Orofacial pain and sensory characteristics of chronic patients compared with controls

Age and sex differences in comorbidities in adult temporomandibular disorders: A cross-sectional study using Korea National Health and Nutrition Examination Survey (KNHANES)

OBJECTIVES

To investigate the relationship between Temporomandibular disorder (TMD) and associated comorbidities in groups matched according to age and sex.

METHODS

Using data from the cross-sectional fifth Korea National Health and Nutrition Examination Survey (KNHANES). Of the 25,534 eligible KNHANES, 17,762 adults aged ≥19 years who responded to survey questionnaire on TMD and comorbidities. Subjects were classified into eight groups according to age and sex. Logistic regression analyses were performed to evaluate the association between TMD and comorbidities according to age and sex.

RESULTS

Of the enrolled participants, 2,107 (11.86%) complained of ≥1 TMD symptoms. In all groups, odds ratios (ORs) for prevalence of TMD were >1 in those with tinnitus. Rhinitis was closely associated with TMD in 6 groups. ORs for TMD with comorbidities according to age and sex were as follows: hypertension, men aged 50-64 years (OR 0.62; CI 0.41-0.94); ischemic heart disease, men aged 35-49 years (4.38; 1.54-12.47); osteoarthritis, women aged 50-64 years (1.38; 1.03-1.86); diabetes mellitus, men aged 35-49 years (0.21; 0.05-0.88); depression, men aged 50-64 years (1.68; 1.00-2.83), women aged 35-49 years (1.39; 1.05-1.85) and women aged 65-80 years (2.01; 1.46-2.77); migraine, men aged 50-64 years (1.60; 1.14-2.25), women aged d35-49 years (1.44; 1.14-1.81) and women aged 35-49 years (1.43; 1.07-1.90); cold hypersensitivity in the hands and feet, men aged 19-34 years (1.64; 1.05-2.58), men aged 35-49 years (1.68; 1.04-2.70), men aged 65-80 years (1.74; 1.09-2.75) and women aged 35-49 years (1.45; 1.15-1.84); olfaction disorder, men aged 50-64 years (2.49; 1.39-4.43); voice disorder, men aged 50-64 years (2.25; 1.28-3.96) and women aged 65-80 years (1.69; 1.09-2.63).

CONCLUSIONS

This study confirmed that the types and effects of comorbidities related to prevalence of TMD may differ according to the patient's age and sex and this result will increase the predictability of the onset of TMD.

Sensory characteristics and chronic facial pain conditions: Cross-sectional study

OBJECTIVES

This study investigated patients with neuropathic, myofascial and other orofacial pain conditions according to the differences and similarities of the sensory profile, and the association between sensory findings and neuropathic or non-neuropathic conditions.

DESIGN

132 healthy controls were compared with 174 orofacial pain patients that were classified into three groups (neuropathic, masticatory myofascial and other orofacial pain condition) and evaluated with a systematized protocol of sensory testing. Data were analyzed with chi-quare and Bonferroni correction (categorical data), Student´s t test, oneway ANOVA, Tukey (quantitative features), Pearson´s coefficient for correlations and logistic regression.

RESULTS

Cold, olfactory and superficial pain thresholds were higher in the group of neuropathic facial pain compared with the other groups, and the highest vibratory thresholds were observed in the group of other orofacial pain conditions. Deep pain thresholds were statistically lower in the group with masticatory myofascial pain.

CONCLUSIONS

Positive sensory findings (eg. hyperalgesia) were more common in the group of patients with masticatory myofascial pain, supporting inflammatory systemic mechanisms, and negative sensory findings not restricted to the trigeminal nerve (eg. hypoesthesia, hyposmia) were more frequent in patients with neuropathic conditions. Non-classical neuropathic orofacial pains also showed sensory impairment from pain chronification and from the overlap with functional disorders.

Tactile Detection in Fibromyalgia: A Systematic Review and a Meta-Analysis

Fibromyalgia is a chronic pain syndrome characterized by sensorimotor deficits and distortions of body representation, that could both be caused by alterations in sensory processing. Several studies suggest a hypersensitivity to various sensory stimulations in fibromyalgia but results on detection of both noxious and non-noxious tactile stimulation, which are particularly relevant for body representation and motor control, remain conflicting. Therefore, the aim of this study is to systematically review and quantify the detection thresholds to noxious and non-noxious tactile stimuli in individuals with fibromyalgia compared to pain-free controls. A systematic review and a meta-analysis were performed in the MEDLINE, EMBASE, CINAHL, Cochrane, PsycInfo and Web of Science databases using keywords related to fibromyalgia, tactile pain detection threshold, tactile detection threshold and quantitative sensory testing. Nineteen studies were included in the review, with 12 in the meta-analysis. Despite the heterogeneity of the results, the data from both the review and from the meta-analysis suggest a trend toward hyperalgesia and no difference of sensitivity to non-noxious tactile stimuli in participants with fibromyalgia compared to healthy controls. This contradicts the hypothesis of a general increase in responsiveness of the central nervous system to noxious and non-noxious stimulations in fibromyalgia. This study shows no alteration of the sensitivity to non-noxious tactile stimulation in fibromyalgia, suggesting that an altered unimodal processing is not sufficient to explain symptoms such as sensorimotor impairments and body representation distortions. Future research should investigate whether alterations in multisensory integration could contribute to these symptoms.

Time of Day Influences Psychophysical Measures in Women With Burning Mouth Syndrome

Burning mouth syndrome (BMS) is a chronic orofacial pain condition that mainly affects postmenopausal women. BMS type I patients report little to no spontaneous pain in the morning and increases in pain through the day, peaking in the afternoon. Quantitative sensory testing (QST) findings from BMS type 1 patients are inconsistent as they fail to capture this temporal variation. We examined how QST in BMS type 1 (n = 18) compared to healthy participants (n = 33) was affected by time of day. QST of the face and forearm included warmth detection threshold (WDT), cold detection threshold (CDT), and heat pain thresholds (HPT), ratings of suprathreshold heat, and pressure pain thresholds (PPT), and was performed twice: once in the morning and once in the afternoon. Compared to healthy participants, BMS patients had higher pain sensitivity to phasic heat stimuli at most temperatures (35°C U = 126.5, p = 0.0006, 39°C U = 186.5, p = 0.0386, 41°C U = 187.5, p = 0.0412, 43°C U = 171, p = 0.0167, 45°C U = 168.5, p = 0.0146) on the forearm, but no differences in pain thresholds (HPT and PPT) regardless of time of day or body area tested. BMS patients had higher WDT (U = 123, p = 0.0172), and lower CDT (U = 98, p = 0.0021) of the forearm and lower WDT of the face (U = 55, p = 0.0494). The differences in forearm WDT (U = 71.5, p = 0.0113) and CDT (U = 70, p = 0.0096) were most pronounced in the morning. In summary, BMS type I patients had increased pain sensitivity on the forearm, but no differences in pain thresholds on the face or forearm. Patients also showed altered thermal sensitivity, which depended on body area tested (heightened in the orofacial region but blunted on the forearm), and was more pronounced in the morning plausibly due to hypervigilance.

A Systematic Review Into the Influence of Temperature on Fibromyalgia Pain: Meteorological Studies and Quantitative Sensory Testing

Fibromyalgia syndrome (FMS) is a chronic widespread pain condition of unknown aetiology. The role of temperature in FMS pain has not been reviewed systematically. The goal of this study was to review the influences of temperature on pain in FMS, from meteorological and quantitative sensory testing (QST) studies. The review was registered with Prospero: ID-CRD42020167687, and followed PRISMA guidance. Databases interrogated were: MEDLINE (via OVID), EMBASE, PubMed, Web of Science, ScienceDirect, CINAHL, and ProQuest (Feb'20). Exclusion criteria were: age <18, animal studies, non-English, and noncontrolled articles. Thirteen studies pertaining to ambient temperature and FMS pain were identified; 9 of these found no uniform relationship. Thirty-five QST studies were identified, 17 of which assessed cold pain thresholds (CPTs). All studies showed numerically reduced CPTs in patients, ranging from 10.9°C to 26.3°C versus 5.9°C to 13.5°C in controls; this was statistically significant in 14/17. Other thermal thresholds were often abnormal. We conclude that the literature provides consistent evidence for an abnormal sensitization of FMS patients' temperature-sensation systems. Additional work is required to elucidate the factors that determine why a subgroup of patients perceive low ambient temperatures as painful, and to characterize that group. PERSPECTIVE: Patients often report increased pain with changes in ambient temperature; even disabling, extreme temperature sensitivity in winter. Understanding this phenomenon may help clinicians provide reassurance and advice to patients and may guide research into the everyday impact of such hypersensitivity, whilst directing future work into the pathophysiology of FMS.

Psychophysical characterisation of burning mouth syndrome-A systematic review and meta-analysis

BACKGROUND

Primary burning mouth syndrome (BMS) is an oro-facial disease with neuropathic characteristics. Psychophysics, such as quantitative sensory testing (QST), is used to sub-classify neuropathic pain syndromes, but their usefulness in characterising BMS is not yet clear.

OBJECTIVE

The aim of this study was to summarise and to quantitatively and qualitatively analyse the available information about QST findings in BMS, and to reflect on possible mechanisms of disease.

METHODS

In this systematic review and meta-analysis, different search strategies were used to screen for articles in PubMed, Embase, EBSCOhost, Cochrane Library, Web of Science, Google Scholar and two sources of conference abstracts. Primary clinical studies focused on QST assessment in patients with BMS were included. Data were synthesised qualitatively and quantitatively. Risk of bias was assessed following the AHRQ guidelines.

RESULTS

Thirteen articles with low to moderate risk of bias and one conference abstract were selected from 45 unique articles that were identified. Individually, the studies reported combinations of thermal and mechanical sensory impairments measured by QST. The meta-analysis showed significant sensory differences between patients and controls in warmth (effect size = 0.683; P < .05) and cold detection thresholds (effect size = -0.580; P < .001).

CONCLUSION

The results indicate that thermal sensitivity seems to be altered in patients with BMS compared to controls, suggesting a small-fibre neuropathy. However, study protocols were highly variable and heterogeneous. Therefore, studies with better designs and complete reporting of results should be performed to bring value to the use of psychophysics in the assessment of BMS.

A perspective from experimental studies of burning mouth syndrome

Burning mouth syndrome (BMS) is one of the most frequently seen idiopathic pain conditions in a dental setting. Peri- and postmenopausal women are most frequently affected, and patients who experience BMS complain of persistent burning pain mainly at the tip and the bilateral border of the tongue. Recent studies have assessed whether BMS is a neuropathic pain condition, based on morphologic changes in biopsied tongue specimens, and whether there are abnormal pain responses in patients with this disease. Somatosensory studies have reported some abnormal findings in sensory and pain detection thresholds with inconsistency; however, the most distinct finding was exaggerated responses to painful stimuli. Imaging and electrophysiologic studies have suggested the possibility of dysregulation of the pain-modulating system in the central nervous system, which may explain the enhanced pain responses despite the lack of typical responses toward quantitative sensory tests. Basic studies have suggested the possible involvement of neuroprotective steroids, although the underlying mechanisms of this condition have not been elucidated. Experimental studies are looking for preferable supportive therapies for BMS patients despite the obscure pathogenesis.

Oral Health and Fibromyalgia Syndrome: A Systemic Review

Fibromyalgia is a syndrome currently considered idiopathic and multifactorial rheumatic that causes an increase in muscle tension and is characterized by muscle pain and chronic fibrous tissues-widespread, fluctuating and migrating-associated with stiffness, asthenia, cognitive disorders, insomnia or sleep disorders, alterations in sensitivity to stimuli. In affected patients, there may be anxiety or depressive disorder development. The aim of this study is, with the help of an interdisciplinary team, to evaluate the correlations between this syndrome and oral health. A literature review was conducted, analyzing the most common scientific databases, more than 200 studies were obtained. Subsequently to the application of filters and revision by the authors, only 18 articles were considered eligible for this review. From the results, it is clear that the correlations between fibromyalgia and oral health mainly concern pain in the oro-maxillofacial district, especially in the temporomandibular joint. This certainly could help for faster diagnosis of the syndrome, which is currently difficult to identify.

Quantitative Sensory Changes Following Gasserian Ganglion Radiofrequency Thermocoagulation in Patients with Medical Refractory Trigeminal Neuralgia: A Prospective Consecutive Case Series

BACKGROUND AND OBJECTIVE

 Microsurgical vascular nerve decompression and percutaneous ablative interventions aiming at the Gasserian ganglion are promising treatment modalities for patients with medical refractory trigeminal neuralgia (TN). Apart from clinical reports on a variable manifestation of facial hypoesthesia, the long-term impact of trigeminal ganglion radiofrequency thermocoagulation (RFT) on sensory characteristics has not yet been determined using quantitative methods.

MATERIAL AND METHODS

 We performed standardized quantitative sensory testing according to the established protocol of the German Research Network on Neuropathic Pain in a cohort of patients with classical (n = 5) and secondary (n = 11) TN before and after percutaneous Gasserian ganglion RFT (mean follow-up: 6 months). The test battery included thermal detection and thermal pain thresholds as well as mechanical detection and mechanical pain sensitivity measures. Clinical improvement was also assessed by means of renowned pain intensity and impairment questionnaires (Short-Form McGill Pain Questionnaire, Pain Disability Index, and Pain Catastrophizing Scale), pain numeric rating scale, and anti-neuropathic medication reduction at follow-up.

RESULTS

 All clinical parameters developed favorably following percutaneous thermocoagulation. Only mechanical and vibration detection thresholds of the affected side of the face were located below the reference frame of the norm population before and after the procedure. Statistically significant persistent changes in quantitative sensory variables caused by the intervention could not be detected in our patient sample.

CONCLUSION

 Our data suggest that TN patients improving considerably after RFT do not undergo substantial long-term alterations regarding quantitative sensory perception.

Somatosensory profiles of patients with chronic myogenic temporomandibular disorders in relation to their painDETECT score

BACKGROUND

The purpose of this study was to characterize patients with chronic temporomandibular disorders (TMD) in terms of existing hyperalgesia against cold, heat and pressure.

METHODS

The extent of hyperalgesia for pressure and thermal sensation in TMD patients was determined by the use of the painDETECT questionnaire ("Is cold or heat in this area occasionally painful?" "Does slight pressure in this area, e.g., with a finger, trigger pain?") and experimental somatosensory testing against thermal and pressure stimuli (Quantitative Sensory Testing; QST). In addition, we explored psychological comorbidity among the chronic TMD patients (hospital anxiety and depression scale, HADS-D and coping strategies questionnaire, CSQ).

RESULTS

Nineteen patients with chronic TMD and 38 healthy subjects participated in the study. N = 12 patients had a painDETECT score ≤ 12, n = 3 patients had a painDETECT score of 13-18 and n = 4 patients had a painDETECT score ≥ 19. TMD patients with painDETECT scores ≥19 had moderately, strong or very strong enhancement of thermal and pressure pain perception, whereas patients with painDETECT scores 13-18 and ≤ 12 responded these questions with "never", "hardly noticed" or "slightly painful" (p < 0.05-0.01). With increasing painDETECT scores we found increased hyperalgesia for pressure (p < 0.01) and thermal stimuli (p < 0.05) in QST. The patients with a painDETECT score ≥ 19 showed increased signs of anxiety (p < 0.05), depression (p < 0.01), praying and hoping (p < 0.05).

CONCLUSION

The present study has shown that the PainDETECT questionnaire can be a helpful additional diagnostic tool. Together with QST, the PainDETECT questionnaire detected hyperalgesia for pressure and thermal sensation. Therefore the PainDETECT questionnaire is helpful to decide which TMD patients should undergo QST.

Changes in the vibration sensitivity and pressure pain thresholds in patients with burning mouth syndrome

OBJECTIVE

To investigate the presence of changes in vibration detection and pressure pain threshold in patients with burning-mouth syndrome (BMS).

DESIGN OF THE STUDY

Case-control study. The sample was composed of 30 volunteers, 15 with BMS and 15 in the control group. The pressure-pain threshold (PPT) and vibration-detection threshold (VDT) were examined. The clinical evaluation was complemented with the McGill Pain Questionnaire (MPQ), Douleur Neuropathique 4 (DN4) and Beck Depression and Anxiety Inventories (BDI and BAI, respectively).

RESULTS

BMS subjects showed a statistically significant higher PPT in the tongue (p = 0.002), right (p = 0.001) and left (p = 0.004) face, and a significant reduction of the VDT in the tongue (p = 0.013) and right face (p = 0.030). Significant differences were also found when comparing the PPT and the VDT of distinct anatomical areas. However, a significant interaction (group × location) was only for the PPT. BMS subjects also showed significantly higher levels of depression (p = 0.01), as measured by the BDI, compared to controls; and a significant inverse correlation between the VDT in the left face and anxiety levels was detected.

CONCLUSIONS

The study of somatosensory changes in BMS and its correlations with the clinical features as well as the levels of anxiety and depression expands current understanding of the neuropathic origin and the possible contribution of psychogenic factors related to this disease.

Functional Alterations of Postcentral Gyrus Modulated by Angry Facial Expressions during Intraoral Tactile Stimuli in Patients with Burning Mouth Syndrome: A Functional Magnetic Resonance Imaging Study

Previous findings suggest that negative emotions could influence abnormal sensory perception in burning mouth syndrome (BMS). However, few studies have investigated the underlying neural mechanisms associated with BMS. We examined activation of brain regions in response to intraoral tactile stimuli when modulated by angry facial expressions. We performed functional magnetic resonance imaging on a group of 27 BMS patients and 21 age-matched healthy controls. Tactile stimuli were presented during different emotional contexts, which were induced via the continuous presentation of angry or neutral pictures of human faces. BMS patients exhibited higher tactile ratings and greater activation in the postcentral gyrus during the presentation of tactile stimuli involving angry faces relative to controls. Significant positive correlations between changes in brain activation elicited by angry facial images in the postcentral gyrus and changes in tactile rating scores by angry facial images were found for both groups. For BMS patients, there was a significant positive correlation between changes in tactile-related activation of the postcentral gyrus elicited by angry facial expressions and pain intensity in daily life. Findings suggest that neural responses in the postcentral gyrus are more strongly affected by angry facial expressions in BMS patients, which may reflect one possible mechanism underlying impaired somatosensory system function in this disorder.

Persistent idiopathic facial pain – a prospective systematic study of clinical characteristics and neuroanatomical findings at 3.0 Tesla MRI

Introduction

Persistent idiopathic facial pain (PIFP) is a poorly understood chronic orofacial pain disorder and a differential diagnosis to trigeminal neuralgia. To address the lack of systematic studies in PIFP we here report clinical characteristics and neuroimaging findings in PIFP.

Methods

Data collection was prospective and standardized in consecutive PIFP patients. All patients underwent 3.0 MRI.

Results

In a cohort of 53 PIFP patients, the average age of onset was 44.1 years. PIFP was found in more women 40 (75%) than men 13 (25%), p < 0.001. There was a high prevalence of bilateral pain 7 (13%), hypoesthesia 23 (48%), depression 16 (30%) and other chronic pain conditions 17 (32%) and a low prevalence of stabbing pain 21 (40%), touch-evoked pain 14 (26%) and remission periods 10 (19%). The odds ratio between neurovascular contact and the painful side was 1.4 (95% Cl 0.4–4.4, p = 0.565) and the odds ratio between neurovascular contact with displacement of the trigeminal nerve and the painful side was 0.2 (95% Cl 0.0–2.1, p = 0.195).

Conclusion

PIFP is separated from trigeminal neuralgia both with respect to the clinical characteristics and neuroimaging findings, as NVC was not associated to PIFP.

Co-occurrence of Pain Symptoms and Somatosensory Sensitivity in Burning Mouth Syndrome: A Systematic Review

Background

Burning mouth syndrome (BMS) is a chronic and spontaneous oral pain with burning quality in the tongue or other oral mucosa without any identifiable oral lesion or laboratory finding. Pathogenesis and etiology of BMS are still unknown. However, BMS has been associated with other chronic pain syndromes including other idiopathic orofacial pain, the dynias group and the family of central sensitivity syndromes. This would imply that BMS shares common mechanisms with other cephalic and/or extracephalic chronic pains. The primary aim of this systematic review was to determine whether BMS is actually associated with other pain syndromes, and to analyze cephalic and extracephalic somatosensory sensitivity in these patients.

Methods

This report followed the PRISMA Statement. An electronic search was performed until January 2015 in PubMed, Cochrane library, Wiley and ScienceDirect. Searched terms included “burning mouth syndrome OR stomatodynia OR glossodynia OR burning tongue OR oral burning”. Studies were selected according to predefined inclusion criteria (report of an association between BMS and other pain(s) symptoms or of cutaneous cephalic and/or extracephalic quantitative sensory testing in BMS patients), and a descriptive analysis conducted.

Results

The search retrieved 1512 reports. Out of these, twelve articles met criteria for co-occurring pain symptoms and nine studies for quantitative sensory testing (QST) in BMS patients. The analysis reveals that in BMS patients co-occurring pain symptoms are rare, assessed by only 0.8% (12 of 1512) of the retrieved studies. BMS was associated with headaches, TMD, atypical facial pain, trigeminal neuralgia, post-herpetic facial pain, back pain, fibromyalgia, joint pain, abdominal pain, rectal pain or vulvodynia. However, the prevalence of pain symptoms in BMS patients is not different from that in the age-matched general population. QST studies reveal no or inconsistent evidence of abnormal cutaneous cephalic and extracephalic somatosensory sensitivity.

Conclusions

There is no evidence for a high rate of other pain symptoms or somatosensory impairments co-occurring with BMS. These results thus suggest that BMS rather depends on specific mechanisms, likely at the trigeminal level. Nevertheless, more thoroughly conducted research is required to draw definitive conclusion.

Pain profiling of patients with temporomandibular joint arthralgia and osteoarthritis diagnosed with different imaging techniques

Background

Clinical differentiation between pain mechanisms of temporomandibular joint (TMJ) arthralgia and osteoarthritis (OA) is challenging. The aims were to compare somatosensory function at the TMJs and conditioned pain modulation (CPM) effects between TMJ arthralgia and OA patients diagnosed clinically and based on different imaging techniques and age- and gender-matched healthy controls (n = 41).

Methods

Patients (n = 58) underwent standard clinical examination and three different TMJ imaging modalities. After each examination, they were classified into arthralgia or OA based on the findings. TMJ region somatosensory testing was performed in all participants. Z-scores were calculated for patients based on healthy reference data. CPM was tested by comparing pressure pain thresholds (PPTs) at TMJ and thenar (control) before, during and after the application of painful and nonpainful cold stimuli. Data were analyzed using analyses of variance.

Results

Somatosensory abnormalities were commonly detected in both patient groups. Assessment of somatosensory function at the TMJ revealed that arthralgia patients were less sensitive to warmth, cold and tactile stimuli than OA patients (P < 0.048). OA patients showed pressure hyperalgesia compared with arthralgia patients (P = 0.025). There was a significant CPM effect at both test sites during painful cold application in all groups (P < 0.001). There was no significant difference in the relative CPM effect between groups except for clinically diagnosed arthralgia patients showing reduced CPM effect compared with controls (P = 0.047).

Conclusions

Pain profiles including somatosensory function differed between TMJ arthralgia and OA patients although CPM effects were similar in patients and controls. Thus, different TMJ pain conditions may share common pain mechanisms but the present study for the first time also indicated that differential pain mechanisms could be involved.

Electronic supplementary material

The online version of this article (doi:10.1186/s10194-016-0653-6) contains supplementary material, which is available to authorized users.

Relation of dopamine receptor 2 binding to pain perception in female fibromyalgia patients with and without depression--A [¹¹C] raclopride PET-study

Dopamine D2/D3 receptor availability at rest and its association with individual pain perception was investigated using the [(11)C] raclopride PET-method in 24 female Fibromyalgia (FMS) participants with (FMS+, N=11) and without (FMS-, N=13) comorbid depression and in 17 healthy women. Thermal pain thresholds (TPT) and pain responses were assessed outside the scanner. We compared the discriminative capacity, i.e. the individual׳s capacity to discriminate between lower and higher pain intensities and the response criterion, i.e. the subject׳s tendency to report pain during noxious stimulation due to psychological factors. [(11)C] raclopride binding potential (BP), defined as the ratio of specifically bound non-displaceable radioligand at equilibrium (BP(ND)) was used as measure of D2/D3 receptor availability. We found significant group effects of BP(ND) in striatal regions (left ventral striatum, left caudate nucleus and left nucleus accumbens) between FMS+ and FMS- compared to healthy subjects. Correlational analysis showed negative associations between TPT and D2/D3 receptor availability in the left caudate nucleus in FMS-, between TPT and D2/D3 receptor availability in the right caudate nucleus in FMS + and positive associations between TPT and D2/D3 receptor availability in the left putamen and right caudate nucleus in healthy controls. The response criterion was positively associated with D2/D3 receptor availability in the right nucleus accumbens in FMS - and negatively with D2/D3 receptor availability in the left caudate nucleus in healthy controls. Finally, no significant associations between D2/D3 receptor availability and discriminative capacity in any of the groups or regions were determined. These findings provide further support for a disruption of dopaminergic neurotransmission in FMS and implicate DA as important neurochemical moderator of differences in pain perception in FMS patients with and without co-morbid depression.

Sensory abnormalities and masticatory function after microvascular decompression or balloon compression for trigeminal neuralgia compared with carbamazepine and healthy controls

OBJECT

Idiopathic trigeminal neuralgia (iTN) is a neurological condition treated with pharmacotherapy or neurosurgery. There is a lack of comparative papers regarding the outcomes of neurosurgery in patients with iTN. The objective of this study was to investigate sensory thresholds and masticatory function in 78 patients with iTN who underwent microvascular decompression (MVD) or balloon compression (BC), and compare these treatments with carbamazepine and 30 untreated healthy controls.

METHODS

The authors conducted a case-controlled longitudinal study. Patients were referred to 1 of 3 groups: MVD, BC, or carbamazepine. All patients were evaluated before and after treatment with a systematic protocol composed of a clinical orofacial questionnaire, Research Diagnostic Criteria for temporomandibular disorders, Helkimo indices, and a quantitative sensory-testing protocol (gustative, olfactory, cold, warm, touch, vibration, superficial, and deep pain thresholds).

RESULTS

Both MVD and BC were effective at reducing pain intensity (p = 0.012) and carbamazepine doses (p < 0.001). Myofascial and articular complaints decreased in both groups (p < 0.001), but only the patients in the MVD group showed improvement in Helkimo indices (p < 0.003). Patients who underwent MVD also showed an increase in sweet (p = 0.014) and salty (p = 0.003) thresholds. The sour threshold decreased (p = 0.003) and cold and warm thresholds increased (p < 0.001) in patients after MVD and BC, but only the patients who underwent BC had an increase in touch threshold (p < 0.001).

CONCLUSIONS

Microvascular decompression and BC resulted in a reduction in myofascial and jaw articular complaints, and the impact on masticatory function according to Helkimo indices was greater after BC than MVD. MVD resulted in more gustative alterations, and both procedures caused impairment in thermal thresholds (warm and cold). However, only BC also affected touch perception. The sensorial and motor deficits after BC need to be included as targets directly associated with the success of the surgery and need to be assessed and relieved as goals in the treatment of iTN.

Diagnostic role of magnetic resonance imaging in assessing orofacial pain and paresthesia

The aim of this study was to compare the efficacy of CT and MRI in evaluating orofacial pain and paresthesia. A total of 96 patients with orofacial pain and/or paresthesia were included in this study. The patients who underwent CT and/or MRI examinations were assessed, and the efficacy of CT and/or MRI examinations in detecting the causative disease of the orofacial pain and paresthesia was evaluated. Seventy (72.9%) of 96 patients underwent CT and/or MRI examinations. Whereas CT examinations detected 2 diseases (4.5%) in 44 tests, 13 diseases (37.1%) were detected in 35 MRI examinations. Seven (53.8%) of 13 diseases, which were detected by MRI, were found in elderly patients. A high percentage of patients, who claimed orofacial pain and paresthesia, have other diseases in their brain, especially in elderly patients, and MRI is more useful than CT for evaluating these patients.