Oxytocin-Dependent Regulation of TRPs Expression in Trigeminal Ganglion Neurons Attenuates Orofacial Neuropathic Pain Following Infraorbital Nerve Injury in Rats.

We evaluated the mechanisms underlying the oxytocin (OXT)-induced analgesic effect on orofacial neuropathic pain following infraorbital nerve injury (IONI). IONI was established through tight ligation of one-third of the infraorbital nerve thickness. Subsequently, the head withdrawal threshold for mechanical stimulation (MHWT) of the whisker pad skin was measured using a von Frey filament. Trigeminal ganglion (TG) neurons innervating the whisker pad skin were identified using a retrograde labeling technique. OXT receptor-immunoreactive (IR), transient receptor potential vanilloid 1 (TRPV1)-IR, and TRPV4-IR TG neurons innervating the whisker pad skin were examined on post-IONI day 5. The MHWT remarkably decreased from post-IONI day 1 onward. OXT application to the nerve-injured site attenuated the decrease in MHWT from day 5 onward. TRPV1 or TRPV4 antagonism significantly suppressed the decrement of MHWT following IONI. OXT receptors were expressed in the uninjured and Fluoro-Gold (FG)-labeled TG neurons. Furthermore, there was an increase in the number of FG-labeled TRPV1-IR and TRPV4-IR TG neurons, which was inhibited by administering OXT. This inhibition was suppressed by co-administration with an OXT receptor antagonist. These findings suggest that OXT application inhibits the increase in TRPV1-IR and TRPV4-IR TG neurons innervating the whisker pad skin, which attenuates post-IONI orofacial mechanical allodynia.

First Bite Syndrome Following Carotid Endarterectomy.

A 67-year-old man with a high position carotid plaque presented with severe pain in ipsilateral parotid region several days after carotid endarterectomy (CEA). The pain occurred at the first bite of each meal and resolved as further bite. We diagnosed the pain as first bite syndrome (FBS). FBS is infrequent but known as a complication associated with parapharyngeal space surgery. The pain is characterized by sharp pain in the parotid region associated with mastication. The cause is unclear but thought to the result from sympathetic denervation of the parotid gland, followed by parasympathetic nerve hypersensitivity. Only five cases associated with carotid endarterectomy (CEA) have been reported. We should be in mind that CEA for high position plaque is one of the risk factors to cause FBS associated with CEA. Neurologists and vascular surgeons as well as otolaryngologists should all be informed FBS as one of the complications after carotid endarterectomy.

Transcutaneous Electrical Nerve Stimulation for Facial Pain.

Transcutaneous electrical nerve stimulation (TENS) has been used for its analgesic effects for chronic pain, including facial pain. Here, we summarize how the electrical stimulation of branches of the trigeminal nerve via TENS has been utilized to reduce pain resulting from trigeminal neuralgia, temporomandibular joint disorder, migraine and other headache types, and ocular pain sensations. TENS has been used for both short-term (one session) and long-term (multiple sessions) pain control with little to no adverse effects reported by subjects. The results of the summarized studies suggest TENS is an effective non-invasive, non-pharmacologic means of pain control for patients with facial pain conditions.

Relation between volume of sphenoid sinuses and protrusion of Vidian nerve: possible applications to Vidian neurectomy.

PURPOSE: Vidian neurectomy is a surgical procedure applied to different pathological conditions, including chronic rhinitis and sphenopalatine neuralgia. The choice of the correct surgical approach depends upon the possible protrusion of Vidian nerve into the sphenoid sinuses. The present study analyzes the possible relationship between protrusion of Vidian nerve and volume of sphenoid sinuses. METHODS: In total, 320 maxillofacial CT-scans were retrospectively assessed. Subjects equally divided among males and females (age range 18-94 years) were divided into three groups according to the profile of Vidian nerve protrusion: type 1: Vidian nerve inside the sphenoid corpus; type 2: partially protruding into the sphenoid sinus; and type 3: entirely protruding into the sphenoid sinus through a stalk. Volume of sphenoid sinuses was extracted through the ITK-SNAP-free software and automatically calculated. Possible statistically significant differences in prevalence of the three types between males and females were assessed through Chi-squared test (p < 0.05). Differences in volume of sphenoid sinuses in subjects included within the three types were assessed through one-way ANOVA test (p < 0.05), separately for males and females. RESULTS: Type 2 was the most prevalent (46.5%), followed by type 1 (38.8%) and type 3 (14.7%), without significant differences according to sex (p > 0.05). Volume significantly increased passing from type 1 to type 3 both in males (p < 0.01) and in females (p < 0.01). CONCLUSIONS: The results prove the existence of a strict relationship between sphenoid sinuses pneumatization and protrusion of the Vidian canal and give a contribution to the knowledge of this important anatomical variant in endoscopic surgery.

Sphenopalatine Neuralgia: An Independent Neuralgia Entity. Pooled Analysis of a Case Series and Literature Review.

BACKGROUND: Structural damage or demyelization of the sphenopalatine ganglion may cause sphenopalatine neuralgia (SN). The current International Classification of Headache Disorders, third edition (ICHD-3) regards SN as a phenotype of cluster headache. Whether SN is an independent neuralgia entity has been debated for years. METHODS: This article presents a case series of SN, a review of all published cases, and a pooled data analysis of the identified cases. RESULTS: Seven patients were identified, with a median age at symptom onset of 59 years. Six cases were secondary to structural lesions surrounding the ipsilateral sphenopalatine ganglion, and all of them experienced significant clinical improvements after removing the primary causes. In the seventh patient, no evidence of underlying disease was found. The literature review showed that SN affected patients spanning a wide range of ages and both sexes. The clinical characteristics of SN might mimic cluster headache with the exception of cluster pattern and treatment response to oxygen. The typical duration of pain episodes in SN was several hours to several days; and in some cases, pain was persistent. Sixty-seven percent (59/88) of patients with SN had structural lesions around the sphenopalatine ganglion. CONCLUSION: SN could possibly be regarded as a different clinical entity from cluster headache. Based on our patients and literature review, SN can be categorized as idiopathic SN and secondary SN. Craniofacial structural lesions should be highly rating and taken into account when SN is suspected.

Effect of myofascial techniques for treatment of persistent arm pain after breast cancer treatment: randomized controlled trial.

OBJECTIVE: To investigate the effect of myofascial therapy in addition to a standard physical therapy program for treatment of persistent arm pain after finishing breast cancer treatment. DESIGN: Double-blinded (patient and assessor) randomized controlled trial. SETTING: University Hospitals Leuven, Belgium. PATIENTS: A total of 50 patients with persistent arm pain and myofascial dysfunctions after breast cancer treatment. INTERVENTION: Over three months, all patients received a standard physical therapy program. The intervention group received in addition 12 sessions of myofascial therapy, and the control group received 12 sessions of placebo therapy. MAIN MEASUREMENTS: Main outcome parameters were pain intensity (primary outcome) (maximum visual analogue scale (VAS) (0-100)), prevalence rate of arm pain, pressure hypersensitivity (pressure pain thresholds (kg/cm2) and pain quality (McGill Pain Questionnaire). Measures were taken before and after the intervention and at long term (6 and 12 months follow-up). RESULTS: Patients in the intervention group had a significantly greater decrease in pain intensity compared to the control group (VAS -44/100 vs. -24/100, P = 0.046) with a mean difference in change after three months between groups of 20/100 (95% confidence interval, 0.4 to 39.7). After the intervention, 44% versus 64% of patients still experienced pain in the intervention and control group, respectively ( P = 0.246). No significant differences were found for the other outcomes. CONCLUSION: Myofascial therapy is an effective physical therapy modality to decrease pain intensity at the arm in breast cancer survivors at three months, but no other benefits at that time were found. There were no long-term effects at 12 months either.

Efficacy of botulinum toxin therapy in treatment of myofascial pain.

The present study aimed to assess the efficacy of using botulinum toxin (BTX) in temporomandibular joint disorders, particularly pertaining to myofascial pain from masseter and temporal muscles. The study included 11 patients who were diagnosed with masseter and temporalis myofascial pain. Visual analog scale for pain and pressure algometry were conducted initially, after 1 month of conservative therapy (control group), and after 1 month of BTX type A injections (study group). Data were statistically analyzed (analysis of variance and Wilcoxon's test) to determine intergroup differences. Both conservative therapy and BTX injections showed reduction in pain scores and increase in pain threshold compared with baseline, and statistically significant differences were noted between both groups. Thus, BTX injections appear to be effective in management of chronic myofascial pain targeting masseter and temporalis muscles.

[Botulinus toxin in complex treatment of myofacial pain syndrome]. / Botulotoksin v kompleksnom lechenii patsientov s miofastsial'nym bolevym sindromom disfunktsii visochno-nizhnecheliustnogo sustava.

The aim of the study was to assess the efficacy of type A Botulinus toxin (BTA) in pain release by TMJ functional pain disorders. The study included 211 patients with TMJ functional pain disorder (20.4% males and 79.6% females; mean age 45.3 years). The patients underwent clinical examination and bioelectric activity assessment of masticatory muscles by electromyography (EMG). EMG specters of 20 healthy volunteers with intact dental arches served as a control. After examination BTA was injected in muscular pain trigger points. All patients had muscular hypertonus, unilateral in 88.6% and bilateral in 11.4%. EMG showed the decrease of masticatory muscle activity on affected side to mean values of 165±20 mkV (30.0%, p<0.05) and on contralateral side to 460±31 mkV (89.6%, p>0.05). BTA injections in tensed muscles released significantly muscle-induced facial pain and improved quality of life. During 6 months follow up myofacial pain disorder relapse was seen in 3 patients. The results allow recommending BTA injection in muscular pain trigger points for treatment of myofacial pain syndrome and prolonged muscle relaxation.

[Extensive tumor of the skull base: sphenoid sinus adenocarcinoma]. / Tumeur étendue de la base du crâne: adénocarcinome du sinus sphénoïdal.

We report a rare case of adenocarcinoma of the sphenoid sinus manifesting as extended skull base tumor. The patient included in the study was a 42-year old woman presenting with unilateral right symptomatology consisting of nasal obstruction, diplopia and hemifacial neuralgias. Clinical examination showed paralysis of the cranial nerve pairs V and VI. Brain scanner showed voluminous heterogeneous sphenoid and clival mass reaching the right cavernous sinus, with a peripheral tissue component at the level of the sphenoid sinus. Biopsy was performed under general anesthesia, through endonasal sphenoidotomy approach. Histological examination showed non-intestinal adenocarcinoma. The patient died due to impaired general condition occurred during examinations. Skull base adenocarcinomas mainly occur in the ethmoid bone. Sphenoid origin is exceptional. Radiological appearance is not specific and suggests malignancy. Diagnosis should be suspected in patients with aggressive tumor, even when it occurs in the midline skull base.

Osteoid osteoma of the temporal bone manifesting as first bite syndrome and a meta-analysis combined with osteoblastoma.

The objectives of this study were to describe a case of osteoid osteoma arising from the temporal bone manifesting only as first bite syndrome as the sole clinical symptom, to perform a meta-analysis of previously reported cases, and to differentiate the clinical characteristics of osteoid osteoma from those of osteoblastoma arising from the temporal bone. In addition to our case, articles addressing osteoid osteoma or osteoblastoma arising from the temporal bone were selected using PubMed, Embase, and the Japan Medical Abstracts Society database (1954 through 2014), with no language preference. The database was searched using the keywords ["osteoid osteoma" OR "osteoblastoma" AND "temporal bone"]. After critical review of 88 studies, 10 cases of osteoid osteoma and 29 cases of osteoblastoma were selected; therefore, including the present case, a total of 40 cases were eligible for qualitative analyses. The mean size of osteoid osteoma was 1.2 cm, which was significantly smaller than that of osteoblastoma (5.1 cm). Radiologically, osteoid osteoma was associated with a lower prevalence of extension into more than two anatomically categorized spaces in comparison with osteoblastoma (P < 0.01). Again, a lower prevalence of erosion of the outer and/or inner tables of the skull in the osteoid osteoma cases was noted (P < 0.05). Conversely, there were no significant differences in the prevalence of representative clinical symptoms, including pain and swelling. According to the present systematic review, osteoid osteoma and osteoblastoma are clinically uniform other than their size or extension.

[Cluster headache differential diagnosis]. / Diagnostic différentiel de l'AVF.

Cluster headache is characterized by disabling stereotyped headache. Early diagnosis allows appropriate treatment, unfortunately diagnostic errors are frequent. The main differential diagnoses are other primary or essential headaches. Migraine, more frequent and whose diagnosis is carried by excess, trigeminal neuralgia or other trigemino-autonomic cephalgia. Vascular or tumoral underlying condition can mimic cluster headache, neck and brain imaging is recommended, ideally MRI.

[Epidemiology, clinical presentation, diagnosis, natural history and screening of cluster headache]. / Épidémiologie, description clinique, diagnostic positif clinique, évolution naturelle, dépistage de l'AVF.

This review is focused on the essential data about epidemiology, clinical presentation, diagnosis, natural history and screening for cluster headache.

[Pathophysiology of cluster headache]. / Physiopathologie de l'algie vasculaire de la face (AVF).

The aetiology of cluster headache is partially unknown. Three areas are involved in the pathogenesis of cluster headache: the trigeminal nociceptive pathways, the autonomic system and the hypothalamus. The cluster headache attack involves activation of the trigeminal autonomic reflex. A dysfunction located in posterior hypothalamic gray matter is probably pivotal in the process. There is a probable association between smoke exposure, a possible genetic predisposition and the development of cluster headache.

The neurosurgical treatment of neuropathic facial pain.

This article reviews the definition, etiology and evaluation, and medical and neurosurgical treatment of neuropathic facial pain. A neuropathic origin for facial pain should be considered when evaluating a patient for rhinologic surgery because of complaints of facial pain. Neuropathic facial pain is caused by vascular compression of the trigeminal nerve in the prepontine cistern and is characterized by an intermittent prickling or stabbing component or a constant burning, searing pain. Medical treatment consists of anticonvulsant medication. Neurosurgical treatment may require microvascular decompression of the trigeminal nerve.

Eagle syndrome.

Eagle syndrome, also known as elongated styloid process, is a condition first described by Watt Eagle in 1937. It occurs when an elongated styloid process or calcified stylohyoid ligament causes recurrent throat pain or foreign body sensation, dysphagia, or facial pain. Additional symptoms may include neck or throat pain with radiation to the ipsilateral ear. It is usually hard to diagnose because the symptoms related to this condition can be confused with those attributed to a wide variety of facial neuralgias. In this article, a case of Eagle syndrome exhibiting unilateral symptoms with bilateral elongation of styloid process is reported.

Width of the normal facial canal measured by high-resolution cone-beam computed tomography.

CONCLUSIONS: In the facial canal, discrepancies between left and right side measurements at each point may be useful in the assessment and diagnosis of facial canal-related pathologies. OBJECTIVES: This study was performed to obtain accurate and high-resolution images of the normal facial canal and measure its widths on cross-sections of the canal at anatomically and clinically important sites using high-resolution cone-beam computed tomography (CBCT). METHODS: CBCT volume data of bilateral temporal bones were obtained from 28 healthy adult volunteers. The widths of the bony facial canals were measured at the meatal foramen, the cochleariform process, the stapes, the pyramidal eminence, and the point of emergence of the chorda tympani in the vertical segment. RESULTS: The widths of the facial canal at each point were similar bilaterally (r = 0.54-0.85, p < 0.01), but showed regional differences and site-specific variations. The narrowest of the five sites was the level of the meatal foramen (p < 0.05), as reported previously. The second narrowest site was the level of the stapes (p < 0.01) followed in order by the level of the cochleariform process, the pyramidal eminence, and the point of emergence of the chorda tympanis (p < 0.01).

Malignant peripheral nerve sheath tumors of the trigeminal nerve: a systematic review of 36 cases.

OBJECT: Malignant peripheral nerve sheath tumors (MPNSTs) are a rare form of malignancy arising from the Schwann cells of peripheral nerves. MPNSTs of the trigeminal nerve are exceptionally rare, with only a handful of reports in the literature. These tumors are typically very aggressive, resulting in significant patient morbidity and a generally grim prognosis. Most current reports suggest that radical resection with radiation therapy offers the best benefit. In this study, the authors systematically reviewed the world English-language literature on MPNSTs of the trigeminal nerve to analyze the presentations, treatment options, and outcomes for patients with this disease. METHODS: A literature search for MPNSTs of the trigeminal nerve confined to nonanimal, English-language articles was conducted utilizing the PubMed database, with additional cases chosen from the references of selected articles. Only cases of confirmed MPNSTs of the trigeminal nerve or its peripheral branches, based upon surgical, pathological, or radiological analysis, were included. RESULTS: From the literature search, 29 articles discussing 35 cases of MPNSTs of the trigeminal nerve were chosen. With the addition of 1 case from their own institution, the authors analyzed 36 cases of trigeminal MPNSTs. The average age of onset was 44.6 years. These tumors were more commonly seen in male patients (77.1%). The gasserian ganglion was involved in 36.1% of the cases. Of the cases in which the nerve distribution was specified (n = 25), the mandibular branch was most commonly involved (72.0%), followed by the maxillary branch (60.0%) and the ophthalmic branch (32.0%), with 44.0% of patients exhibiting involvement of 2 or more branches. Altered facial sensation and facial pain were the 2 most commonly reported symptoms, found in 63.9% and 52.8% of patients, respectively. Mastication difficulty and diplopia were seen in 22.2% of patients, facial weakness was seen in 19.4%, and hearing loss was present in 16.7%. With regard to the primary treatment strategy, 80.6% underwent resection, 16.7% underwent radiation therapy, and 2.9% received chemotherapy alone. Patients treated with complete resection followed by postoperative radiation therapy had the most favorable outcomes, with no patients showing evidence of disease recurrence with a mean follow-up of 34.6 months. Patients treated with incomplete resection followed by postoperative radiation therapy had more favorable outcomes than patients treated with incomplete resection without radiation therapy or radiation therapy alone. CONCLUSIONS: Trigeminal MPNSTs most commonly present as altered facial sensation or facial pain, although they exhibit a number of other clinical manifestations, including the involvement of other cranial nerves. While a variety of treatment options exist, due to their highly infiltrative nature, aggressive resection followed by radiation therapy appears to offer the greatest chance of recurrence-free survival.