Transformation of neural coding for vibrotactile stimuli along the ascending somatosensory pathway.

In mammals, action potentials fired by rapidly adapting mechanosensitive afferents are known to reliably time lock to the cycles of a vibration. How and where along the ascending neuraxis is the peripheral afferent temporal code transformed into a rate code are currently not clear. Here, we probed the encoding of vibrotactile stimuli with electrophysiological recordings along major stages of the ascending somatosensory pathway in mice. We discovered the main transformation step was identified at the level of the thalamus, and parvalbumin-positive interneurons in thalamic reticular nucleus participate in sharpening frequency selectivity and in disrupting the precise spike timing. When frequency-specific microstimulation was applied within the brainstem, it generated frequency selectivity reminiscent of real vibration responses in the somatosensory cortex and could provide informative and robust signals for learning in behaving mice. Taken together, these findings could guide biomimetic stimulus strategies to activate specific nuclei along the ascending somatosensory pathway for neural prostheses.

Endoscopic and Image Analysis of the Airway in Patients with Mucopolysaccharidosis Type IVA.

Mucopolysaccharidosis (MPS) is a hereditary disorder arising from lysosomal enzymes deficiency, with glycosaminoglycans (GAGs) storage in connective tissues and bones, which may compromise the airway. This retrospective study evaluated patients with MPS type IVA with airway obstruction detected via endoscopy and imaging modalities and the effects of surgical interventions based on symptoms. The data of 15 MPS type IVA patients (10 males, 5 females, mean age 17.8 years) were reviewed in detail. Fiberoptic bronchoscopy (FB) was used to distinguish adenotonsillar hypertrophy, prolapsed soft palate, secondary laryngomalacia, vocal cord granulation, cricoid thickness, tracheal stenosis, shape of tracheal lumen, nodular deposition, tracheal kinking, tracheomalacia with rigid tracheal wall, and bronchial collapse. Computed tomography (CT) helped to measure the deformed sternal angle, the cross-sectional area of the trachea, and its narrowest/widest ratio (NW ratio), while angiography with 3D reconstruction delineated tracheal torsion, kinking, or framework damage and external vascular compression of the trachea. The NW ratio correlated negatively with age (p < 0.01), showing that airway obstruction progressed gradually. Various types of airway surgery were performed to correct the respiratory dysfunction. MPS type IVA challenges the management of multifactorial airway obstruction. Preoperative airway evaluation with both FB and CT is strongly suggested to assess both intraluminal and extraluminal factors causing airway obstruction.

Montgomery T-Tube Airway Restoration and Swallowing Rehabilitation for a Near-Hanging Female.

Patients who fail to commit suicide by hanging often end up with laryngotracheal injuries, which may lead to a compromised airway, swallowing dysfunction, and dysphonia. Previous studies have mainly focused on airway management after near-hanging attempts. Few have shed light on the treatment of swallowing dysfunction after laryngotracheal injuries. Here, we present a near-hanging patient who developed complete dysphagia shortly afterward. We used a Montgomery T-tube as an endolaryngeal stent, combined with swallowing rehabilitation. The patient's swallowing ability was gradually restored one month after the surgery, and the stent was removed six months later. The present case report exemplifies the unique way of using the Montgomery T-tubes in clinical practice. Among the patients with airway stenosis affecting the larynx and extending to the vocal cords, Montgomery T-tube may be the only stent that can help manage strictures at the level of the vocal cords and in the supraglottic region, restoring swallowing function and maintaining the airway.

Airway Management of the Deformed Trachea Using T-Tube Stents in Patients with Mucopolysaccharidosis Type IVA.

INTRODUCTION: Mucopolysaccharidosis (MPS) type IVA usually results in airway obstruction due to thoracic cage deformity and crowding of intrathoracic structures, causing tracheal compression by the tortuous innominate artery. OBJECTIVES: To offer an alternative and effective method in dealing with the challenged deformity of the airway in patients with MPS type IVA. METHODS: We present 3 patients with MPS type IVA who underwent airway stenting using Montgomery® T-tube stents. Three-dimensional reconstructed computed tomography was essential to design the T-tube and evaluate the anatomical relationship between the innominate artery and the trachea. The Y-shaped Montgomery® Pediatric Safe-T-Tube™ is more suitable for MPS type IVA. Regular follow-ups using fiberoptic bronchoscopy are necessary to evaluate the complications. RESULTS: All 3 patients had good outcomes during the follow-ups until present, despite the complication of granulation formation, which was resolved by revising the limbs of the T-tube. CONCLUSIONS: T-tube stents placed below the vocal cord may restore airway patency and preserve laryngeal function, including respiration, phonation, and swallowing, in patients with MPS type IVA.

A sinusoidal transformation of the visual field is the basis for periodic maps in area V2.

Retinotopic maps of many visual areas are thought to follow the fundamental principles described for the primary visual cortex (V1), where nearby points on the retina map to nearby points on the surface of V1, and orthogonal axes of the retinal surface are represented along orthogonal axes of the cortical surface. Here we demonstrate a striking departure from this mapping in the secondary visual area (V2) of the tree shrew best described as a sinusoidal transformation of the visual field. This sinusoidal topography is ideal for achieving uniform coverage in an elongated area like V2, as predicted by mathematical models designed for wiring minimization, and provides a novel explanation for periodic banded patterns of intra-cortical connections and functional response properties in V2 of tree shrews as well as several other species. Our findings suggest that cortical circuits flexibly implement solutions to sensory surface representation, with dramatic consequences for large-scale cortical organization.

A common computational principle for vibrotactile pitch perception in mouse and human.

We live surrounded by vibrations generated by moving objects. These oscillatory stimuli propagate through solid substrates, are sensed by mechanoreceptors in our body and give rise to perceptual attributes such as vibrotactile pitch (i.e. the perception of how high or low a vibration's frequency is). Here, we establish a mechanistic relationship between vibrotactile pitch perception and the physical properties of vibrations using behavioral tasks, in which vibratory stimuli were delivered to the human fingertip or the mouse forelimb. The resulting perceptual reports were analyzed with a model demonstrating that physically different combinations of vibration frequencies and amplitudes can produce equal pitch perception. We found that the perceptually indistinguishable but physically different stimuli follow a common computational principle in mouse and human. It dictates that vibrotactile pitch perception is shifted with increases in amplitude toward the frequency of highest vibrotactile sensitivity. These findings suggest the existence of a fundamental relationship between the seemingly unrelated concepts of spectral sensitivity and pitch perception.

Otorhinolaryngological Management in Taiwanese Patients with Mucopolysaccharidoses.

Background: Mucopolysaccharidoses (MPSs) are lysosomal storage disorders wherein glycosaminoglycans accumulate because the enzymes that degrade them are insufficient. The earliest symptoms, which are the main reasons for seeking consultation, are otorhinolaryngological and commonly occur in MPS I, II, IV, and VI. This retrospective study aimed to determine the occurrence of otorhinolaryngological manifestations in MPS patients in Taiwan and to analyze the prognosis of surgical intervention, including its effect on symptoms. Methods: We reviewed 42 patients (30 males and 12 females), with a median age of 20.5 years, who had MPS (16.7% type I, 35.7% type II, 19.0% type IIIB, 21.4% type IVA, and 7.2% type VI). The following otorhinolaryngological manifestations were collected: annual number of upper respiratory tract infections (URTIs) and otitis media with effusion (OME) episodes, adenoid size, tonsillar size, and apnea-hypopnea index (AHI). Results: Among 42 patients, we found recurrent otitis media in 42.9% of the patients, hearing loss in 83.3% (mixed: 52.4%, conductive: 21.4%, and sensorineural: 9.5%), frequent URTIs in 47.6%, and obstructive sleep apnea syndrome in 35.7%. Moreover, 76% of the patients underwent ear, nose, and throat (ENT) surgery, including adenoidectomy, tonsillectomy, tympanostomy with ventilation tube insertion, tracheotomy, and supraglottoplasty. Conclusions: MPS patients had a high incidence of ENT problems. ENT surgery reduced the severity of hearing loss, degree of symptoms related to upper airway obstruction, and severity of respiratory tract and otological infections of patients with MPS.

Aortotracheal fistula after slide tracheoplasty in a patient with dextrocardia, left pulmonary artery sling and tracheal stenosis: a case report.

BACKGROUND: Aortotracheal fistula (ATF) is an uncommon and fatal complication of tracheal or aortic surgery, especially among pediatric patients. CASE PRESENTATION: We reported a case in a 1-year-old boy with dextrocardia, left pulmonary artery sling and long segment tracheal stenosis. He received slide tracheoplasty at 9 months of age and had post-operative refractory granulation at distal trachea status post repeated balloon dilatation and laser vaporization. Episodes of hemoptysis occurred on post-operative day 81. Bronchoscopy revealed a pulsating pseudoaneurysm at lower trachea which ruptured during the procedure Urgent surgical repair under cardiopulmonary bypass with deep hypothermic circulatory arrest was done. No recurrent bleeding or significant neurologic deficits noticed at a 4-month follow-up. CONCLUSION: Congenital anomaly that changes the spatial relationship between trachea and aorta could have contributed to formation of ATF. This warrant future attention when managing tracheal granulation with this not uncommon anatomy.

Respiratory tract infections in children with tracheostomy.

BACKGROUND: Children with tracheostomy are at increased risk for respiratory tract infections, yet the risk involved in tracheostomy related infections is unclear. METHODS: We conducted a retrospective review of the medical records of children who underwent tracheostomy between January 2002 and December 2016 at a teaching hospital in Taipei. Demographics, underlying disease, indication for tracheostomy, laboratory data and management, and long-term outcome data were collected. Infection episodes were grouped into definite, possible, non-bacterial pneumonia, and local infection groups. RESULTS: Ninety patients were enrolled. Forty-two (46.7%) patients had infections that required hospitalization. Definite bacterial pneumonia accounted for 12 (8.5%) episodes, 113 episodes (80.1%) were possible bacterial pneumonia, 12 (8.5%) were non-bacterial pneumonia, and 4 (2.8%) were local infections. Patients with definite and possible bacterial pneumonia were found to have a longer hospital duration than patients with non-bacterial pneumonia (p=0.024), with mean hospitalization stays of 8.83±5.59 days and 5.67±2.55 days, respectively. The median duration from tracheostomy to bacterial pneumonia was 1.78 years (range, 0.04- 11.38) whereas for the non-bacterial pneumonia group it was 0.57 years (range, 0.04-6.61). Cerebral palsy (CP) (adjusted odds ratio [AOR] 3.65; 95% confidence interval [CI]: 1.11-11.99; p=0.033) and gastroesophageal reflux disease (GERD) (AOR 2.84; 95% CI: 1.09-7.38; p=0.033) were independently associated with respiratory tract infections in these children. CONCLUSION: In this study, CP and GERD were associated with infections in children with tracheostomy. Bacterial and non-bacterial pneumonia are difficult to differentiate clinically which may lead to unnecessary antibiotics use.

Successful Rescue of a Ruptured Tracheoinnominate Fistula with Extracorporeal Membrane Oxygenation, Endovascular Stents, and Debranching Surgical Bypass.

We reported a case of ruptured tracheoinnominate fistula in a 14-year-old boy with history of repeated sternotomy. Tracheostomy was performed at age 2 years. Slide tracheoplasty was done at age 13 years. He presented to outpatient clinic with episodic hemosputum. Massive blood emanated from stoma during bronchoscopy evaluation. Venous-arterial extracorporeal membrane oxygenation was installed for resuscitation. A contrast-enhanced computed tomography (CT) and angiography confirmed the diagnosis. Immediate control of bleeding was achieved by an endovascular stent graft deployed at innominate artery. Massive hemorrhage recurred on day 7. An aortic arch stent was inserted and all arch vessels debranching via supraclavicular collar excision was performed. A covered stent was used to fenestrate the aortic stent and establish antegrade blood flow to all neck vessels via left common carotid artery. The patient remained stable at 10-month follow-up. Combination of extracorporeal membrane oxygenation, endovascular intervention, and surgical bypass could be effective in treating critical patients.

Bilateral vocal fold immobility in a single tertiary hospital in northern Taiwan: A 23-year retrospective review.

To determine the natural history of patient with bilateral vocal fold immobility (BVFI), and to identify the factors or predictors associated with the tracheostomy and duration of cannulation for those who require tracheostomy.A retrospective review was carried out at a single tertiary referral center over a 23-year period of infants less than 1 year old who presented with BVFI. All information related to sex, etiology, gestational age at birth, vocal fold (VF) position at diagnosis, presence of concomitant airway disease, age at attainment of VF movement, age at decannulation, and current tracheostomy status were recorded to perform descriptive and comparative analyses.Forty-one patients were enrolled, and the tracheostomy rate was 80.5% (33/41). Those with a median VF position had a higher rate of tracheostomy in comparison with those with a paramedian VF position (P = .003). Among patients who underwent tracheostomy, 77.4% (24/31) were eventually decannulated. The median duration of cannulation was 4.4 years (range: 0.8 - 10.7 years). Those who were found to have attainment of VF movement at less than 1-year-old had a shorter duration of cannulation than others (mean: 1.9 years vs 5.2 years, P < .001). The mortality rate of those patients who received tracheostomy was 9.7% (3/31).Although a high tracheostomy rate was found in BVFI patients, most of them underwent decannulation. The earlier attainment of VF movement is achieved, the shorter duration of cannulation is required. This information is important for physicians while following up BVFI patients who have undergone tracheostomy.

Functional Synaptic Architecture of Callosal Inputs in Mouse Primary Visual Cortex.

Callosal projections are thought to play a critical role in coordinating neural activity between the cerebral hemispheres in placental mammals, but the rules that govern the arrangement of callosal synapses on the dendrites of their target neurons remain poorly understood. Here we describe a high-throughput method to map the functional organization of callosal connectivity by combining in vivo 3D random-access two-photon calcium imaging of the dendritic spines of single V1 neurons with optogenetic stimulation of the presynaptic neural population in the contralateral hemisphere. We find that callosal-recipient spines are more likely to cluster with non-callosal-recipient spines with similar orientation preference. These observations, based on optogenetic stimulation, were confirmed by direct anatomical visualization of callosal synaptic connections using post hoc expansion microscopy. Our results demonstrate, for the first time, that functional synaptic clustering in a short dendritic segment could play a role in integrating distinct neuronal circuits.

Epidemiology and antimicrobial susceptibility of non-typeable Haemophilus influenzae in otitis media in Taiwanese children.

BACKGROUND: Concerns about non-typeable Haemophilus influenzae (NTHi) in otitis media (OM) have grown after the introduction of pneumococcal conjugate vaccine (PCV). We aim to better understand the clinical role of NTHi in pediatric OM. METHODS: Middle ear fluid samples from children <18 years with OM were obtained from 2010 to 2015. For culture-positive episodes (Streptococcus pneumoniae, H. influenzae, Moraxella catarrhalis, and Streptococcus pyogenes), patients' demographic and clinical information were reviewed and analyzed. RESULTS: A total of 783 episodes were included with 31.8% of isolates as positive. S. pneumoniae was recovered in 69.4%, NTHi in 24.6%, M. catarrhalis in 5.6%, and S. pyogenes in 4.0% of culture-positive episodes. The proportion of pneumococcal OM has declined since 2012 (P for trend <0.005), but NTHi OM rose simultaneously (P for trend = 0.009). Factors associated with increased risk of NTHi infection included less spontaneous otorrhea (OR 0.15, 95% CI 0.06-0.39, P < 0.001), absence of fever (OR 0.30, 95% CI 0.14-0.66, P = 0.003), concurrent sinusitis (OR 2.91, 95% CI 1.36-6.20, P = 0.006), previous ventilation tube insertion (OR 12.02, 95% CI 3.15-45.92, P < 0.001) and recurrent OM (OR 3.43, 95% CI 1.01-11.71, P = 0.049). The susceptibility of NTHi to amoxicillin/clavulanate was 82.0%. CONCLUSIONS: NTHi OM has trended upward in the post-PCV era. Concurrent sinusitis, previous ventilation tube insertion, and recurrent OM were associated with NTHi OM implicated a correlation between NTHi and complex OM. In consideration of NTHi infection, we suggest amoxicillin/clavulanate as the first-line therapy for OM among Taiwanese children.

Acute otitis media caused by Streptococcus pneumoniae serotype 19A ST320 clone: epidemiological and clinical characteristics.

BACKGROUND: Streptococcus pneumoniae serotype 19A ST320, a highly multiresistant and virulent clone, has emerged as a common pathogen causing acute otitis media (AOM) in children. METHODS: Patients aged 0-18 years with AOM who presented at Mackay Memorial Hospital, Taipei, Taiwan were prospectively enrolled between December 1, 2009, and November 30, 2012. For each patient, a specimen of middle-ear fluid was obtained and cultured. S. pneumoniae isolates were tested by serotyping, antibiotic-resistance profiling, and multilocus sequence typing. Demographic characteristics and clinical history of patients with pneumococcal AOM were recorded. RESULTS: Pneumococcal AOM was observed in 108 (24.8%) of 436 episodes. One hundred and four isolates of S. pneumoniae were available for study. The most common serotypes were 19A (67 isolates, 64.4%), followed by 19F (16 isolates, 15.4%), and 3 (7 isolates, 6.7%). Among the 85 sequence-typed isolates, Serotype 19A ST320 (50, 58.8%) was the most frequent. Children with AOM caused by Serotype 19A ST320 were younger (33.9 ± 21.4 months vs. 46.7 ± 35.9 months, p = 0.04) and had a higher rate of spontaneous rupture of the tympanic membrane (64.0% vs. 40%, p = 0.05) than those caused by isolates of other sequence types. Serotype 19A ST320 caused 90% of AOM episodes in children aged ≤ 12 months and had had higher resistance rates to penicillin according to meningeal breakpoints (p = 0.011), amoxicillin (p < 0.001) and trimethoprim/sulfamethoxazol (p < 0.001). CONCLUSIONS: It is better to use pneumococcal conjugate vaccine effective against Serotype 19A in early infancy to prevent the first and subsequent episodes of AOM in children in Taiwan.

A 12-year-experience with tracheostomy for neonates and infants in northern Taiwan: Indications, hospital courses, and long-term outcomes.

BACKGROUND: Tracheostomy is a valuable procedure in infants and neonates with chronic respiratory failure or severe airway obstruction. The aim of this study is to identify the indication, hospital course, and long-term outcome in a cohort of infants who required tracheostomy in a neonatal and pediatric tertiary care center in northern Taiwan. METHODS: Medical records of infants, who underwent tracheostomy between January 2002 and December 2013, were retrospectively reviewed. Demographics, indication for tracheostomy, hospital course, discharge disposition, further hospitalization and surgery, and long-term outcome data were collected. RESULTS: Fifty-six patients were enrolled. The median gestational age was 38.0 weeks, and median birth weight was 2770 g. he median age at tracheostomy was 104.5 days. The primary indications for tracheostomy were airway obstruction in 35 patients (62.5%), craniofacial anomalies in 7 (12.5%), neuromuscular disorder in 7 (12.5%), cardiopulmonary disorder in 5 (8.9%), and brain injury-related problem in 2 (3.6%). Twenty-two patients (39.3%) were decannulated successfully, and the median time from tracheostomy to decannulation was 2.1 years. Overall mortality rate was 3.6%, but no death was related to tracheostomy. Forty-nine patients underwent regular follow-up at our hospital, and 46 patients (93.9%) required further hospitalization, and 30 (61.2%) underwent further surgery related to a respiratory problem or tracheostomy. Ratio of delayed growth at the time of tracheostomy (28.6%) did not have significant difference at 1 year of age (21.4%) and 2 years of age (25.0%). CONCLUSION: In this study, the most common indication for tracheostomy in neonates and infants was airway obstruction. Excluding patients with neuromuscular diseases, a successful decannulation rate of >50% can be achieved.

Intraductal injection as an effective drug delivery route in the management of salivary gland diseases.

While conservative approaches for chronic sialoadenitis are in current use, the utility of intraductal injection therapy remains unclear. The purpose of this study is to provide evidence that substances delivered through intraductal injection of the salivary gland are able to be effectively distributed throughout the gland. Methylene blue dye (0.1 %) was injected intraductally into a porcine parotid gland (5 ml) of one group and the porcine submandibular gland (1 or 2 ml, n = 6 for each preparation) of another group. After the injection, the ductal systems were evaluated, sectioned, and observed microscopically. Color area analysis was performed on submandibular gland sections, and the infiltration ratio of the dye was calculated. The papillae of both Stensen's and Wharton's duct openings were easily identified with intraductally delivered methylene blue dye. The dye infiltration began from the central ductal region of the gland and could be easily observed to gradually disperse to the peripheral regions in each acinar. There were no statistically significant differences in infiltration ratios between anterior, midline, and posterior section of the submandibular gland. Also, there were no statistically significant differences in the ratios between 1 and 2 ml injections at all the three section positions. This study demonstrated that desired substances can be evenly delivered throughout the salivary gland through intraductal injections. The use of intraductal injections might serve as a potential therapeutic procedure in the management of salivary gland diseases.

Pediatric sialendoscopy in Asians: A preliminary report.

BACKGROUND/PURPOSE: The sialendoscopic approach in treating pediatric salivary gland disorders has been reported with great success through the years. Whereas this success has been widely reported in Caucasian populations, relatively little has been reported regarding the use of this procedure in pediatric patients in Asian countries. The purpose of this study is to report our preliminary experience in pediatric sialendoscopy. METHODS: The data from 20 patients (<18years old), who underwent sialendoscopy for obstructive sialoadenitis in the Department of Otorhinolaryngology of Mackay Memorial Hospital between October 2013 and November 2015, were reviewed. RESULTS: Twelve of our 20 patients (60%) were diagnosed with sialolithiasis and 8 of our 20 patients (40%) presented with non-lithiasis obstructive sialoadenitis. Ductal stenosis was found in 13 patients, and 18 patients had debris/mucous plug formation. The overall success rate was 95% (19/20) in our series, and 85% (17/20) of the patients had achieved a complete remission after a single sialendoscopy procedure. CONCLUSIONS: Sialendoscopy is an ideal treatment in the management of obstructive sialoadenitis in Asian pediatric patients. If necessary, Holmium:YAG laser lithotripsy and sialostent placement could be applied, and both procedures are well tolerated in pediatric patients.