Use of suction electrodes for measurement of intrinsic tongue muscular endurance during lingual pressure generation.

BACKGROUND: Lingual pressure (LP) generation is cooperatively controlled not only by the intrinsic tongue (I-ton) muscles but also by hyoid muscle activation. However, the measurement of endurance and fatigue properties of I-ton muscles is difficult due to the instability of electrodes. OBJECTIVE: The purpose of this study was to apply suction electrodes to measure electromyograms (EMGs) of I-ton muscle and to evaluate integrated EMG amplitude (iEMG) and mean power frequency (MPF) of EMG in the I-ton and hyoid muscles performing continuous LP. METHODS: Twenty healthy adult volunteers (10 males, 10 females, mean age 28.8 years) were instructed to perform 10-s LP generation tasks at 25%, 50%, 75% and 100% of maximum LP in randomised order with visual feedback. During each task, EMGs of the I-ton, suprahyoid (S-hyo), infrahyoid (I-hyo) and masseter (Mass) muscles were simultaneously recorded. The iEMG and MPF of EMG burst during 10-s LP tasks were compared. The recording period was divided into three substages to analyse temporal changes with the Friedman test. RESULTS: During the 10-s task, the iEMG significantly increased as the LP strength increased (p < .001). There was no time-dependent change in the I-ton iEMG; however, the MPF of the I-ton EMG burst decreased in all tasks (p < .05). The S-hyo and I-hyo iEMGs gradually increased, especially with strong LP (p < .01). CONCLUSION: While I-ton muscles may easily fatigue during 10-s LP generation, S-hyo and I-hyo muscles may help compensate for the weakened I-ton muscle activity by increasing their activity to maintain LP.

The effect of tongue elevation muscle training in patients with obstructive sleep apnea: A randomised controlled trial.

BACKGROUND: Oropharyngeal myofunctional therapy is a multi-component therapy effective to reduce the severity of obstructive sleep apnoea (OSA). However, existing protocols are difficult to replicate in the clinical setting. There is a need to isolate the specific effectiveness of each component of the therapy. OBJECTIVE: To assess the effects of a 6 weeks tongue elevation training programme in patients with OSA. METHODS: We conducted a multicentre randomised controlled trial. Eligible participants were adults diagnosed with moderate OSA who presented low adherence to continuous positive airway pressure therapy (mean use <4 h per night). The intervention group completed a 6 weeks tongue elevation training protocol that consisted in anterior tongue elevation strength and endurance tasks with the Iowa Oral Performance Instrument. The control group completed a 6 weeks sham training protocol that involved expiratory muscle training at very low intensity. Polygraphy data, tongue force and endurance, and OSA symptoms were evaluated pre- and post-intervention. The primary outcome was apneoa-hypopnea index (AHI). RESULTS: Twenty-seven patients (55 ± 11 years) were recruited. According to modified intention-to-treat analysis (n = 25), changes in AHI and c did not significantly differ between groups. Daytime sleepiness (Epworth Sleepiness Scale) and tongue endurance significantly improved in the intervention group compared to the control group (p = .015 and .022, respectively). In the intervention group, 75% of participants had a decrease in daytime sleepiness that exceeded the minimal clinically important difference. CONCLUSION: Six weeks of tongue elevation muscle training had no effect on OSA severity.

Regional genioglossus reflex responses to negative pressure pulses in people with obstructive sleep apnea.

Tongue and upper airway dilator muscle movement patterns during quiet breathing vary in people with obstructive sleep apnea (OSA). Many patients have inadequate or counterproductive responses to inspiratory negative airway pressure that likely contributes to their OSA. This may be due, at least in part, to inadequate or nonhomogeneous reflex drive to different regions of the largest upper airway dilator, genioglossus. To investigate potential regional heterogeneity of genioglossus reflex responses in OSA, brief suction pulses were applied via a nasal breathing mask and an electromyogram (EMG) was recorded in four regions (anterior oblique, anterior horizontal, posterior oblique, and posterior horizontal) using intramuscular fine wire electrodes in 15 people with OSA. Genioglossus short-latency reflex excitation amplitude had regional heterogeneity (horizontal vs. oblique regions) when expressed in absolute units but homogeneity when normalized as a percentage of the immediate (100 ms) prestimulus EMG. Regional variability in reflex morphology (excitation and inhibition) was present in one-third of the participants. The minimum cross-sectional area (CSA) of the pharyngeal airway was quantified using MRI and may be related to the amplitude of the short-latency reflex response to negative pressure as we found that people with a smaller CSA tended to have a greater reflex amplitude (e.g., horizontal region r2 = 0.41, P = 0.01). These findings highlight the complexity of genioglossus reflex control, the potential for regional heterogeneity, and the functional importance of upper airway anatomy in mediating genioglossus reflex responses to rapid changes in negative pressure in OSA.NEW & NOTEWORTHY Our findings indicate that 30% of participants had regional heterogeneity in reflex morphology (excitation/inhibition) to brief pulses of negative upper-airway pressure across anterior oblique, anterior horizontal, posterior oblique, and posterior horizontal regions of the genioglossus muscle. Reflex excitation amplitude was proportional to prestimulus drive, with increased activation in oblique compared with horizontal regions of the posterior tongue. People with narrower upper-airway anatomy tended to have increased genioglossus reflex amplitude to negative pressure pulses during wakefulness.

[Acupoint injection combined with Vitalstim electrical stimulation for post-stroke dysphagia:a randomized controlled trial].

OBJECTIVE: To observe the clinical efficacy of acupoint injection combined with Vitalstim electrical stimulation for post-stroke dysphagia. METHODS: A total of 98 patients with dysphagia after first stroke were randomized into an acupoint injection group (35 cases, 2 cases dropped off), an electrical stimulation group (31 cases, 3 cases dropped off) and a combination group (32 cases, 3 cases dropped off). Injection of mecobalamin into Tunyan point, Vitalstim electrical stimulation and the combination of injection of mecobalamin into Tunyan point and Vitalstim electrical stimulation were applied respectively in the 3 groups, once a day, 10 times as one course, 2 courses were required. Before and after treatment, the tongue muscle thickness and video fluoroscopic swallowing study (VFSS) score were observed in the 3 groups. RESULTS: After treatment, the tongue muscle thickness was decreased (P<0.05), the VFSS scores were increased (P<0.05) compared with before treatment in the 3 groups, and the variation of tongue muscle thickness and VFSS score in the combination group was greater than the acupoint injection group and the electrical stimulation group (P<0.05). CONCLUSION: Both acupoint injection of mecobalamin and Vitalstim electrical stimulation have therapeutic effect on dysphagia after stroke, and the two have synergistic effect.

Acupoint injection combined with Vitalstim electrical stimulation for post-stroke dysphagia:a randomized controlled trial / 中国针灸

OBJECTIVE@#To observe the clinical efficacy of acupoint injection combined with Vitalstim electrical stimulation for post-stroke dysphagia.@*METHODS@#A total of 98 patients with dysphagia after first stroke were randomized into an acupoint injection group (35 cases, 2 cases dropped off), an electrical stimulation group (31 cases, 3 cases dropped off) and a combination group (32 cases, 3 cases dropped off). Injection of mecobalamin into Tunyan point, Vitalstim electrical stimulation and the combination of injection of mecobalamin into Tunyan point and Vitalstim electrical stimulation were applied respectively in the 3 groups, once a day, 10 times as one course, 2 courses were required. Before and after treatment, the tongue muscle thickness and video fluoroscopic swallowing study (VFSS) score were observed in the 3 groups.@*RESULTS@#After treatment, the tongue muscle thickness was decreased (P<0.05), the VFSS scores were increased (P<0.05) compared with before treatment in the 3 groups, and the variation of tongue muscle thickness and VFSS score in the combination group was greater than the acupoint injection group and the electrical stimulation group (P<0.05).@*CONCLUSION@#Both acupoint injection of mecobalamin and Vitalstim electrical stimulation have therapeutic effect on dysphagia after stroke, and the two have synergistic effect.

Cambios histológicos del tejido muscular estriado lingual en ratas Sprague Dawley (Rattus norvegicus) para estimar el intervalo postmortem / Histological changes of lingual striated muscle tissue in Sprague Dawley rats (Rattus norvegicus) for estimating the postmortem interval

RESUMEN: El intervalo postmortem (IPM) equivale al tiempo que ha transcurrido desde que un ser humano ha muerto hasta su examinación postmortem. Después de la muerte, el cuerpo experimenta modificaciones en su composición física y química denominados cambios postmortem expresados por signos que pueden ser analizados para el cálculo del IPM. El objetivo del estudio fue describir los cambios histológicos presentes en la musculatura estriada lingual de rata en diferentes IPM. Se utilizaron 10 ratas machos Sprague dawley de dos meses de edad. Los animales fueron eutanasiados y dejados a temperatura ambiente (4 - 14 ?C) para tomar muestras de la lengua a distintos IPM (0, 6, 12, 24, 48, 72, 96 y 120 horas postmortem). El estudio se llevó a cabo considerando las recomendaciones de la Guía para el Cuidado y Uso de Animales de Laboratorio. Las muestras fueron fijadas en formaldehido tamponado a 10 % y procesadas para su inclusión en paraplast. Se realizaron cortes de 5 μm de grosor y fueron teñidas con HE para su análisis con microscopía óptica. Los cambios histológicos en las células musculares estriadas de la lengua estaban asociados a los distintos IPM. A las 6 horas postmortem, hubo cambios iniciales en la morfología nuclear y su pigmentación. A las 12 y 24 horas postmortem, se observaron cambios en las estrías musculares y aumento en el número de casos con alteraciones nucleares. A las 48 y 72 horas postmortem, eran evidentes las vacuolas citoplasmáticas, cambios en la coloración de las miofibras y aumento en las alteraciones nucleares. A las 92 y 120 horas postmortem, se observó disminución de las estrías musculares y núcleos celulares. Los núcleos eran picnóticos y puntiformes; hubo pérdida de la morfología celular y presencia de musculo liso. En conclusión, los cambios de la histología del músculo estriado lingual de rata permiten estimar el IPM. Este modelo podría ser aplicable a la medicina forense.

SUMMARY: The postmortem interval (PMI) equals the time that has elapsed since a human being has died until his postmortem examination. After death, the body experiences modifications in its physical and chemical composition know as postmortem changes expressed by signs that can be analyzed for the calculation of the MPI. The aim of the study was to describe the histological changes present in rat lingual striated musculature in different PMIs. 10 two-month-old male Sprague dawley rats were used. The animals were euthanized and left at room temperature (4-14 ?C) to sample the tongue at different PMIs (0, 6, 12, 24, 48, 72, 96 and 120 hours postmortem). The study was carried out considering the recommendations of the Guide for the Care and Use of Laboratory Animals. The samples were fixed in 10% buffered formaldehyde and processed for inclusion in paraplast. 5 μm thick sections were made and stained with HE for análisis with light microscopy. Histological changes in the striated muscle cells of the tongue were associated with the different PMIs. At 6 hours postmortem, there were initial changes in nuclear morphology and its pigmentation. At 12 and 24 hours postmortem, changes in muscle striae and an increase in the number of cases with nuclear alterations were observed. At 48 and 72 hours postmortem, cytoplasmic vacuoles, changes in myofiber coloration, and increased nuclear alterations were evident. At 92 and 120 hours postmortem, a decrease in muscle striae and cell nuclei was observed. The nuclei were pyknotic and pinpoint; there was loss of cell morphology and presence of smooth muscle. In conclusion, changes in the histology of rat lingual skeletal muscle make it possible to estimate MPI. This model could be applicable to forensic medicine.

Tongue pressure waveform analysis for ascertaining the influence of tongue muscle composition on articulation.

BACKGROUND: Rate force development is associated with performance and muscle composition in whole-body muscle. Although rate force development on tongue muscle can be examined using tongue pressure waveform, there have been only few investigations on this topic. OBJECTIVES: This study's main purpose was to investigate the reliability of tongue pressure waveform analysis and its relationship with articulation and tongue muscle composition. In addition, we also investigated the association between tongue muscle composition and articulation. METHODS: Forty-five community-dwelling individuals aged >20 years participated. We analysed tongue pressure waveform, including maximum tongue pressure (MTP), time to peak, mean rate of tongue force development and peak rate of tongue force development (PRTFD). We also assessed oral diadochokinesis. Magnetic resonance imaging of the tongue provided data on tongue muscle composition, including tongue volume, fat mass, lean muscle mass and fat percentage. We evaluated the reliability of tongue pressure waveform analysis. Moreover, we examined the coefficients between tongue pressure waveform analysis, oral diadochokinesis and tongue composition. RESULTS: We detected a high reliability of MTP and PRTFD. MTP and PRTFD were significantly correlated with tongue muscle composition. MTP was not significantly correlated with oral diadochokinesis. PRTFD was significantly positively correlated with oral diadochokinesis. Tongue fat mass and fat percentage were negatively correlated with oral diadochokinesis of /ta/ and /ka/. CONCLUSIONS: Peak rate of tongue force development is a highly reliable method for tongue pressure analysis and is useful for elucidating the functional importance of tongue muscle function on articulation. We speculated that fatty infiltration of the tongue adversely affects articulation.

Age-related composition changes in swallowing-related muscles: a Dixon MRI study.

BACKGROUND: Dysphagia is considered a social problem in the super-aging society. However, age-related changes in swallowing-related muscles have not been fully deciphered. AIMS: We aimed to identify intramuscular fatty infiltration and muscle atrophy in multiple swallowing-related muscles on magnetic resonance imaging (MRI). Moreover, an appropriate muscle strength parameter for the evaluation of swallowing-related muscle mass was examined. METHODS: We analyzed the Dixon MRI results of 20 elderly and 20 young adults without head and neck cancer, stroke, neuromuscular disease, or whole-body sarcopenia to evaluate intramuscular fatty infiltration (IMF) and lean muscle mass (LMM) in the tongue, geniohyoid, and pharyngeal muscles. The pharyngeal lumen size was also assessed. Tongue pressure, jaw-opening strength, occlusal force, and head-lifting strength were evaluated within a week before and after MRI. RESULTS: Aging significantly affected the IMF of the swallowing-related muscles, and the tongue muscle was most affected, followed by the pharyngeal muscle and then the geniohyoid muscle. Only the LMM of the geniohyoid muscle significantly decreased with aging. The pharyngeal lumen size did not significantly differ between the elderly and young participants, and only tongue pressure was significantly correlated with tongue, geniohyoid, and pharyngeal muscle mass. CONCLUSIONS: IMF is primarily associated with age-related composition changes in swallowing-related muscles, and it is commonly observed in the tongue and pharyngeal muscles. The geniohyoid muscle is more at risk of muscle atrophy rather than fatty infiltration. In addition, tongue pressure can be a parameter for the evaluation of swallowing-related muscle mass.

Effect of Dysphagia Rehabilitation Using Kinesiology Taping on Oropharyngeal Muscle Hypertrophy in Post-Stroke Patients: A Double Blind Randomized Placebo-Controlled Trial.

BACKGROUND: It has recently been shown that suprahyoid muscle exercise using kinesiology taping (KT) increases the activation of the suprahyoid muscle in healthy adults, suggesting a potential therapeutic clinical exercise for dysphagia rehabilitation. This study investigated the effect of dysphagia rehabilitation using KT in stroke patients with dysphagia. METHODS: Thirty subjects in South Korea were enrolled in this prospective placebo-controlled double-blind study. Participants were randomly assigned to the experimental and sham groups. In the experimental group, the tape was attached to the hyolaryngeal complex, pulled downward with approximately 70% tension, and then attached to the sternum and the clavicle bilaterally. In the sham group, the tape was applied similarly but without the tension. Both groups performed voluntary swallowing 50 times (10 times swallowing per set, times 5 sets) a day for 4 weeks with KT applied. Outcome measures were assessed using portable ultrasound equipment. The parameter measured was the change in thickness of the tongue muscle, mylohyoid muscle, and the anterior belly of the digastric muscle. RESULTS: The experimental group showed statistically significant changes in the thickness of the tongue muscle, mylohyoid muscle, and anterior belly of the digastric muscle than the sham group (p = 0.007, 0.002, and 0.001). CONCLUSION: Dysphagia rehabilitation using KT is a technique that may promote oropharyngeal muscle thickness in patients with dysphagia after stroke.

Crosslinked nanogel-based porous hydrogel as a functional scaffold for tongue muscle regeneration.

Surgical resection in tongue cancer can impair speech and swallowing, reducing quality of life. There is a need for biomaterials that can regenerate tongue muscle tissue defects. Ideally, such a biomaterial would allow controlled release of therapeutic proteins, support the survival and differentiation of therapeutic cells, and promote tongue muscle regeneration in vivo. The aim of the current study was to assess these factors in an acryloyl group-modified crosslinked nanogel, consisting of cholesterol-bearing pullulan hydrogel nanoparticles, to determine its potential as a regenerative therapeutic following tongue resection. The hydrogel demonstrated substantial porosity and underwent slow biodegradation. When loaded with a model protein, the gel enabled sustained protein release over two weeks in serum, with no initial burst release. Mouse myoblasts demonstrated adhesion to the hydrogel and cell survival was observed up to one week. Gel-encapsulated myoblasts demonstrated normal myotube differentiation. Myoblast-loaded gels were implanted in a tongue defect in mice, and there was a significant increase in newly-regenerated myofibers in gel-implanted animals. The developed biomaterial platform demonstrates significant potential as a regenerative treatment following tongue resection, as it facilitates both protein and cell-mediated therapy, and stimulates tongue muscle regeneration in vivo.

Relationship between tongue muscle quality and swallowing speed in community-dwelling older women.

OBJECTIVE: The aim of this study was to investigate the relationship between tongue muscle quality index, which was represented as tongue muscle pressure divided by tongue muscle mass, and swallowing speed in community-dwelling older women. METHODS: The inclusion criteria for this cross-sectional study were that participants be community-dwelling older women aged 65 years and above without dysphagia. The exclusion criteria were stroke and Parkinson's disease that directly cause dysphagia. We measured tongue muscle thickness and maximum tongue pressure and the tongue muscle quality index, which was defined as the maximum tongue pressure divided by tongue muscle thickness. We investigated swallowing speed via a 100 ml water swallowing test. To assess the relationship between tongue muscle characteristics and swallowing speed, we performed stepwise multiple regression analysis. RESULTS: Ninety-three participants were enrolled in this study (mean age: 84.2 ± 4.7 years). A stepwise multiple regression analysis showed that age (ß = - 0.292, p < 0.01) and tongue muscle quality index (ß = 0.267, p < 0.01) were related to swallowing speed. CONCLUSION: We found that tongue muscle quality index was related to swallowing speed in community-dwelling older women. According to our findings, it is possible that the tongue muscle quality index is a useful parameter for assessing swallowing speed in older women without dysphagia.

Tongue function is important for masticatory performance in the healthy elderly: a cross-sectional survey of community-dwelling elderly.

PURPOSE: The aim of this study was to determine the influences of oral motor function such as tongue function and bite force on masticatory performance in the elderly. METHODS: We randomly selected 245 subjects who has 28 natural teeth among community-dwelling elderly. We evaluated masticatory performance using a gummy jelly, and also measured bite force, tongue muscle force, and the speed of tongue movement. RESULTS: We found that reduced masticatory performance to be associated with decreased the speed of tongue movement and/or tongue muscle force, indicating that reduced oral motor function also influences masticatory performance. CONCLUSIONS: These results suggest that keeping oral motor function, as well as maintenance of occlusal support, to be important for maintaining masticatory function in the elderly.

Model-based inverse estimation for active contraction stresses of tongue muscles using 3D surface shape in speech production.

This paper presents a novel inverse estimation approach for the active contraction stresses of tongue muscles during speech. The proposed method is based on variational data assimilation using a mechanical tongue model and 3D tongue surface shapes for speech production. The mechanical tongue model considers nonlinear hyperelasticity, finite deformation, actual geometry from computed tomography (CT) images, and anisotropic active contraction by muscle fibers, the orientations of which are ideally determined using anatomical drawings. The tongue deformation is obtained by solving a stationary force-equilibrium equation using a finite element method. An inverse problem is established to find the combination of muscle contraction stresses that minimizes the Euclidean distance of the tongue surfaces between the mechanical analysis and CT results of speech production, where a signed-distance function represents the tongue surface. Our approach is validated through an ideal numerical example and extended to the real-world case of two Japanese vowels, /ʉ/ and /ɯ/. The results capture the target shape completely and provide an excellent estimation of the active contraction stresses in the ideal case, and exhibit similar tendencies as in previous observations and simulations for the actual vowel cases. The present approach can reveal the relative relationship among the muscle contraction stresses in similar utterances with different tongue shapes, and enables the investigation of the coordination of tongue muscles during speech using only the deformed tongue shape obtained from medical images. This will enhance our understanding of speech motor control.

Functional MRI vs. navigated TMS to optimize M1 seed volume delineation for DTI tractography. A prospective study in patients with brain tumours adjacent to the corticospinal tract.

BACKGROUND: DTI-based tractography is an increasingly important tool for planning brain surgery in patients suffering from brain tumours. However, there is an ongoing debate which tracking approaches yield the most valid results. Especially the use of functional localizer data such as navigated transcranial magnetic stimulation (nTMS) or functional magnetic resonance imaging (fMRI) seem to improve fibre tracking data in conditions where anatomical landmarks are less informative due to tumour-induced distortions of the gyral anatomy. We here compared which of the two localizer techniques yields more plausible results with respect to mapping different functional portions of the corticospinal tract (CST) in brain tumour patients. METHODS: The CSTs of 18 patients with intracranial tumours in the vicinity of the primary motor area (M1) were investigated by means of deterministic DTI. The core zone of the tumour-adjacent hand, foot and/or tongue M1 representation served as cortical regions of interest (ROIs). M1 core zones were defined by both the nTMS hot-spots and the fMRI local activation maxima. In addition, for all patients, a subcortical ROI at the level of the inferior anterior pons was implemented into the tracking algorithm in order to improve the anatomical specificity of CST reconstructions. As intra-individual control, we additionally tracked the CST of the hand motor region of the unaffected, i.e., non-lesional hemisphere, again comparing fMRI and nTMS M1 seeds. The plausibility of the fMRI-ROI- vs. nTMS-ROI-based fibre trajectories was assessed by a-priori defined anatomical criteria. Moreover, the anatomical relationship of different fibre courses was compared regarding their distribution in the anterior-posterior direction as well as their location within the posterior limb of the internal capsule (PLIC). RESULTS: Overall, higher plausibility rates were observed for the use of nTMS- as compared to fMRI-defined cortical ROIs (p < 0.05) in tumour vicinity. On the non-lesional hemisphere, however, equally good plausibility rates (100%) were observed for both localizer techniques. fMRI-originated fibres generally followed a more posterior course relative to the nTMS-based tracts (p < 0.01) in both the lesional and non-lesional hemisphere. CONCLUSION: NTMS achieved better tracking results than fMRI in conditions when the cortical tract origin (M1) was located in close vicinity to a brain tumour, probably influencing neurovascular coupling. Hence, especially in situations with altered BOLD signal physiology, nTMS seems to be the method of choice in order to identify seed regions for CST mapping in patients.

A new surgical strategy for treatment of tongue squamous cell carcinoma based on anatomic study with preliminary clinical evaluation.

BACKGROUND: This study characterized the infiltration of primary tumors along the intrinsic and extrinsic muscles of the tongue in oral tongue squamous cell carcinoma (OTSCC), to create a new surgical strategy that is suitable for most stages. A preliminary evaluation of this novel surgical approach was also conducted. METHODS: An anatomic study of macroscopic specimens from 10 human cadavers and 100 OTSCC patients was conducted. The anatomic characteristics of the primary tumors and the origin and distribution of fibers of the intrinsic and extrinsic tongue muscles were observed and measured. After initial treatment with curative intent, the 100 patients were regularly followed-up with clinical examination and imaging. RESULT: Based on the anatomic characteristics of the primary tumors and tongue muscles, a new surgical approach was developed, and was described as muscle anatomy tongue surgery (MATS). MATS proved suitable for almost all stages of OTSCC. According to the morphology of the invasive tumor front, the 100 cases were divided into four types. The rate of 2-year local disease control was 98%, locoregional control 86%, disease-free survival 85%, and overall survival 89%. Tongue functions were perfectly recovered in more than 60% of the patients. CONCLUSION: Application of the principles of MATS to the treatment of OTSCC proved suitable for almost all stages of the disease. MATS is a novel surgical technique that may improve outcomes in tongue cancer surgery.

Improved nTMS- and DTI-derived CST tractography through anatomical ROI seeding on anterior pontine level compared to internal capsule.

Imaging of the course of the corticospinal tract (CST) by diffusion tensor imaging (DTI) is useful for function-preserving tumour surgery. The integration of functional localizer data into tracking algorithms offers to establish a direct structure-function relationship in DTI data. However, alterations of MRI signals in and adjacent to brain tumours often lead to spurious tracking results. We here compared the impact of subcortical seed regions placed at different positions and the influences of the somatotopic location of the cortical seed and clinical co-factors on fibre tracking plausibility in brain tumour patients. The CST of 32 patients with intracranial tumours was investigated by means of deterministic DTI and neuronavigated transcranial magnetic stimulation (nTMS). The cortical seeds were defined by the nTMS hot spots of the primary motor area (M1) of the hand, the foot and the tongue representation. The CST originating from the contralesional M1 hand area was mapped as intra-individual reference. As subcortical region of interests (ROI), we used the posterior limb of the internal capsule (PLIC) and/or the anterior inferior pontine region (aiP). The plausibility of the fibre trajectories was assessed by a-priori defined anatomical criteria. The following potential co-factors were analysed: Karnofsky Performance Scale (KPS), resting motor threshold (RMT), T1-CE tumour volume, T2 oedema volume, presence of oedema within the PLIC, the fractional anisotropy threshold (FAT) to elicit a minimum amount of fibres and the minimal fibre length. The results showed a higher proportion of plausible fibre tracts for the aiP-ROI compared to the PLIC-ROI. Low FAT values and the presence of peritumoural oedema within the PLIC led to less plausible fibre tracking results. Most plausible results were obtained when the FAT ranged above a cut-off of 0.105. In addition, there was a strong effect of somatotopic location of the seed ROI; best plausibility was obtained for the contralateral hand CST (100%), followed by the ipsilesional hand CST (>95%), the ipsilesional foot (>85%) and tongue (>75%) CST. In summary, we found that the aiP-ROI yielded better tracking results compared to the IC-ROI when using deterministic CST tractography in brain tumour patients, especially when the M1 hand area was tracked. In case of FAT values lower than 0.10, the result of the respective CST tractography should be interpreted with caution with respect to spurious tracking results. Moreover, the presence of oedema within the internal capsule should be considered a negative predictor for plausible CST tracking.

Sexual dimorphism in the histologic organization of the muscle fibers in human tongue.

Tongue movements are critical for speech, swallowing, and respiration; and tongue dysfunction could lead to dysarthria, dysphagia, and obstructive sleep apnea, respectively. Our current understanding of the contributions of specific tongue muscles (TOs) to precise movement patterns is limited. Likewise, there is still little information regarding the orientation of histologic muscle fibers of the tongue in humans, especially between men and women. Thus, the aim of this study was to compare the histologic organization in the tongue of men and women. Ten tongues were studied in human specimens obtained from necropsies (five men and five women). The muscles were analyzed using histology, and the morphometric parameters were measured using Image Pro-Plus Software (Image Pro-Plus 6.0; Media Cybernetics, Silver Spring, MD). Slices were obtained from the anterior, median, and posterior parts of the tongue. We classified and estimated the percentages of transverse (T), oblique (O), and longitudinal (L) fibers in the tongue. To quantify the percentage of fibers in each category in the tongue, the shape coefficient (Shape Z) was estimated. Statistical differences were found between the orientation of the muscle fibers of men and women only for the middle region of the tongue. The middle region of the tongue in women compared with men has a smaller difference in the variation of the percentage of fibers T (P=0.0004), O (P=0.0006), and L (P=0.0013). These morphologic findings are probably related to physiological differences.

A Study on the Morphologic Change of the Tongue Muscle in Down Syndrome Children

Anatomy of oral cavity in Down syndrome is characterized by hypotonic macroglossia, small oral cavity, narrow palate with high-arch shape and hypertrophy of tonsil and adenoid. Because of such a anatomic characteristics, they show difficulty in respiration, mastication, swallowing and articulation. So far we operated on 135 children with Down syndrome for partial glossectomy in average volume of 4.6cc. This study is histopathologic finding of partially resected tongue in 4 cases, analyzed by histochemical stain and electron microscopy. The results of histochemical study showed predominant of Type 2 myofiber and interstitial edema, fibrosis and chronic nonspecific inflammation. In the study of electron microscope, the size and number of mitochondria were increased, but structural abnormality was not showed.

CHANGES IN MOTO-NEURONOTROPHIC FACTOR AND ITS RECEPTOR IN TONGUE MUSCLE POST-DENERVATION OF THE HYPOGLOSSAL NERVE / 解剖学报

We have used our anti-MNTF monoclonal antibody (MNTF-McAb) and MNTF-anti- idiotypic monoclonal antibody (MNTF-Id-McAb) to study the changes in localization and quantities of MNTF and its receptor in tongue muscles of 30 adult rats after 4 days, 2, 3 and 5 weeks, and 2 and 5 months of post-denervation of the hypoglossal nerve. The LSM VIDAS image analysis results revealed that 4 days post-denervation, the MNTF content in tongue muscles of the denervated side had reduced to 75%-80%as compared to the control intact side 100%, however, the reduction of MNTF receptor was insignificant; 2-3 weeks post- denervation, the contents of MNTF and its receptor in the denervated side were significantly reduced to 65%-70% and 50%-55%, respectively; 5 weeks post- denervation, the contents of MNTF and its receptor had started to increase especially for the receptor; and gradually the contents of both MNTF and its receptor in denervated side had recovered and reached to a similar levels as in the control side at 2 months and 5 months post-denervation. These results indicated that MNTF and its receptor are synthesized by the tongue muscle cells and their syntheses are regulated by the hypoglossal nerve; and that there is a close relationship between MNTF and its receptor with the regeneration of hypoglossal nerve.