Tzu-Yu Hsiao

Dysphagia after radiotherapy : Endoscopic examination of swallowing in patients with nasopharyngeal carcinoma

Dysphagia is a late sequela compromising the lives of more than one fourth of patients with nasopharyngeal carcinoma (NPC) who survive long after radiotherapy. By using fiberoptic endoscopic examination of swallowing as a modality for dysphagia evaluation, we were able to easily recognize the functional and anatomic changes in 31 dysphagic NPC patients. The majority of patients were found to aspirate after the act of swallowing (77.4%). Seventeen (54.8%) had tongue atrophy, and 9 (29%) had vocal cord palsy. Dysfunctions such as dry mouth (45.2%), velopharyngeal incompetence (58%), premature leakage (41.9%), delay or absence of swallow reflex (87.1%), poor pharyngeal constriction (80.6%), pharyngeal residue retention (83.9%), penetration or aspiration (93.5%), and silent aspiration (41.9%) were noted in these patients. Multiple dysfunctions were demonstrated in each patient. Abnormality of pharyngeal constriction and/or aberrant upper esophageal sphincter function played the major role in the postswallow aspiration of these irradiated NPC patients. Clinically compromised patients (weight loss of ≥5 kg in 1 year or pneumonia) had more of the above anatomic and functional impairments. The radiation dosage and volume bore no correlation to the time of symptom onset, or to the occurrence of functional changes.

Dysphagia in Patients with Nasopharyngeal Cancer After Radiation Therapy: A Videofluoroscopic Swallowing Study

This study evaluated swallowing status and the factors influencing swallowing in patients with nasopharyngeal carcinoma (NPC) after radiation therapy. During the period from July 1995 to June 1999, this cross-sectional study used videofluoroscopic swallowing study (VFSS) to evaluate 184 NPC patients who had completed radiation therapy [113 cases had completed radiation therapy ≤12 months prior to evaluation (acute group) and 71 cases had completed radiation therapy >12 months prior to evaluation (chronic group)]. The numbers of patients with tumors in each of the four stages were as follows: 24 in stage I, 45 in stage II, 41 in stage III, and 74 in stage IV. Swallowing abnormalities of the acute and chronic groups were correlated with multiple variables, including gender, age, the stage of the tumor, use of either neoadjuvant chemotherapy or radiosensitizer, and radiation modality. The analytical results indicated that the chronic group had a significantly higher proportion of swallowing abnormalities. Radiation modality, chemotherapy, and tumor staging were not significantly associated with swallowing dysfunction. Trend analysis revealed a progressive deterioration of most parameters of swallowing function in this group of patients. These findings indicate that swallowing function continues to deteriorate over time, even many years after radiation therapy in patients with NPC. Our results indicate that the time elapsed since radiation therapy correlates with the severity of dysphagia in NPC patients.

Ischemic conditioning by short periods of reperfusion attenuates renal ischemia/reperfusion induced apoptosis and autophagy in the rat

Prolonged ischemia amplified iscehemia/reperfusion (IR) induced renal apoptosis and autophagy. We hypothesize that ischemic conditioning (IC) by a briefly intermittent reperfusion during a prolonged ischemic phase may ameliorate IR induced renal dysfunction. We evaluated the antioxidant/oxidant mechanism, autophagy and apoptosis in the uninephrectomized Wistar rats subjected to sham control, 4 stages of 15-min IC (I15 × 4), 2 stages of 30-min IC (I30 × 2), and total 60-min ischema (I60) in the kidney followed by 4 or 24 hours of reperfusion. By use of ATP assay, monitoring O2-. amounts, autophagy and apoptosis analysis of rat kidneys, I60 followed by 4 hours of reperfusion decreased renal ATP and enhanced reactive oxygen species (ROS) level and proapoptotic and autophagic mechanisms, including enhanced Bax/Bcl-2 ratio, cytochrome C release, active caspase 3, poly-(ADP-ribose)-polymerase (PARP) degradation fragments, microtubule-associated protein light chain 3 (LC3) and Beclin-1 expression and subsequently tubular apoptosis and autophagy associated with elevated blood urea nitrogen and creatinine level. I30 × 2, not I15 × 4 decreased ROS production and cytochrome C release, increased Manganese superoxide dismutase (MnSOD), Copper-Zn superoxide dismutase (CuZnSOD) and catalase expression and provided a more efficient protection than I60 against IR induced tubular apoptosis and autophagy and blood urea nitrogen and creatinine level. We conclude that 60-min renal ischemia enhanced renal tubular oxidative stress, proapoptosis and autophagy in the rat kidneys. Two stages of 30-min ischemia with 3-min reperfusion significantly preserved renal ATP content, increased antioxidant defense mechanisms and decreased ischemia/reperfusion enhanced renal tubular oxidative stress, cytosolic cytochrome C release, proapoptosis and autophagy in rat kidneys.

Measurement of mucosal wave propagation and vertical phase difference in vocal fold vibration.

Examination of the surface wave properties of the vocal fold mucosa is becoming an important part of assessment of vocal function. A key wave property is propagation velocity, which determines the phase delay between the upper and lower margins of the vocal folds. Excised canine larynges were used to measure this phase delay, and therewith propagation velocity. The motion of two flesh points was tracked stroboscopically. Differential displacements between the flesh points were matched to displacements of a model. A least-squared fit of the data to the model provided the numeric values of propagation velocity, which varied from 0.5 m/s to about 2.0 m/s, depending on fundamental frequency. The corresponding phase delay along the medial surface of the vocal folds varied from about 60°/mm to 30°/mm.

Transcutaneous ultrasound for evaluation of vocal fold movement in patients with thyroid disease

BACKGROUND Preoperative evaluation of recurrent laryngeal nerve function is important in the context of thyroid surgery. Transcutaneous ultrasound may be useful to visualize vocal fold movement when evaluating thyroid disease. METHODS A 7-18 MHz linear array transducer was placed transversely on the midline of the thyroid cartilage at the anterior neck of patients with thyroid disease. The gray-scale technique was used, with the scan setting for the thyroid gland. RESULTS Between August 2008 and March 2010, 705 patients, including 672 patients with normal vocal fold movement and 33 patients with vocal fold paralysis were enrolled. They included 159 male and 546 female patients. Their ages ranged from 10 to 88 years. Vocal fold movement could be seen by ultrasound in 614 (87%) patients, including 589 (88%) patients with normal vocal fold movement and 25 (76%) patients with vocal fold paralysis (p=0.06). The mean age of patients with visible and invisible vocal fold movement was 46.6 and 57.9 years old, respectively (p=0.001). Ultrasound was able to see vocal fold movement in 533 (98%) female patients but only in 81 (51%) male patients (p=0.001). Among the patients with vocal fold paralysis, ultrasound revealed palsied vocal folds in 17 of 18 (94%) female patients but in only 8 of 15 (53%) male patients (p=0.01). CONCLUSION Transcutaneous ultrasound represents an alternative tool to evaluate vocal fold movement for more than 85% of patients with thyroid disease, including more than 90% of female patients and about half of male patients.

Effect of subglottic pressure on fundamental frequency of the canine larynx with active muscle tensions.

The relation between subglottic pressure and the fundamental frequency of vocal fold vibration was studied by means of evoked phonation in an in vivo canine model. The evoked-phonation model involved electrical stimulation of the midbrain that resulted in consistent responses by respiratory and laryngeal musculature, accompanied by phonation. The dynamic stiffness properties of the vocal folds, especially the “cover,” were investigated by delivering various amounts of air pressure to the larynx from an opening in the trachea. The fundamental frequency of vocal fold vibration increased linearly with subglottic pressure. The slopes ranged from 22.4 to 118.7 Hz per kilopascal in 7 animals. The results indicated that the dependence of fundamental frequency on subglottic pressure is a passive mechanical phenomenon.

Effects of functional electrical stimulation on dysphagia caused by radiation therapy in patients with nasopharyngeal carcinoma.

PurposeThis study aimed to assess the effectiveness of functional electrical stimulation on the swallowing function of irradiated nasopharyngeal carcinoma patients with dysphagia.Materials and methodsTwenty nasopharyngeal carcinoma subjects with dysphagia were divided into a functional electrical stimulation (FES) and a home rehabilitation program (HRP) group. Each subject completed a quality of life questionnaire on swallowing and a videofluoroscopic study at the commencement and the end of the procedures. The FES group received functional electrical stimulation of the supra-hyoid muscles over 15 sessions. The HRP group performed self-swallowing exercises at home. The evaluation parameters included the quality of life questionnaire scores, the penetration–aspiration scale (PAS), the movement of the hyoid bone, and the amount of pyriform sinuses stasis.ResultsMost swallowing outcomes of the FES group improved after FES. The quality of life score (p = 0.003), the duration of the movement of thin barium through the hyoid (p = 0.001), the moving speed of paste barium through the hyoid (p = 0.028), and the pyriform sinus stasis area of the paste barium (p = 0.026) reached significant difference in the FES group. Most swallowing outcomes did not improve in the HRP group. The degree of improvement in the movement speed of the hyoid bone in the thin barium (p = 0.018) and the PAS of the paste barium (p = 0.016) were statistically significantly greater in the FES group than in the HRP group.ConclusionFES will improve the swallowing function of NPC patients with dysphagia and bring about better quality of life.

ELASTICITY OF HUMAN VOCAL FOLDS MEASURED IN VIVO USING COLOR DOPPLER IMAGING

Noninvasive measurement of human vocal fold (VF) vibratory length was made during normal phonation to calculate the corresponding elasticity. A fixed-ends rubber string phantom that was driven by a vibrating motor was built to simulate the horizontal VF movement. The vibratory artefact of color Doppler imaging (CDI) was used to characterize and quantify the high-frequency tissue vibration with small amplitude. Because the frequency and the length of vibrating VFs were obtained simultaneously, the stress-strain relation and the Youngs moduli of the VFs could be calculated. For the six vocally normal adult volunteers (3 M, 3 F, ages from 19 to 51 years old), the effective vibrating lengths of the vocal fold in low pitch were about 1.4 to 1.6 cm and 1.3 to 1.5 cm for men and women, respectively. The VFs lengths extended to about 1.7 to 1.8 cm in pitch over an octave higher and the stress-strain relation was nonlinear. However, in the range of lower pitch, the VF stress was relatively linear with respect to the strains and the Youngs moduli were about 30 to 120 kPa in men and 120 to 300 kPa in women.

Prolonged Effect of Botulinum Toxin Injection in the Treatment of Cricopharyngeal Dysphagia: Case Report and Literature Review

Cricopharyngeus (CP) muscle spasm can lead to severe dysphagia. Myotomy of the CP muscle was the treatment of choice. Recently, botulinum toxin type A (BtxA) has been used for CP spasm. It usually brings improvement in deglutition but most patients require reinjection in 3–5 months. We report a 35-year-old man who had an arteriovenous malformation hemorrhage in the brain stem resulting in CP spasm and consequently severe dysphagia. He received BtxA injection and deglutition and nutrition remained good one year after treatment. A literature review analyzing 28 patients and our patient showed negative correlations between age and BtxA dose and between age and duration. Efficacy was positively correlated with duration and BtxA dose was positively correlated with pretreatment severity. In conclusion, physicians would use higher doses on patients with more severe cases but use lower doses on older patients. Those who obtained better post-treatment results would enjoy longer effective duration. Thus, the effective duration of the BtxA is multifactorial.

Vocal process granuloma – A result of long-term observation in 53 patients

Vocal process granulomas are benign lesions involved in the healing of posterior glottis injuries. Here, we report the results of our conservative treatment of vocal process granulomas. Fifty-three patients with 54 occurrences of granulomas between 1998 and 2007 were enrolled. All patients were observed without surgical excision or specific medications and regularly monitored with telescopic examinations until the granulomas disappeared. Data on age, sex, clinical presentation, prior history of intubation or gastroesophageal reflux, telescopic findings, management and clinical course were reviewed. There were 41 males and 12 females. The mean ages of granuloma occurrence were 48.1 years in men and 41.6 years in women (p=0.16). Symptoms included hoarseness in 42 patients, cough in 13 patients, lumping sensation in the throat in 15 patients and sore throat in 14 patients. Ten occurrences were stable during the follow-up period, and the other 44 (81%) achieved complete remission (mean period of 30.6 weeks). The remission patterns included progression and remission in 6 occurrences, slow remission in 22 and rapid remission in 16. The remission rate of granulomas was not significantly related to age (p=0.71), sex (p=0.43), prior intubation (p=0.71), acid reflux (p=0.47), unilateral/bilateral lesions (p=1.00) or granuloma size (p=0.46). The remission time was significantly shorter in patients with prior intubation (p=0.04), but not significantly associated with age (p=0.89), sex (p=0.87), acid reflux (p=0.91), unilateral/bilateral lesions (p=0.26) or granuloma size (p=0.96). Long-term observation has demonstrated that vocal process granulomas can be cured at high remission rates without implementing specific treatments.