Effect of Ionizing Radiation on Neuromuscular Junctions in Mouse Tongues

Characteristics of Tongue Pressure Measured by Novel Multisite Flexible Sensors in Nasopharyngeal Carcinoma Patients With Dysphagia

OBJECTIVE

To explore characteristics of tongue pressure changes in nasopharyngeal carcinoma (NPC) patients with dysphagia after radiotherapy using a novel system with multisite flexible sensors.

DESIGN

Prospective observational study.

SETTING

Inpatient rehabilitation centers and community dwellings.

PARTICIPANTS

Nineteen patients with dysphagia after radiotherapy for NPC and 19 healthy participants were recruited for this study (N=38).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

A new 9-site (3 × 3) flexible tongue pressure sensor was used to measure tongue-to-palate pressure across different parts of the tongue. The oral tongue was divided into 3 parts: anterior tongue region (TAR), central tongue region (TCR), and posterior tongue region (TPR); 3 sensors were placed on each part. The mean tongue pressure and endurance time at the 3 sites in the TAR, TCR, and TPR were analyzed. The ratios of the mean TAR, TCR, and TPR values were calculated.

RESULTS

Pressures of TAR, TCR, and TPR in NPC patients with dysphagia were significantly lower than those in healthy participants (P<.05). The pressure in TPR decreased most significantly, followed by that in TCR. The endurance times of TAR and TCR were longer than those of healthy participants (P<.05). The endurance time of TPR was not significantly different between the patients and healthy participants (P>.05). Ratios of pressure between TAR and TCR and TAR and TPR in patients were lower than that in healthy participants (P<.05). There was no significant difference in the TCR to TPR pressure ratio between patients and healthy participants (P>.05).

CONCLUSIONS

Tongue pressure significantly decreased in NPC patients with dysphagia, and the drop in pressure was most pronounced in the TPR area. The results of our study indicate that we should pay attention to the pressure training of the TPR during treatments. The endurance time of the TAR and TCR increased significantly, which may be due to bolus transport compensation. Therefore, clinical rehabilitation strategies should aim to increase the endurance time training in NPC patients after radiotherapy to help increase the effectiveness of the swallowing process in patients.

Effects of Lingual Effort on Swallow Pressures Following Radiation Treatment

PURPOSE

This article investigated the effects of increased oral lingual pressure on pharyngeal pressures during swallowing in patients who have undergone radiotherapy for head and neck cancer. It was hypothesized that increased oral lingual pressure would result in increased pharyngeal pressures.

METHOD

A within-subject experimental design was used with 20 participants who were status post external beam radiotherapy for head and neck cancer. Participants completed typical swallows and swallows with increased lingual force during manofluoroscopic swallow studies. The swallow condition order was randomized across participants.

RESULTS

Manometric data revealed significant differences in swallow pressure by condition at the base of tongue and upper esophageal sphincter sensor locations without significant pressure differences in the lower pharynx. The effortful lingual swallows resulted in higher mean pressures at all locations.

CONCLUSIONS

The results of this study suggest that use of a maneuver designed to increase oral tongue effort can also increase pharyngeal tongue base pressure. Therefore, therapeutic activities used to generate greater pressure of the oral tongue may also alter pharyngeal response. Further research is needed to determine the direct clinical effect on swallow function for individuals with head and neck cancer.

Establishing validity of the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V)

PURPOSE

The Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) was developed to provide a protocol and form for clinicians to use when assessing the voice quality of adults with voice disorders (Kempster, Gerratt, Verdolini Abbott, Barkmeier-Kramer, & Hillman, 2009). This study examined the reliability and the empirical validity of the CAPE-V when used by experienced voice clinicians judging normal and disordered voices.

METHOD

The validity of the CAPE-V was examined in 2 ways. First, we compared judgments made by 21 raters of 22 normal and 37 disordered voices using the CAPE-V and the GRBAS (grade, roughness, breathiness, asthenia, strain; see Hirano, 1981) scales. Second, we compared our raters' judgments of overall severity to a priori consensus judgments of severity for the 59 voices.

RESULTS

Intrarater reliability coefficients for the CAPE-V ranged from .82 for breathiness to .35 for strain; interrater reliability ranged from .76 for overall severity to .28 for pitch.

CONCLUSIONS

Although both CAPE-V and GRBAS reliability coefficients varied across raters and parameters, this study reports slightly improved rater reliability using the CAPE-V to make perceptual judgments of voice quality in comparison to the GRBAS scale. The results provide evidence for the empirical (concurrent) validity of the CAPE-V.

Effects of Chemoradiotherapy on Tongue Function in Patients With Head and Neck Cancer

In this review article, the effects of radiotherapy ± chemotherapy on tissues and on oropharyngeal swallowing are reviewed. In addition, normal tongue function for swallowing is reviewed, as are the effects of tongue exercise programs designed to improve tongue strength and swallow functioning. Current literature on swallow exercise programs for head and neck cancer patients is provided. Also discussed are potential new avenues for research in this population.

Ultrasonic quantification of geniohyoid cross-sectional area and tissue composition: a preliminary study of age and radiation effects

BACKGROUND

This study developed and used a new, noninvasive approach to quantify cross-sectional area and tissue composition within the geniohyoid (GH) muscle in normal adults and head and neck cancer patients.

METHODS

B-mode ultrasound was used to measure GH cross-sectional area at rest and during four speech gestures and GH tissue composition at rest in normal young adults, patients with SCC head and neck cancer treated with primary radiotherapy, and normal older adults age matched with the patients.

RESULTS

Patients exhibited significantly greater GH cross-sectional area than young subjects at rest and in effortful conditions. Significantly greater muscle tissue variability across GH quadrants was observed in patients compared with normal subjects and in older compared with younger subjects.

CONCLUSIONS

B-mode ultrasound area analyses and tissue classification techniques can be used to quantify muscle changes, such as those resulting from age, radiotherapy, or rehabilitation for head and neck cancer.

Swallowing and tongue function following treatment for oral and oropharyngeal cancer

This study examined tongue function and its relation to swallowing in 13 subjects with oral or oropharyngeal cancer treated with primary radiotherapy +/- chemotherapy and 13 age- and sex-matched control subjects. Measures of swallowing and tongue function were obtained using videofluoroscopy, pretreatment and 2 months posttreatment. Maximum isometric strength and endurance at 50% of maximum strength were obtained with the Iowa Oral Performance Instrument (IOPI). Control subjects were tested once. All subjects with head and neck cancer were evaluated pretreatment and 2 months posttreatment. No significant differences were found for the tongue function measures pre- and 2 months posttreatment in the group with head and neck cancer. Significantly higher tongue strength was observed in the control than in the group with head and neck cancer both pre- and posttreatment. No significant differences were found for the 2 groups for tongue endurance measures. Significant correlations of tongue strength and endurance and some swallow measures were found pre- and posttreatment for the group with head and neck cancer and for the control group. These correlations included oral and pharyngeal temporal swallow measures and oropharyngeal swallow efficiency. Pretreatment differences between the 2 groups in tongue strength were likely related to tumor bulk, pain, and soreness. Two-month posttreatment differences were likely related to radiation +/- chemotherapy changes to the oral and pharyngeal mucosa. This study provides support for the hypothesis that tongue strength plays a role in oropharyngeal swallowing, particularly related to the oral phase of the swallow.

Biology of taste buds and the clinical problem of taste loss

Taste buds are the anatomical structures that mediate the sense of taste. They comprise taste cells and nerve fibers within specialized epithelial structures. Taste cells are traditionally described by histologic methods as basal, dark, intermediate, and light cells, with the nerve fibers surrounding and infiltrating the taste buds. By means of immunohistochemical methods, taste cells and gustatory nerve fibers can be classified in functional groups based on the expression of various cell adhesion molecules and other proteins. When taste buds become damaged, the loss of the ability to taste results. This loss is not uncommon and can impact health and quality of life. Patients who receive radiation therapy for head and neck cancer often experience taste loss, which leads to compromised nutritional intake and a worse outcome than patients who do not experience taste loss. The mode of radiation damage to taste cells and nerve fibers has been investigated using cell adhesion molecules, synaptic vesicle proteins, and other cell markers. The light and intermediate cells are preferentially affected by ionizing radiation, whereas the nerve fibers remain structurally intact. Experimental studies of radiation-induced taste loss are performed via a unique animal/human model.