Losartan Prevents Maladaptive Auditory-Somatosensory Plasticity After Hearing Loss via Transforming Growth Factor-β Signaling Suppression

OBJECTIVES: Hearing loss disrupts the balance of auditory-somatosensory inputs in the cochlear nucleus (CN) of the brainstem, which has been suggested to be a mechanism of tinnitus. This disruption results from maladaptive auditory-somatosensory plasticity, which is a form of axonal sprouting. Axonal sprouting is promoted by transforming growth factor (TGF)-β signaling, which can be inhibited by losartan. We investigated whether losartan prevents maladaptive auditory-somatosensory plasticity after hearing loss. METHODS: The study consisted of two stages: determining the time course of auditory-somatosensory plasticity following hearing loss and preventing auditory-somatosensory plasticity using losartan. In the first stage, rats were randomly divided into two groups: a control group that underwent a sham operation and a deaf group that underwent cochlea ablation on the left side. CNs were harvested 1 and 2 weeks after surgery. In the second stage, rats were randomly divided into either a saline group that underwent cochlear ablation on the left side and received normal saline or a losartan group that underwent cochlear ablation on the left side and received losartan. CNs were harvested 2 weeks after surgery. Hearing was estimated with auditory brainstem responses (ABRs). Western blotting was performed for vesicular glutamate transporter 1 (VGLUT1), reflecting auditory input; vesicular glutamate transporter 2 (VGLUT2), reflecting somatosensory input; growth-associated protein 43 (GAP-43), reflecting axonal sprouting; and p-Smad2/3. RESULTS: Baseline ABR thresholds before surgery ranged from 20 to 35 dB sound pressure level. After cochlear ablation, ABR thresholds were higher than 80 dB. In the first experiment, VGLUT2/VGLUT1 ratios did not differ significantly between the control and deaf groups 1 week after surgery. At 2 weeks after surgery, the deaf group had a significantly higher VGLUT2/VGLUT1 ratio compared to the control group. In the second experiment, the losartan group had a significantly lower VGLUT2/VGLUT1 ratio along with significantly lower p-Smad3 and GAP-43 levels compared to the saline group. CONCLUSION: Losartan might prevent axonal sprouting after hearing loss by blocking TGF-β signaling thereby preventing maladaptive auditory-somatosensory plasticity.

Diagnosis of Middle Ear Effusion in Neonate and Infant: Pitfalls of Conventional Impedance Audiometry Using 226 Hz Probe Tone / 대한이비인후과학회지

Middle ear effusion is one of the most common causes which results in refer on hearing screening of infants. Evaluation of middle ear state has been emphasized because the causes and severity of hearing impairment determine the manner of rehabilitation. As a complimentary diagnostic method of middle ear effusion, tympanometry using 226 Hz probe tone has been most commonly used in adult and older children. However, recent reports have indicated obviously that the use of a 1000 Hz tympanometry is more reliable in younger infants and neonates than 226 Hz. This attributes to the developmental changes in acoustic properties and anatomic changes of middle ear structures and ear canal. Given the data reported up to the present, 1000 Hz tympanometry is recommended to diagnose middle ear effusion in children younger than 6 months.

Audiologic Results of Ossiculoplasty Using Malleus Footplate Assembly: The Comparison between Autologous Incus and Hydroxyapatite

BACKGROUND AND OBJECTIVES: Absence of incus is one of the most common ossicular anomalies and also frequently found in chronic otitis media or chornic otitis media with cholesteatoma. Ossiculoplasty with malleus footplate assembly (MFA) can be an excellent option in the above situations. We reviewed our procedures and evaluated the hearing results of ossiculoplasty using the MFA. SUBJECTS AND METHODS: This study retrospectively reviews a series of 32 patients who underwent MFA ossiculoplasty between September 2001 and March 2010 in an academic tertiary referral center. The autologous incus or hydroxyapatite (HA) was used as materials for reconstruction. RESULTS: Thirteen of 32 patients (40.6%) had ossicular chain anomaly, 9 patients (28.1%) had congenital cholesteatoma and 8 patients (25.0%) had chronic otitis media with cholesteatoma and 2 patients (6.3%) had chronic otitis media. The patients with ossicular chain ano-maly showed the greatest air-bone gap (ABG) closure. Overall, postoperative ABG was 17.7+/-11.7 dB at postoperative 6 months and 19.7+/-14.3 dB at postoperative 1 year, compared with preoperative ABG of 37.9+/-9.3 dB. There was no statistical difference of ABG at postoperative 12 months, 24 months between MFA using incus (n=17) and HA (n=15)(p=0.300, and p=0.563). There was no meaningful difference of postoperative ABG between the patients with combined mastoidectomy (n=10) and those without mastoidecmoy (n=22)(p=0.555). No extrusions occurred. CONCLUSIONS: MFA can be an effective option in the case of absent incus expecting good postoperative hearing results.

The Correlation between Severity of Sleep Apnea, Sleep and Mood Related Scales, and Activity During Sleep in Obstructive Sleep Apnea Syndrome Patients / 수면정신생리

OBJECTIVES: This study aims to analyze the association between the severity of sleep apnea, sleep and mood related scales, and activity during sleep in obstructive sleep apnea syndrome (OSAS) patients. METHODS: One hundred seventy six drug-free male patients confirmed as OSAS (average age=43+/-11 years) were selected through nocturnal polysomnography (NPSG). OSAS was diagnosed with apnea-hypopnea index (AHI) >5, mean AHI was 39.6+/-26.0. Sleep related scales were Stanford Sleepiness Scale (SSS), Epworth Sleepiness Scale (ESS), Pittsburg Sleep Quality Index (PSQI) and Morningness-Eveningness Scale (MES). Mood related scales were Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), State-Trait Anxiety Inventory (STAI) I, II and Profile of Mood States (POMS). NPSG was performed overnight with both wrist actigraphy (WATG). Parameters produced from WATG were total activity score, mean activity score and fragmentation index. We analyzed the correlation between each scale, AHI scored from NPSG and activity score analyzed from WATG. RESULTS: ESS showed significant positive correlation with PSQI, BDI, BAI and STAI I, II, respectively (p<0.01). SSS showed significant positive correlation with PSQI and BAI (p<0.05, p<0.01). BAI showed significant positive correlation with total activity score, mean activity score and fragmentation index (p<0.05, p<0.01, p<0.05). Total activity score showed significant positive correlation with ESS and BAI, respectively (p<0.05). Fragmentation index showed significant positive correlation with ESS, PSQI and BAI (p<0.05, p<0.01, p<0.05). AHI, indicator of sleep apnea is showed no significant correlation with each sleep and mood related scale. CONCLUSION: The degree of daytime sleepiness tends to be associated with night sleep satisfaction, depression and anxiety, and the activity during sleep rather than the severity of sleep apnea.

Comparing Quantitative EEG and Low Resolution Electromagnetic Tomography Imaging between Deficit Syndrome and Non-Deficit Syndrome of Schizophrenia / 수면정신생리

OBJECTIVES: Deficit schizophrenia (DS) constitutes a disease separate from non-deficit schizophrenia (NDS). The aim of the current study was to compare the quantitative EEG and low resolution electromagnetic tomography (LORETA) imaging between DS and NDS. METHODS: This study was performed by 32 channels EEG for 42 schizophrenia patients who we categorized into DS and NDS using proxy instrument deficit syndrome (PDS). We performed the absolute power spectral analyses for delta, theta, alpha, low beta and high beta activities. We compared power spectrum between two groups using Independent t-test. Partial correlation test was performed with clinical parameters. Standardized LORETA (sLORETA) was used for comparison of cortical activity, and statistical nonparametric mapping (SnPM) was applied for the statistical analysis. RESULTS: DS showed significantly increased delta and theta absolute power in fontal and parietal region compared with NDS (p<0.05). Power spectrum showed significant correlation with 'anergia' and 'hostility/suspiciousness' subscale of brief psychiatric rating scale (BPRS)(p<0.05). sLORETA found out the source region (anterior cingulate cortex/limbic part) that delta activity was significantly increased in DS (p=0.042). CONCLUSIONS: DS showed different cortical activity compared with NDS. Our results may suggest QEEG and LORETA could be the marker in differentiating between DS and NDS.

Pleomorphic Adenoma Causing Facial Nerve Palsy / 대한이비인후과학회지

Facial nerve palsy due to the benign parotid tumor is extremely rare. The authors experienced a case of pleomorphic adenoma in parotid gland, showing retrograde extension to mastoid bone along the facial nerve, resulting facial nerve palsy. An 82-year-old woman with facial nerve palsy for six years was revealed to have a solid mass in the close proximity to mastoid tip with contrast enhancement on computed tomography (CT). The mass extended into the air cells of temporal bone at the exiting site of the facial nerve through stylomastoid foramen. Based on the CT findings and her facial nerve palsy, initial diagnosis was facial nerve schwannoma. Mass was removed via transmastoid approach. The pathology was pleomorphic adenoma and direct nerve invasion was not observed.

Hearing Rehabilitation with Bone Anchored Hearing Aid: Experience in 14 Patients / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Bone anchored hearing aid (BAHA) is an alternative method applicable to patients with chronic draining ear, congenital aural atresia and single sided deafness, who cannot benefit from conventional air conduction hearing aids. The objective of this study was to evaluate the experience of 14 patients who underwent BAHA surgery. SUBJECTS AND METHOD: We retrospectively reviewed the medical records of 14 patients who underwent BAHA surgery. Preoperative pure tone air and bone conduction thresholds and air-bone gap, postoperative BAHA-aided thresholds were measured. Hearing improvement as a result of implantation and complications related to implant were evaluated. RESULTS: The most common indication for BAHA was congenital aural atresia (8 patients) and the rest consisted of chronic otitis media (3 patients) and unilateral sensorineural hearing loss (3 patients). The average threshold improvement with BAHA was 40 dB and 34 dB in patients with congenital aural atresia and chronic otitis media, respectively. Patients with unilateral hearing loss had a postoperative aided threshold of 25 dB. Complications were limited to the periabutment skin problem in two patients. One patient received revision surgery replacing the diseased skin with split-thickness skin graft from a thigh and the other patient received surgery to remove the abutment and the wound was closed with rotation flap, leaving the fixture underneath the skin. CONCLUSION: BAHA could be one of the safe and reliable treatment options available for auditory rehabilitation. Systematic evaluation for candidate selection might be needed to increase hearing gain and decrease co-morbidity.

Usefulness of Intraoperative Computed Tomography in Facial Bone Fracture Repair and Sinus Surgery / 대한이비인후과학회지

BACKGROUND AND OBJECTIVE: The usefulness of intraoperative CT (iCT) in rhinologic surgery including reduction of facial bone fracture and sinus surgery was evaluated. SUBJECTS AND METHOD: Medical records and radiological findings of 17 patients who took iCT at the Medical Center between December 2008 and February 2010 were reviewed retrospectively. The mean follow-up period was 2.2 months. The 17 patients included 14 facial bone fractures and three sinus surgeries. Indications for iCT and the need for additional procedure after iCT were investigated. All operations were performed by the senior author. RESULTS: Indications for iCT were comminuted nasal bone fracture with or without septal fracture, displaced zygoma fracture and orbital blowout fracture. The complex frontal sinus anatomy either by anatomic variation or tumor invasion was an indication for iCT in sinus surgery cases. Additional surgeries were necessary after iCT for five patients (29.4%) as follows: nasal bone reduction (2), zygomatic bone reduction (1), and the removal of meningioma (1) and inverted papilloma (1). Except for one patient, all patients showed satisfactory surgical outcomes in terms of completeness of fracture reduction or surgical removal of sinus pathology. CONCLUSION: In complex facial bone fracture or sinus diseases, an iCT helps to evaluate the completeness of fracture reduction or sinus dissection during the surgery and to decide the necessity for further surgery.

Recurrent Vertigo after Cochlear Implantation / 대한평형의학회지

Post-operative dizziness and vertigo have been variously reported from 30 to 60% after cochlear implantation. There have been reported that delayed vertigo is the most common type and characterized by similarities with dizziness in Meniere's syndrome. Authors experienced a man who had delayed onset of vertigo, which developed six months after cochlear implantation on the left side. Postoperative left caloric response was decreased in both warm and cold stimulation. The direction of spontaneous nystagmus during spell was right side with torsional down beat and definite catch up saccades were observed during head thrust test on the plane of the left horizontal canal and posterior canal, which was resolved on the next day. These episodic and recurrent spells of vertigo might suggest that the hydropic changes of labyrinth corresponding to the pathology of Meniere's disease occurred in this patient.

Effect of SOD Pretreatment on Ultrastructural Changes in Rectus Femoris Muscle of Rats After Irradiation / 대한해부학회지

Irradiation which acts directly and produces the reactive oxygen radicals by ionizing water molecules, causes significant morbidity and mortality. The muscle is damaged by direct action, oxygen radicals and the alterations of microcirculation and metabolism after irradiation. The changes of SOD immunoreactivities in muscles of the rats after irradiation were observed. The ultrastructural changes of the irradiated muscles with the pretreatment of SOD (superoxide dismutase) or without were also investigated. A total of 60 healthy Sprague-Dawley male rats weighing from 200g to 250g were used as experimental animals. Under urethane (1.15g/kg. IP.2 times) anesthesia,30 Gy irradiation to lower extremities by PICKER-C9 Cobalt-60 teletherapy unit was done. 15,000 unit/kg of SOD was administered intraperitoneally 1 hour before irradiation. The experimental animals were sacrificed 1 day, 3 days, 7 days, 2 weeks and 4 weeks after irradiation. The superficial portions of the mid-belly of the rectus femoris muscles were obtained and sliced into portions, 2 mm in length, 1 mm in width and in thickness. The specimens were prepared by routine methods for the electron microscopic observation. All preparations were stained with uranyl acetate and lead citrate and observed with a Hitachi-600 electron microscope. The other parts of mid-belly of the rictus femoris muscles were sectioned in 14 micrometer thickness with cryostat at -20 degrees C. The immunoreactivities of SOD by use of antihuman Cu, Zn-and Mn-SOD antibodies were observed. The results were obtained as follows . 1. After irradiation, the immunoreactivities of SOD in the rictus femoris muscle were decreased. 2 weeks after irradiation, the immunoreactivities of Cu, Zn-SOD were trace, which was lowest.4 weeks after irradiation, the immunoreactivities were trace or weak. 1 day after irradiation, the immunoreactivities of Mn-SOD were trace, which was lowest. The immunoreactivities of Mn-SOD were increased gradually 4 weeks after irradiation, the immunoreactivities of Mn- SOD were moderate or weak. 2. The ultrastructural changes in the rectus femoris muscles of the rats were getting severer and severer after irradiation. 2 weeks after irradiation, unclear A band and I band, myofibrillolysis, increased and dilated cistemae of sarcoplasmic reticulum and mitochondria with dilated cristae and electron lucent matrix were seen. 4 weeks after irradiation, lysis of sarcomere and increased cisternae of sarcoplasmic reticulum were seen. 3. The ultrastructural changes in the rectus femoris muscles of the rats were getting worse and worse after 3 days of irradiation with the pretreatment of SOD. 2 weeks after irradiation with the pretreatment of SOD, myofibrillolysis, increased and dilated cisternae of sarcoplasmic reticulum and damaged mitochondria were seen. 4 weeks after irradiation with the pretreatment of SOD, the ultrastructures of rectus femoris muscles were recovered to normal. Consequently, after irradiation of 30 Gy, the immunoreactivities of SOD are decreased and SOD attenuates the reversible changes of ultrastructures in muscles.

A Case of Common Bile Duct Cancer with Mucosal and Submucosal Spread to Gallbladder and Common Hepatic Duct / 대한소화기내시경학회지

Cholangiocarcinoma is a form of adenocarcinoma arising from the intrahepatic or extrahepatic biliary epithelium. Apparent predisposing factors include some chronic hepatobiliary parasitic infsttations, congenital anomalies with ectatic ducts, sclerosing cholangitis and chronic ulcerative colitis and occupational exposure to possible biliary tract carcinogens. Patients with cholangiocarcinoma usually present with biliary obstruction, painless jaundice, pruritus, weight loss and acholic stools. Because the obstructing process is gradua1, the cholangiocarcinoma is often far advanced by the time it presents clinically. The diagnosis is most frequently made by cholangiography following ultrasound demonstration of dilated intrahepatic bile ducts. We report a case of common bile duct cancer spreading to gallbladder and common hepatic duct along the biliary mucosal epitherium and submucosal tissue in 68-year-old female patient along with a review of literature.