Min-Hyun Park

Comparison of cognitive function in deaf children between before and after cochlear implant.

Objectives: This study was conducted to examine improvements of cognitive abilities after cochlear implantation in deaf children. We also examined the psychosocial factors that predict good outcomes of cochlear implantation. Design: A neuropsychological test battery was administered to 17 deaf children (mean age, 7 yr 2 mo) before receiving the cochlear implant, and they were reassessed with the same test at 6-mo follow-up. Their parents completed questionnaires concerning their medical and educational history, parenting style, and parental emotional problems. Results: Deaf children showed marked improvement in speedy and delicate motor coordination and visual organization abilities. Their cognitive functions of comprehension, concentration, and sequential processing, as measured by nonverbal tests, were found to have improved from the levels of borderline to mild mental retardation to that of near-normal range. However, their performances on Information, Comprehension and Similarity, and Mathematics subtests requiring verbal abilities did not show significant changes. Deaf children’s working memory improved significantly after cochlear implantation. However, they showed more omission errors in the visual attention test at follow-up than before cochlear implantation. Such inattentiveness for visual stimuli in children post-implantation could be attributed to distractibility of these children toward external noise. Mothers’ depression was negatively correlated with scores of acquired knowledge of deaf children. Conclusion: At the 6-mo follow-up after cochlear implant, deaf children showed marked improvement in nonverbal cognitive functions and working memory. Conversely, their verbal abilities did not significantly change. Maternal factors were found to be important for predicting the prognosis of cochlear implantation. The absence of a control group precludes the possibility of drawing any firm conclusions because the effect of the implant cannot be teased apart from the effects of maturation and training. Future studies should address this question with the use of appropriate control groups.

Complications Associated With Autologous Rib Cartilage Use in Rhinoplasty: A Meta-analysis

IMPORTANCE Although autologous rib cartilage is a preferred source of graft material in rhinoplasty, rib cartilage for dorsal augmentation has been continuously criticized for its tendency to warp and for high donor-site morbidities. However, no meta-analysis or systemic review on complications associated with autologous rib cartilage use in rhinoplasty has been conducted. OBJECTIVE To carry out a systematic review and a meta-analysis of available literature to evaluate complications regarding autologous rib cartilage in rhinoplasty. DATA SOURCES The studies reporting complications associated with the autologous rib cartilage use in rhinoplasty were systematically reviewed by searching the MEDLINE, PubMed, and Embase databases for sources published from 1946 through June 2013. STUDY SELECTION The selected articles included clinical studies conducted with at least 10 patients and at least 1 postoperative long-term complication or donor-site morbidity in rhinoplasty. Excluded were nonhuman studies; review articles; case reports; abstracts; and reports of nasal reconstruction as indication for surgery, use of homologous rib cartilage, and diced or laminated methods. DATA EXTRACTION AND SYNTHESIS Two investigators independently reviewed all studies and extracted the data using a standardized form. A meta-analysis was performed using a random-effects model. MAIN OUTCOMES AND MEASURES Number of patients; follow-up duration; and rates of complication, donor-site morbidity, and revision surgery. Also noted were study authors and year of publication. RESULTS Ten studies involving a total 491 patients were identified. Mean follow-up across all studies was 33.3 months. In meta-analysis, the combined rates were 3.08% (95% confidence interval [CI], 0%-10.15%) for warping, 0.22% (95% CI, 0%-1.25%) for resorption, 0.56% (95% CI, 0%-2.61%) for infection, 0.39% (95% CI, 0%-1.97%) for displacement, 5.45% (95% CI, 0.68%-13.24%) for hypertrophic chest scarring, 0% (95% CI, 0%-0.32%) for pneumothorax, and 14.07% (95% CI, 6.19%-24.20%) for revision surgery. CONCLUSIONS AND RELEVANCE The overall long-term complications and donor-site morbidity rates associated with autologous rib cartilage use in rhinoplasty were low. Warping and hypertrophic chest scarring showed relatively higher rates, warranting a surgeons attention. Because a limited number of studies and patients were eligible, and consistent definitions of complications were lacking in this meta-analysis, future studies with a larger series of patients and objective outcome measurements are needed to obtain more reliable results. LEVEL OF EVIDENCE 4.

Assessment of Cerebral Glucose Metabolism in Cat Deafness Model: Strategies for Improving the Voxel-Based Statistical Analysis for Animal PET Studies

PurposeThe aim of this study was to establish the procedures for 3D voxel-based statistical analysis of 2-deoxy-2-[18F]fluro-d-glucose-positron emission tomography (FDG-PET) images of a cat’s brain obtained using a small animal-dedicated PET system and to assess the utility of this approach in investigating the cerebral glucose metabolism in an animal model of cortical deafness.ProceduresThis study compared several different strategies for the spatial processing of PET data acquired twice from eight cats before and after inducing deafness in terms of the comparability of the statistical analysis results to the established pattern of the cerebral glucose metabolic changes in the deaf animals.ResultsThe accuracy of the spatial preprocessing procedures and the statistical significance of the comparison were improved by removing the background activities outside the brain regions. The use of the spatial normalization parameters obtained from the mean image of the realigned data set for individual data also helped improve the statistical significance of the paired t testing. It was also found that an adjustment of the registration options was also important for increasing the precision of the realignment.ConclusionsA method for voxel-based analysis of the PET data of a cat’s brain was optimized. The results demonstrated the high localization accuracy and specificity of this method, which is expected to be useful for examining the brain PET data of medium-sized animals such as cats.

Temporomandibular joint herniation into the external auditory canal.

Herniation of the temporomandibular joint (TMJ) into the external auditory canal (EAC) is a very rare condition, and it mostly occurs in patients with bony wall defects in the anterior EAC. The purpose of this study was to evaluate the clinical and radiological findings and the treatment results of TMJ herniation into the EAC by reviewing a large sample of temporal bone computed tomography (CT) scans.

Cross-modal and compensatory plasticity in adult deafened cats: a longitudinal PET study.

Although much is known about the cerebral neural plasticity that occurs after deafness, it is unclear how much time is required for its development or what other cortical changes may consequently occur. This study provides a longitudinal assessment of cerebral cortical neural plasticity, as manifested in adult deafened cats. A total of 5 male cats were subjected to whole cortex analysis of glucose metabolic activity via 2-deoxy-2[(18)F] fluoro-D-glucose (FDG) micro-positron emission tomography (PET). The imaging was performed at the baseline state of normal hearing and then at 4, 9, 24, and 33 months after the induction of deafness. We compared glucose metabolism between the normal hearing state and each deafened state by using voxel-based statistical analysis (P<0.005). Significant changes were observed in the primary auditory (A1) and primary visual (V1) cortices. A bilateral metabolic decrease was observed in A1 areas and in temporal auditory fields, the extent of which was significantly increased at Month 9. Then it was declined at Month 24. And finally it was disappeared by Month 33. Auditory cortical plasticity subsequent to deafness was thus demonstrated. Furthermore, a significant metabolic upsurge occurred in bilateral occipital areas at Month 33. This increase, involving bilateral occipital and thalamic areas of V1, suggests compensatory hyperactivity of the visual cortex after deafness.

MBP-positive and CD11c-positive cells are associated with different phenotypes of Korean patients with non-asthmatic chronic rhinosinusitis.

Background Asthmatic nasal polyps primarily exhibit eosinophilic infiltration. However, the identities of the immune cells that infiltrate non-asthmatic nasal polyps remain unclear. Thus, we thought to investigate the distribution of innate immune cells and its clinical relevance in non-asthmatic chronic rhinosinusitis (CRS) in Korea. Methods Tissues from uncinate process (UP) were obtained from controls (n = 18) and CRS without nasal polyps (CRSsNP, n = 45). Nasal polyps (NP) and UP were obtained from CRS with nasal polyps (CRSwNP, n = 56). The innate immune cells was evaluated by immunohistochemistry such as, eosinophil major basic protein (MBP), tryptase, CD68, CD163, CD11c, 2D7, human neutrophil elastase (HNE) and its distribution was analyzed according to clinical parameters. Results In comparisons between UP from each group, CRSwNP had a higher number of MPB+, CD68+, and CD11c+ cells relative to CRSsNP. Comparisons between UP and NP from CRSwNP indicated that NP have a higher infiltrate of MBP+, CD163+, CD11c+, 2D7+ and HNE+ cells, whereas fewer CD68+ cells were found in NP. In addition, MBP+ and CD11c+ cells were increased from UP of CRSsNP, to UP of CRSwNP, and to NP of CRSwNP. Moreover, in UP from CRSwNP, the number of MBP+ and CD11c+ cells positively correlated with CT scores. In the analysis of CRSwNP phenotype, allergic eosinophilic polyps had a higher number of MBP+, tryptase+, CD11c+, 2D7+ cells than others, whereas allergic non-eosinophilic polyps showed mainly infiltration of HNE+ and 2D7+ cells. Conclusions The infiltration of MBP+ and CD11c+ innate immune cells show a significant association with phenotype and disease extent of CRS and allergic status also may influences cellular phenotype in non-asthmatic CRSwNP in Korea.

Implication of vibration induced nystagmus in Meniere's disease

Conclusion. The incidence of ipsilesional beating vibration induced nystagmus (VIN) is significantly higher in Menieres disease (MD) with lower canal paresis (CP) group on caloric test and the intensity of VIN shows significant positive correlation with CP. Considering previous reports showing predominant loss of type II hair cells in MD and discrepancy of the results between caloric test and head thrust test in MD patients, VIN may provide valuable information regarding the functional reservoir of vestibular type II hair cells in MD. Objectives. Clinical presentation of MD is dynamic and nystagmus changes phase to phase, which is attributed to the recovery process in addition to central compensation after active vertigo attack of MD. VIN has been shown to reflect the side difference of peripheral vestibular excitability and is well correlated with the severity of caloric weakness in vestibular neuritis. Aim of this study was to compare the intensity and the direction of VIN with CP in unilateral MD. Materials and methods. 52 patients with unilateral definite MD on AAO-HNS guideline (1995) were included. Auditory and vestibular function tests including caloric test, post-head shaking nystagmus (HSN) and VIN were evaluated during symptom free period and cases with spontaneous nystagmus were excluded. Vibratory stimuli (100 Hz) were applied to either mastoid alternatively. Eye movement was recorded using video nystagmography system. The horizontal component of VIN was compared with HSN and caloric test. Results. 37 patients (71%) showed VIN. VIN to ipsilesional side was in 10 and to contralesional side in 27. In patients with CP over 43% (N =23), 2 beated to ipsilesional side, 17 to contralesional side and 4 showed no VIN. In patients with CP of less than 43% (N =29), 8 beated to ipsilesional side, 10 to contralesional side and 11 showed no VIN (p<0.05). 33 patients (63%) showed HSN and 24 patients of them (72%) showed contralesional nystagmus. The intensity of VIN shows significant positive correlation with the degree of CP on caloric test (Spearmans rho =0.340, p<0.05).

Usefulness of computed tomography Hounsfield unit density in preoperative detection of cholesteatoma in mastoid ad antrum.

PURPOSE This study was performed to evaluate the usefulness of Hounsfield unit (HU) to better distinguish cholesteatoma from other inflammatory conditions in the mastoid ad antrum before primary mastoid surgery. MATERIALS AND METHODS We enrolled 82 patients who underwent tympanomastoidectomy for treatment of chronic otitis. Forty-one patients were pathologically diagnosed with cholesteatoma, whereas the others were diagnosed with inflammatory granulation. These lesions were confirmed, and HU was measured in preoperative computed tomography. The difference in HU between cholesteatoma and non-cholesteatoma tissues was analyzed, and the improvement in the diagnosis of cholesteatoma after inclusion of HU data was calculated. RESULTS The HU was calculated as 42.68 ± 24.42 in the cholesteatoma group and 86.07 ± 26.50 in the non-cholesteatoma group. The differences between the 2 groups were statistically different (Student t test, P < .01). By applying the HU, the sensitivity (51.2%-80.5%), specificity (80.5%-87.8%), positive predictive value (72.4%-86.8%), and negative predictive value (62.3%-81.8%) to diagnose cholesteatoma improved. CONCLUSIONS The HU density was found to be statistically different between cholesteatoma and inflammatory granulation tissue in mastoid antrum. An improved diagnosis of cholesteatoma was achieved after adjusting for the HU.

Feasibility of Template-Guided Attenuation Correction in Cat Brain PET Imaging

PurposeAttenuation correction (AC) is important in quantitative positron emission tomography (PET) imaging of medium-sized animals such as the cat. However, additional time for transmission (TX) scanning and tracer uptake is required in PET studies with animal-dedicated PET scanners because post-injection TX scanning is not available in these systems. The aim of this study was to validate a template-guided AC (TGAC) method that does not require TX PET data for AC in cat 2-deoxy-2-[F-18fluoro-D-glucose (FDG) brain PET imaging.MethodsPET scans were acquired using a microPET Focus 120 scanner. TX data were obtained using a 68Ge point source before the injection of FDG. To generate the attention map (μ-map) template for the TGAC, a target image of emission (EM) PET was selected, and spatial normalization parameters of individual EM data onto the target were reapplied to the corresponding μ-maps. The inverse transformations of the μ-map template into the individual spaces were performed, and the transformed template was forward projected to generate the AC factor. The TGAC method was compared with measured AC (MAC) and calculated AC (CAC) methods using region of interest (ROI) and SPM analyses.ResultsThe ROI analysis showed that the activity of the TGAC EM PET images strongly correlated with those of the MAC data (