Temporalis Research Articles

Does the Use of Botulinum Toxin in Treatment of Myofascial Pain Disorder of the Masseters and Temporalis Muscles Reduce Pain, Improve Function, or Enhance Quality of Life?

The efficacy of botulinum toxin for management of myofascial pain disorder (MPD) remains controversial. The purpose was to determine if the use of onabotulinumtoxinA (onabotA) in patients with MPD reduces pain, improves function, or enhances quality of life (QoL). This is a multicenter, prospective, randomized, double-blinded, placebo-controlled clinical trial. Subjects with orofacial pain were screened for MPD as defined by the Diagnostic Criteria for Temporomandibular Disorders. The primary predictor variable was MPD treatment with random assignment to onabotA or placebo (saline). The primary outcome variable was pain before treatment (T0) and at 1month (T1) using a visual analog scale. Secondary outcome variables included pain at 2months (T2) and 3months (T3), maximal incisal opening (MIO), jaw function (jaw functional limitation scale), and QoL (Short Form 36) measured at T0, T1, T2, and T3. Covariates included subject demographics, prior treatments, and temporomandibular joint signs/symptoms. Descriptive and bivariate statistics included χ2 test, Fisher's exact test, or t-test. Seventy five subjects with a mean age of 37 (±11) and 35 (±12) years in the onabotA and placebo groups, respectively (P=.6). Females represented 32 (86%) and 29 (76%), respectively (P=.3). Mean visual analog scale pain score in the onabotA group was 58 (±15), 39 (±24), 38 (±23), and 38 (±20) at T0, T1, T2, and T3, respectively; and the placebo group was 54 (±14), 40 (±23), 34 (±20), and 36 (±22) at T0, T1, T2, and T3, respectively. There was no statistically significant difference in pain between groups at any time point (P=.36). There was no statistically significant difference between groups in MIO (P=.124), jaw function (P=.236), or QoL domains (P>.05) at any time point. Within-group improvement in pain was seen in both groups (P<.005). Within-group improvement in jaw function was seen in the onabotA (P=.007) and placebo (P=.005) groups. There was no within-group improvement in MIO or QoL with either group (P>.05). OnabotA and saline (placebo) injections both decrease pain and improve jaw function in subjects with MPD.

De Ritis ratio in elderly glioblastoma patients treated with chemoradiation: A comprehensive analysis of serum biomarkers.

We aimed to comprehensively investigate the prognostic value of pretreatment laboratory parameters in elderly patients with glioblastoma treated with temozolomide (TMZ)-based chemoradiation. Patients aged ≥ 65 years from 4 institutions with newly diagnosed IDH-wild-type glioblastoma who received radiotherapy (RT) with concurrent TMZ between 2006 and 2021 were included. Patient factors (age, Karnofsky performance status (KPS), temporalis muscle thickness), molecular factors (MGMT promoter methylation, EGFR amplification, TERT promoter mutation, and TP53 mutation status), treatment factors (extent of resection, and RT dose), and pretreatment laboratory parameters (serum De Ritis ratio, glucose level, neutrophil-to-lymphocyte ratio, platelet count, and systemic immune-inflammation index) were included in the analysis. The primary endpoint was overall survival (OS). In total, 490 patients were included in the analysis. The median follow-up period was 12.3 months (range, 1.6-149.9 months). Median OS was significantly prolonged in patients with De Ritis ratio < 1.2 (18.2 vs 15.3 months, P = .022) and in patients with glucose level < 150mg/dL (18.7 vs 16.5 months, P = .034) per univariate analysis. In multivariate analysis, KPS ≥ 70, MGMT promoter methylation, extent of resection greater than partial resection, De Ritis ratio < 1.2, and glucose level < 150mg/dL were significant prognostic factors for improved OS. Along with well-known prognostic factors, pre-RT serum biomarkers, including the De Ritis ratio and glucose level, also had prognostic value in elderly patients with glioblastoma treated with TMZ-based chemoradiation.

Sensory innervation of masseter, temporal and lateral pterygoid muscles in common marmosets

Myogenous temporomandibular disorders is associated with an increased responsiveness of nerves innervating the masseter (MM), temporal (TM), and lateral pterygoid muscles (LPM). This study aimed to examine sensory nerve types innervating MM, TM and LPM of adult non-human primate—common marmosets. Sensory nerves were localized in specific regions of these muscles. Pgp9.5, marker for all nerves, and NFH, a marker for A-fibers, showed that masticatory muscles were primarily innervated with A-fibers. The proportion of C- to A-fibers was highest in LPM, and lowest in MM. All C-fibers (pgp9.5+/NFH-) observed in masticatory muscles were peptidergic (CGRP+) and lacked mrgprD and CHRNA3, a silent nociceptive marker. TrpV1 was register in 17% of LPM nerves. All fibers in masticatory muscles were labeled with GFAP+, a myelin sheath marker. There were substantially more peptidergic A-fibers (CGRP+/NFH+) in TM and LPM compared to MM. MM, TM and LPM NFH+ fibers contained different percentages of trkC+ and parvalbumin+, but not trkB+ fibers. Tyrosine hydroxylase antibodies, which did not label TG, highlighted sympathetic fibers around blood vessels of the masticatory muscles. Overall, masticatory muscle types of marmosets have similarities and differences in innervation patterns.

TRAUMATIC BRAINSTEM INJURY DUE TO BLUNT FORCE TRAUMA: AN AUTOPSY CASE REPORT

Trauma is the leading cause of morbidity and mortality in patients under 35-years of age and the sixth leading cause of death worldwide, but primary traumatic brainstem injury after blunt force trauma to the head is a rare event. A forensic autopsy was performed on a 35 years old female who was found dead in an apartment building with both her hands and feet tied together and mouth closed with duct tape. External examination showed the victim suffered from blunt force trauma to the head, face, both arms and legs. Internal examination of the body showed hematomas on the scalp, temporal muscles and deep neck muscles and organs, subarachnoid, intraventricular and brainstem haemorrhage and contusion, along with signs of asphyxiation. Trauma to the occipital region of the head not only can cause traumatic brain injury but can also cause trauma to the brainstem as a result from acute hyperflexion of the neck. Haemorrhages and contusions of the brainstem can lead to changes in the respiratory system, depending on the location of the lesions. Cause of death was concluded to be force trauma to the occipital region causing primary brainstem injury with the mechanism of death of asphyxia.

Determination of masseter and temporal muscle thickness by ultrasound and muscle hardness by shear wave elastography in healthy adults as reference values.

The purpose of this study is to prospectively investigate the reference values of masseter and temporal muscle thicknesses by ultrasonography and muscle hardness values by shear wave elastography in healthy adults. The sample of the study consisted of a total of 160 healthy individuals aged between 18 and 59, including 80 women and 80 men. By examining the right and left sides of each participant, thickness and hardness values were obtained for 320 masseter muscles and 320 temporal muscles in total. The mean masseter muscle thickness was found to be 1.09 cm at rest and 1.40 cm in contraction. The mean temporal muscle thickness was found to be 0.88 cm at rest and 0.98 cm in contraction. The thickness values of the masseter and temporal muscles were significantly greater in the male participants than in the female participants (P < .001). While there were significant differences between the right and left masseter muscle thickness values at rest and in contraction, the values of the temporal muscles did not show a significant difference between the sides. While the resting hardness (rSWE) of the masseter muscle was transversally 6.91 kPa and longitudinally 8.49 kPa, these values in contraction (cSWE) were found, respectively, 31.40 and 35.65 kPa. The median temporal muscle hardness values were 8.84 kPa at rest and 20.43 kPa in contraction. Masseter and temporal muscle hardness values at rest and in contraction were significantly higher among the male participants compared to the female participants (P < .001). In this study, reference values for the thickness and hardness of the masseter and temporal muscles are reported. Knowing these values will make it easier to assess pain in the masseter and temporal muscles and determine the diagnosis and prognosis of masticatory muscle pathologies by allowing the morphological and functional assessments of these muscles, and it will identify ranges for reference parameters.

Impact of obesity on the structures and functions of the stomatognathic system: A morphofunctional approach

ObjectiveThe prevalence of obesity is increasing significantly worldwide, raising great concern among health professionals. This observational study evaluated the electromyographic activity and thickness of the masseter and temporalis muscles, in addition to the maximum molar bite force, in obese and eutrophic subjects. MethodsSixty subjects were divided into three groups: I (7–12 years), II (13–20 years), III (21–40 years) and sex: with 10 men and 10 women for each group. Electromyographic recordings of the masticatory muscles were obtained during mandibular tasks. The masticatory muscles thicknesses were obtained at rest and during dental clenching. The maximum molar bite forces were measured on the right and left sides. The difference in outcome measures between the groups and sex was analyzed using Mann-Whitney U test (p < 0.05) and analysis of covariance (ANCOVA). ResultsElectromyographic activity in the masseter and temporal muscles consistently displayed lower levels in obese subjects of both sexes across all three age groups during mandibular tasks. Additionally, greater thickness of the masticatory muscles was observed in obese subjects of both sexes across all three age groups. Obese women in Group II displayed higher values of molar bite force, both on the right and left sides, compared to eutrophic women. On the other hand, women in Group III exhibited higher values of molar bite force on the right side in comparison to eutrophic women. ConclusionsThis study underscores the potential impact of obesity on the morphofunctional aspects of the stomatognathic system in subjects aged 7 to 40 years.

MATHEMATICAL SUBSTANTIATION OF BIOMECHANICAL BASES OF PATHOLOGICAL WEAR OF HARD TISSUES OF TEETH

Using the Bernoulli principle, the muscles that raise, laterally shift, and advance the mandible were studied. The biomechanical component of the pathogenesis of pathological tooth abrasion was revealed. The role of "fast" and "strong" muscles in the process of excessive abrasion of hard tissues is revealed. Applying the Bernoulli principle to the study of muscles, the ratio of muscle length to its cross-sectional area was expressed mathematically in terms of coefficients. The average values of the coefficients of the same muscles in the control group on the priority and secondary sides differ insignificantly, which indicates a balanced work: the muscles are equally "fast" and equally "strong". Compared to the control group, the first group of patients showed a tendency to a more pronounced difference in the physical qualities of the muscles: strength begins to prevail in some, and speed in others. Clinically, this is manifested at the initial stage of abrasion of hard tooth tissues. A decrease in the temporalis and masseter muscle coefficients in the second group compared to the control group indicates a decrease in muscle length. The gradual increase in the ratios of the wing-shaped lateral muscle from the first to the second group on both the priority and secondary sides of chewing indicates its greater length relative to the cross-sectional area, and therefore, the acquisition of the quality of "speed". In patients of the third group, the difference in the ratio coefficients with the control group and between the priority and balancing sides is more pronounced. Increasingly, the temporalis and masseter muscles acquire the physical quality of "strength", and the wing-like muscles "speed". It is noteworthy that the coefficients of the wing-shaped muscles in patients of the second and third groups on the secondary side are increased compared to the priority side of chewing. Violation of the balance between the physical qualities of the muscles "strength" and "speed" affects the development of pathological tooth abrasion.

Lipotranferences in post neurosurgical esthetic defects

Background: There are numerous procedures in which, beyond adequate manipulation of the temporalis muscle and cranial closure, patients may present bone and muscle defects due to atrophy and consequent facial asymmetry, causing psychological discomfort and functional deterioration. The objective of our work is to combine the knowledge of plastic surgery and apply it to cranial reconstructions with fat transfers in post-neurosurgical patients, analyzing its results. Methods: During the year 2022, 45 fat transfer procedures were performed for the correction of craniofacial defects, of which 29 were female and 16 were male. All had a surgical history of pterional craniotomies and their variants, orbitozygomatic and transzygomatic approaches, with the consequent volume deficit. Results: The procedure was performed on an outpatient basis, with local anesthesia, and in an average time of 30–40 min. The lower hemiabdominal region was used as the donor area, processing the fat using the decantation technique and injecting it into the receptor area at the craniofacial level. The patients tolerated the procedure adequately without intraoperative complications or superadded events. Conclusion: Fat transfer is a minimally invasive, effective, and cost-effective technique that plastic surgery offers us to implement in post-neurosurgical patients, as it achieves natural results that stand the test of time.

Isolated unilateral temporalis muscle hypertrophy of unknown etiology: a case report and literature review.

The initial instance of isolated unilateral temporalis muscle hypertrophy (IUTMH) was reported in 1990. Since then, only few cases have been documented. The cause of this condition remains ambiguous; however, it is presumed to be linked to compensatory and stress-induced hypertrophy. We introduce a rare case of the diagnosis and treatment of IUTMH. A 39-year-old woman presented with a steadily enlarging pain-free swelling on the left side of her face, first noticed a month ago. Apart from a hyperthyroidism medication regimen her medical history was unremarkable. She had no history of temporomandibular joint disease, bruxism, surgery, or trauma. However, she complained of having been under substantial stress lately. Contrast-enhanced magnetic resonance imaging revealed asymmetric temporalis muscle hypertrophy. The treatment plan consisted of administering type A botulinum toxin injections into left temporalis muscle, supplemented by lifestyle changes and relaxation techniques. At a follow-up visit 9 months after the injections, the muscle contour was normalized both in physical and in radiologic examinations. While further supportive evidence is needed, it can be anticipated that cosmetic treatment with botulinum toxin, rather than surgical interventions, will become the standard treatment of IUTMH.

Does increasing vertical dimension of occlusion in centric relation affect muscular activity? An electromyographic study.

In many esthetic treatments, clinicians may consider the option to modify the maxillo mandibular position. A raise of the vertical dimension of occlusion (VDO) may help restore esthetics, increase the space for dental materials, and reduce the invasiveness of dental procedures. Traditionally, VDO increases are done by using the centric relation (CR) position. Despite a long history of use, the neuromuscular effects of different maxillo mandibular relations are not fully studied. The aim of this study was to investigate the effect of alterations of maxillo-mandibular relation from maximal intercuspal position (MIP) to a raised VDO CR position on jaw-elevator muscle activity. Fifteen healthy individuals were asked to carry out maximal voluntary clenching (MVC) in MIP and in CR on individual splints. Electromyographic (EMG) activity of the masseter and anterior temporalis muscles was assessed in μV as the root mean square of the amplitude. Specific indexes and ratios were also computed. Data analyzed in MIP and CR were compared by paired student's t-tests. MVC levels were not negatively affected by a VDO increase in CR position. On the contrary masseter muscles showed a statistically significant increase (p < 0.005). No significant effect on the anterior temporalis was observed. These results suggest that no immediate negative effect on maximum voluntary clenching was induced by a VDO increase in CR position. A slight increase observed in EMG clenching levels could be explained by the increase in VDO when clenching on the splint. The results of this study support the use of CR position as a pragmatic reference position due to the absence of relevant or negative changes in neuromuscular function.

Changes in temporal muscle dimensions and their clinical impact in out-of-hospital cardiac arrest survivors

ObjectiveThis study investigates temporal muscle atrophy in out-of-hospital cardiac arrest patients post-resuscitation, seeking associations with neurological outcomes and factors associated with atrophy. MethodsUsing data from six Japanese intensive care units, adult patients’ post-resuscitation who underwent head computed tomography scans on admission and two to five days post-admission were assessed. Temporal muscle area, thickness, and density were quantified from a single cross-sectional image. Patients were categorized into 'atrophy' or 'no atrophy' groups based on median daily temporal muscle atrophy rates. The primary outcome was changes in temporal muscle dimensions between admission and follow-up two to five days later. Secondary outcomes included assessing the impact of temporal muscle atrophy on 30-day survival, as well as identifying any clinical factors associated with temporal muscle atrophy. ResultsA total of 185 patients were analyzed. Measurements at follow-up revealed significant decreases in temporal muscle area (214 vs. 191 mm2, p < 0.001), thickness (4.9 vs. 4.7 mm, p < 0.001), and density (46 vs. 44 HU, p < 0.001) compared to those at admission. The median daily rate for temporal muscle area atrophy was 2.0% per day. There was no significant association between temporal muscle atrophy and 30-day survival (hazard ratios, 0.71; 95% CI, 0.41–1.23, p = 0.231). Multivariable logistic regression found no clinical factors significantly associated with temporal muscle atrophy. ConclusionsTemporal muscle atrophy in post-resuscitation patients occurs rapidly at 2.0% per day. However, there was no significant association with 30-day mortality or any identified clinical factors. Further investigation into its long-term functional implications is warranted.

Frailty in Traumatic Brain Injury-The Significance of Temporal Muscle Thickness.

Temporal muscle thickness (TMT) on cranial CT scans has recently been identified as a prognostic imaging parameter for assessing a patient's baseline frailty. Here, we analyzed whether TMT correlates with Traumatic brain injury (TBI) severity and whether it can be used to predict outcome(s) after TBI. We analyzed the radiological and clinical data sets of 193 patients with TBI who were admitted to our institution and correlated the radiological data with clinical outcomes after stratification for TMT. Our analyses showed a significant association between high TMT and increased risk for intracranial hemorrhage (p = 0.0135) but improved mRS at 6 months (p = 0.001) as compared to patients with low TMT. Congruent with such findings, a lower TMT was associated with falls and reduced outcomes at 6 months (p < 0.0001 and p < 0.0001). High TMT was robustly associated with head trauma sequelae but was also associated with good clinical outcomes in TBI patients. These findings consolidate the significance of TMT as an objective marker of frailty in TBI patients; such measurements may ultimately be leveraged as prognostic indicators.

Ecological correlates of three-dimensional muscle architecture within the dietarily diverse Strepsirrhini.

Analysis of muscle architecture, traditionally conducted via gross dissection, has been used to evaluate adaptive relationships between anatomical form and behavioral function. However, gross dissection cannot preserve three-dimensional relationships between myological structures for analysis. To analyze such data, we employ diffusible, iodine-based contrast-enhanced computed tomography (DiceCT) to explore the relationships between feeding ecology and masticatory muscle microanatomy in eight dietarily diverse strepsirrhines: allowing, for the first time, preservation of three-dimensional fascicle orientation and tortuosity across a functional comparative sample. We find that fascicle properties derived from these digital analyses generally agree with those measured from gross-dissected conspecifics. Physiological cross-sectional area was greatest in species with mechanically challenging diets. Frugivorous taxa and the wood-gouging species all exhibit long jaw adductor fascicles, while more folivorous species show the shortest relative jaw adductor fascicle lengths. Fascicle orientation in the parasagittal plane also seems to have a clear dietary association: most folivorous taxa have masseter and temporalis muscle vectors that intersect acutely while these vectors intersect obliquely in more frugivorous species. Finally, we observed notably greater magnitudes of fascicle tortuosity, as well as greater interspecific variation in tortuosity, within the jaw adductor musculature than in the jaw abductors. While the use of a single specimen per species precludes analysis of intraspecific variation, our data highlight the diversity of microanatomical variation that exists within the strepsirrhine feeding system and suggest that muscle architectural configurations are evolutionarily labile in response to dietary ecology-an observation to be explored across larger samples in the future.

CHARACTERISTICS OF ELECTROMYOGRAPHIC INDICATORS IN PATIENTS WITH LOWER JAW FRACTURES AFTER SURGICAL TREATMENT BY ORTHOPEDIC CORRECTION

The issues of the need for immobilization and postoperative orthopedic rehabilitation of patients after fractures of the lower jaw were studied to eliminate the risk of complications such as violation of the occlusal relationship of the teeth, contracture of the lower jaw, increased muscle tone, and as a result, the development of pathology from the temporomandibular joint. A comparative analysis of electromyographic parameters and palpation of the masticatory and temporal muscles in patients with fractures of the lower jaw and healthy individuals proves the need for the use of orthopedic correction methods for the rehabilitation of the victims.

Sarcopenia and Hypoxia in Patients with Obstructive Sleep Apnea

Objectives. Obstructive sleep apnea (OSA) is associated with a variety of health issues. Both OSA and sarcopenia are associated with metabolic disorders; however, there is limited literature assessing the correlation between them. Therefore, we aimed to investigate sarcopenia using temporal muscle thickness (TMT) in patients with obstructive sleep apnea (OSA) and the association between sarcopenia and hypoxia. Methods. We enrolled patients with OSA and healthy controls. Both groups underwent brain magnetic resonance imaging (MRI) scans, including three-dimensional T1-weighted imaging. TMT, a marker for sarcopenia, was obtained based on the T1-weighted imaging and compared between the groups. Additionally, we analyzed the correlation between TMT and clinical factors in patients with OSA. Results. In total, 40 patients with OSA and 52 healthy controls were evaluated. There was no difference in TMT between patients with OSA and healthy controls ( 10.425 ± 2.13 vs. 10.400 ± 1.94 mm, p = 0.953 ). In the correlation analysis, age was negatively correlated with TMT ( r = − 0.356 , p = 0.023 ), and lowest oxygen saturation ( r = − 0.558 , p &lt; 0.001 ) in patients with OSA. Conclusion. Our results demonstrated negative correlations between TMT and lowest oxygen saturation in the patients with OSA. These findings suggest potential relationships between sarcopenia and hypoxia in patients with OSA. Thus, these results underline the importance of maintaining oxygen saturation in patients with OSA by implementing active treatment. This study also demonstrates the feasibility of sarcopenia assessment by measuring TMT through conventional head MRI in patients with various neurological disorders.

A Bilateral Craniectomy Technique for In Vivo Photoacoustic Brain Imaging

Due to the high possibility of mechanical damage to the underlying tissues attached to the rat skull during a craniectomy, previously described methods for visualization of the rat brain in vivo are limited to unilateral craniotomies and small cranial windows, often measuring 4–5 mm. Here, we introduce a novel method for producing bilateral craniectomies that encompass frontal, parietal, and temporal bones via sequential thinning of the skull while preserving the dura. This procedure requires the removal of a portion of the temporalis muscle bilaterally, which adds an additional 2–3 mm exposure within the cranial opening. Therefore, while this surgery can be performed in vivo, it is strictly non-survival. By creating large, bilateral craniectomies, this methodology carries several key advantages, such as the opportunity afforded to test innovate imaging modalities that require a larger field of view and also the use of the contralateral hemisphere as a control for neurophysiological studies.

Electromyographic Evaluation of Masticatory Muscle Activity in Individuals with and without Cleft Lip/Palate: A Systematic Review and Meta-analysis.

This study aims to systematically review and meta-analyze the electromyographic activity of masticatory muscles in cleft palate and non-cleft patients, and identify influencing factors. Systematic Review and Meta-analysis. Patients with cleft lip/ palate. Patients without CL/P. Electrical activity of masseter and temporalis muscles at rest and during peak activation. After a comprehensive search in MEDLINE, Web of Science, EMBASE, Scopus, and Cochrane's CENTRAL up to December 2022, without language or date restrictions. Eligible trials were selected based on the PECO question and assessed for bias using Cochrane's ROBINS-E tool. Eight clinical trials with 474 participants were included in the review. Then relevant data was extracted from included studies using customized forms. A random-effects meta-analysis was performed to combine the results of the studies, meta-analyses showed that CL/P patients have elevated electrical activity in the masseter (P = .01) and temporalis (P = <.01) muscles at rest compared to non-cleft control patients. During maximum bite force, cleft patients exhibited a statistically significant decrease in electrical activity in both the masseter (P = .03) and temporalis (P = <.01) muscles. According to our meta-analysis, cleft patients exhibited increased resting muscle activity but decreased activity during maximum bite force, indicating reduced efficiency of masticatory muscles compared to non-cleft patients. These differences can be attributed to anatomical variations, compensatory mechanisms, and previous treatments.

Relationship between masseter muscle activity during wakefulness and temporomandibular disorder-related symptoms.

Masseter muscle activity during wakefulness may be associated with temporomandibular disorder (TMD)-related symptoms, psychosocial status and pain-related disability; however, this relationship is unclear. This study aimed to determine the relationship between masseter muscle electromyography (EMG) burst/duration during wakefulness and TMD-related symptoms, psychosocial status and pain-related disability. Sixty participants were assessed masseter muscle activity during wakefulness using a data-logger-type ultraminiature EMG system and TMD-related symptoms, psychosocial status and pain-related disability through Axis I and II of the diagnostic criteria for TMD (DC/TMD). EMG bursts lasting longer than 0.25 s but less than 2.0 s and those lasting longer than 2.0 s were classified as phasic and tonic bursts, respectively. Participants with palpation-related pain in the temporalis and masseter muscles, as assessed through the DC/TMD examination form in Axis I, had more bursts (number/h) (p = .035 and p = .009, respectively) and longer duration (time/h) (p = .013 and p = .004, respectively) of tonic bursts of the masseter muscle during wakefulness. Participants with palpation-related pain in the masseter muscles had higher oral behaviour scores during wakefulness using Axis II (p = .001), which affected the number and duration of tonic bursts of the masseter muscle activity during wakefulness (p = .011 and p = .007, respectively). As tonic bursts mainly reflect clenching, individuals with pain in the masseter muscles by palpation may have a high frequency and longer duration of clenching, as well as a high frequency of oral behaviours during wakefulness.

Case of Metastatic Atypical Meningioma to Lung: Utility of Cytological Preparations for Intraoperative Diagnosis

Abstract Introduction/Objective Meningiomas are the most common primary intracranial and intraspinal tumors. They are typically benign with an indolent behavior but can metastasize extracranially to the skin, bone, lymph node and liver. Lung metastasis is exceptionally rare, and the diagnosis can be challenging, especially during intraoperative diagnosis without ancillary studies. We describe a metastatic atypical meningioma to the lung for which intraoperative cytology facilitated the diagnosis and guided management. Methods/Case Report A 53-year-old woman with a history of left frontal atypical meningioma and multiple surgical resections for recurrences at outside hospitals, presented with an incidental left lung nodule. A lung wedge resection was performed and submitted for intraoperative diagnosis. Gross examination revealed a well-circumscribed, tan- white, and rubbery subpleural nodule. Cytological preparations— Diff-Quik and H&amp;E stains—and frozen section were prepared. Cytologically, the nodule displayed cohesive distinctive papillary whorls of uniform eosinophilic cells with indistinct cell membranes, round to oval nuclei with central nucleoli and intranuclear pseudoinclusions. The frozen section exhibited similar cytological features, few identifiable whorls and predominantly solid sheets of tumor cells typical of non-small cell carcinoma. Based primarily on the cytological findings, the intraoperative diagnosis was a neoplasm with papillary growth pattern, and a metastasis was favored based on the whorled pattern and clinical history; no further resection was performed. Permanent sections displayed mitoses and no necrosis. Immunohistochemical analysis revealed positivity for somatostatin receptor 2a, progesterone receptor, and EMA (focal); no staining was seen with pancytokeratin, TTF-1, or p40. A diagnosis of atypical meningioma, WHO grade 2, was rendered. Subsequently, an atypical cranial and temporalis muscle meningioma at the site of the prior craniotomy bone flap was resected and had an identical molecular profile (1p36 deletion) to that in the lung, further supporting metastasis to the lung. Results (if a Case Study enter NA) NA Conclusion This case illustrates a rare presentation of metastatic atypical meningioma and highlights the distinctive intraoperative utility of cytology preparations—architectural and cytological details—for diagnosis and appropriate management. Cytology preparations can be a valuable tool and complement frozen sections, in which certain morphological features may be less obvious or confounded by freezing artifact.

Persistent myogenic temporomandibular disorders: Are navigation-guided botulinum toxin-A injections into the lateral pterygoid muscles effective?

BackgroundBotulinum toxin has proven effective in treating persistent myogenous temporomandibular disorders (M-TMDs) unresponsive to conservative therapies. While the usual injection sites are the masseter and temporalis muscles, the deeper lateral pterygoid muscle (LPM) is often overlooked due to its difficulty of access and the risk of local complications. This study aims to evaluate the effectiveness of botulinum toxin-A injections (BTX-A) in the LPM with MR-guided navigation of patients with persistent M-TMDs. MethodsThis retrospective study enrolled 34 patients suffering from M-TMDs despite conservative therapies with a total of 51 injection sessions. All of them were treated by BTX-A injections in the LPM using MR-guided navigation, masseter and temporalis with clinical guidance. The effectiveness of the treatment was evaluated with measures of maximum pain-intensity scores of breakthrough and background pain, maximal interincisal mouth opening (MIO), and the presence of joint sounds. The assessment was conducted before injections, and subsequently, at 1 and 3 months postoperatively. Adverse events and perception of improvement with the treatment were also reported for each injection sessions. ResultsBTX-A injections in the LPM significantly improved pain scores intensity with a reduction of 65 % and 49 % respectively at the 1- and 3-month follow-ups, with peak effectiveness at 1 month. This study showed also a statistically significant improvement in mean MIO at 3 months post-injection and a decrease in joint sounds with persistence in 9,7 % of cases at 3-month follow-up compared to 41,2 % at baseline. No significant adverse events were observed. Patients treated with BTX-A injections in the LPM had a subjective complete improvement in their perception of treatment efficacy in 63 % of cases at the end of the follow-up period. ConclusionsThis study reports clinical experience on the use of MR-guided navigation to perform accurate, reliable, and safe BTX-A injections in the LPM. Although our results appear to be encouraging regarding symptom improvement of patients suffering from persistent M-TMDs, this approach may not be feasible as a primary standard procedure for managing M-TMDs. Further research is necessary to explore potential reproducible, safe, and cost-effective alternatives to enhance the accessibility of the LPM in clinical practice.