Neutral Head Position Research Articles

Forward Head Posture and Activation of Rectus Capitis Posterior Muscles.

Rectus capitis posterior (RCP) muscles have physical attachments to the pain-sensitive spinal dura. Atrophy of these muscles is associated with chronic headache in some patients. The authors suspect that the significance of atrophy in the RCP muscles has been undervalued because the functional role of these muscles is not well defined. To determine whether a statistically significant change in normalized levels of electromyographic activity in RCP muscles occurs when the head is voluntarily moved from a self-selected neutral head position to a protruded head position. Fine wire, intramuscular electrodes were used to collect electromyographic data as asymptomatic participants moved their head from a neutral head position into a forward head position and back into the neutral head position. This sequence was repeated 4 times. Normalized levels of electromyographic activity were quantified using a 2-head position × 2 sides of the body repeated measures design that incorporated mixed-effects β regression models. Twenty participants were studied. Electromyographic activity collected from RCP muscles was found to increase as the head was voluntarily moved from a self-selected neutral head position (11% of maximum voluntary isometric contraction [MVIC] in RCP minor, 14% of MVIC in RCP major) into a protruded head position (35% of MVIC in RCP minor, 39% of MVIC in RCP major) (P<.001). Rectus capitis posterior muscles may contribute to segmental stabilization of the occipitoatlantal and atlantoaxial joints by helping to maintain joint congruency during movement of the head.

Sternomental distance and sternomental displacement as predictors of difficult laryngoscopy and intubation in adult patients.

Background:Several morphometric airway measurements have been used to predict difficult laryngoscopy (DL). This study evaluated sternomental distance (SMD) and sternomental displacement (SMDD, difference between SMD measured in neutral and extended head position), as predictors of DL and difficult intubation (DI).Materials and Methods:We studied 610 adult patients scheduled to receive general anesthesia with tracheal intubation. SMD, SMDD, physical, and airway characteristics were measured. DL (Cormack-Lehane grade 3/4) and DI (assessed by Intubation Difficulty Scale) were evaluated. The optimal cut-off points for SMD and SMDD were identified by using receiver operating characteristic (ROC) analysis. Multivariate logistic regression was used to predict DL and ROC curve was used to assess accuracy on developed regression model.Results:The incidence of DL and DI was 15.4% and 8.3%, respectively. The cut-off values for SMD and SMDD were ≤14.75 cm (sensitivity 66%, specificity 60%) and ≤5.25 cm (sensitivity 70%, specificity 53%), respectively, for predicting DL. The area under the curve (AUC) with 95% confidence interval (CI) for SMD was 0.66 (0.60–0.72) and that for SMDD was 0.687 (0.63–0.74). Multivariate analysis with logistic regression identified inter-incisor distance, neck movement <80°, SMD, SMDD, short neck and history of snoring as predictors and the predictive model so obtained exhibited a higher diagnostic accuracy (AUC: 0.82; 95% CI 0.77–0.86). SMDD, but not SMD, correlated with DI.Conclusions:Both SMD and SMDD provide a rapid, simple, objective test that may help identifying patients at risk of DL. Their predictive value improves considerably when combined with the other predictors identified by logistic regression.

The airway device preference may affect the overlapping of the common carotid artery by the internal jugular vein.

Anatomical variation in the internal jugular vein (IJV), as well as its small size, tendency to collapse, and proximity to the common carotid artery (CCA) makes central venous cannulation via the IJV a technically challenging procedure, especially in pediatric patients. We evaluated the effects of laryngeal mask airway insertion and endotracheal intubation (ETT) on the anatomical relationship between the IJV and the CCA in neutral and 40° head away positions. After parental consent 92 patients with ASA physical status I-II, aged 0-17, undergoing elective urological surgery were enrolled and divided into two groups according to the airway management device used for anesthesia: Group laryngeal mask airway (n=63) and Group ETT (n=29). An ultrasonographic evaluation was performed before and after airway instrumentation at neutral and 40° head rotation. The IJV position in relation to the CCA was noted, and the overlap percentage of the CCA was calculated as the ratio of the CCA length covering by the internal jugular vein to the transverse diameter of the CCA. With no airway device insertion, the position of the IJV was found to be anterolateral to the CCA in the majority of patients (48.8% vs 35.3%, right vs left IJV) in the neutral head position. While there was no significant change in the overlap percentages of the CCA after laryngeal mask airway insertion in the neutral head position [48.71% vs 57.30% for the right IJV (difference in median: -21.20; 95% confidence interval (CI) of difference: -56.92 to 14.52; P=0.133); 52.54% vs 60.36% for the left IJV (difference in median: -10.3; 95% CI of difference: -41.49 to 20.89; P=0.128)], it increased significantly in the 40° head away position on both sides [50.11% vs 64.83% for the right IJV (difference in median: -55; 95% CI of difference: -84 to -25.24; P=0.01); 53.82% vs 71.20% for the left IJV (difference in median: -46; 95% CI of difference: -86.85 to -5.15; P=0.004)]. However, the overlap percentages of CCA decreased significantly on the right side with patients in a neutral head position (31.23% vs 6.27%, difference in median: 19; 95% CI of difference: -5.68 to 43.68; P=0.002) and on both sides in the 40° head away position [29.50% vs 16.19%, difference in median: 26; 95% CI of difference: 2.84 to 49.16; P=0.03 and 47% vs 31.94%, difference in median: 9.50; 95% CI of difference: -40.87 to 59.87; P=0.03 for the right and left sides, respectively] after ETT insertion. Laryngeal mask airway with 40° head rotation increases, whereas ETT decreases, the overlap percentage of CCA by IJV. Both head position and airway management methods have an influence on the overlap of the CCA by the IJV in pediatric patients.

The Hang Power Clean

The Hang Power Clean

Pre-Treatment Objective Diagnosis and Post-Treatment Outcome Evaluation in Patients with Vascular Pulsatile Tinnitus Using Transcanal Recording and Spectro-Temporal Analysis.

ObjectiveAlthough vascular pulsatile tinnitus (VPT) has been classified as “objective”, VPT is not easily recognizable or documentable in most cases. In response to this, we have developed transcanal sound recording (TSR) and spectro-temporal analysis (STA) for the objective diagnosis of VPT. By refining our initial method, we were able to apply TSR/STA to post-treatment outcome evaluation, as well as pre-treatment objective diagnosis.MethodsTSR was performed on seven VPT patients and five normal controls before and after surgical or interventional treatment. VPT was recorded using an inserted microphone with the subjects placed in both upright and supine positions with 1) a neutral head position, 2) head rotated to the tinnitus side, 3) head rotated to the non-tinnitus side, and 4) a neutral position with ipsi-lesional manual cervical compression. The recorded signals were analyzed in both time and time-frequency domains by performing a short-time Fourier transformation.ResultsThe pre-treatment ear canal signals of all VPT patients demonstrated pulse-synchronous periodic structures and acoustic characteristics that were representative of their presumptive vascular pathologies, whereas those the controls exhibited smaller peaks and weak periodicities. Compared with the pre-treatment signals, the post-treatment signals exhibited significantly reduced peak- and root mean square amplitudes upon time domain analysis. Additionally, further sub-band analysis confirmed that the pulse-synchronous signal of all subjects was not identifiable after treatment and, in particular, that the signal decrement was statistically significant at low frequencies. Moreover, the post-treatment signals of the VPT subjects revealed no significant differences when compared to those of the control group.ConclusionWe reconfirmed that the TSR/STA method is an effective modality to objectify VPT. In addition, the potential role of the TSR/STA method in the objective evaluation of treatment outcomes in patients with VPT was proven. Further studies incorporating a larger sample size and more refined recording techniques are warranted.

The scapula backward tipping test: An inter-rater reliability study

The purpose of this study was to determine the reliability of the scapula backward tipping test (SBTT) in detecting the presence of pectoralis minor (PM) tightness and subsequently scapula forward tipping, in a symptomatic population. PM tightness with scapula forward tipping has been described to cause pain and dysfunction in the shoulder region. 30 patients with a diagnosis of shoulder pain were randomly assigned and examined by 2 musculoskeletal physical therapists at a time. The procedure consisted of having the individual lay on the stomach in a neutral head position with palms in the anatomical position. The examiner firmly stabilized the inferior angle of the scapula with one hand and the fingers of the other hand hooked the under surface of the coracoid process. A gentle yet firm pull was imparted in an upward direction to sense tightness and to observe movement of the acromion up to the tragus of the ear. A comparison was made with the other side to sense restriction. Inter-rater reliability was determined using the kappa statistic. The SBTT was found to be reproducible between examiners (Kappa=0.735, SE of kappa=0.123, 95% confidence interval), with a percentage agreement of 86.67%. The SBTT may be incorporated as a simple yet effective test to determine the presence of PM tightness and subsequently scapula forward tipping.

Robot-assisted placement of depth electrodes along the long Axis of the amygdalohippocampal complex

Abstract Background Classically, transoccipital hippocampal depth electrode implantation requires a stereotactic headframe and arc and the patient to be placed in a seated or prone position, which can be cumbersome to position and uncomfortable for the surgeon. Robotic intracranial devices are increasingly being utilized for stereotactic procedures such as stereolectroencephalography (SEEG) but commonly require patients be placed in head-neutral position to perform facial registration. Objective Here we describe a novel robotic implantation technique where a stereotactic intracranial robot is used to place bilateral hippocampal depth electrodes in the lateral position. Methods Four patients underwent SEEG depth electrode placement, which included placement of bilateral hippocampal depth electrodes. Each patient was positioned in the lateral position and registered to the robot with laser facial registration. Trajectories were planned with the robotic navigation software, which then identified the appropriate entry points and trajectories needed to reach the targets. After electrode implantation, target localization was confirmed using computed tomography (CT). Results Electrodes targeting the amygdalohippocampal complex were accurate and there were no complications in this group. An average of seven electrodes were placed per patient. Ictal onset was localized for each patient. All patients subsequently underwent temporal lobectomy and 75% have been seizure free since surgery. Conclusions We have developed the Robot-Assisted Lateral Transoccipital Approach (RALTA), which is an advantageous technique for placing bilateral amygdalohippocampal depth electrodes using robotic guidance. Benefits of this technique include fewer electrodes required per patient and ease of positioning compared with seated or prone positioning.

La distance acromio-claviculaire est corrélée à la version glénoïdienne

BackgroundThe acromiohumeral distance (ACHD) is a radiographic parameter for evaluating the presence of a rotator cuff rupture. Previous investigations have demonstrated that several factors may influence the magnitude of the acromiohumeral distance, but glenoid version has not yet been considered. HypothesisOur hypothesis was that there is a direct correlation between glenoid version and acromiohumeral distance as well as subacromial clearance. MethodsFour right glenohumeral joints from adult fresh cadavers were anatomically dissected to the level of the rotator cuff. After fixation to a board and positioning of the humeral head in neutral position, an osteotomy of the glenoid neck was carried out and the version was altered in steps of 5°. The ACHD as well as the subacromial clearance (SAC) were measured for every degree of glenoid version. ResultsThe ACHD increased with increased anteversion and consistently decreased with increased retroversion of the glenoid. The SAC also depended on glenoid version: neutral version was associated with a minimal clearance under the anterior third of the acromion, retroversion transferred the minimal SAC posteriorly and anteversion transferred minimal SAC under the coracoacromial ligament. ConclusionOur results indicate that glenoid version correlates directly with the magnitude of ACHD and SAC. Therefore, variations of glenoid version can lead to false interpretations of cuff integrity. Type of studyBiomechanical investigation. Level of evidenceNot possible to define.

Impact of patient positioning on radiotherapy dose distribution: An assessment in parotid tumor

Purpose: We intended to study the impact of patient positioning on the dose distribution within target volume and organs at risk in patients with parotid malignancies treated with 3D conformal radiotherapy (3D-CRT) with photon wedge pair (WP) or intensity modulated radiotherapy (IMRT). Methods: Three patients with a non-Hodgkin’s lymphoma of the right parotid gland were consecutively immobilized using thermoplastic cast in 2 positions: supine with head in neutral position (HN) and with head turned 90° to the left side (HT). Images for treatment planning purpose were acquired in both positions. For both positions, photon WP plans and 5 field IMRT plans were generated, after contouring clinical target volume (CTV), planning target volume (PTV= CTV + 5 mm margin) and organs at risk (OAR). All plans were evaluated for target coverage and dose to OARs. Results: Both CTV and PTV were apparently larger in HN compared with HT (31.76±8.89 cc, 30.31±7.83 cc and 62.49±19.01 cc, 58.89±15.33 cc) respectively. The CI value for PTV was slightly better for HT compared to HN position in both the WP and IMRT plans. The homogeneity was comparable in both the head positions in case of WP plan. The mean HI of PTV was increased in case of IMRT plan at HT versus HN position (1.108 vs. 1.097). A change in head position from HN to HT with wedge pair plan resulted in a reduction of brainstem D max and D mean . Lesser dose was observed in HN position for contralateral parotid. A difference of 0.9 Gy in the average D max to spinal cord was seen. The values of D mean to mandible, oral cavity, ipsilateral and contralateral cochlea were higher in the HT position. A change in head position from HN to HT with IMRT plan resulted in a dose reduction in average D max to brainstem. The spinal cord D max increased at the HT position by 1.2 Gy. The dose to contralateral parotid and cochlea was comparable in both the positions. However, the D mean to oral cavity was reduced at HT position. Whereas for IMRT versus wedge pair plan at head neutral position average D mean to the contralateral parotid was reduced with the IMRT plan. A considerable reduction in D max to spinal cord and D mean to ipsilateral cochlea was observed. A slight increase in average D max to brainstem and was observed with the IMRT plan. The doses to the remaining OARs were lesser in case of IMRT plan. For IMRT versus wedge pair plan at head tilt position slight increase in average D max to brainstem was observed in case of IMRT plan. A considerable reduction in D max to spinal cord and D mean to ipsilateral cochlea was observed. The doses to the remaining OARs were reduced with IMRT plan. Conclusion: Change in head position from neutral to 90° contralateral tilt for wedge pair plan in parotid tumor may considerably reduce dose to the brainstem and spinal cord with a modest increase in dose to mandible, oral cavity, contralateral parotid, and bilateral cochlea. The alteration in head position has minimal impact on IMRT planning.

The acromiohumeral distance and the subacromial clearance are correlated to the glenoid version

BackgroundThe acromiohumeral distance (ACHD) is a radiographic parameter for evaluating the presence of a rotator cuff rupture. Previous investigations have demonstrated that several factors may influence the magnitude of the acromiohumeral distance, but glenoid version has not yet been considered. HypothesisOur hypothesis was that there is a direct correlation between glenoid version and acromiohumeral distance as well as subacromial clearance. MethodsFour right glenohumeral joints from adult fresh cadavers were anatomically dissected to the level of the rotator cuff. After fixation to a board and positioning of the humeral head in neutral position, an osteotomy of the glenoid neck was carried out and the version was altered in steps of 5°. The ACHD as well as the subacromial clearance (SAC) were measured for every degree of glenoid version. ResultsThe ACHD increased with increased anteversion and consistently decreased with increased retroversion of the glenoid. The SAC also depended on glenoid version. Neutral version was associated with a minimal clearance under the anterior third of the acromion, retroversion transferred the minimal SAC posteriorly and anteversion transferred minimal SAC under the coracoacromial ligament. ConclusionOur results indicate that glenoid version correlates directly with the magnitude of ACHD and SAC. Therefore, variations of glenoid version can lead to false interpretations of cuff integrity. Type of studyBiomechanical investigation. Level of evidenceNot possible to define.

Effect of head and jaw position on respiratory-related motion of the genioglossus.

Head and jaw position influence upper airway patency and electromyographic (EMG) activity of the main upper airway dilator muscle, the genioglossus. However, it is not known whether changes in genioglossus EMG activity translate into altered muscle movement during respiration. The aim of this study was to determine the influence of head and jaw position on dilatory motion of the genioglossus in healthy adult men during quiet breathing by measuring the displacement of the posterior tongue in six positions--neutral, head extension, head rotation, head flexion, mouth opening, and mandibular advancement. Respiratory-related motion of the genioglossus was imaged with spatial modulation of magnetization (SPAMM) in 12 awake male participants. Tissue displacement was quantified with harmonic phase (HARP) analysis. The genioglossus moved anteriorly beginning immediately before or during inspiration, and there was greater movement in the oropharynx than in the velopharynx in all positions. Anterior displacements of the oropharyngeal tongue varied between neutral head position (0.81 ± 0.41 mm), head flexion (0.62 ± 0.45 mm), extension (0.39 ± 0.19 mm), axial rotation (0.39 ± 0.2 mm), mouth open (1.24 ± 0.72 mm), and mandibular advancement (1.08 ± 0.65 mm). Anteroposterior displacement increased in the mouth-open position and decreased in the rotated position relative to cross-sectional area (CSA) (P = 0.002 and 0.02, respectively), but CSA did not independently predict anteroposterior movement overall (P = 0.057). The findings of this study suggest that head position influences airway dilation during inspiration and may contribute to variation in airway patency in different head positions.

Tetra-ataxiometric Posturography in Patients with Migrainous Vertigo

Background: Migraine is a common disorder characterized by headache attacks frequently accompanied by vestibular symptoms like dizziness, vertigo, and balance disorders. Clinical studies support a strong link between migraine and vertigo rather than between other headache types and vertigo or nonvertiginous dizziness. There is a lack of consensus regarding the pathophysiology of migrainous vertigo. Activation of central vestibular processing during migraine attacks and vasospasm-induced ischemia of the labyrinth are reported as the probable responsible mechanisms. Because vestibular examination alone does not provide enough information for diagnosis of migrainous vertigo, posturography systems which provide objective assessment of somatosensory, vestibular, and visual information would be very helpful to show concomitant involvement of the vestibular and somato-sensorial systems. There are few posturographic studies on patients with migraine but it seems that how balance is affected in patients with migraine and/or migrainous vertigo is still not clear. We want to investigate balance function in migraineurs with and without vertigo with a tetra-ataxiometric posturography system and our study is the first study in which tetra-ataxiometric static posturography was used to evaluate postural abnormalities in a well-defined population of patients with migrainous vertigo. Objective: To investigate balance functions in migraineurs with and without vertigo with a tetra-ataxiometric posturography system. Study Design: Prospective, nonrandomized, controlled study. Setting: Pamukkale University Hospital, Neurology and Physical Therapy and Rehabilitation outpatient clinics. Methods: Sixteen patients with migrainous vertigo, 16 patients with migraine without aura and no vestibular symptoms, and 16 controls were included in the study. Computerized static posturography system was performed and statistical analyses of fall, Fourier, Stability, and Weight distribution indexes were performed. The tetra-ataxiometric posturography device measures vertical pressure fluctuations on 4 independent stable platforms, each placed beneath 2 heels and toe parts of the patient; inputs from these platforms are integrated and processed by a computer digitally. Four separate plates are used and perpendicular pressures of the anterior and posterior feet are measured. Pressure of each force plate is measured and data was analyzed by the software program. Limitations: A very small, non-randomized, and controlled study with the inability to find an answer to the mechanism of involvement of the somatosensorial system and vestibular system in migrainous headaches. Results: The distribution of patients with posturographical abnormalities in the migrainous vertigo group was significantly different than the control group. Distribution of the patients with posturographical abnormalities in the high frequencies of the head-right position was significantly different in the migrainous vertigo group than in the control group and distribution of the patients with posturographical abnormalities in high frequencies of the head-right position was significantly different in the migraine group than in the controls groups. The stability index of the migrainous vertigo group was significantly higher than in the control group when tested on in the neutral-head position with open eyes. Conclusion: In this first study of tetra-ataxiometric static posturography evaluating postural abnormalities in a well-defined population of patients with migrainous vertigo, the central part of the vestibular apparatus would be responsible of postural abnormalities in patients with migraine and migrainous vertigo. Key words: Fall index, migraine, migrainous vertigo, static posturography

Test-retest reliability of assessing cervical proprioception using cervical range of motion device

Background: Cervical proprioception plays an important role in the stability and optimal functional of the cervical spine and assessment of cervical proprioception is integral in the assessment and management of cervical spine dysfunction. Cervical range of motion (CROM) device is an effective tool, simple and cost effective tool to assess cervical proprioception. The objective of the study was to establish the test-retest reliability of a CROM in assessing cervical proprioception in asymptomatic individuals. Methods: Twenty healthy adults (mean age 37±8 years) were recruited and test retest reliability of CROM device in assessing cervical proprioception was assessed. Cervico-cephalic kinaesthetic sensibility tests - Neutral Head Positioning (NHP) and Target head Positioning (THP) tests were used to assess cervical proprioception. The test retest reliability was assessed in 2 sessions each session is separated with the other by 48 hours. Results: The test-retest reliability of measurements made with the CROM was verified with ICC values for all cervical measurements ranging between 0.66 (CI: 0.1, 0.8) for Target Head Position – rotation right to 0.93 (0.8, 0.9) (CI: 0.8-0.9) for THP – Rotation right. The correlation analysis found there are high and significant correlations between the test and retest results indicating that the reliability of the test can be established (positive correlation coefficients ranging from 0.524 – 0.863). Conclusion: CROM device can be used to quantify cervical proprioception errors with acceptable level of reliability in asymptomatic individuals.

Comparison of Cervical Proprioception in Individuals with and without Latent Myofascial Trigger points

Background:Myofascial trigger points are an extremely common cause of pain. Purpose: Primarily to associate the presence of latent MTP in upper trapezius in individuals and their effect on cervical proprioception Methods: 60 women, 20-35 years of age were assessed via a pressure algometer and cervical range of motion of motion machine Results: It was found that the individuals with latent trigger points showed a higher deviation error than individuals without latent trigger points in Neutral Head Position test and Head Target Repositioning test which were found to be statistically significant. Conclusion: On comparison, individuals with latent myofascial trigger points had a statistically significant difference in neutral head positioning error and head target repositioning error at the cervical spine Keywords: cervical, proprioception, latent, trigger point, pain

Wearing American Football helmets increases cervicocephalic kinaesthetic awareness in "elite" American Football players but not controls.

BackgroundWhile there have been investigations into the reduced neck injury rate of wearing protective helmets, there is little information on its effects on normal kinaesthetic neck function. This study aims to quantify the kinaesthetic and movement effects of the American football helmet.MethodsFifteen British Collegiate American football players (mean age 22.2, SD 1.9; BMI kg.m2 26.3, SD 3.7) were age and size matched to 11 non-American football playing university students (mean age 22.5, SD 3.6; BMI 24.3, SD 3.3 kg.m2). Both groups had their active cervical range of motion and head repositioning accuracy measured during neck flexion/extension using a modified cervical range of motion device and a similarly modified football helmet.ResultsWearing helmets significantly reduced active cervical range of motion in extension in both groups (P = 0.007 and P = 0.001 Controls and American Footballers respectively). While both groups had similar repositioning when not wearing a helmet (flexion P = 0.99; extension P = 0.52), when wearing helmets, American football players appeared to be more accurate in relation to cervical kinaesthetic repositioning (ANOVA: P = 0.077: flexion effect size =0.84; extension effect size =0.38).ConclusionsWearing American football helmets significantly reduces the active cervical range of motion in extension, along with a change in the neutral head position. American footballers have a greater accuracy in repositioning their head from flexion (potentially enhanced proprioception) when wearing a helmet. This finding might allow development of a simple objective test to help discern presence of minor concussive or cervical musculoskeletal injury on or off the field.

The Sequence of Swallowing Events During the Chin-Down Posture.

This study investigated the effect of the chin-down posture on the sequence of swallowing events in healthy adults. Sixteen healthy participants performed 45 5-ml thin liquid swallows during videofluoroscopy: 5 neutral head position, 30 chin-down posture, and then 10 neutral head position. Eight swallowing events were measured: the time of hyoid burst, bolus head in the pharynx, bolus tail in the pharynx, laryngeal vestibule closure (LVC), upper esophageal sphincter (UES) opening, bolus head in the UES, bolus tail exiting the pharynx, and laryngeal vestibule opening (LVO). Our key finding is that LVC was one of the first 3 swallowing events in 69% of neutral swallows and in 78% of chin-down swallows (p = .006). Also, LVO occurred last in 14% of chin-down swallows but never occurred last in the preceding neutral swallows (p ≤ .001). Thus, in chin-down swallows, LVC occurred earlier and LVO occurred later. The chin-down posture may be beneficial for individuals with delayed onset of LVC and reduced duration of the LVC. Future studies are needed to examine this effect in individuals with dysphagia.

Findings of Abnormal Videofluoroscopic Swallowing Study Identified by High-Resolution Manometry Parameters

ObjectiveTo identify the parameters of high-resolution manometry (HRM) with a significant correlation to abnormal findings of videofluoroscopic swallowing study (VFSS). DesignProspective study. SettingHospital rehabilitation department. ParticipantsPatients with dysphagia symptoms (N=40). InterventionParticipants were evaluated once using VFSS in neutral head position and evaluated twice using HRM with 5mL of thin fluid. Main Outcome MeasuresHRM parameters included maximal pressure, area integral, rise time, duration of the velopharynx and tongue base, maximal pressure of pre–upper esophageal sphincter (UES), low pharynx, cricopharyngeus, minimal UES pressure, UES activity time, and nadir UES duration. HRM parameters were compared with the findings of VFSS. Receiver operating characteristic analysis was performed to obtain the cutoff value, sensitivity, and specificity of HRM parameters for the prediction of findings of VFSS. ResultsThe maximum pressure of the velopharynx showed a significantly positive prediction for most abnormal parameters of VFSS in the pharyngeal phase. Nadir UES pressure duration was significant for impaired laryngeal elevation, residue at pyriformis sinus, and combination of penetration and aspiration. The maximum pressure of the velopharynx <180.0 showed 100% sensitivity and 75% specificity for the presence of penetration and aspiration, and the cutoff point of 178.8 showed 86.7% sensitivity and 75% specificity for the presence of subglottic aspiration. ConclusionsThis study identified significant HRM parameters that are highly specific for individual abnormalities of VFSS, suggesting the cutoff value, sensitivity, and specificity. Because HRM could inform the quantitative measurement of pharyngeal weakness, the cutoff value for HRM parameters could be used to predict aspiration in patients with pharyngeal weakness.

Obstructive airway in Morquio A syndrome, the past, the present and the future

Patients with severe tracheal obstruction in Morquio A syndrome are at risk of dying of sleep apnea and related complications. Tracheal obstruction also leads to life-threatening complications during anesthesia as a result of the difficulty in managing the upper airway due to factors inherent to the Morquio A syndrome, compounded by the difficulty in intubating the trachea. A detailed description of the obstructive pathology of the trachea is not available in the literature probably due to lack of a homogenous group of Morquio A patients to study at any one particular center. We present a series of cases with significant tracheal obstruction who were unrecognized due to the difficulty in interpreting tracheal narrowing airway symptoms. Our goal is to provide the guidelines in the management of these patients that allow earlier recognition and intervention of tracheal obstruction. Sagittal MRI images of the cervical spine of 28 Morquio A patients (12±8.14years) showed that19/28 (67.9%) patients had at least 25% tracheal narrowing and that narrowing worsened with age (all 8 patients over 15years had greater than 50% narrowing). Eight out of 28 patients were categorized as severe (>75%) tracheal narrowing when images were evaluated in neutral head and neck position. Of the 19 patients with tracheal narrowing, compression by the tortuous brachiocephalic artery was the most common cause (n=15). Evidence of such tracheal narrowing was evident as early as at 2years of age. The etiology of tracheal impingement by the brachiocephalic artery in Morquio A appears to be due to a combination of the narrow thoracic inlet crowding structures and the disproportionate growth of trachea and brachiocephalic artery in relationship to the chest cavity leading to tracheal tortuosity. In conclusion, tracheal narrowing, often due to impression from the crossing tortuous brachiocephalic artery, increases with age in Morquio A patients. Greater attention to the trachea is needed when evaluating cervical spine MRIs as well as other imaging and clinical investigations, with the goal of establishing a timely treatment protocol to reduce the mortality rate in this patient population.

Characterizing functional connectivity patterns during saliva swallows in different head positions.

BackgroundThe anatomical rationale and efficacy of the chin tuck in improving airway protection for some people with swallowing disorders have been well researched and established. However, there are still open questions regarding whether brain activity for swallowing control is altered while performing this chin-tuck maneuver.MethodsIn this study, we collected EEG signals from 55 healthy adults while swallowing in the neutral and chin-tuck head positions. The time-frequency based synchrony measure was used to form brain networks. We investigated both the small-world properties of these brain networks and differences among the constructed brain networks for the two head positions during swallowing tasks.ResultsWe showed that brain networks for swallowing in both head positions exhibit small-world properties. Furthermore, we showed that swallowing in the chin-tuck head position affects brain networks in the Alpha and Gamma frequency bands.ConclusionsAccording to these results, we can tell that the parameter of head position should be considered in future investigations which utilize EEG signals during swallowing activity.

Effect of Different Head Positions in Lateral Decubitus Posture on Intraocular Pressure in Treated Patients With Open-Angle Glaucoma.

To investigate the effects of different head positions in the lateral decubitus posture on intraocular pressure (IOP) in medically treated patients with open-angle glaucoma (OAG). Prospective observational study. setting: Institutional. Twenty patients with bilateral OAG who received only latanoprost as treatment. IOP was measured using an ICare Pro tonometer in the sitting, supine, right, and left lateral decubitus posture. In lateral decubitus posture, IOP measurements were taken with 3 different head positions (30 degrees higher than, 30 degrees lower than, and parallel to the center of the thoracic vertebra) in a randomized sequence. Comparison of the IOPs between the dependent (lower-sided) and nondependent eyes in the lateral decubitus postures with different head positions. We also analyzed the differences in IOPs between the better and worse eyes. IOP was higher in the dependent eyes than in the nondependent eyes in lateral decubitus posture, regardless of the head position (all P < .05). Lower head position increased the IOP of dependent eyes, compared with the neutral or higher head position. However, the amounts of IOP elevation seen during the changes of body posture or head position were not significantly different between the better and worse eyes. Low head position elevates IOP of the dependent eyes of medically treated OAG patients compared with neutral head position in the lateral decubitus posture. Adjustment of the height of a pillow may help mitigate IOP elevations resulting from lying on the side with a low or no pillow in glaucoma patients.