-reviewed literature relating to the aetiology, clinical presentation, investigation and treatment of geniculate neuralgia.

DATA SOURCES

Articles published in English between 1932 and 2012, identified using Medline, Embase and Cochrane databases.

METHODS

The search terms 'geniculate neuralgia', 'nervus intermedius neuralgia', 'facial pain', 'otalgia' and 'neuralgia' were used to identify relevant papers.

RESULTS

Fewer than 150 reported cases were published in English between 1932 and 2012. The aetiology of the condition remains unknown, and clinical presentation varies. Non-neuralgic causes of otalgia should always be excluded by a thorough clinical examination, audiological assessment and radiological investigations before making a diagnosis of geniculate neuralgia. Conservative medical treatment is always the first-line therapy. Surgical treatment should be offered if medical treatment fails. The two commonest surgical options are transection of the nervus intermedius, and microvascular decompression of the nerve at the nerve root entry zone of the brainstem. However, extracranial intratemporal division of the cutaneous branches of the facial nerve may offer a safer and similarly effective treatment.

CONCLUSION

The response to medical treatment for this condition varies between individuals. The long-term outcomes of surgery remain unknown because of limited data.

Factors that influence Tolosa-Hunt syndrome and the short-term response to steroid pulse treatment

Some but not all patients with Tolosa-Hunt syndrome (THS) have dramatic responses to steroid treatment. A systematic study about the factors that may influence the steroid response of THS patients has not been published. We retrospectively identified 40 patients diagnosed with THS and treated with steroids with respect to patient age at onset, gender, the cranial nerve(s) involved, as well as imaging findings and laboratory tests. Within the context of these data we evaluated the therapeutic efficacy of steroid treatment and recurrence of attacks. We did not note a significant relationship between genders, whether THS was benign or inflammatory, the distribution of cranial nerve palsies, the initial dose of steroids and the effectiveness of steroid treatment for relief of orbital pain or cranial nerve palsies at 72 h or 1 week after treatment. Our study reveals that a rapid alleviation of pain by steroid treatment is a characteristic feature of THS patients. The alleviation of cranial nerve palsy is somewhat slower and more variable, and may involve additional mechanisms. There is an effect of patient age and whether attacks will recur (recurrence was more likely in patients who were young at the time of first attack), whether THS will be benign or inflammatory (more likely to be inflammatory in young patients) and the short-term response of cranial nerve palsy to steroid treatment, which was more effective in young patients. These relationships may be of value in counseling patients presenting with THS.

Validation of ICHD-3 beta diagnostic criteria for 13.7 Tolosa-Hunt syndrome: Analysis of 77 cases of painful ophthalmoplegia

BACKGROUND

Three editions of International Classification of Headache Disorders (ICHD) diagnostic criteria for Tolosa-Hunt syndrome (THS) have been published in 1988, 2004 and 2013, in ICHD-3 beta, there have been considerable changes [corrected]. The validity of these new diagnostic criteria remains to be established.

METHODS

We retrospectively identified 77 patients with non-traumatic painful ophthalmoplegia (PO) admitted between 2003 and 2013. We reviewed patients' age at onset and gender, time courses between onset of pain and development of cranial nerve palsy, the cranial nerves involved, imaging findings, therapeutic efficacy of steroid treatment and recurrence of attacks.

RESULTS

THS was the most frequent type of PO (46/77). In THS patients, the third cranial nerve was most commonly involved (76.3%). The median time interval between pain and cranial nerve palsy was two days, although in five patients (10.9%) the interval ranged from 16 to 30 days. Definitely abnormal MRI findings were found in 24 patients (52.2%).

CONCLUSIONS

It is essential to rule out other causes of PO in diagnosing THS, with MRI playing a crucial role in differential diagnosis. It may be helpful to understand and master the entity of THS for researchers and clinicians to adjust the gradation and ranking of the diagnostic criteria.

Oral pre-trigeminal neuralgia pain: clinical differential diagnosis and descriptive study results

AIMS

To better quantify oral pre-trigeminal neuralgia (PTN) symptoms, attempt to identify PTN symptoms that could reliably differentiate between PTN and odontogenic tooth pain, and determine whether an anesthetic test would reliably differentiate these disorders.

METHODOLOGY

This was accomplished through a survey of symptom recall for 49 trigeminal neuralgia patients who had PTN tooth and/or gum pain.

RESULTS

The variability of oral PTN symptoms, factors that worsened or improved them, and how dental anesthesia affected them, explain the reason for variations found in the literature. A throbbing pain quality is not in the literature, but present for 63% of respondents.

CONCLUSIONS

No specific PTN symptom would reliably differentiate PTN from odontogenic tooth pain. The results also suggest that an anesthetic test would not be totally reliable for differentiating these disorders. A protocol is provided that should help practitioners identify the tooth pain source when there is no dental pathology.

Diagnostic imaging for temporomandibular disorders and orofacial pain

The focus of this article is diagnostic imaging used for the evaluation of temporomandibular disorders and orofacial pain patients. Imaging modalities discussed include conventional panoramic radiography, panoramic temporomandibular joint imaging mode, cone beam computed tomography, and magnetic resonance imaging. The imaging findings associated with common diseases of the temporomandibular joint are presented and indications for brain imaging are discussed. Advantages and disadvantages of each imaging modality are presented as well as illustrations of the various imaging techniques.

Sensorimotor and Pain Modulation Brain Abnormalities in Trigeminal Neuralgia: A Paroxysmal, Sensory-Triggered Neuropathic Pain

OBJECTIVE

Idiopathic trigeminal neuralgia (TN) is characterized by paroxysms of severe facial pain but without the major sensory loss that commonly accompanies neuropathic pain. Since neurovascular compression of the trigeminal nerve root entry zone does not fully explain the pathogenesis of TN, we determined whether there were brain gray matter abnormalities in a cohort of idiopathic TN patients. We used structural MRI to test the hypothesis that TN is associated with altered gray matter (GM) in brain areas involved in the sensory and affective aspects of pain, pain modulation, and motor function. We further determined the contribution of long-term TN on GM plasticity.

METHODS

Cortical thickness and subcortical GM volume were measured from high-resolution 3T T1-weighted MRI scans in 24 patients with right-sided TN and 24 healthy control participants.

RESULTS

TN patients had increased GM volume in the sensory thalamus, amygdala, periaqueductal gray, and basal ganglia (putamen, caudate, nucleus accumbens) compared to healthy controls. The patients also had greater cortical thickness in the contralateral primary somatosensory cortex and frontal pole compared to controls. In contrast, patients had thinner cortex in the pregenual anterior cingulate cortex, the insula and the orbitofrontal cortex. No relationship was observed between GM abnormalities and TN pain duration.

CONCLUSIONS

TN is associated with GM abnormalities in areas involved in pain perception, pain modulation and motor function. These findings may reflect increased nociceptive input to the brain, an impaired descending modulation system that does not adequately inhibit pain, and increased motor output to control facial movements to limit pain attacks.

Trigeminal neuralgia and persistent idiopathic facial pain

Trigeminal neuralgia (TN) and persistent idiopathic facial pain (PIFP) are two of the most puzzling orofacial pain conditions and affected patients are often very difficult to treat. TN is characterized by paroxysms of brief but severe pain followed by asymptomatic periods without pain. In some patients a constant dull background pain may persist. This constant dull pain sometimes makes the distinction from PIFP difficult. PIFP is defined as continuous facial pain, typically localized in a circumscribed area of the face, which is not accompanied by any neurological or other lesion identified by clinical examination or clinical investigations. The pain usually does not stay within the usual anatomic boundaries of the trigeminal nerve distribution and is a diagnosis of exclusion. Epidemiologic evidence on TN, and even more so on PIFP, is quite scarce, but generally both conditions are considered to be rare diseases. The etiology and underlying pathophysiology of TN, and more so PIFP, remain unknown. Treatment is based on only few randomized controlled clinical trials and insufficiently evaluated surgical procedures.

Pulsed radiofrequency treatment for trigeminal neuralgia

Background:

Pulsed radiofrequency (PRF) treatment is defined as the delivery of short pulses of radiofrequency via a needle tip, which does not result in an actual thermal lesions. There are mixed views regarding the use of PRF for trigeminal neuralgia (TN). In our opinion, one of the main reasons for the contrasting views is the insufficient PRF dose employed in previous studies. In a recent study on the effects of PRF on resiniferatoxin-induced neuropathic pain in an animal model, the anti-allodynic effects of PRF were significantly greater when the PRF exposure duration was increased from 2 to 6 minutes.

Objectives:

The primary objective of this retrospective study is to report the results for 36 consecutive patients who underwent PRF treatment for TN, for 6 minutes at 45 V at a pulsed frequency of 4 Hz and a pulse width of 10 ms.

Patients and Methods:

For the study, we obtained procedural records of 36 consecutive patients. Their current state of pain was evaluated over a telephonic survey and the post-procedural data at 2, 6, and 12 months were retrieved thereafter from the patient records. The main outcome measure was excellent pain relief (more than 80%), which was assessed at 2, 6, and 12 months.

Results:

The percentages of patients who showed excellent pain relief (> 80% pain relief) at 2, 6, and 12 months were 73.5% (25/34), 61.8% (21/34), and 55.9% (19/34), respectively. The percentages of patients showing satisfactory pain relief (50–80% pain relief) at 2, 6, and 12 months were 14.7% (5/34), 17.6% (6/34), and 17.6% (6/34), respectively, and those of patients showing less than satisfactory pain relief (< 50% pain relief) at 2, 6, and 12 months were 11.8% (4/34), 20.6% (7/34), and 23.5% (8/34), respectively. No complications were reported, and none of the patients required hospitalization.

Conclusions:

PRF of the trigeminal ganglion should be further evaluated as an alternative treatment method for TN.

Use of single- and multi-drug regimens in the management of classic (idiopathic) trigeminal neuralgia: an 11-year experience at a single Sri Lankan institution

AIM

The aim of this retrospective study was to evaluate the outcome of medical treatment of classic trigeminal neuralgia and to assess the factors affecting the choice of drug regimen (single or multiple), and the duration of treatment for pain control.

METHODS

A total of 260 consecutive patients were included in the study. Sixty-one patients with less than 6 months' follow up were excluded. All patients were treated with carbamazepine alone or in combination with other drugs. The dosage was adjusted according to the level of pain control and side-effects.

RESULTS

Treatment was terminated in 99 patients (49.7%) after a mean follow-up period of 36.46 months (standard deviation: ±26.5). Of these, 39.4% were on a single drug. Carbamazepine was the drug used in 36 patients. The rest (61%) needed various combinations of drugs. One-hundred patients (50.3%) continued with medical treatment during the follow-up period. Of these, 67.4% were on multi-drug therapy.

CONCLUSION

The present study showed that the administration of multidrug regimens is a useful alternative in controlling trigeminal neuralgia in patients who are unable to tolerate higher doses of carbamazepine. Age, sex, ethnicity, and the side of affliction did not have a significant influence on the choice of drug regimen and the duration of treatment for pain control.

Lacrimal dacryostenosis with severe facial pain misdiagnosed as trigeminal neuralgia

A 47-year-old woman developed intermittent shooting pain around the right side of the nose and eyes. A neurologist initially diagnosed trigeminal neuralgia, but carbamazepine did not improve the pain. Two months later, she presented with a pus-like eye discharge and was referred to us for further examination. Poor saline irrigation from the lacrimal puncta and computed tomography findings of a swollen lacrimal sac indicated a diagnosis of lacrimal dacryostenosis. At this point, the pain and dizziness as a side effect of carbamazepine had become intolerable. Endoscopic intranasal dacryocystorhinostomy confirmed stenosis of the nasolachrymal duct and a thickened lacrimal sac. The postoperative course was uneventful, and the facial pain disappeared. This experience suggests the importance of recognizing lacrimal dacryostenosis as a differential diagnosis of facial pain around the eyes and nose. We also recommend a review of an original diagnosis of trigeminal neuralgia if carbamazepine fails to relieve facial pain.

A fMRI evaluation of lamotrigine for the treatment of trigeminal neuropathic pain: pilot study

Using functional magnetic resonance imaging (fMRI) methods, we evaluated the effects of lamotrigine vs placebo in a double-blind 1:1 randomized trial. Six patients with neuropathic pain were recruited for the study. All subjects had baseline pain >4/10 on a visual analog scale (VAS) and allodynia to brush as inclusion criteria for the study. Patients underwent two fMRI sessions, with half of the subjects receiving placebo first and half receiving drug first (based on the blinding protocol). Lamotrigine decreased their average pain intensity level from 5.6 to 3.5 on a VAS. All subjects had brush, cold, and heat applied to the affected and mirror-unaffected sides of their face. The results show: 1) in a small cohort, lamotrigine had a significant effect on heat VAS but not on the other stimuli; and 2) contrast analysis of fMRI results for heat stimuli applied to the affected face for lamotrigine vs placebo produced an overall decrease in blood oxygen dependent level signal, suggesting a potential inhibitory effect of the drug on predominantly cortical regions (frontal, parietal, and temporal).

Binocular motility system and temporomandibular joint internal derangement: a study in adults

INTRODUCTION

Ocular convergence defects have been confirmed in adults with temporomandibular joint (TMJ) dysfunction, but few studies of the relationship of the oculomotor apparatus to TMJ disc displacement have been reported. The purpose of this study was to examine the impact of disc displacement on the oculomotor capacity of the eyes in adults.

METHODS

Fifty symptomatic patients with bilateral TMJ disc displacement (13 men, 37 women; mean age, 28.84 +/- 8.22 years; range, 18-40 years) were compared with the same number of asymptomatic volunteers with normal disc position (14 men, 36 women; mean age, 29.96 +/- 5.04 years; range, 18-37 years). All subjects underwent standardized clinical examinations, bilateral TMJ magnetic resonance imaging, and sensorial and motor orthoptic tests by an orthoptist.

RESULTS

Subjects with TMJ disc displacement had alterations in binocular function, including reductions in convergence (P <0.023) and positive fusional vergence (break point [P <0.046] and recovery point [P <0.045]) compared with those with normal disc positions.

CONCLUSIONS

Significant alternations in binocular function were seen in patients with TMJ disc displacement compared with healthy control subjects.

[Improvement of diagnosis and treatment of glossopharyngeal neuralgia]

Differential diagnosis of neuralgias affecting the cranial nerves and of facial pain is often difficult. Glossopharyngeal neuralgia is much less common than trigeminal neuralgia and is not well known. Idiopathic neuralgia of the glossopharyngeal nerve sometimes occurs in association with neurovascular compression syndrome of the vagus and trigeminal nerves. High-resolution MRI of the brain stem with three-dimensional visualization allows a secure diagnosis of neurovascular compression and is useful in the planning of appropriate microsurgical decompression (Jannetta's operation).

Temporomandibular dysfunction: an often overlooked cause of chronic headaches

OBJECTIVE

To review and discuss the role of temporomandibular dysfunction (TMD) as a cause of chronic headaches and facial pain.

DATA SOURCES AND STUDY SELECTION

A literature review was performed using the PubMed database for English-language articles published between January 1, 1981, and August 31, 2006, using the following keywords: temporomandibular dysfunction, temporomandibular disorder, temporomandibular joint, and chronic headache. Additional information was obtained from a review of current medical texts.

RESULTS

Allergists and immunologists are frequently called on to evaluate patients with chronic headaches and facial pain. TMD is known to cause recurrent facial discomfort and headaches. Many individuals with the disorder present with headache or facial discomfort as their only chief complaint. They mistakenly think it is a "sinus" headache. Nearly 10 million Americans are affected by the disorder, and early studies estimate that TMD pain is the cause of chronic headaches in 14% to 26% of individuals with recurrent headaches.

CONCLUSIONS

TMD is a likely underdiagnosed cause of chronic headache and facial discomfort. As such, many patients with the disorder are routinely mislabeled as experiencing chronic sinusitis and are unnecessarily subjected to multiple courses of broad-spectrum antibiotics and other unnecessary therapy. TMD can be readily diagnosed by a careful history and physical examination. Patients typically respond well to conservative therapy, which includes behavioral modification and nonsteroidal anti-inflammatory drugs. The disorder should be suspected in individuals with a long-standing history of chronic daily headaches and facial pain without objective evidence of sinus, neurologic, or intracranial abnormalities.