Multi-triangulations as complexes of star polygons

Maximal $(k+1)$-crossing-free graphs on a planar point set in convex position, that is, $k$-triangulations, have received attention in recent literature, with motivation coming from several interpretations of them. We introduce a new way of looking at $k$-triangulations, namely as complexes of star polygons. With this tool we give new, direct, proofs of the fundamental properties of $k$-triangulations, as well as some new results. This interpretation also opens-up new avenues of research, that we briefly explore in the last section.Comment: 40 pages, 24 figures; added references, update Section

Paediatric cochlear implantation: studies that inform consent

Introduction: In paediatric cochlear implant (CI) surgery, understanding the likelihoods of different outcomes is important to facilitate education of families, informed consent, setting expectations, and guiding clinical care. Method: The SCIC database and clinical records were reviewed for different cohorts of children with a CI including those with additional disabilities; CHARGE syndrome; cochlear nerve aplasia and hypoplasia; and revision CI surgery. A prospective study of outcomes at one week post-operatively was performed. Results: Five studies presented in published papers report on outcomes, risk factors and objective measurements that inform consent and management choices. Additional disabilities were present in 30% of children, who had poorer spoken language. Risk factors associated with additional disabilities included syndromes, chromosomal abnormalities, neonatal jaundice, prematurity, congenital cytomegalovirus infection, and inner ear anatomical abnormalities. In CHARGE syndrome and in cochlear nerve dysplasia (CND) paediatric CI outcomes are variable, influenced also by additional disabilities and abnormal anatomy. IN CND 73% of children developed some spoken language. Spoken language understanding using the CI was achieved in 47% of ears with cochlear nerve aplasia and 89% with hypoplasia. In CHARGE syndrome, all congenitally profoundly deaf children had CND and used sign language. Only a few also developed spoken language. For children with CHARGE syndrome and progressive hearing loss CI surgery enhanced understanding of spoken language and maintained spoken language as their main mode of communication. Revision CI surgery is associated with increased electrode impedance, a marker of intracochlear fibrosis. Impedance increased significantly following revision ContourTM device surgery. In explant-reimplant surgery 61% of children achieved pre-operative speech perception by six months after surgery. Children can be reassured that CI surgery is associated with minimal pain and dizziness at one week post-operatively. Conclusion: Our research enables greater understanding of the likelihoods of different outcomes with paediatric CI surgery and factors that may affect outcomes. This information is useful for clinicians and families

The Impact of primary ciliary dyskinesia on the upper respiratory tract

Primary Ciliary Dyskinesia (PCD) is an autosomal recessive genetic condition affecting the function of motile cilia. The upper respiratory tract is lined with ciliated epithelium and hence a hallmark of PCD is the development, from the neonatal period onwards, of persisting secretion retention and suppurative infection in the middle ear, nose and facial sinuses. This review aims to remind the clinician involved in the care of a patient with PCD of the complexities of making the diagnosis of chronic rhinosinusitis (CRS) and chronic otitis media with effusion (ChOME), the morbidity associated with CRS and ChOME and of current evidence of best practice for the management of these conditions.6 page(s

Pediatric cochlear implantation : associated with minimal postoperative pain and dizziness

Objective: To prospectively document the surgical pain, assessing analgesia use as a proxy, and postoperative dizziness in children over the first week after cochlear implantation. Study Design: Prospective. Setting: Tertiary referral hospital and cochlear implant program. Patients: Children aged 0 to 16 years inclusive undergoing cochlear implant surgery, who returned to see the primary surgeon for the postoperative 1-week follow-up appointment. Interventions: One-week postoperative collection of data via direct questioning of parents and children. Main Outcome Measures: Analgesia use, duration of analgesia use and dizziness (nil, slight, or moderate), type of surgery, and radiologic findings. Results: Data were available for 61 of 98 children aged 5 months to 15 years. Children underwent first side implant (n = 27), sequential second side implant (n = 15), bilateral simultaneous (n = 16), and explant reimplantation (n = 3). On average, children used paracetamol for only 1.9 days after discharge from the hospital. Longer average paracetamol use was associated with bilateral simultaneous surgery (3.3 d after discharge from the hospital) and also the younger age group of 0 to 12 months (3.2 d). Slight dizziness was reported by 8% of all children at 1 week postsurgery. No child had marked dizziness or unsteadiness. Four children had large vestibular aqueducts on radiology scans, two (50%) of these children has slight unsteadiness at 1 week postoperatively. Conclusion: Our study shows cochlear implant surgery is well tolerated by children. This information enables better counseling of families and children considering cochlear implantation.3 page(s

Primary ciliary dyskinesia : overlooked and undertreated in children

Primary ciliary dyskinesia (PCD) is a multi-organ disorder associated with chronic oto-sino-pulmonary disease, neonatal respiratory distress, situs abnormalities and reduced fertility. Repeated respiratory tract infections leads to the almost universal development of bronchiectasis. These clinical manifestations are a consequence of poorly functioning motile cilia. However, confirming the diagnosis is quite difficult and is often delayed, so the true incidence of PCD may be significantly higher than current estimates. Nasal nitric oxide has been earmarked as a useful screening tool for identifying patients, but its use is limited in pre-school-aged children. Due to the rarity of PCD, the evidence base for management is somewhat limited, and treatment regimens are extrapolated from other suppurative lung disorders, like cystic fibrosis.7 page(s

Impedance, neural response telemetry, and speech perception outcomes after reimplantation of cochlear implants in children

OBJECTIVE: To compare mean impedance levels, neural response telemetry (NRT), and auditory perception after initial and explant-reimplant pediatric cochlear implants. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral hospital and cochlear implant program. PATIENTS: Children 0 to 16 years inclusive who have undergone explant-reimplant of their cochlear implant. INTERVENTION: Impedance levels, NRT, and speech perception performance. MAIN OUTCOME MEASURES: Impedance, NRT, and auditory perception at switch on, 3 months, 12 months, 3 years, and 5 years after initial cochlear implant and reimplantation. RESULTS: The explant-reimplant group receiving Cochlear contour array had significantly (p < 0.001) raised impedance at switch on, 3 months, 12 months, and 3 years, compared with their initial implant. The explant-reimplant group receiving Cochlear straight array had marginally significant (p = 0.045) raised impedance at switch on, 3 months, 12 months, and 3 and 5 years. Infection was associated with greater increases in impedance in the reimplant Contour group. NRT was increased in the explant-reimplant group but not significantly (p = 0.06). Auditory perception returned to preexplant levels within 6 months in 61% of children. CONCLUSION: Impedance is higher after explant-reimplant and remains increased for years after explant-reimplant with Cochlear contour and to a lesser degree the straight array device.9 page(s

CHARGE syndrome and Cochlear implantation : difficulties and outcomes in the paediatric population

Objectives: CHARGE syndrome is a complex cluster of congenital abnormalities, these children may have absent or hypoplastic auditory nerves. Our objective was to assess preoperative factors and outcomes for paediatric cochlear implant recipients with CHARGE syndrome, to enable better surgical preparation and family counselling. Methods: The Sydney Cochlear Implant Centre database was searched for children with CHARGE syndrome who had received a cochlear implant at ages 16 and less. Data were collected regarding clinical history; hearing assessments; MRI and CT scan findings; preoperative transtympanic electrical Auditory Brainstem Response (ABR); intraoperative findings and intraoperative electrical ABR and Neural Response Telemetry; and language outcomes in terms of main language used and Categories of Auditory Performance scores (0–7 ranking). Results: Ten children were identified. All seven prelingual profoundly deaf children with CHARGE syndrome had hypoplastic or absent auditory nerves bilaterally on MRI scans. Middle ear anatomy was often abnormal, affecting surgical landmarks and making identification of the cochlea very difficult in some cases. Three cases required repeated surgery to obtain successful cochlear implant insertion, one under CT scan image guided technique. All seven children used sign language, or simpler gestures, as their main mode of communication. Two children of of these children, who were implanted early, also attained some spoken language. CAP scores ranged from 0 to 6. The three children with CHARGE syndrome and progressive sensorineural hearing loss had a normal auditory nerve in at least one ear on MRI scans. All had preoperative verbal language, with CAP scores of 6, and continued with CAP scores of 6 following receipt of the cochlear implant. Conclusion: Children with CHARGE and congenital profound hearing loss all had hypoplasia or absent auditory nerves, affecting their outcomes with cochlear implants. They often had markedly abnormal middle ear anatomy and CT image guided surgery can be helpful. These children should be offered a bilingual early intervention approach, using sign language and verbal language, to ensure best language outcomes. Children with CHARGE syndrome and progressive profound hearing loss did well with cochlear implants and continue to be able to use verbal language.6 page(s

Cochlear implant outcomes in cochlea nerve aplasia and hypoplasia

Objective: To assess cochlear implant (CI) outcomes, and factors affecting outcomes, for children with aplasia/hypoplasia of the cochlea nerve. We also developed a new grading system for the nerves of the internal auditory meatus (IAM) and cochlea nerve classification. Study Design: Retrospective patient review. Setting: Tertiary referral hospital and cochlear implant program. Patients: Children 0 to 16 years inclusive with a CI who had absent/hypoplastic cochlea nerve on magnetic resonance imaging (MRI). Intervention: Cochlear implant. Main Outcome Measures: MRI, trans-tympanic electrical auditory brainstem response, intraoperative electrical auditory brainstem response, Neural Response Telemetry, Categories of Auditory Perception score, Main mode of communication. Results: Fifty CI recipients (26 males and 24 females) were identified, 21 had bilateral CIs, 27 had developmental delay. MRI showed cochlea nerve aplasia in 64 ears, hypoplasia in 25 ears, and a normal nerve in 11 ears. Main mode of communication was analyzed for 41 children: 21 (51%) used verbal language (15 speech alone, 5 speech plus some sign, 1 bilingual in speech and sign), and 20 (49%) used sign language (10 sign alone, 9 sign plus some speech, 1 tactile sign). Seventy-three percent of children used some verbal language. Cochlea nerve aplasia/hypoplasia and developmental delay were both significant factors affecting main mode of communication. Categories of Auditory Performance scores were available for 59 CI ears; 47% with CN Aplasia (IAM nerve grades 0-III) and 89% with CN hypoplasia (IAM nerve grade IV) achieved Categories of Auditory Performance scores of 5 to 7 (some verbal understanding) (p=0.003). Conclusion: Our results are encouraging and useful when counselling families regarding the likelihood of language outcomes and auditory understanding.8 page(s

Presentation of primary ciliary dyskinesia in children : 30 years' experience

Aim: Primary ciliary dyskinesia (PCD) is a rare (1:15 000) condition resulting in recurrent suppurative respiratory tract infections, progressive lung damage and hearing impairment. As the diagnosis is often delayed for years, the purpose of this study was to review the presenting features of children with PCD attending Australia's initial diagnostic PCD service over a 30-year period. Method: A retrospective review of the symptoms of children diagnosed with PCD at Concord Hospital between 1982 and 2012 was undertaken. Results: One thousand thirty-seven paediatric patients were referred for assessment and underwent nasal ciliary brushing. Eighty-four (8.1%) had PCD based on microscopic analysis of nasal cilia. This included 81 with ciliary ultrastructural abnormalities demonstrated on electron microscopy and 3 with a suggestive phenotype, reduced ciliary beat frequency and a family history of PCD. The median age at diagnosis was 6.4 years (range 0.1 to 18.2 years). Forty-six per cent had situs abnormalities and 31% had a family member with PCD. Recurrent cough (81%), rhinosinusitis (71%), recurrent otitis media (49%) and neonatal respiratory distress (57%) were reported. Bronchiectasis at presentation was documented in 32%. Situs abnormalities and neonatal respiratory distress were present together in 26%. Conclusion: PCD remains under-recognised by health-care workers. The combination of neonatal respiratory distress, chronic suppurative cough and rhinosinusitis was the most common documented symptom cluster at presentation in cases of PCD. A heightened awareness of the clinical features of the disease may help to lower the age at diagnosis, facilitate appropriate treatment and improve long-term outcomes.5 page(s