A pain in the ear: Two case reports of nervus intermedius neuralgia and narrative review.

OBJECTIVE: Present two cases of nervus intermedius neuralgia (NIN) in which patients described unilateral deep ear pain as their primary complaint and present a summary of NIN cases reported in the literature. BACKGROUND: The nervus intermedius is a tiny branch of the facial nerve that, with neuralgia, can present as a deep ear pain (NIN). The International Classification of Headache Disorders, 3rd edition, (ICHD-3) criteria for an NIN diagnosis include a unilateral deep ear pain with possible radiation that occurs in paroxysms with sharp pain and a tactile trigger. METHODS: A PubMed search was conducted for NIN and geniculate neuralgia. Two patients recently diagnosed with NIN at a single clinic were selected for case reports to highlight the variability of symptom presentation. RESULTS: The two cases reported here and the 127 cases reported in the literature show a wider range of presentations than included in the ICHD-3 criteria, including variable pain radiation sometimes diagnosed as concurrent trigeminal, glossopharyngeal, or occipital neuralgia. Pain was reported as constant or paroxysmal, as well as dull, sharp, or neuralgiform with inconsistent presence of triggers. While ICHD-3 does mention reported taste change, lacrimation, and salivation, the literature reports a much wider range of potential features associated with NIN. Optimal medical treatment is unclear given the predominance of surgical reporting of positive response to microvascular decompression, nerve sectioning, or other procedures. The two cases described here were successfully managed medically. CONCLUSION: NIN can present as described in the ICHD-3, but a more variable presentation may be possible. More studies are needed to clarify presentation, optimal medical treatment, and surgical indications for patients with NIN, especially when patients have no clear neurovascular conflict on neuroimaging.

Characteristics and natural disease history of persistent idiopathic facial pain, trigeminal neuralgia, and neuropathic facial pain.

OBJECTIVE: This study aimed to characterize key features, and to assess the clinical development of common nondental facial pain syndromes such as persistent idiopathic facial pain (PIFP), trigeminal neuralgia (TN), and neuropathic facial pain (NEUROP). METHODS: This is a longitudinal study in which prospective questionnaire data of patients presenting to a specialized outpatient clinic were collected from 2009 to 2019. A telephone interview was conducted with the same patients in 2020 to assess the natural disease history. RESULTS: n = 411 data sets of patients with chronic facial pain were compiled. Among these were n = 150 patients with PIFP, n = 111 patients with TN, and n = 86 patients with NEUROP. Guideline therapy had not been initiated in 38.7% (58/150; PIFP), 19.8% (22/111; TN), and 33.7% (29/86; NEUROP) patients. Of the patients with PIFP, 99.3% (149/150) had primarily consulted a dentist due to their pain syndrome. The additional telephone interview was completed by 236 out of the 411 patients (57.4%). Dental interventions in healthy teeth had been performed with the intention to treat the pain in many patients (78/94 [83.0%] PIFP; 34/62 [54.8%] TN; 19/43 [44.2%] NEUROP), including dental extractions. 11.3% (7/43) of the patients with TN had never profited from any therapy. In contrast, 29.8% (28/94) of the patients with PIFP had never profited from any therapy. Furthermore, the primary pharmaceutical therapy options suggested by national guidelines were, depending on the substance class, only considered to be effective by 13.8% (13/94; antidepressants) and 14.9% (14/94; anticonvulsants) of the patients with PIFP. CONCLUSIONS: Facial pain syndromes pose a considerable disease burden. Although treatment of TN seems to be effective in most patients, patients with PIFP and NEUROP report poor effectiveness even when following guideline therapy suggestions. In addition, unwarranted dental interventions are common in facial pain syndromes.

Differences in the Clinical Characteristics of Persistent Idiopathic Facial Pain (Atypical Odontalgia) Patients with or Without Neurovascular Compression of the Trigeminal Nerve.

BACKGROUND: Persistent idiopathic facial pain (PIFP) is the unexplained pain along the territory of the trigeminal nerve, including nonorganic tooth pain called atypical odontalgia (AO). Though PIFP is debilitating to patients' livelihood and well-being, its pathophysiology remains poorly understood. Although neurovascular compression (NVC) of the trigeminal nerve is known to be associated with trigeminal neuralgia (TN), the relationship between NVC and other orofacial pains has not been fully elucidated. METHODS: In this study, we investigated the differences in the characteristics of PIFP (primarily AO) patients in the presence or absence of NVC. A retrospective analysis was performed on data from 121 consecutive patients who had been diagnosed with unilateral PIFP according to the criteria of the International Classification of Headache Disorders (ICHD)-3 and underwent magnetic resonance imaging scans of the head. RESULTS: In the group without NVC, characteristic findings were significant for psychiatric morbidity, somatization, and pain disability, when compared with the group with NVC. Furthermore, the group without NVC exhibited significant headache, noncardiac chest pain, shortness of breath, and pain catastrophizing. CONCLUSIONS: These results suggest that PIFP patients can be divided into two groups: one consistent with a neuropathic pain phenotype when NVC is present and a functional somatic symptom phenotype when presenting without NVC. Our findings may enable a more precise understanding of pathophysiology of PIFP and lead to better treatment strategies.

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.

Comparative study of shockwave therapy and low-level laser therapy effects in patients with myofascial pain syndrome of the trapezius.

The objective of the study was to compare the effects of shockwave therapy and laser therapy on pain, neck functionality, and quality of life in patients with myofascial pain syndrome of the trapezius. 61 patients (> 18 years) were randomly allocated to two treatment groups: (1) 31 patients received soft laser therapy once daily in a 3-week period for a total of 15 sessions, (2) 30 patients received shockwave therapy once in a week for 3 weeks, totalling 3 treatments. Resting pain and pain tolerance were assessed by a 100 mm visual analogue scale; functional status and quality of life were measured by specific questionnaires (Neck Disability Index, SF-36) before and after the 3-week therapy and at the 15th week follow-up visit. All measured parameters improved significantly in both groups at week 3 and week 15. Comparing the two groups, patients receiving shockwave therapy demonstrated significantly better changes in pain tolerance (mean between-group differences at visit 1-0 = 14.911, 95% CI = 2.641-27.182, mean between-group differences at visit 2-0 = 17.190, 95% CI = 4.326-30.055 in the left trapezius), neck functionality (mean between-group differences at visit 1- 0 = 0.660, 95% CI = - 1.933 to 3.253, mean between-group differences at visit 2-0 = 1.072, 95% CI = - 2.110 to 4.254), and in all domains using SF-36 QoL questionnaire. The only parameter in which the laser group showed significantly higher benefits was at week 15 for resting pain (mean between-group differences at visit 2-0 = - 1.345, 95% CI = - 14.600 to 11.910). The results of our study point to a conclusion that both laser and shockwave therapy are effective in myofascial pain syndrome, though we found shockwave therapy to be somewhat more beneficial. Clinical trial registration number NCT03436459 ( https://clinicaltrials.gov/ct2/show/NCT03436459 ).

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.

[Real Time Fuctional Magnetic Resonance Imaging Biofeedback: a New Generation of Neurotherapy].

The review summarizes the data related to the potential of the real time fMRI biofeedback (the rt-fMRI), a novel technology implementing instructing patients to modify the neural activity in the certain brain regions related to the disordered function. The recent positive results were gained for a treatment of the post-stroke impairments, the Parkinson disease, the pain syndrome, the tinnitus, the alcohol and nicotine abuse, the major depression, and phobias of contamination and spiders. The intervention Was found to be less promising for schizophrenia and nearly ineffective for the criminal antisocial personality disorder. The reliability of the results is mostly poor due to suboptimal study designs, lack of the control groups, and insufficient sample sizes. The article deals with biological basis of the technology, its current applications and perspectives; and also its method- ologicdl and methodical problems.

The effects of levetiracetam, sumatriptan, and caffeine in a rat model of trigeminal pain: interactions in 2-component combinations.

BACKGROUND: Levetiracetam is an antiepileptic drug with analgesic efficacy shown in pain models and small clinical trials. Sumatriptan is used in acute migraine treatment. Caffeine is widely consumed in some beverages/foods and is also an adjuvant in analgesic formulations. We examined the effects of systemic levetiracetam, sumatriptan, and caffeine and their interactions in 2-component combinations in the rat orofacial formalin test, a model of trigeminal pain. METHODS: Rats received a subcutaneous injection of formalin solution into the perinasal area, and the total time spent in nociceptive behavior (face rubbing) was quantified. The antinociceptive effect of drugs/drug combinations was assessed 1 hour after per os administration. The type of interaction between levetiracetam/sumatriptan and caffeine was examined by comparing the effects of a fixed, effective dose of levetiracetam/sumatriptan alone with the effects of the same dose applied with increasing, subeffective doses of caffeine. The type of interaction between levetiracetam and sumatriptan was determined by isobolographic analysis. RESULTS: Levetiracetam (1-50 mg/kg) and sumatriptan (0.5-5 mg/kg) produced significant and dose-dependent antinociceptive effects in both phases of the orofacial formalin test (P ≤ 0.001). Caffeine (7.5-100 mg/kg) produced significant antinociception in the second phase of the test (P = 0.04). Caffeine (1-7.5 mg/kg) significantly reduced the antinociceptive effects of levetiracetam (25 mg/kg) (first phase P = 0.002, second phase P < 0.001) and sumatriptan (2.5 mg/kg) (first phase P = 0.014, second phase P = 0.027); dose-dependent inhibition was observed in the second phase. Levetiracetam and sumatriptan exerted an additive interaction in the second phase of the orofacial formalin test. CONCLUSIONS: Results indicate that levetiracetam may be useful for treatment of pain in the trigeminal region. Dietary caffeine might decrease the effects of levetiracetam and sumatriptan; this needs to be considered in clinical settings. A levetiracetam-sumatriptan combination could also be useful in trigeminal pain treatment. Its efficacy and adverse effects should be examined clinically.

Ultrasound-guided stellate ganglion block: safety and efficacy.

Cervical sympathetic and stellate ganglion blocks (SGB) provide a valuable diagnostic and therapeutic benefit to sympathetically maintained pain syndromes in the head, neck, and upper extremity. With the ongoing efforts to improve the safety of the procedure, the techniques for SGB have evolved over time, from the use of the standard blind technique, to fluoroscopy, and recently to the ultrasound (US)-guided approach. Over the past few years, there has been a growing interest in the ultrasound-guided technique and the many advantages that it might offer. Fluoroscopy is a reliable method for identifying bony surfaces, which facilitates identifying the C6 and C7 transverse processes. However, this is only a surrogate marker for the cervical sympathetic trunk. The ideal placement of the needle tip should be anterolateral to the longus colli muscle, deep to the prevertebral fascia (to avoid spread along the carotid sheath) but superficial to the fascia investing the longus colli muscle (to avoid injecting into the muscle substance). Identifying the correct fascial plane can be achieved with ultrasound guidance, thus facilitating the caudal spread of the injectate to reach the stellate ganglion at C7-T1 level, even if the needle is placed at C6 level. This allows for a more effective and precise sympathetic block with the use of a small injectate volume. Ultrasound-guided SGB may also improve the safety of the procedure by direct visualization of vascular structures (inferior thyroidal, cervical, vertebral, and carotid arteries) and soft tissue structures (thyroid, esophagus, and nerve roots). Accordingly, the risk of vascular and soft tissue injury may be minimized.

The pterygopalatine ganglion and its role in various pain syndromes: from anatomy to clinical practice.

The postsynaptic fibers of the pterygopalatine or sphenopalatine ganglion (PPG or SPG) supply the lacrimal and nasal glands. The PPG appears to play an important role in various pain syndromes including headaches, trigeminal and sphenopalatine neuralgia, atypical facial pain, muscle pain, vasomotor rhinitis, eye disorders, and herpes infection. Clinical trials have shown that these pain disorders can be managed effectively with sphenopalatine ganglion blockade (SPGB). In addition, regional anesthesia of the distribution area of the SPG sensory fibers for nasal and dental surgery can be provided by SPGB via a transnasal, transoral, or lateral infratemporal approach. To arouse the interest of the modern-day clinicians in the use of the SPGB, the advantages, disadvantages, and modifications of the available methods for blockade are discussed.▪

Altered regional brain morphology in patients with chronic facial pain.

BACKGROUND: Persistent idiopathic facial pain (PIFP) is defined as a persistent, unilateral facial pain, not associated with sensory loss or other physical signs and with no obvious structural abnormalities that would sufficiently explain pain experience. OBJECTIVE: We were interested whether there is evidence of altered brain morphology in patients with PIFP as it has been described in other chronic pain conditions. METHODS: Using voxel-based morphometry we investigated regional gray matter volume in 11 PIFP patients and 11 age- and sex-matched healthy controls. Furthermore we calculated lateralization indices (LI) to investigate differences in interhemispheric gray matter asymmetries. RESULTS: We report a decrease in gray matter volume in the left anterior cingulate gyrus and left temporo-insular region, as well as in the left and right sensory-motor area, projecting to the representational area of the face. Analyses of LI values demonstrated an increased rightward asymmetry in the middle-anterior insular cortex in patients in comparison with healthy controls. CONCLUSION: Our data support previous findings showing that chronic pain states are display-altered brain morphology in brain regions know to be part of the pain system.

Idiopathic ophthalmodynia and idiopathic rhinalgia: two topographic facial pain syndromes.

OBJECTIVE: To describe 2 topographic facial pain conditions with the pain clearly localized in the eye (idiopathic ophthalmodynia) or in the nose (idiopathic rhinalgia), and to propose their distinction from persistent idiopathic facial pain. BACKGROUND: Persistent idiopathic facial pain, burning mouth syndrome, atypical odontalgia, and facial arthromyalgia are idiopathic facial pain syndromes that have been separated according to topographical criteria. Still, some other facial pain syndromes might have been veiled under the broad term of persistent idiopathic facial pain. METHODS: Through a 10-year period we have studied all patients referred to our neurological clinic because of facial pain of unknown etiology that might deviate from all well-characterized facial pain syndromes. RESULTS: In a group of patients we have identified 2 consistent clinical pictures with pain precisely located either in the eye (n=11) or in the nose (n=7). Clinical features resembled those of other localized idiopathic facial syndromes, the key differences relying on the topographic distribution of the pain. CONCLUSIONS: Both idiopathic ophthalmodynia and idiopathic rhinalgia seem specific pain syndromes with a distinctive location, and may deserve a nosologic status just as other focal pain syndromes of the face. Whether all such focal syndromes are topographic variants of persistent idiopathic facial pain or independent disorders remains a controversial issue.

Electrical stimulation of sphenopalatine ganglion for acute treatment of cluster headaches.

INTRODUCTION: Cluster headaches (CH) are primary headaches marked by repeated short-lasting attacks of severe, unilateral head pain and associated autonomic symptoms. Despite aggressive management with medications, oxygen therapy, nerve blocks, as well as various lesioning and neurostimulation therapies, a number of patients are incapacitated and suffering. The sphenopalatine ganglion (SPG) has been implicated in the pathophysiology of CH and has been a target for blocks, lesioning, and other surgical approaches. For this reason, it was selected as a target for an acute neurostimulation study. METHODS: Six patients with refractory chronic CH were treated with short-term (up to 1 hour) electrical stimulation of the SPG during an acute CH. Headaches were spontaneously present at the time of stimulation or were triggered with agents known to trigger clusters headache in each patient. A standard percutaneous infrazygomatic approach was used to place a needle at the ipsilateral SPG in the pterygopalatine fossa under fluoroscopic guidance. Electrical stimulation was performed using a temporary stimulating electrode. Stimulation was performed at various settings during maximal headache intensity. RESULTS: Five patients had CH during the initial evaluation. Three returned 3 months later for a second evaluation. There were 18 acute and distinct CH attacks with clinically maximal visual analog scale (VAS) intensity of 8 (out of 10) and above. SPG stimulation resulted in complete resolution of the headache in 11 attacks, partial resolution (>50% VAS reduction) in 3, and minimal to no relief in 4 attacks. Associated autonomic features of CH were resolved in each responder. Pain relief was noted within several minutes of stimulation. CONCLUSION: Sphenopalatine ganglion stimulation can be effective in relieving acute severe CH pain and associated autonomic features. Chronic long-term outcome studies are needed to determine the utility of SPG stimulation for management and prevention of CH.

[The role of therapeutic exercises in the combined treatment and rehabilitation of patients with pain syndrome associated with the dysfunction of temporomandibular joint].

In a group of patients with pain syndrome associated with the dysfunction of temporomandibular joint positive results of combined therapy and rehabilitative treatment including remedial gymnastics persisted significantly longer than in controls (p < 0.01). Results of long-term follow-up confirmed the desirability of rehabilitation based on therapeutic exercises. This approach permits to enhance the effectiveness of therapy and rehabilitation of patients with pain syndrome associated with the dysfunction of temporomandibular joint, reduce the number of the patients' visits for repeated treatment and its total duration during a year.

Anatomy of Trigeminal Neuromodulation Targets: From Periphery to the Brain.

The trigeminal nerve complex is a very important and somewhat unique component of the nervous system. It is responsible for the sensory signals that arise from the most part of the face, mouth, nose, meninges, and facial muscles, and also for the motor commands carried to the masticatory muscles. These signals travel through a very complex set of structures: dermal receptors, trigeminal branches, Gasserian ganglion, central nuclei, and thalamus, finally reaching the cerebral cortex. Other neural structures participate, directly or indirectly, in the transmission and modulation of the signals, especially the nociceptive ones; these include vagus nerve, sphenopalatine ganglion, occipital nerves, cervical spinal cord, periaqueductal gray matter, hypothalamus, and motor cortex. But not all stimuli transmitted through the trigeminal system are perceivable. There is a constant selection and modulation of the signals, with either suppression or potentiation of the impulses. As a result, either normal sensory perceptions are elicited or erratic painful sensations are created. Electrical neuromodulation refers to adjustable manipulation of the central or peripheral pain pathways using electrical current for the purpose of reversible modification of the function of the nociceptive system through the use of implantable devices. Here, we discuss not only the distal components, the nerve itself, but also the sensory receptors and the main central connections of the brain, paying attention to the possible neuromodulation targets.

Post-traumatic external nasal pain syndrome (a trigeminal based pain disorder).

Little has been written about persistent external nasal pain after injury to the nose in the neurologic or headache literature. In clinical practice, this can be a disabling and treatment refractory condition. The external portion of the nose is highly innervated by branches of the ophthalmic and maxillary divisions of the trigeminal nerve including the nasociliary nerve, external nasal nerve, infratrochlear nerve, anterior ethmoidal nerve, and infraorbital nerve. As these nerves are located on the external portion of the nose just deep enough to the skin they can be easily traumatized with any impact to the nose. Four patients with what is termed the post-traumatic external nasal pain syndrome are reported in this paper, describing the clinical presentation of the disorder and providing treatment options. Post-traumatic external nasal pain syndrome appears to be a novel form of trigeminal-based pain not previously reported in the neurologic literature.

Exertional headache as unusual presentation of the syndrome of an elongated styloid process.

We present the case of a 34-year-old man with a 2-year history of pain related to efforts in heavy lifting, beginning in the right ear and radiating to the neck and to the vertex. He underwent multiple negative neuroimaging examinations, until a 3-dimensional computerized tomography scan of the pharyngeal region evidenced an elongated styloid process. A diagnosis of Eagle's syndrome was made. The excision of the elongated styloid process was performed, resulting in complete and lasting pain relief. We focus on Eagle's syndrome and in particular on this atypical presentation.

Oral immunoglobulin induces mononuclear cell apoptosis in patients suffering from idiopathic chronic pain syndrome: results from a pilot study.

OBJECTIVE: The objective of this clinical pilot study was to examine the induction of apoptosis in mononuclear cells on treatment of patients with chronic pain syndrome with oral immunoglobulin produced from bovine colostrum (BCC). DESIGN: The 4 patients suffering from chronic idiopathic pain (idiopathic facial pain, CRPS or fibromyalgia) who were enrolled in the study had previously successfully been treated with BCC (varying individual doses). Mononuclear cells from peripheral blood were analyzed for representative cytokines in the serum as well as by TUNEL-assay to detect apoptotic cellular events 14 days after the last treatment with BCC and 14 days after restarting the treatment protocol with BCC. The clinical response (pain and quality of life parameters using a visual analogue scale (VAS)) were determined regularly in each patient. RESULTS: The findings showed a disturbed apoptosis homeostasis in 3 of the 4 patients. These results were accompanied by a relief of the pain symptoms. The 4th patient was found not to need any further analgetic treatment since she demonstrated only nonsignificant changes in her laboratory screening and immunological parameters and by the end of the study she was also completely free of pain (long-term treatment with BCC). CONCLUSIONS: In spite of the low patient number, the results were obtained with a sufficiently high degree of control because of the study design. The agreement of the clinical data with our laboratory measurements suggests that the induction of apoptotic events in mononuclear cells is the result of the dominant immunological effects of BCC treatment.

Neuroimaging of muscle pain in humans.

Neuroimaging has provided important information on how acute and chronic pain is processed in the human brain. The pain experience is now known to be the final product of activity in distributed networks consisting of multiple cortical and subcortical areas. Due to the complex nature of the pain experience, a single cerebral representation of pain does not exist. Instead, pain depends on the context in which it is experienced and is generated through variable expression of the different aspects of pain in conjunction with modulatory influences. While considerable data have been generated about the supraspinal organization of cutaneous pain, little is known about how nociceptive information from musculoskeletal tissue is processed in the brain. This is in spite of the fact that pain from musculoskeletal tissue is more frequently encountered in clinical practice, poses a bigger diagnostic problem and is insufficiently treated. Differences are known to exist between acute pain from cutaneous and muscular tissue in both psychophysical responses as well as in physiological characteristics. The 2 tissue types also differ in pain sensitivity to the same stimuli and in their response to analgesic substances. In this review, characteristics of acute and chronic muscle pain will be presented together with a brief overview of the methods of induction and psychophysical assessment of muscle pain. Results from the neuroimaging literature concerned with phasic and tonic muscle pain will be reviewed.