The challenges of starting a cochlear implant programme in a developing country.

PURPOSE OF REVIEW: Deafness is indeed a silent disability in many parts of the world, and the majority of people who have hearing impairment live in developing countries. With rising economy and developing nations becoming hub of industrialization, hearing loss may increase in these countries. In this review, the authors have elected to focus the discussion on India to frame the challenges of cochlear implants in a developing country. This article reviews the common causes of hearing loss, the challenges faced by those with hearing impairment and why the penetration of these devices is low and also reviews some reasons for the inability of the government to support the implant programme in India. RECENT FINDINGS: Early identification of hearing is crucial towards ensuring appropriate hearing rehabilitation; it is, however, challenged by various factors, including public awareness, absence of a national new born screening programme, accessibility to diagnostic centres, availability of trained personnel and equipment and patient affordability. Cochlear implants are a proven auditory rehabilitative option for individuals with severe to profound sensorineural hearing loss, who otherwise do not benefiting from hearing aids. Nevertheless, only a small percentage of these individuals receive cochlear implants, and cost remains a leading prohibitive factor, particularly in developing countries. For example, in India, the personal average annual income is well below US $2000, whereas these devices cost between$12,000 and $25,000, exclusive of hospital and staff fees. Hence, the technology is virtually unavailable to the masses. SUMMARY: To overcome the cost limitation of those who would benefit from cochlear implants countries such as India and China have started to develop their own indigenous implants

Radiographic Assessment and Surgical Implications of Arcuate Eminence Pneumatization.

BACKGROUND: The middle cranial fossa (MCF) approach is a valuable yet technically challenging technique. Identification of the superior semicircular canal (SCC) using the arcuate eminence (AE) was proposed as a surface landmark. However, the AE is sometimes absent, with inconsistent relationship to the SCC. Air cells in the AE area facilitate safer identification of the SCC. The aim of this study is to determine the radiographic prevalence of AE pneumatization. METHODS: Two hundred consecutive fine-cut temporal bone CT scans were retrospectively reviewed. The region of the petrosal bone at and above the level of the SCC dome was assessed for the presence of air cells, and graded 0 (no pneumatization) to 2 (well pneumatized). RESULTS: Four hundred temporal bones were studied. The average age was 49 years (range 18-89). Of all AE assessments, 47 (12%) were nonpneumatized, 62 (15%) partially pneumatized, and 291 (73%) well pneumatized. There was no significant correlation between patient age and pneumatization grade (p = 0.72). CONCLUSION: The SCC is a valuable landmark in MCF surgery as it holds consistent relationships to adjacent critical structures. Surrounding air cells should facilitate safer initial identification of the SCC, as the AE region is well pneumatized in 73% of patients

Contemporary Neuroradiographic Assessment of the Cochleo-Carotid Partition.

PURPOSE: The cochleo-carotid partition (CCP) describes the intimate anatomic relationship between the petrous carotid artery and the cochlear basal turn. This partition bears significant surgical and unique clinical relevance. The purpose of this paper is to radiographically assess the CCP and discuss its clinical implications. METHODS: A total of 155 consecutive fine-cut temporal bone CT scans were retrospectively reviewed, and study scans were digitally analyzed in both axial and coronal views. The shortest distance between the petrous carotid canal and the cochlear basal turn was measured. RESULTS: In all, 310 temporal bones were studied, with a mean CCP of 1.9 mm (range 0.2-8.5, SD 1.1). The following CCP measurements were obtained: ≤1.0 mm [n = 46 (14.8%)]; 1.1-2.0 mm [n = 161 (51.9%)]; 2.1-3.0 mm [n = 29 (9.4%)], and ≥4.0 mm [n = 12 (4.2%)]. One temporal bone (0.3%) had complete CCP dehiscence. There was a positive correlation between each patient\u27s right and left CCP measures (p \u3c 0.005) and a significant negative correlation between CCP grade and age (p = 0.027). CONCLUSIONS: The CCP is a narrow anatomic confinement measuring ≤2 mm in 66.7% of patients. Potential implications of the CCP include iatrogenic risks, its possible function as a third inner ear window in patients with audiovestibular symptoms, and pathophysiology of new-onset tinnitus following cochlear implantation

Analysis of carotid artery injury in patients with basilar skull fractures.

OBJECTIVES: Determine the prevalence of carotid artery injury (CAI) in patients with basilar skull fractures and describe significant demographic and radiographic risk factors for CAI. STUDY DESIGN: From January 2004 to December 2008, medical records of 1,279 consecutive adult patients treated for basilar skull fractures at a tertiary care academic hospital were retrospectively reviewed. Diagnostic angiography was performed in 112 patients because of concern for CAI. Computed tomographic studies of the head and cranial base were reviewed for evidence of pneumocephalus, petrous carotid canal fractures, and sphenoid bone fractures. RESULTS: Mean age of patients undergoing angiography was 38.7 years, and 85 patients (75.9%) were male subjects. Thirty-five (50%) of 70 discrete cerebrovascular injuries on angiography involved the carotid canal. The prevalence of CAI in patients with basilar skull trauma was 2.0%. CAI was associated with female sex (p = 0.001), whereas lower Glasgow Coma Scale score approached statistical significance (p = 0.07). Sensitivity and specificity of the 3 computed tomographic findings individually were 44% to 68% and 41% to 67%, respectively. With all 3 findings concurrently, 85% specificity and 80% negative predictive value for CAI were obtained, although sensitivity declined. CONCLUSION: The frequency of CAI in patients with basilar skull fractures was higher than that in those without basilar skull involvement. Female sex was strongly associated with CAI. The intimate anatomic relationship between the carotid artery and the cranial base posit substantial diagnostic and therapeutic challenges for the contemporary cranial base surgeon, and thus, understanding the epidemiology and risk factors for CAI is of paramount importance

Contemporary angiographic assessment and clinical implications of the vein of labbé in neurotologic surgery.

BACKGROUND: To better understand the drainage patterns of the 3 largest superficial anastomotic veins (SAVs), namely, vein of Labbé (VL), the vein of Trolard (VT), and the superficial sylvian vein (SSV). To assess the dominance of the VL in the superficial cortical venous system, because this vein may be encountered in neurotologic surgery and its interruption may result in a venous infarct of the temporal lobe. METHODS: The database of the radiology department at the University of Cincinnati was used to identify all patients who underwent a diagnostic angiographic study between September 1, 2009, and January 1, 2010. Studies were excluded if there were intracranial masses or vascular lesions. Angiograms were assessed for the presence of the VL, VT, and SSV, as well as vessel dominance, determined by their relative calibers. RESULTS: A total of 101 patients (81%) underwent bilateral and 48 unilateral angiography, for a total of 250 studies. Mean age was 55 years (range, 16-83 yr). Seventy-seven patients (53%) were females. The most common pattern observed was the presence of all 3 SAVs (78%). The VL was absent or poorly developed in 34 studies (14%) and was the dominant superficial vein in 51 (20%), of which 28 (55%) occurred on the right. CONCLUSION: Considerable variability is demonstrated in the drainage patterns of the SAVs. Care should be taken in neurotologic surgery to avoid injuring the VL because this may represent the single dominant drainage pathway of the lateral surface of the temporal lobe in a large number of patients

Do contemporary temporal bone fracture classification systems reflect concurrent intracranial and cervical spine injuries?

OBJECTIVES/HYPOTHESIS: Temporal bone fractures (TBFs) are a frequent manifestation of head trauma. We investigated the prevalence of concurrent intracranial injuries (ICIs) and cervical spine injuries (CSIs) in a series of patients with TBFs and attempted to identify significant associations between current TBF classification systems and either ICI or CSI. STUDY DESIGN: Retrospective case series with chart review. METHODS: The records of all patients ≥18 years of age diagnosed with a basilar skull fracture, including TBF, at a level I trauma center from 2004 to 2009 were reviewed. Patient demographics, mechanism of injury, and Glasgow Coma Scale (GCS) scores were collected. Imaging studies were reviewed to classify TBF using the traditional longitudinal-transverse-mixed and otic capsule-sparing versus -involving systems and identify concurrent ICI and CSI. RESULTS: Of 1,279 patients, 202 (15.8%) met inclusion criteria. There were 160 (79.2%) males. Sixteen (7.9%) patients had bilateral TBFs. Falls (n = 66, 32.7%) represented the most common mechanism for TBF. Longitudinal (n = 96, 44.0%) and otic capsule-sparing (n = 209, 95.9%) fractures were the most prevalent subtypes. There were 184 (91.1%) patients who sustained ICI and 18 (8.9%) who demonstrated CSI. Longitudinal, transverse, mixed, otic capsule-sparing, or otic capsule-involving TBF subtypes had no statistically significant associations with mechanism of injury, GCS score, or concomitant ICI or CSI. CONCLUSIONS: More than 90% of patients sustaining TBF presented with concomitant ICI, and 9% sustained CSI. Current TBF classification systems do not correlate with these outcomes. A more sophisticated, multidisciplinary classification system encompassing radiographic and clinical findings may better predict neurologic, neuro-otologic, and skull base complications

Clinical efficiency and safety of the oticon medical neuro cochlear implant system: a multicenter prospective longitudinal study

Objective This prospective longitudinal cohort study at six tertiary referral centers in Canada and Denmark describes the clinical efficiency and surgical safety of cochlear implantation with the Oticon Medical Neuro cochlear implant system, including the Neuro Zti implant, the EVO electrode array, and the Neuro One sound processor. Methods Patients were adult cochlear implant candidates with bilateral sensorineural hearing loss. Results The mean HINT scores in quiet pre-operatively and at 3, 6, and 12 months post-activation were 13%, 58%, 67%, and 72%, respectively, and in noise (+10 dB SNR) 13%, 46%, 53%, and 59%, respectively. The mean improvement from baseline to 6 months post-activation was 54% in quiet and 40% in noise. The surgical major complication incidence rate was 0% and the post-surgical major complication incidence rate (until 12 months post-activation) was 4%. There was no adverse event that was fatal, that required explantation, or that resulted in sound processor nonuse, and no implant failure. Conclusion Cochlear implantation with the Oticon Medical Neuro system enables speech identification both in quiet and in noise and audiologic outcomes continue to improve in the year following activation. No substantial adverse events occurred during the surgical implantation procedure and during the 12 months post-activation.Funding Agencies|Oticon Medical</p