Auditory system dysfunction due to infantile thiamine deficiency: long-term auditory sequelae.

Eleven infants who were fed a thiamine-deficient formula for a mean of 3 months were evaluated for immediate and long-term auditory abnormalities. At presentation, 8 infants had auditory neuropathy spectrum disorder (ANSD), which resolved with supplementary thiamine in 5 children, was permanent in 2 children, and deteriorated in 1 patient who died at the age of 7 years. An additional patient had an auditory pattern corresponding to that of auditory neuropathy of brain stem origin. The 2 remaining patients had unilateral cochlear hearing loss. Six to 8 years later, all patients with transient ANSD had normal audiograms, 2 patients had unilateral cochlear hearing loss, and the rest had neural hearing loss. All survivors had a language developmental delay and impaired speech intelligibility of varying degrees, especially in the presence of background noise. Thiamine is crucial for normal auditory development and function, and its deficiency may be considered an acquired metabolic cause of ANSD in infants.

Audiometric and imaging characteristics of distal renal tubular acidosis and deafness.

OBJECTIVE: Primary distal renal tubular acidosis with sensorineural hearing loss is a rare autosomal recessive disease, usually caused by mutations in the ATP6V1B1 gene. The aim of this study was to characterise the phenotype of this disease, with emphasis on the auditory findings, in a cohort of Israeli children. STUDY DESIGN: Prospective study of five children, from three unrelated families, with distal renal tubular acidosis and bilateral sensorineural hearing loss, with mutations in the ATP6V1B1 gene. METHODS: The following were collected from patients' medical records: biochemical and renal data, age at distal renal tubular acidosis diagnosis, and age at hearing loss. Hearing loss progression as well as current hearing status were assessed, and high resolution computed tomography of the temporal bone was performed. All patients underwent genetic testing. RESULTS: Four patients were diagnosed with distal renal tubular acidosis before the age of six months and one at 24 months. All had the classical findings of low blood pH and inappropriately high urine pH. Hearing loss was diagnosed between the ages of three months and two years. The hearing loss was bilateral, asymmetrical and progressive, occasionally with a conductive component. Two children underwent cochlear implantation, at ages 10 and 15 years. High resolution computed tomography, performed in four patients between the ages of 2.5 and 15 years, showed bilaterally enlarged vestibular aqueducts. This was the only radiological abnormality in the inner ear in all cases. A different mutation in the ATP6V1B1 gene was found in each family. CONCLUSION: Several types of mutations in the ATP6V1B1 gene may cause distal renal tubular acidosis and sensorineural hearing loss. Patients display a typical progressive type of hearing loss and have enlarged vestibular aqueducts, with no other abnormalities being observed on imaging.

Transient deafness in young candidates for cochlear implants.

This study describes 5 infants who were diagnosed with auditory neuropathy (AN) associated with severe to profound neural hearing loss shortly after birth. However, on repetition of the tests 7-12 months later, all infants showed full or partial recovery. The follow-up electrophysiological patterns were characterized by the appearance of wave I, followed by wave III and V, reflecting synchronization of auditory pathways and improvement in auditory nerve function. Suspected causative or contributory factors were neonatal hyperbilirubinemia, hypoxia, ischemia, and central nervous system immaturity, alone or in combination. These findings indicate that lack of an auditory brain stem response does not necessarily mean no hearing and that the situation where AN exists can improve. Thus, clinicians should be made aware that although cochlear implants may yield better auditory performance when applied early, they should be considered a therapeutic option only after repeated measures have proved persistent AN, and no child should be considered for an implant until a behavioral measure of hearing has been obtained.

Recycled vertical flow constructed wetland (RVFCW)--a novel method of recycling greywater for irrigation in small communities and households.

The use of greywater for irrigation is becoming increasingly common. However, raw greywater is often contaminated and can cause environmental harm and pose health risks. Nevertheless, it is often used without any significant pretreatment, a practice mistakenly considered safe. The aim of this study was to develop an economically sound, low-tech and easily maintainable treatment system that would allow safe and sustainable use of greywater for landscape irrigation in small communities and households. The system is based on a combination of vertical flow constructed wetland with water recycling and trickling filter, and is termed recycled vertical flow constructed wetland (RVFCW). The RVFCW's properties, removal efficiency, hydraulic parameters and feasibility were studied, as well as the environmental effects of the treated greywater, as reflected by soil and plant parameters over time. The RVFCW was efficient at removing virtually all of the suspended solids and biological oxygen demand, and about 80% of the chemical oxygen demand after 8h. Fecal coliforms dropped by three to four orders of magnitude from their initial concentration after 8h, but this was not always enough to meet current regulations for unlimited irrigation. The treated greywater had no significant negative impact on plants or soil during the study period. The feasibility analysis indicated a return over investment after approximately three years. We concluded that the RVFCW is a sustainable and promising treatment system for greywater use that can be run and maintained by unskilled operators.

Hyperacusis in Williams syndrome: characteristics and associated neuroaudiologic abnormalities.

BACKGROUND: Hyperacusis and phonophobia are common, debilitating symptoms in Williams syndrome (WS), yet little is known about their underlying audiologic and neurologic processes. METHODS: The mothers of 49 subjects with WS were asked to complete the Hyperacusis Screening Questionnaire. Subjects with reported hyperacusis and sufficient developmental capacity underwent comprehensive audiological and brain auditory evoked response (BAER) testing. Findings were compared with those from pair-matched typically developing control subjects. RESULTS: Forty-one of the 49 children with WS (84%) had hyperacusis of moderate to severe degree, which began in infancy. Of these, 21 (mean age 15.8 +/- 5.5 years) were quantitatively tested. Subjects with WS reported discomfort at sound intensities on average 20 dB lower than control subjects. Pure-tone audiometry and distortion products otoacoustic emission test revealed a high-frequency cochlear hearing loss. An absence of ipsilateral acoustic reflex responses to maximum stimulation was significantly more common in the subjects with WS than controls. On BAER testing, the WS group had a significant prolongation in wave I latency. CONCLUSIONS: Hyperacusis in Williams syndrome (WS) is associated with a high-frequency hearing loss resembling the configuration of noise-induced hearing loss. The hyperacusis and hearing loss in WS may stem from a deficiency in the acoustic reflex resulting from auditory nerve dysfunction. Additional mechanisms that may mediate hyperacusis in WS and should be evaluated in future studies include recruitment, malformation of the facial canal, and haploinsufficiency of the elastin gene.

Increased growth of young citrus trees under reduced radiation load in a semi-arid climate.

This study investigated the effects of radiation heat-load reduction by shading on the growth and development of citrus trees in a warm subtropical region. The experiment was conducted from mid-June until late October when daily maximal air temperature averaged 29.3 degrees C. Two-year-old de-fruited Murcott tangor (Citrus reticulata BlancoxCitrus sinensis (L.) Osb.) trees were grown under 30% or 60% shade tunnels, or 60% flat shade (providing midday shade only), using highly reflective aluminized nets. Non-shaded trees were used as the control. Shading reduced direct more than diffuse radiation. Daily radiation was reduced by 35% for the 30% Tunnel and 60% Flat treatments, and by 55% for the 60% Tunnel. Two days of intensive measurement showed that shading increased average sunlit leaf conductance by 44% and photosynthesis by 29%. Shading did not significantly influence root and stem dry weight growth, but it increased the increment in leaf dry weight during the three month period by an average of 28% relative to the control, while final tree height in the 30% Tunnel treatment exceeded the control by 35%. Shoot to root and shoot mass ratios increased and root mass ratio decreased due to shading because of the increase in leaf dry weight. Shading increased starch concentration in leaves while the shadiest treatment, 60% Tunnel, decreased starch concentration in the roots. Carbon isotope ratio (delta(13)C) of exposed leaves that developed under shading was significantly reduced by 1.9 per thousand in the 60% Tunnel, indicating that shading increased CO(2) concentrations at the chloroplasts (C(c)), as would be expected from increased conductance. Substomatal CO(2) concentrations, C(i), computed from leaf net CO(2) assimilation rate and conductance values, also indicate that shading increases internal CO(2) concentrations. Based on tree dry mass, tree height, and total carbohydrates fractions, the 30% Tunnel and the 60% Flat were the optimal shade treatments.

[The current approach to hemangiomas and vascular malformations of the head and neck].

Though most hemangiomas do not need treatment, a significant minority are associated with complications and external deformities that demand intervention. Steroids play an important role in therapy, but not infrequently afford only partial and temporary benefit. Thanks to improvements in the surgical approach and equipment, hemostasis control devices and laser techniques, we can now treat patients who would otherwise go untreated. Moreover, in certain cases, we can now recommend earlier intervention, saving patients from years of living with deformities and the concomitant psychosocial problems. Vascular anomalies of the head and neck include venular, venous and arteriovenous malformations. These lesions are slow growing vascular ectasia that never involute spontaneously and almost always require intervention. Treatment includes laser therapy, injection of sclerosing agents, embolization through angiography and surgery, which in many cases is the only definitive treatment. We present the current treatment approach and describe our experience in the treatment of 16 patients.

Management of drooling in individuals with neurodisability: a surgical experience.

From 1975 to 1 January 1999, 1103 neurologically involved patients (mean age 13.2 years; 686 males, 417 females) referred with problematic drooling, or sialorrhea, were assessed at a pediatric rehabilitation center by a team consisting of an otolaryngologist, speech pathologist, and a dentist. The initial standard treatment for persistent sialorrhea (in the compliant or aware patient) is oral-motor training. A group of 522 patients with persistent significant drooling after a minimum of 6 months of oral-motor training, or profuse drooling in the presence of a low cognitive level, underwent surgery, usually when over 6 years of age. From 1978 to 1 January 1998, the operation of first choice was submandibular duct relocation (SDR), and was completed in a total of 226 patients. Midway through 1988, sublingual gland excision was also completed at the time of submandibular duct relocation (SDRSGE); 249 of these procedures have been completed to January 1st 1999. Those patients who had SDRSGE had significantly fewer complications that required additional surgery than those that had SDR only. However, the impact of surgery on the drooling as evaluated in subsets of both groups (SDR n=115, SDRSGE n=106) was statistically similar. The study of 11 children with salivary gland radionuclitide scans to determine the effect of submandibular duct surgery on gland function was inconclusive. The pattern of oral-motor function in 26 children studied after SDRSGE surgery suggested that those children with severe impairment of volitional motor function and profuse drooling tended to have a poorer outcome following surgery compared to those with milder impairments.

Branchio-oculo-facial syndrome.

Branchio-oculo-facial (BOF) syndrome is a rare autosomal dominant disorder that has a distinct phenotype with characteristic craniofacial abnormalities. These consist of branchial anomalies, including supra-auricular sinuses, and aplastic cervical skin lesions, with possible ectopic dermal thymus, malformed auricles, stenotic external auditory canals, conductive hearing loss, ocular abnormalities (microphthalmia and lacrimal duct obstruction), and pseudocleft of the upper lip. Extracraniofacial malformations are uncommon. We describe two new cases of BOF and discuss the classical clinical presentation and differential diagnosis. Our two patients presented with facial nerve paralysis and were also were found to have inner ear dysplasias with associated sensorineural hearing loss which, to our knowledge, have not been described in the literature in association with this syndrome.

Comparison of thyroid, auricular, and costal cartilage donor sites for laryngotracheal reconstruction in an animal model.

OBJECTIVE: To evaluate and compare the use of autogenous thyroid cartilage with that of auricular and costal cartilage in laryngotracheoplasty (LTP). DESIGN: A blinded comparison of LTP techniques using anterior thyroid, auricular, or costal cartilage as graft material in a rabbit model. Histological and anatomical analyses were performed on the laryngeal specimens 1, 4, and 6 weeks after surgery. The following factors were analyzed in each specimen: graft viability, cartilage proliferation, perichondrial viability, degree of necrosis, inflammatory response, and degree of epithelialization. SUBJECTS: Fifty-seven New Zealand adult male rabbits, aged 6 months, were divided into 3 study groups (19 animals in each group) initially and equally into the 3 time periods. RESULTS: No episodes of respiratory compromise occurred in any of the animals in the 3 study groups. Gross inspection of the laryngotracheal complex in the thyroid cartilage group revealed no evidence of laryngeal structural compromise. There was no statistical difference between the 3 types of cartilage used for reconstruction for the variables of graft or perichondrial viability, degree of necrosis, or inflammatory response at 1, 4, or 6 weeks. Cartilage proliferation in the thyroid cartilage group was decreased compared with that in the other 2 groups at 1 week. The amount of proliferation increased in this group and was equal to the amount present in the other 2 groups 4 and 6 weeks after surgery. Complete epithelialization of the graft material was present in all 3 groups at 4 and 6 weeks after reconstruction. CONCLUSIONS: The use of autogenous thyroid cartilage for LTP compares favorably with that of other methods of reconstruction that use either auricular or costal cartilage in the rabbit model. This technique is a viable alternative for single-stage LTP and has the added advantage of using a single incision.

Mastoid buffering properties: I. Gas partial pressures.

Differences in the gas partial pressures between the middle ear (ME) cavity and the blood are an important factor in ME gas economy. Differences in gas partial pressures between various regions of the ME-mastoid air cell system (ME-MACS) could play a role as well. To determine whether gas partial pressure differences do occur between various compartments in the ME, we measured the rate of gas diffusion from one compartment to another in both an artificial model and in the ME-MACS of human temporal bones. The rate of gas diffusion between various areas of the ME and the mastoid tip was found to be rapid, with a half-life on the order of 2 minutes (range 0.8 to 5.3 minutes). We suggest that this high diffusion rate prevents the buildup of significant differences in gas composition in the ME-MACS system, which can therefore be regarded as a homogeneous gas pocket.

Increased otoacoustic-emission amplitude secondary to cochlear lesions.

OBJECTIVE: The measurements of transient evoked otoacoustic emissions and distortion-product otoacoustic emissions are being used increasingly, both as an objective hearing test clinically, and as a research tool to investigate the micromechanical aspects of cochlear function. We hypothesized that localized damage in the apical or middle cochlear turns may have an influence on the micromechanics and the function of adjacent, apparently normal cochlea. For that purpose, we used an animal model of localized apical and middle-turn cochlear lesions. METHOD: Extent of damage was assessed by scanning electron microscopy and the function of the damaged cochlea by change in the otoacoustic emission (OAE) levels. RESULTS: We found that localized damage to the apical or middle turn may be accompanied by an increase in OAE measured from adjacent apparently normal cochlea. CONCLUSION: Explanations to this phenomenon are suggested, and possible clinical associations such as to Meniere's disease and to sudden hearing loss are reviewed.

Optical imaging of intrinsic signals in chinchilla auditory cortex.

We have assessed sound frequency and intensity responses in primary auditory cortex of the (ketamine) anesthetized chinchilla using optical imaging of intrinsic signals. Temporal cortex was exposed via a 10-mm craniotomy and a windowed chamber was mounted. A 4-second period of gated tones (10 ms rise/fall; 50 ms plateau; 10/s) was presented to the contralateral ear at levels between 0 and 80 dB SPL. The cortical surface was illuminated with 540 nm light and video images captured in 0.5-second bins for 7.5 s (Imager 2001; Optical Imaging). Intrinsic signals were first apparent 0.5-1 s after stimulus onset, and were maximal after 3-4 s; they decayed over several seconds. The cortical area in which intrinsic activity was detected corresponded closely with electrophysiologically defined AI cortex. Intrinsic signals can reliably be detected to stimuli at 30-40 dB SPL, and in general, the area of intrinsic signal activity tends to expand with increasing stimulation level. Using stimulation levels of 80 dB SPL, we show that low-frequency stimuli (0.5-1 kHz) evoke intrinsic signals in anterior areas whilst posterior areas are activated by high-frequency stimuli (e.g. 16 kHz). Thus a low- to high-frequency tonotopic organization is seen along this axis.

The outcome after perinatal management of infants with potential airway obstruction.

Masses in the head and neck are being detected prenatally with increasing frequency, necessitating the need for management of potential upper airway obstruction at delivery. Establishment of the airway at delivery and its maintenance thereafter are critical. This should optimally be performed with the baby still attached to the placental circulation. The importance of multidisciplinary team management, including a high risk obstetrician, neonatologist, pediatric otolaryngologist, pediatric thoracic surgeon, and an anesthetist, cannot be overemphasized. Endotracheal intubation is attempted first, if unsuccessful then is followed by insertion of a rigid bronchoscope. Tracheotomy should be reserved for airway obstructions, which are not amenable to endotracheal intubation or in babies in whom exchange from a bronchoscope to endotracheal tube cannot be safely performed. The management of six infants with prenatally diagnosed potential airway obstruction is presented. Morbidity and mortality still ultimately depend on the severity of the existent anomalies.

Prognostic factors in the treatment of lymphatic malformations.

OBJECTIVE: To find factors that may influence the treatment outcomes of lymphatic malformations of the head and neck in children. DESIGN: Charts of patients treated surgically for lymphatic malformations of the head and neck between 1988 and 1996 at our tertiary care children's hospital were reviewed retrospectively. Outcomes were correlated with age at presentation, associated symptoms, anatomical site (s) of involvement, extent of disease, length of time between first symptoms and surgery, completeness of removal, and histologic pattern. PATIENTS: Of 85 children treated, 74 underwent primary surgical excision at our hospital. Follow-up ranged from 6 months to 8 years, with a mean of 3 years. RESULTS: The overall recurrence rate, judged by functional or cosmetic deformity, was 22%. Two neonates died of the disease. Factors associated with a better prognosis were a single anatomical site of involvement; location in the neck, even if involving 2 sites; and the impression of completeness of resection at the time of surgery. Findings associated with a higher recurrence rate included younger age (especially neonates) and the presence of associated symptoms (ie, infection, dyspnea, dysphagia, and hemorrhage). The histologic pattern and the length of time from diagnosis to treatment were not significantly associated with the prognosis. CONCLUSIONS: We recommend aggressive, timely surgical excision for lymphatic malformations of the head and neck. The timing of surgery should be based on the child's functional and cosmetic deformity at the time of presentation and on the likelihood of complete excision, weighed against the morbidity associated with surgical excision.

Objective and subjective nasal airflow.

PURPOSE: This study was designed to assess whether a correlation exists between the rhinomanometric measurement of nasal resistance, nasal airflow, and the subjective sensation of airflow. MATERIALS AND METHODS: Sixteen patients with recurrent maxillary sinusitis were examined before and after uncinectomy during functional endoscopic sinus surgery. Subjective nasal sensation of airflow was assessed by means of a visual scale before and after uncinectomy. Rhinomanometry was performed three times for every patient: before anesthesia, and before and after uncinectomy. The subjective nasal sensation of airflow was compared with the nasal airflow and resistance to flow as measured by rhinomanometry. RESULTS: Rhinomanometric measurements were almost the same before and after uncinectomy, with no significant difference, whereas patients reported a significant improvement in nasal airflow. CONCLUSION: Rhinomanometric measurements of nasal airflow and resistance often have no correlation to the patients's sensation of airflow. However, because it is the patients' ultimate concern to breathe more comfortably, the rhinomanometer has little clinical value.

[The parapharyngeal space: tumors and surgical approaches].

The potential parapharyngeal space contains the great vessels of the neck, cranial nerves IX-XII, the sympathetic chain and lymph nodes. Surgical access is difficult and the infrequency of tumors in it make surgery of this part of the head and neck a challenge, 8 women and 2 men (mean age 54.7, range 31-70 years) with tumors of the parapharyngeal space operated on during the past 6 years are presented. The most common surgical approach was the cervical submandibular, used in 6 of our patients with relative ease and minimal complications. Tumors of deep lobe parotid origin should be operated through a transparotid approach. Large benign or malignant tumors have a better prognosis when the transcervical transmandibular approach is used, providing wider access.

Inverted papilloma of the nose and paranasal sinuses: a study of 56 cases and review of the literature.

Over a period of 32 years, 56 patients with inverted papilloma of the nasal cavity and paranasal sinuses were diagnosed and treated at Beilinson Medical Center, Israel. Four patients (7%) had an associated malignancy. Several surgical approaches were used: limited intranasal excision in 5 patients with an 80% failure rate, a Caldwell-Luc approach in 21 patients with a 48% recurrence rate, and lateral rhinotomy with medial maxillectomy in 18 patients with only a 22% failure rate; a selected group of 9 patients underwent an endoscopic procedure, with a 22% recurrence rate. Our results and a review of 19 published reports suggest that medial maxillectomy via lateral rhinotomy remains the treatment of choice for most cases of inverted papilloma. The role of endoscopic excision in selected patients is discussed.

Well-differentiated thyroid carcinoma.

PURPOSE: This study presents our experience with 728 patients treated in our department for well-differentiated thyroid carcinoma between 1954-1994. MATERIALS AND METHODS: The retrospective evaluation of the prognostic implications of the clinical and pathological findings was performed. Age, sex, histological variants, tumor size, and locoregional and distant spread were evaluated as risk factors in relation to the prognosis. RESULTS: During follow-up, which ranged from 1 to 31 years, 125 locoregional and/or distant metastases developed (17.2% of the patients), 87 of which occurred in the first 10 years after initial therapy. Thirty-two patients with papillary cancer and 20 with follicular cancer died of causes related to malignancy of the thyroid. CONCLUSION: The experience gained in our department has led us to adopt an aggressive approach in the treatment of patients with well-differentiated carcinoma of the thyroid gland.

Huge saccular cyst of the larynx: a case report.

Lateral laryngeal saccular cysts of the larynx that herniate through the thyrohyoid membrane are quite rare. We present a case of a huge midcervical cyst which occurred as a result of extreme neglect of a lateral saccular cyst. This case provided us with a unique opportunity to characterize the late stages of this pathology. The differential diagnosis of cervical cysts and treatment approaches are discussed.