Oropharyngeal swallowing after stroke in the left basal ganglion/internal capsule

Correlation between lesion location and dysphagia characteristics in post-stroke patients

OBJECTIVE

To assess the correlation between lesion location and swallowing function characteristics in post-stroke dysphagia (PSD) patients.

MATERIALS AND METHODS

We enrolled 133 PSD. The patients were divided into supratentorial and infratentorial stroke groups. We compared the measurements in the videofluoroscopic swallowing study (VFSS) with 3ml and 5 ml of diluted and thickened barium liquid data between supratentorial and brainstem stroke groups. We further compared the difference of VFSS measurements between patients with left hemispheric or right hemispheric lesions (further divided into unilateral hemispheric cortical and subcortical subgroups) and brianstem leison stroke group.To explore the lesion location's effect on different bolus volume, the VFSS measurements of 3ml and 5ml in each subgroups were compared respectively. The measurements of VFSS included the oral transit time, soft palate elevation duration, hyoid bone movement duration (HMD), UES opening duration, pharyngeal transit duration (PTD), stage of ansition duration, and laryngeal closure duration (LCD), the upper esophageal sphincter opening (UESO), hyoid bone superior horizontal displacement, and hyoid bone anterior horizontal displacement. General swallowing function was assessed using the Penetration Aspiration Scale (PAS) and Functional Oral Intake Scale (FOIS). We performed the paired t-test, Spearman's correlation, and Kruskal-Wallis test analysis to characterize the parameters among the groups.

RESULTS

Fifty-eight patients were assessed in the final analysis. The HMD (p = 0.019), PTD (p = 0.048) and LCD (p = 0.013) were significantly different between the supratentorial and brainstem lesion groups in 5ml volume. The HMD was significantly different (p = 0.045) between the left cortical and brainstem lesion groups. Significant differences in the HMD (p = 0.037) and LCD (p = 0.032) between the left subcortical and brainstem lesion groups were found in 5ml volume bolus. There was no group different when taking the 3ml volume bolus. Regarding the relationship between food bolus volume and swallowing functions, only the UESO demonstrated a significant difference in the subcortical lesion of the right hemisphere (p = 0.0032) compared the 3 ml and 5 ml volume bolus. The PTD demonstrated a moderate correlation with the PAS scores (r = 0.38, p = 0.0044). The HMD (r = 0.32, p = 0.018) and LCD (r = 0.29, p = 0.039) demonstrated weak correlations with the PAS scores. We did not identify any correlation between the VFSS parameters and FOIS scores in each subgroup level.

CONCLUSION

The PSD with brainstem lesion shows more sever dysfunction in the pharyngeal phases. The left hemisphere was engaged in both the oral and pharyngeal phases. Lesions in the bilateral cortical, subcortical, and brainstem regions may impair sensory input.

The Cortical and Subcortical Neural Control of Swallowing: A Narrative Review

Swallowing is a sophisticated process involving the precise and timely coordination of the central and peripheral nervous systems, along with the musculatures of the oral cavity, pharynx, and airway. The role of the infratentorial neural structure, including the swallowing central pattern generator and cranial nerve nuclei, has been described in greater detail compared with both the cortical and subcortical neural structures. Nonetheless, accumulated data from analysis of swallowing performance in patients with different neurological diseases and conditions, along with results from neurophysiological studies of normal swallowing have gradually enhanced understanding of the role of cortical and subcortical neural structures in swallowing, potentially leading to the development of treatment modalities for patients suffering from dysphagia. This review article summarizes findings about the role of both cortical and subcortical neural structures in swallowing based on results from neurophysiological studies and studies of various neurological diseases. In sum, cortical regions are mainly in charge of initiation and coordination of swallowing after receiving afferent information, while subcortical structures including basal ganglia and thalamus are responsible for movement control and regulation during swallowing through the cortico-basal ganglia-thalamo-cortical loop. This article also presents how cortical and subcortical neural structures interact with each other to generate the swallowing response. In addition, we provided the updated evidence about the clinical applications and efficacy of neuromodulation techniques, including both non-invasive brain stimulation and deep brain stimulation on dysphagia.

Kinematic analysis of chewing and swallowing function after cervical spine surgery

PURPOSE

Although movement of the hyoid bone is different for masticatory swallowing and liquid swallowing in normal subjects, it has not been studied after cervical spine surgery. Therefore, we analyzed the swallowing dynamics of masticatory swallowing in anterior cervical spine disease surgery using foods that require chewing close to actual meals.

METHODS

A day before and one week after the surgery, a videofluoroscopic swallow study (VFSS) was performed, and the distance of hyoid bone movement in the anterior and superior directions, amount of opening of the upper esophageal sphincter (UES), time of passage through the pharynx, number of swallows, and amount of pharyngeal residual were measured on the VFSS images during a masticatory swallow of corn flakes. The swallowing function was evaluated by DSS (dysphagia severity scale) and FOIS (functional oral intake scale). Imaging software was used for the measurements.

RESULTS

Postoperative hyoid movement during masticatory swallowing was not significantly different for anterior movement but significantly limited in upward movement (p = 0.002); UES opening volume was significantly decreased (p < 0.001), and bolus residue was significantly worse (p < 0.001), compared to preoperative. The pharyngeal transit time was not significantly different; the number of swallows increased (p < 0.001), along with DSS (p < 0.001) and FOIS (p < 0.001), with significant differences before and after surgery, indicating worsened swallowing function.

CONCLUSIONS

Swallowing function worsened in masticatory swallowing after surgery for cervical spine disease, mainly due to the restriction of upward movement of the hyoid bone and the resulting increase in pharyngeal residuals after swallowing.

Quantitative Analysis of Temporal Parameters Correlated with Aspiration and Lesion Location in Stroke Patients

The purpose of this study was to identify differences in temporal parameters correlating to the presence of aspiration and the severity of penetration-aspiration scale (PAS) in patients with dysphagia after stroke. We also investigated whether there was a significant difference in temporal parameters based on the location of the stroke lesion. A total of 91 patient videofluoroscopic swallowing study (VFSS) videos of stroke patients with dysphagia were retrospectively analyzed. Various temporal parameters including oral phase duration, pharyngeal delay time, pharyngeal response time, pharyngeal transit time, laryngeal vestibule closure reaction time, laryngeal vestibule closure duration, upper esophageal sphincter opening duration and upper esophageal sphincter reaction time were measured. Subjects were grouped by the presence of aspiration, PAS score, and location of the stroke lesion. Pharyngeal response time, laryngeal vestibule closure duration, and upper esophageal sphincter opening duration were significantly prolonged in the aspiration group. These three factors showed positive correlation with PAS. In terms of stroke lesion, oral phase duration was significantly prolonged in the supratentorial lesion group, while upper esophageal sphincter opening duration was significantly prolonged in the infratentorial lesion group. We have demonstrated that quantitative temporal analysis of VFSS can be a clinically valuable tool identifying dysphagia pattern associated with stroke lesion or aspiration risk.

Effect of Oral Apraxia on Dysphagia in Patients with Subacute Stroke

Aim of this study was to investigate the effect of post-stroke oral apraxia on dysphagia in patients with subacute stroke. We retrospectively analyzed the clinical data of 130 supratentorial stroke patients from January 2015 to February 2021 who underwent a formal limb and oral apraxia test and videofluoroscopic swallowing study (VFSS), and we compared the patients in two groups: the apraxia and non-apraxia (oral apraxia score > 45 and ≤ 45 points, respectively). All the patients participated in the standardized testing battery. The test variables were videofluoroscopic dysphagia scale (VDS), oral transit time (OTT), pharyngeal delay time (PDT), pharyngeal transit time, and penetration-aspiration scale (PAS); we conducted multivariable regression analysis with those parameters to confirm the significance of oral apraxia as a clinical determinant of post-stroke dysphagia. The mean oral apraxia scores were 38.4 and 47.6 points in the apraxia and non-apraxia groups, respectively (p < 0.001). The apraxia group had a higher proportion of delayed OTT for the 2-mL-thick liquid than the non-apraxia group (17.6% and 4.2%, respectively; p = 0.011). Oral apraxia was a significant determinant of VDS (p < 0.001), delayed OTT of 2-mL-thick liquids (p = 0.028), delayed PDT of cup drinking for thin liquid (p = 0.044), and PAS scores (p = 0.003). The presence of oral apraxia was significantly associated with dysphagia, especially with the VFSS parameters of the oral phase (thick liquid), pharyngeal phase (cup drinking for thin liquid) of swallowing, and increased risk of aspiration in subacute stroke patients. Thus, a formal assessment of oral apraxia is needed for stroke patients with dysphagia.

The Role of White Matter in the Neural Control of Swallowing: A Systematic Review

Background: Swallowing disorders (dysphagia) can negatively impact quality of life and health. For clinicians and researchers seeking to improve outcomes for patients with dysphagia, understanding the neural control of swallowing is critical. The role of gray matter in swallowing control has been extensively documented, but knowledge is limited regarding the contributions of white matter. Our aim was to identify, evaluate, and summarize the populations, methods, and results of published articles describing the role of white matter in neural control of swallowing.

Methods: We completed a systematic review with a multi-engine search following PRISMA-P 2015 standards. Two authors screened articles and completed blind full-text review and quality assessments using an adapted U.S. National Institute of Health's Quality Assessment. The senior author resolved any disagreements. Qualitative synthesis of evidence was completed.

Results: The search yielded 105 non-duplicate articles, twenty-two of which met inclusion criteria. Twenty were rated as Good (5/22; 23%) or Fair (15/22; 68%) quality. Stroke was the most represented diagnosis (n = 20; 91%). All studies were observational, and half were retrospective cohort design. The majority of studies (13/22; 59%) quantified white matter damage with lesion-based methods, whereas 7/22 (32%) described intrinsic characteristics of white matter using methods like fractional anisotropy. Fifteen studies (68%) used instrumental methods for swallowing evaluations. White matter areas commonly implicated in swallowing control included the pyramidal tract, internal capsule, corona radiata, superior longitudinal fasciculus, external capsule, and corpus callosum. Additional noteworthy themes included: severity of white matter damage is related to dysphagia severity; bilateral white matter lesions appear particularly disruptive to swallowing; and white matter adaptation can facilitate dysphagia recovery. Gaps in the literature included limited sample size and populations, lack of in-depth evaluations, and issues with research design.

Conclusion: Although traditionally understudied, there is sufficient evidence to conclude that white matter is critical in the neural control of swallowing. The reviewed studies indicated that white matter damage can be directly tied to swallowing deficits, and several white matter structures were implicated across studies. Further well-designed interdisciplinary research is needed to understand white matter's role in neural control of normal swallowing and in dysphagia recovery and rehabilitation.

Association of Lesion Pattern and Dysphagia in Acute Intracerebral Hemorrhage

[Figure: see text].

The impact of dysphagia on quality of life in stroke patients

The objective of this study was to investigate the quality of life in stroke patients using a swallowing quality of life (SWAL-QOL) questionnaire. The correlation between SWAL-QOL questionnaire outcome and videofluoroscopic dysphagia scale (VDS) scores in stroke patients was also determined.This cross-sectional study was retrospectively conducted with 75 stroke patients with dysphagia symptoms. Videofluoroscopic swallowing study (VFSS) and SWAL-QOL questionnaires were performed for all patients. These patients were divided into an oral feeding group and a tube feeding group. SWAL-QOL scores were compared between the 2 groups. The severity of dysphagia was estimated by VDS scores according to the videofluoroscopic swallowing study results. The relationships between SWAL-QOL scores and VDS scores were also investigated.The composite score was 48.82 ± 19.51 for the tube feeding group and 53.17 ± 25.42 for the oral feeding group. There were significant differences in burden and sleep subdomains of the SWAL-QOL between the 2 groups (P = .005 and P = .012, respectively). There was a significant negative correlation between the composite score of SWAL-QOL outcome and the total VDS score (r = -0.468, P = .012). The pharyngeal-phase score of the VDS had significant negative correlations with the SWAL-QOL subdomains of burden (r = -0.327, P = .013), mental health (r = -0.348, P = .008), and social functioning (r = -0.365, P = .029).To improve the quality of life of stroke patients, dysphagia rehabilitation should focus on the pharyngeal phase of dysphagia.

Cortical and Subcortical Control of Swallowing-Can We Use Information From Lesion Locations to Improve Diagnosis and Treatment for Patients With Stroke?

Purpose Swallowing is a complex process, mediated by a broad bilateral neural network that spans from the brainstem to subcortical and cortical brain structures. Although the cortex's role in swallowing was historically neglected, we now understand, especially through clinical observations and research of patients with stroke, that it substantially contributes to swallowing control. Neuroimaging techniques (e.g., magnetic resonance imaging) have helped significantly to elucidate the role of cortical and subcortical brain areas, in general, and the importance of specific areas in swallowing control in healthy individuals and patients with stroke. We will review recent discoveries in cortical and subcortical neuroimaging research studies and their generalizability across patients to discuss their potential implications and translation to dysphagia diagnosis and treatment in clinical practice. Conclusions Stroke lesion locations have been identified that are commonly associated across patients with the occurrence and recovery of dysphagia, suggesting that clinical brain scans provide useful information for improving the diagnosis and treatment of patients with stroke. However, individual differences in brain structure and function limit the generalizability of these relationships and emphasize that the extent of the motor and sensory pathology in swallowing, and how the patient recovers, also depends on a patient's individual brain constitution. The involvement of the damaged brain tissue in swallowing control before the stroke and the health of the residual, undamaged brain tissue are crucial factors that can differ between individuals.

Effect of thalamic deep brain stimulation on swallowing in patients with essential tremor

Objective

Deep brain stimulation (DBS) of the ventral intermediate nucleus (VIM) is a mainstay treatment for severe and drug‐refractory essential tremor (ET). Although stimulation‐induced dysarthria has been extensively described, possible impairment of swallowing has not been systematically investigated yet.

Methods

Twelve patients with ET and bilateral VIM‐DBS with self‐reported dysphagia after VIM‐DBS were included. Swallowing function was assessed clinically and using by flexible endoscopic evaluation of swallowing in the stim‐ON and in the stim‐OFF condition. Presence, severity, and improvement of dysphagia were recorded.

Results

During stim‐ON, the presence of dysphagia could be objectified in all patients, 42% showing mild, 42% moderate, and 16 % severe dysphagia. During stim‐OFF, all patients experienced a statistically significant improvement of swallowing function.

Interpretation

VIM‐DBS may have an impact on swallowing physiology in ET‐patients. Further studies to elucidate the prevalence and underlying pathophysiological mechanisms are warranted.

Pathophysiology of Oropharyngeal Dysphagia Assessed by Videofluoroscopy in Patients with Dementia Taking Antipsychotics

OBJECTIVES

The objective of this study was to assess the pathophysiology of oropharyngeal dysphagia (OD) in patients with dementia, specifically in those taking antipsychotics (APs).

DESIGN

A cross-sectional study was performed from January 2011 to May 2017 in a general hospital.

SETTING AND PARTICIPANTS

We included 114 patients with dementia, of which 39 (34.2%) were taking APs (82.5 ± 7.8 years, Barthel Index 52.28 ± 30.42) and 29 patients without dementia (82.4 ± 6.7 years, Barthel Index 77.71 ± 24.7) and OD confirmed by a videofluoroscopy.

MEASURES

Demographical and clinical factors as well as swallowing function of patients with dementia with OD were compared with older patients without dementia with OD. We also compared patients with dementia taking and not taking APs. Impaired efficacy during videofluoroscopy was defined as the presence of oral and/or pharyngeal residue, and impaired safety (unsafe swallow) was defined as aspiration or penetration. Receiver operating characteristic curves were drawn for laryngeal vestibule closure (LVC) time to predict unsafe swallow.

RESULTS

87.7% of patients with dementia presented impaired efficacy of swallow and 74.6% impaired safety [penetration-aspiration scale (PAS) 3.94 ± 1.94]. 86.2% of patients without dementia presented impaired efficacy and 44.8% impaired safety (PAS 2.21 ± 1.92). Time to LVC was significantly delayed in patients with dementia taking APs in comparison with patients without dementia (LVC 0.377 ± 0.093 vs 0.305 ± 0.026, P = .003). In contrast, there were no differences in the PAS and LVC time in patients with dementia taking and not taking APs (PAS 3.96 ± 0.26 vs 3.88 ± 0.22, LVC 0.398 ± 0.117 vs 0.376 ± 0.115, NS). LVC time ≥0.340 seconds predicted unsafe swallow in patients with dementia with an accuracy of 0.71.

CONCLUSIONS/IMPLICATIONS

Patients with dementia presented high prevalence and severity of videofluoroscopy signs of impaired efficacy and safety of swallow and a more severe impairment in airway protection mechanisms (higher PAS and LVC delay). Clinical practice should implement specific protocols to prevent OD and its complications in these patients. AP treatment did not significantly worsen swallowing impairments.

Relationship between pharyngeal response time and lateralized brain lesion in stroke

Objectives: To analyze the relationship between pharyngeal response time (PRT) and lateralization of brain lesions. Methods: A Cross-sectional study. 73 videofluoroscopic swallow studies (VFSS)were conducted on patients after stroke The study subjects were divided into : group 1 (G1) consisting of 39 individuals with left cortical lesion and group 2 (G2) consisting of 34 individuals with right cortical lesions. The VFSS of G1 and G2 subjects were analyzed using puree (A) and liquid (B) consistencies, and  were also subdivided into young adults and older persons. . The mean PRT was divided into times shorter and longer than 250 ms. Results: No statistically significant difference was observed between G1 and G2 for the A and B consistencies, being obtained : G1 (A mean: 56.6 ms; B mean: 99.5 ms; A mean: 3627 ms; B mean: 1712 ms) and G2 (A mean: 79.6 ms; B mean: 110.7 ms; A mean: 2040 ms, B mean: 1529 ms), for PRT shorter (A:p = .673; B: p = 1.000) and longer (A: p = .435; B: p = .847) than 250 ms, respectively. No statistically significant difference was found regarding the variable age in the comparison between young and old adults for mean PRT according to the A and B consistencies in G1 (A: p = .260; B: p = .732) and G2 (A: p = .586; B: p = .104). Conclusion: No relationship between PRT and lateralization of brain lesion was observed with respect to subject age and to the swallowing of different food consistencies.

Mapping acute lesion locations to physiological swallow impairments after stroke

Dysphagia is a common deficit after a stroke, and it is frequently associated with pneumonia, malnutrition, dehydration, and poor quality of life. It is not yet fully clear which brain regions are directly related to swallowing, and how lesions affect swallow physiology. This study aimed to assess the statistical relationship between acute stroke lesion locations and impairment of specific aspects of swallow physiology. We performed lesion symptom mapping with 68 retrospectively recruited, acute, first-ever ischemic stroke patients. Lesions were determined on diffusion weighted MRI scans. Post-stroke swallow physiology was determined using the Modified Barium Swallow Study Impairment Profile (MBSImP©™). The relationship between brain lesion location and 17 physiological aspects of swallowing were tested using voxel-based and region-based statistical associations corrected for multiple comparisons using permutation thresholding. We found that laryngeal elevation, anterior hyoid excursion, laryngeal vestibular closure, and pharyngeal residue were associated with lesioned voxels or regions of interests. All components showed distinct and overlapping lesion locations, mostly in the right hemisphere, and including cortical regions (inferior frontal gyrus, pre- and postcentral gyrus, supramarginal gyrus, angular gyrus, superior temporal gyrus, insula), subcortical regions (thalamus, amygdala) and white matter tracts (superior longitudinal fasciculus, corona radiata, internal capsule, external capsule, ansa lenticularis, lenticular fasciculus). Our findings indicate that different aspects of post-stroke swallow physiology are associated with distinct lesion locations, primarily in the right hemisphere, and primarily including sensory-motor integration areas and their corresponding white matter tracts. Future studies are needed to expand on our findings and thus, support the development of a neuroanatomical model of post-stroke swallow physiology and treatment approaches targeting the neurophysiological underpinnings of swallowing post stroke.

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Different aspects of swallow physiology are associated with distinct stroke lesion locations.

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Sensory-motor integration areas and white matter tracts are crucial for swallow physiology.

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Mostly regions in the right and only few in the left hemisphere contribute to swallow physiology.

Relationship Between Subcortical Hemorrhage Size and Characteristics of Dysphagia

The subcortex is an important region in terms of swallowing function that passes fibers from the swallowing center to the cortex. However, studies on the relationship between the hemorrhage size and characteristics of dysphagia were lacking. In the present study, the relationship between subcortical hemorrhage size and characteristics of dysphagia was assessed in patients with subcortical hemorrhage. This study recruited retrospectively 49 subcortical hemorrhage patients with dysphagia. The hemorrhage size was measured and the clinical dysphagia scale (CDS) was used to evaluate the severity of dysphagia. The relationship between CDS score and hemorrhage size was analyzed. Subjects were divided into 2 groups according to average hemorrhage size of the subjects. The CDS scores of the 2 groups were compared and the relationship between each CDS item and hemorrhage size was analyzed. A significant positive correlation was observed between hemorrhage size and total CDS score. Also, a significant correlation was observed when patients over 70 years of age were excluded. The total CDS score in the large hemorrhage group was significantly higher than the CDS score in the small hemorrhage group. The CDS items including tracheostomy, lip sealing, tongue protrusion, laryngeal elevation, and reflex coughing were significantly correlated with hemorrhage size. In this study, the hemorrhage size in patients with subcortical hemorrhage correlated with the severity of dysphagia. In addition, the hemorrhage size was correlated with specific CDS items. These findings should be considered when treating subcortical hemorrhage patients with dysphagia in a clinical setting.

Swallowing outcomes in patients with subcortical stroke associated with lesions of the caudate nucleus and insula

Objective The present study was performed to investigate the relationships between swallowing outcomes and lesion location, bolus characteristics, and age in patients with subcortical stroke.

PATIENTS

Patients with subcortical and insular stroke (mean age, 57.38 ± 12.71 years) were investigated. All patients (n = 21) completed both brain magnetic resonance imaging studies and videofluoroscopic swallowing studies. Main Outcome Measures The oral transit duration, pharyngeal transit duration (PTD), laryngeal response duration, and Penetration-Aspiration Scale (PAS) score were applied to examine the efficiency of propulsion and airway protection in three swallowing tasks. Path analyses were performed to assess the relationships between swallowing outcomes and lesion location, age, bolus viscosity, and bolus volume. Results Caudate nucleus (CN) lesions were associated with higher PAS scores. Insular lesions were associated with a longer PTD. Advanced age was associated with a longer PTD. Bolus viscosity significantly moderated the association between CN lesions and higher PAS scores. Conclusions In the present cohort, CN lesions impacted airway protection and insular lesions impacted pharyngeal transit. An increased bolus viscosity reduced the aspiration severity. These results suggest that lesion location is an important indicator to predict subsequent dysphagia in patients with subcortical stroke.

Laryngeal Closure during Swallowing in Stroke Survivors with Cortical or Subcortical Lesion

BACKGROUND

One of the major, and most harmful, symptoms of dysphagia in stroke survivors is aspiration. Survivors of unilateral cortical strokes with dysphagia and resulting aspiration have been reported to have greater initiation delays in laryngeal closure than those who did not aspirate. Few studies have reported such data in survivors of subcortical stroke.

METHODS

This study measured initiation of laryngeal closure (ILC) and laryngeal closure duration (LCD) in 2 groups of subjects: 15 stroke survivors with cortical lesions and 15 stroke survivors with subcortical lesions. Means and standard deviations of ILC and LCD were analyzed on 5-mL thin liquid and 5-mL puree boluses using a 100-ms timer during subsequent analysis of videofluoroscopic swallowing examinations. Statistical comparisons were used by repeated measures analysis of variance. Significance level was set at P < .05.

RESULTS

ILC was significantly longer in stroke survivors with a subcortical lesion than in those with a cortical lesion for both bolus consistencies. However, there were no significant differences between the 2 groups in LCD. Stroke survivors with a subcortical lesion had a greater incidence of penetration or aspiration and silent aspiration than those with a cortical lesion and a longer delay in the ILC.

CONCLUSIONS

Subcortical lesions may put these survivors at greater risk of aspiration due to delayed initial laryngeal closure and reduced oral and laryngeal sensation. The subcortical damage, which occurs at the basal ganglia, may interrupt the ILC.

Orosensory contributions to dysphagia: a link between perception of sweet and sour taste and pharyngeal delay time

Pharyngeal delay is a significant swallowing disorder often resulting in aspiration. It is suspected that pharyngeal delay originates from sensory impairment, but a direct demonstration of a link between oral sensation and pharyngeal delay is lacking. In this study involving six patients with complaints of dysphagia, taste sensation of the oral tongue was measured and subsequently related to swallowing kinematics. It was found that a response bias for sour taste was significantly correlated with pharyngeal delay time on paste, highlighting oral sensory contributions to swallow motor dysfunctions. Investigating the precise nature of such a link between oral sensation and dysphagia would constitute a basis for understanding the disorder. The results of this study highlight oral sensory contributions to pharyngeal swallow events and provide impetus to examine this link in larger samples of dysphagic patients.

A noninvasive swallowing measurement system using a combination of respiratory flow, swallowing sound, and laryngeal motion

The assessment of swallowing function is important for the prevention of aspiration pneumonia. We developed a new swallowing monitoring system that uses respiratory flow, swallowing sound, and laryngeal motion. We applied this device to 11 healthy volunteers and 10 patients with dysphagia. Videofluoroscopy (VF) was conducted simultaneously with swallowing monitoring using our device. We measured laryngeal rising time (LRT), the time required for the larynx to elevate to the highest position, and laryngeal activation duration (LAD), the duration between the onset of rapid laryngeal elevation and the time when the larynx returned to the lowest position. In addition, we evaluated the coordination between swallowing and breathing. We found that LAD was correlated with a VF-derived parameter, pharyngeal response duration (PRD) in healthy subjects (LAD: 959 ± 259 ms vs. PRD: 1062 ± 149 ms, r = 0.60); however, this correlation was not found in the dysphagia patients. LRT was significantly prolonged in patients (healthy subjects: 320 ± 175 ms vs. patients: 465 ± 295 ms, P < 0.001, t test). Furthermore, frequency of swallowing immediately after inspiration was significantly increased in patients. Therefore, the new device may facilitate the assessment of some aspects of swallowing dysfunction.

Brain regions involved in swallowing: Evidence from stroke patients in a cross-sectional study

Background:

Limited data available about the mechanisms of dysphagia and areas involving swallow after brain damage; accordingly it is hard to predict which cases are more likely to develop swallowing dysfunction based on the neuroimaging. The aim of this study was to investigate the relationship between brain lesions and dysphagia in a sample of acute conscious stroke patients.

Materials and Methods:

In a cross-sectional study, 113 acute conscious stroke patients (69 male mean [standard deviation (SD)] age 64.37 [15.1]), participated in this study. Two neurologists and one radiologist localized brain lesions according to neuroimaging of the patients. Swallowing functions were assessed clinically by an expert speech pathologist with the Mann Assessment of Swallowing Ability (MASA). The association of brain region and swallowing problem was statistically evaluated using Chi-square test.

Results:

Mean (SD) MASA score for the dysphagic patients was 139.61 (29.77). Swallowing problem was significantly more prevalent in the right primary sensory (P = 0.03), right insula (P = 0.005), and right internal capsule (P = 0.05).

Conclusion:

It may be concluded from these findings that the right hemisphere lesions associated with occurring dysphagia. Further studies using more advanced diagnostic tools on big samples particularly in a perspective structure are needed.

Dysphagia Post Subcortical and Supratentorial Stroke

BACKGROUND

Studies have recognized that the damage in the subcortical and supratentorial regions may affect voluntary and involuntary aspects of the swallowing function. The current study attempted to explore the dysphagia characteristics in patients with subcortical and supratentorial stroke.

METHODS

Twelve post first or second subcortical and supratentorial stroke patients were included in the study. The location of the stroke was ascertained by computed tomography and magnetic resonance imaging. The characteristics of swallowing disorder were assessed by video fluoroscopic swallowing assessment/fiberoptic endoscopic evaluation of swallowing. The following main parameters were analyzed: oral transit time, pharyngeal delay time, presence of cricopharyngeal muscle achalasia (CMA), distance of laryngeal elevation, the amounts of vallecular residue and pyriform sinus residue (PSR), and the extent of pharyngeal contraction.

RESULTS

Eighty-three percent of the 12 patients were found suffering from pharyngeal dysphagia, with 50% having 50%-100% PSRs, 50% having pharyngeal delay, and 41.6% cases demonstrating CMA. Simple regression analysis showed PSRs were most strongly associated with CMA. Pharyngeal delay in the study can be caused by infarcts of basal ganglia/thalamus, infarcts of sensory tract, infarcts of swallowing motor pathways in the centrum semiovale, or a combination of the three.

CONCLUSION

Subcortical and supratentorial stroke may result in pharyngeal dysphagia such as PSR and pharyngeal delay. PSR was mainly caused by CMA.

Tongue pressure modulation for initial gel consistency in a different oral strategy

Background

In the recent hyper-aged societies of developed countries, the market for soft diets for patients with dysphagia has been growing and numerous jelly-type foods have become available. However, interrelationships between the biomechanics of oral strategies and jelly texture remain unclear. The present study investigated the influence of the initial consistency of jelly on tongue motor kinetics in different oral strategies by measuring tongue pressure against the hard palate.

Methods

Jellies created as a mixture of deacylated gellan gum and psyllium seed gum with different initial consistencies (hard, medium or soft) were prepared as test foods. Tongue pressure production while ingesting 5 ml of jelly using different oral strategies (Squeezing or Mastication) was recorded in eight healthy volunteers using an ultra-thin sensor sheet system. Maximal magnitude, duration and total integrated values (tongue work) of tongue pressure for size reduction and swallowing in each strategy were compared among initial consistencies of jelly, and between Squeezing and Mastication.

Results

In Squeezing, the tongue performed more work for size reduction with increasing initial consistency of jelly by modulating both the magnitude and duration of tongue pressure over a wide area of hard palate, but tongue work for swallowing increased at the posterior-median and circumferential parts by modulating only the magnitude of tongue pressure. Conversely, in Mastication, the tongue performed more work for size reduction with increasing initial consistency of jelly by modulating both magnitude and duration of tongue pressure mainly at the posterior part of the hard palate, but tongue work as well as other tongue pressure parameters for swallowing showed no differences by type of jelly.

Conclusions

These results reveal fine modulations in tongue-palate contact according to the initial consistency of jelly and oral strategies.

Videofluoroscopic assessment of pharyngeal stage delay reflects pathophysiology after brain infarction

OBJECTIVES/HYPOTHESIS

The pathophysiology of dysphagia caused by brain infarction varies with the site of the lesion in the brain. Patients with suprabulbar lesions have demonstrated delayed triggering of pharyngeal stage including delayed laryngeal elevation. Patients with severe pharyngeal stage delay have a high risk of intractable aspiration to the lower respiratory tract. Despite this, few studies have compared the pharyngeal stage delay with the lesion site. We defined a new temporal parameter of the pharyngeal stage delay to assess laryngeal elevation delay against the bolus inflow into the pharyngeal space. This study aimed to elucidate whether this parameter of pharyngeal stage delay is clinically useful to assess the pathophysiology of brain lesions after brain infarction.

STUDY DESIGN

Case-control study.

METHODS

Videofluoroscopic assessment of swallowing examinations was performed from January 7, 2000 to March 29, 2011 at Kyushu University Hospital. We evaluated the pharyngeal stage delay using motion analysis on videofluoroscopic swallowing examination in patients with normal swallowing and brain infarction patients divided into pathophysiologic lesion groups. Laryngeal elevation delay time and pharyngeal delay time were analyzed.

RESULTS

Significant differences in laryngeal elevation delay time were observed between each pathophysiologic lesion group. However, pharyngeal delay time remained similar among groups. Brain infarctions of corticobulbar tract and basal ganglion were significantly associated with laryngeal elevation delay time prolongation.

CONCLUSIONS

Laryngeal elevation delay time with low-viscosity contrast medium is a recommended parameter to discriminate the corticobulbar tract and the basal ganglion lesion.

Effects of enhanced bolus flavors on oropharyngeal swallow in patients treated for head and neck cancer

BACKGROUND

Treatment for head and neck cancer can reduce peripheral sensory input and impair oropharyngeal swallow. This study examined the effect of enhanced bolus flavor on liquid swallows in these patients.

METHODS

Fifty-one patients treated for head and neck cancer with chemoradiation or surgery and 64 healthy adult control subjects served as subjects. All were randomized to receive sour, sweet, or salty bolus flavor. Patients were evaluated at 7-10 days, 1 month, and 3 months after completion of tumor treatment. Control subjects received 1 assessment.

RESULTS

All bolus flavors affected oropharyngeal swallow; sour flavor significantly shortened pharyngeal transit time across all evaluations.

CONCLUSIONS

Sour flavor influenced the swallow of patients treated for head and neck cancer, as well as that of control subjects in a manner similar to those with neurologic impairment observed in an earlier study. Sour flavor may improve the speed of pharyngeal transit regardless of whether a patient has suffered peripheral or central sensory damage.

Deep-brain-stimulation does not impair deglutition in Parkinson's disease

OBJECTIVE

A large proportion of patients with Parkinson's disease develop dysphagia during the course of the disease. Dysphagia in Parkinson's disease affects different phases of deglutition, has a strong impact on quality of life and may cause severe complications, i.e., aspirational pneumonia. So far, little is known on how deep-brain-stimulation of the subthalamic nucleus influences deglutition in PD.

METHODS

Videofluoroscopic swallowing studies on 18 patients with Parkinson's disease, which had been performed preoperatively, and postoperatively with deep-brain-stimulation-on and deep-brain-stimulation-off, were analyzed retrospectively. The patients were examined in each condition with three consistencies (viscous, fluid and solid). The 'New Zealand index for multidisciplinary evaluation of swallowing (NZIMES) Subscale One' for qualitative and 'Logemann-MBS-Parameters' for quantitative evaluation were assessed.

RESULTS

Preoperatively, none of the patients presented with clinically relevant signs of dysphagia. While postoperatively, the mean daily levodopa equivalent dosage was reduced by 50% and deep-brain-stimulation led to a 50% improvement in motor symptoms measured by the UPDRS III, no clinically relevant influence of deep-brain-stimulation-on swallowing was observed using qualitative parameters (NZIMES). However quantitative parameters (Logemann scale) found significant changes of pharyngeal parameters with deep-brain-stimulation-on as compared to preoperative condition and deep-brain-stimulation-off mostly with fluid consistency.

CONCLUSION

In Parkinson patients without dysphagia deep-brain-stimulation of the subthalamic nucleus modulates the pharyngeal deglutition phase but has no clinically relevant influence on deglutition. Further studies are needed to test if deep-brain-stimulation is a therapeutic option for patients with swallowing disorders.

Relevance of subcortical stroke in dysphagia

BACKGROUND AND PURPOSE

Unilateral cortical lesions are associated with dysphagia in ischemic stroke. It is unclear, however, whether acute subcortical stroke is associated with a similar risk of dysphagia. The aim of this study was to determine the occurrence of dysphagia in purely subcortical stroke and identify dysphagia characteristics.

METHODS

Between 2003 and 2005, videofluoroscopic swallow studies (VFSSs) were completed in 20 consecutive ischemic stroke patients with purely subcortical lesions (right hemisphere damage [RHD]=10, left hemisphere damage [LHD]=10) and 25 age-matched controls. Individuals were classified with dysphagia when at least 2 swallowing measures were 2 standard deviations above mean scores for the control group. Lesion volume, hemisphere, and location were determined from diffusion-weighted magnetic resonance imaging scans.

RESULTS

Seven subcortical stroke patients (35%) met VFSS criteria for dysphagia (LHD=5, RHD=2); 4 patients presented with clinically significant dysphagia. A significant interaction between hemisphere and lesion location was identified. Whereas 3 of 5 patients with dysphagia (60%) had lesions to the left periventricular white matter (PVWM), LHD patients without dysphagia did not have PVWM lesions. In contrast, no RHD patients with PVWM lesions had dysphagia, and 6 of 8 patients without dysphagia (75%) had PVWM lesions. Oral transfer was significantly slower in patients with subcortical stroke compared with the healthy adults.

CONCLUSIONS

Lesions to the left PVWM may be more disruptive to swallowing behavior than similar lesions to the right PVWM. Swallowing deficits involving oral control and transfer may be a marker of subcortical neural axis involvement.

The neurobiology of swallowing and dysphagia

The neurobiological study of swallowing and its dysfunction, defined as dysphagia, has evolved over two centuries beginning with electrical stimulation applied directly to the central nervous system, and then followed by systematic investigations that have used lesioning, transmagnetic stimulation, magnetoencephalography, and functional magnetic resonance imaging. The field has evolved from mapping the central neural pathway and peripheral nerves, to defining the importance of specific regions of the lower brain stem in terms of interneurons that provide sequential control for multiple muscles in the most complex reflex elicited by the nervous system, the pharyngeal phase of swallowing. The field is now emerging into defining how the higher cortical regions interact with this brain stem control and is providing a broader perspective of how the intact nervous system functions to control the three phases of swallowing (i.e., oral, pharyngeal, and esophageal). Much of the present interest focuses on how to retrain a damaged nervous system using a variety of stimulus techniques, which follow fundamentals in rehabilitation of the nervous system.

Comparison of 2 interventions for liquid aspiration on pneumonia incidence: a randomized trial

BACKGROUND

Aspiration pneumonia is common among frail elderly persons with dysphagia. Although interventions to prevent aspiration are routinely used in these patients, little is known about the effectiveness of those interventions.

OBJECTIVE

To compare the effectiveness of chin-down posture and 2 consistencies (nectar or honey) of thickened liquids on the 3-month cumulative incidence of pneumonia in patients with dementia or Parkinson disease.

DESIGN

Randomized, controlled, parallel-design trial in which patients were enrolled for 3-month periods from 9 June 1998 to 19 September 2005.

SETTING

47 hospitals and 79 subacute care facilities.

PATIENTS

515 patients age 50 years or older with dementia or Parkinson disease who aspirated thin liquids (demonstrated videofluoroscopically). Of these, 504 were followed until death or for 3 months.

INTERVENTION

Participants were randomly assigned to drink all liquids in a chin-down posture (n = 259) or to drink nectar-thick (n = 133) or honey-thick (n = 123) liquids in a head-neutral position.

MEASUREMENTS

The primary outcome was pneumonia diagnosed by chest radiography or by the presence of 3 respiratory indicators.

RESULTS

52 participants had pneumonia, yielding an overall estimated 3-month cumulative incidence of 11%. The 3-month cumulative incidence of pneumonia was 0.098 and 0.116 in the chin-down posture and thickened-liquid groups, respectively (hazard ratio, 0.84 [95% CI, 0.49 to 1.45]; P = 0.53). The 3-month cumulative incidence of pneumonia was 0.084 in the nectar-thick liquid group compared with 0.150 in the honey-thick liquid group (hazard ratio, 0.50 [CI, 0.23 to 1.09]; P = 0.083). More patients assigned to thickened liquids than those assigned to the chin-down posture intervention had dehydration (6% vs. 2%), urinary tract infection (6% vs. 3%), and fever (4% vs. 2%).

LIMITATIONS

A no-treatment control group was not included. Follow-up was limited to 3 months. Care providers were not blinded, and differences in cumulative pneumonia incidence between interventions had wide CIs.

CONCLUSION

No definitive conclusions about the superiority of any of the tested interventions can be made. The 3-month cumulative incidence of pneumonia was much lower than expected in this frail elderly population. Future investigation of chin-down posture combined with nectar-thick liquid may be warranted to determine whether this combination better prevents pneumonia than either intervention independently.

Postoperative swallowing function after posterior fossa tumor resection in pediatric patients

OBJECTIVE

After tumor resection involving the posterior fossa, postoperative swallowing dysfunction may be anticipated. This retrospective study was designed to document swallowing abnormalities in children after posterior fossa brain tumor surgery and to recommend management approaches for children at risk for aspiration.

METHODS

Twenty-four children referred postoperatively for a video fluoroscopic swallow study (VFSS) out of 127 children undergoing posterior fossa surgery for brain tumor resection from 1998 to 2001 were evaluated for oral, pharyngeal, and cervical esophageal transits.

CONCLUSION

Less than half of the 24 children swallowed functionally within the first week after surgery. VFSS was an appropriate tool for diagnosing swallowing dysfunction, which is impossible to determine at bedside. Children with brain stem involvement and more difficult recovery had significantly worse swallowing function and greater aspiration. We recommend that children with compromised swallowing function should not feed orally until a radiographic swallowing assessment demonstrates functional and safe swallowing with or without therapeutic intervention.

Quantifying swallowing function after stroke: A functional dysphagia scale based on videofluoroscopic studies

OBJECTIVE

To develop a sensitive, specific scale for quantifying functional dysphagia in stroke patients, using results obtained from videofluoroscopic swallowing studies.

DESIGN

Data collected from a serial oral and pharyngeal videofluoroscopic swallowing study.

SETTING

A dysphagia clinic in a department of rehabilitation medicine at a tertiary care university hospital.

PARTICIPANTS

One hundred three consecutively admitted stroke patients.

INTERVENTIONS

Videoflurorscopy to measure a scale of 11 variables: lip closure score, bolus formation, residue in oral cavity, oral transit time, triggering of pharyngeal swallow, laryngeal elevation and epiglottic closure, nasal penetration, residue in valleculae, coating of pharyngeal wall after swallow, and pharyngeal transit time.

MAIN OUTCOME MEASURES

Polychotomous linear logistic regression analysis of videofluoroscopic and aspiration results. Scale sensitivity and specificity, and the correlation between the total score of the scale and aspiration grade were analyzed.

RESULTS

The scale's sensitivity and specificity for detecting supraglottic penetration and subglottic aspiration were 81%, 70.7%, and 78.1%, 77.9%, respectively. A significant positive correlation was found between the scale's total score and the severity of aspiration (Spearman's r =.58943, p =.00001).

CONCLUSION

This functional dysphagia scale, which was based on a videofluoroscopic swallowing study in stroke patients, is a sensitive and specific method for quantifying the severity of dysphagia.

Swallow-related cerebral cortical activity maps are not specific to deglutition

Cortical representation of swallow-related motor tasks has not been systematically investigated. In this study, we elucidated and compared these cortical representations to those of volitional swallow using block-trial and single-trial methods. Fourteen volunteers were studied by functional magnetic resonance imaging. Cortical activation during both swallowing and swallow-related motor tasks that can be performed independent of swallowing, such as jaw clenching, lip pursing, and tongue rolling, was found in four general areas: the anterior cingulate, motor/premotor cortex, insula, and occipital/parietal region corresponding to Brodmann's areas 7, 19, and 31. Regions of activity, volume of activated voxels, and increases in signal intensity were found to be similar between volitional swallow and swallow-related motor tasks. These findings, using both block-trial and single-trial techniques, suggest that cerebral cortical regions activated during swallowing may not be specific to deglutitive function.

Cerebral cortical representation of reflexive and volitional swallowing in humans

The purpose of this study was to compare cerebral cortical representation of experimentally induced reflexive swallow with that of volitional swallow. Eight asymptomatic adults (24-27 yr) were studied by a single-trial functional magnetic resonance imaging technique. Reflexive swallowing showed bilateral activity concentrated to the primary sensory/motor regions. Volitional swallowing was represented bilaterally in the insula, prefrontal, cingulate, and parietooccipital regions in addition to the primary sensory/motor cortex. Intrasubject comparison showed that the total volume of activity during volitional swallowing was significantly larger than that activated during reflexive swallows in either hemisphere (P < 0.001). For volitional swallowing, the primary sensory/motor region contained the largest and the insular region the smallest volumes of activation in both hemispheres, and the total activated volume in the right hemisphere was significantly larger compared with the left (P < 0.05). Intersubject comparison showed significant variability in the volume of activity in each of the four volitional swallowing cortical regions. We conclude that reflexive swallow is represented in the primary sensory/motor cortex and that volitional swallow is represented in multiple regions, including the primary sensory/motor cortex, insular, prefrontal/cingulate gyrus, and cuneus and precuneus region. Non-sensory/motor regions activated during volitional swallow may represent swallow-related intent and planning and possibly urge.

Pretreatment swallowing function in patients with head and neck cancer

BACKGROUND

Few objective data characterizing the pretreatment swallow function of patients with head and neck cancer are available.

METHODS

Pretreatment swallowing function in 352 patients with various lesions was evaluated with videofluoroscopy and compared with control subjects.

RESULTS

Patients had significantly longer oral and pharyngeal transit times, greater amounts of oral and pharyngeal residue, shorter cricopharyngeal opening durations, and lower swallow efficiencies. Swallow function worsened significantly with increased tumor stage, and patients with oral or pharyngeal lesions had worse swallow function than patients with laryngeal lesions. Frequency of complaint of swallow difficulty before treatment was 59%. Patients with lower stage tumors had fewer complaints of swallowing, as did patients with oral cavity lesions.

CONCLUSIONS

Despite demonstrating significant differences from control subjects, patients had highly functional swallows before treatment. The tendency for patients not to perceive a swallowing problem is consistent with the highly functional nature of their pretreatment swallow.

How people with stroke and healthy older people experience the eating process

The aim of this study was to describe the process of eating, experiences of eating and oral functions. Participants consisted of 30 people with first stroke and localization of the damage verified by computer topography (CT), and 15 healthy older people. All were observed during test-meals, interviewed about eating, and oral functions were tested. The results demonstrated that most (21) people with stroke had some difficulties in eating and expressed feelings of fear and shame about eating and changed physical and social appearance, mainly related to difficulties in preparing and transporting food to the mouth as well as swallowing deficits.

Outcomes of individualized interventions in patients with severe eating difficulties

The aim of this case study is to describe the outcomes of individualized interventions for patients with severe eating difficulties. The participants were 15 patients who had severe eating difficulties following a stroke or brain tumor and were receiving oral feeding or tube feeding. Interventions focused on training functions needed for eating, activities in eating, and discussions with the patient. Improvements were especially noted in eating activities, and some improvements were noted in oral movements and nutritional status. Before the interventions, none of the patients ate regular food; afterward, six did, and in four patients, the feeding tube was removed. The patients said eating was easier, and they could eat in a safe way. Furthermore, they appreciated the attention to their experience during meals. Although the impairments were not always alleviated, the patients found means to cope with their eating difficulties.

The influence of bolus volume and viscosity on anterior lingual force during the oral stage of swallowing

The influence of bolus volume and viscosity on the distribution of anterior lingual force during the oral stage of swallowing was investigated using a new force transducer technology. The maximum force amplitudes from 5 normal adults were measured simultaneously at the mid-anterior, right, and left lateral tongue margins during 10 volitional swallows of 5-, 10-, and 20-ml volumes of water, applesauce, and pudding. Results indicated significant increases in peak force amplitude as viscosity increased. Volume did not significantly influence maximum lingual force amplitudes. Individual subjects demonstrated consistent patterns of asymmetrical force distribution across the lingual margins tested. The results suggest that bolus-specific properties influence the mechanics of oral stage lingual swallowing. This finding has important clinical implications in the assessment and treatment of dysphagic individuals.

Effects of a sour bolus on oropharyngeal swallowing measures in patients with neurogenic dysphagia

This study examines the effects of a sour bolus (50% lemon juice, 50% barium liquid) on pharyngeal swallow measures in two groups of patients with neurogenic dysphagia. Group 1 consisted of 19 patients who had suffered at least one stroke. Group 2 consisted of 8 patients with dysphagia related to other neurogenic etiologies. All patients were selected because they exhibited delays in the onset of the oral swallow and delays in triggering the pharyngeal swallow on boluses of 1 ml and 3 ml liquid barium during videofluoroscopy. Results showed significant improvement in oral onset of the swallow in both groups of patients and a significant reduction in pharyngeal swallow delay in Group 1 patients and in frequency of aspiration in Group 2 patients with the sour as compared to the non-sour boluses. Other selected swallow measures in both subject groups also improved with the sour bolus. Volume effects were present but not as consistently as in prior studies. Implications for swallow therapy are discussed.

Biomechanical analysis of the pharyngeal swallow in postsurgical patients with anterior tongue and floor of mouth resection and distal flap reconstruction

The purpose of this study was to examine changes in the biomechanics of pharyngeal swallow after surgery in eight patients (six men and two women) with anterior tongue and floor of mouth resections with distal flap reconstruction. Eight normal age-matched subjects were also studied. Swallowing performance was assessed following a standardized protocol with videofluoroscopy preoperatively and at 1 and 3 months postoperatively for the oral cancer patients. The normal subjects received a single videofluoroscopic study. Computer-assisted biomechanical analysis was used to mark the movements of specific oropharyngeal structures over time throughout the swallow of calibrated boluses. Statistical analyses revealed that tongue base, pharyngeal wall, hyoid, laryngeal, and cricopharyngeal movements during the swallow were altered significantly after surgery for the cancer patients. Some oropharyngeal structural movements differed from those of normal control subjects before surgery. In this study, biomechanical measures indicated that there was recovery in some aspects of the pharyngeal swallow in this patient group. The duration of tongue base to pharyngeal wall contact, which was significantly reduced preoperatively and at 1 month after surgery, increased significantly to within normal levels by the 3-month postoperative evaluation. Duration of laryngeal closure and the onset of laryngeal closure relative to cricopharyngeal opening also improved significantly to within normal levels by the 3-month postoperative evaluation.