1.Novel Variant of FDXR as a Molecular Etiology of Postlingual Post-synaptic Auditory Neuropathy Spectrum Disorder via Mitochondrial Dysfunction: Reiteration of the Correlation between Genotype and Cochlear Implantation Outcomes
Bong Jik KIM ; Yujin KIM ; Ju Ang KIM ; Jin Hee HAN ; Min Young KIM ; Hee Kyung YANG ; Chae-Seo RHEE ; Young Cheol KANG ; Chun-Hyung KIM ; Byung Yoon CHOI
Clinical and Experimental Otorhinolaryngology 2024;17(3):206-216
Objectives:
. FDXR encodes mitochondrial ferredoxin reductase, which is associated with auditory neuropathy spectrum disorder (ANSD) and optic atrophy. To date, only two studies have described FDXR-related hearing loss. The auditory rehabilitation outcomes of this disease entity have not been investigated, and the pathophysiological mechanisms remain incompletely understood. Here we report a hearing-impaired individual with co-segregation of the FDXR variant and post-synaptic type ANSD, who underwent cochlear implantation (CI) with favorable outcomes. We suggest a possible pathophysiological mechanism of adult-onset ANSD involving mitochondrial dysfunction.
Methods:
. A 35-year-old woman was ascertained to have ANSD. Exome sequencing identified the genetic cause of hearing loss, and a functional study measuring mitochondrial activity was performed to provide molecular evidence of pathophysiology. Expression of FDXR in the mouse cochlea was evaluated by immunohistochemistry. Intraoperatively, electrically evoked compound action potential (ECAP) responses were measured, and the mapping parameters were adjusted accordingly. Audiological outcomes were monitored for over 1 year.
Results:
. In lymphoblastoid cell lines (LCLs) carrying a novel FDXR variant, decreased ATP levels, reduced mitochondrial membrane potential, and increased reactive oxygen species levels were observed compared to control LCLs. These dysfunctions were restored by administering mitochondria isolated from umbilical cord mesenchymal stem cells, confirming the pathogenic potential of this variant via mitochondrial dysfunction. Partial ECAP responses during CI and FDXR expression in the mouse cochlea indicate that FDXR-related ANSD is post-synaptic. As a result of increasing the pulse width during mapping, the patient’s CI outcomes showed significant improvement over 1-year post-CI.
Conclusion
. A novel FDXR variant associated with mitochondrial dysfunction and post-synaptic ANSD was first identified in a Korean individual. Additionally, 1-year post-CI outcomes were reported for the first time in the literature. Excellent audiologic results were obtained, and our results reiterate the correlation between genotype and CI outcomes in ANSD.
2.Early Postoperative Benefits in Receptive and Expressive Language Development After Cochlear Implantation Under 9 Months of Age in Comparison to Implantation at Later Ages
Seung Jae LEE ; Heonjeong OH ; Kyu Ha SHIN ; Sung-Min PARK ; Yun Kyeong KIM ; Do Hyun JUNG ; Jiyeon YANG ; Yejun CHUN ; Min Young KIM ; Jin Hee HAN ; Ju Ang KIM ; Ngoc-Trinh TRAN ; Bong Jik KIM ; Byung Yoon CHOI
Clinical and Experimental Otorhinolaryngology 2024;17(1):46-55
Objectives:
. The recent expansion of eligibility for cochlear implantation (CI) by the U.S. Food and Drug Administration (FDA) to include infants as young as 9 months has reignited debates concerning the clinically appropriate cut-off age for pediatric CI. Our study compared the early postoperative trajectories of receptive and expressive language development in children who received CI before 9 months of age with those who received it between 9 and 12 months. This study involved a unique pediatric cohort with documented etiology, where the timing of CI was based on objective criteria and efforts were made to minimize the influence of parental socioeconomic status.
Methods:
. A retrospective review of 98 pediatric implantees recruited at a tertiary referral center was conducted. The timing of CI was based on auditory and language criteria focused on the extent of delay corresponding to the bottom 1st percentile of language development among age-matched controls, with patients categorized into very early (CI at <9 months), early (CI at 9–12 months) and delayed (CI at 12–18 months) CI groups. Postoperative receptive/expressive language development was assessed using the Sequenced Language Scale for Infants receptive and expressive standardized scores and percentiles.
Results:
. Only the very early CI group showed significant improvements in receptive language starting at 3 months post-CI, aligning with normal-hearing peers by 9 months and maintaining this level until age 2 years. During this period (<2 years), all improvements were more pronounced in receptive language than in expressive language.
Conclusion
. CI before 9 months of age significantly improved receptive language development compared to later CI, with improvements sustained at least up to the age of 2. This study supports the consideration of earlier CI, beyond pediatric Food and Drug Administration labeling criteria (>9 months), in children with profound deafness who have a clear deafness etiology and language development delays (<1st percentile).
3.Anti-N-methyl-D-aspartate Receptor Encephalitis after Herpes Simplex Virus Infection
In Woo PARK ; Yong Bum KIM ; Pil Wook CHUNG ; Heui Soo MOON ; Bum Chun SUH ; Won Tae YOON ; Dong Wook NAMGUNG ; Hong Jik KIM ; Young Kyun KIM ; Su Hyun PARK
Journal of the Korean Neurological Association 2018;36(2):93-96
Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis has clinical features of psychiatric symptoms, loss of memory, seizure, dyskinesia and autonomic dysfunction. While Anti-NMDA receptor encephalitis was initially reported in young women with ovarian teratoma, viral infections can trigger anti-NMDA receptor encephalitis as well. Among them, herpes virus is the most common. We report a patient who developed the anti-NMDA receptor encephalitis 47 days after herpes virus encephalitis, which is, to our knowledge, the first case in Korea.
Anti-N-Methyl-D-Aspartate Receptor Encephalitis
;
Dyskinesias
;
Encephalitis
;
Encephalitis, Herpes Simplex
;
Female
;
Herpes Simplex
;
Humans
;
Korea
;
Memory
;
Seizures
;
Simplexvirus
;
Teratoma
4.Spontaneous Thrombosis of Posterior Inferior Cerebellar Artery Aneurysm Presenting as Cerebellar Infarction.
Hong Jik KIM ; Pil Wook CHUNG ; Yong Bum KIM ; Heui Soo MOON ; Bum Chun SUH ; Won Tae YOON ; Dong Wook NAMGUNG ; In Woo PARK
Journal of the Korean Neurological Association 2017;35(2):92-94
Ischemic stroke caused by spontaneous thrombosis of posterior inferior cerebellar artery (PICA) aneurysm has been rarely reported. A 52-year-old man presented with sudden headache, dizziness, and gait disturbance. Diffusion-weighted MRI showed acute infarction in left PICA territory. A saccular aneurysm with internal thrombus at the distal PICA was detected by CT angiography and conventional angiography. The thrombus resolved spontaneously at 2 months after stroke onset with aspirin medication. At that time, endovascular coiling was underwent successfully to prevent aneurysmal rupture.
Aneurysm*
;
Angiography
;
Arteries*
;
Aspirin
;
Cerebral Infarction
;
Dizziness
;
Gait
;
Headache
;
Humans
;
Infarction*
;
Magnetic Resonance Imaging
;
Middle Aged
;
Pica
;
Rupture
;
Stroke
;
Thrombosis*
5.Severe Right Internal Carotid Artery Stenosis Mimicking Behavioral Variant Frontotemporal Dementia.
Dong Wook NAMGUNG ; Yong Bum KIM ; Pil Wook CHUNG ; Heui Soo MOON ; Bum Chun SUH ; Won Tae YOON ; Woo Hyun SON ; Hong Jik KIM ; In Woo PARK
Journal of the Korean Neurological Association 2017;35(3):133-137
Many kinds of degenerative, psychiatric, and cerebrovascular diseases can mimic behavioral variant frontotemporal dementia. We present a 73-year-old woman who presented with apathy, inappropriate social behavior, and persecutory delusion. A neuropsychological examination revealed frontal/executive dysfunction with relative sparing of episodic memory. Magnetic resonance imaging and F-18 fluorodeoxyglucose positron-emission tomography produced normal findings. However, magnetic resonance angiography revealed severe right internal carotid stenosis. After carotid stenting, her behavioral symptoms disappeared and did not recur during an 18-month follow-up.
Aged
;
Apathy
;
Behavioral Symptoms
;
Carotid Artery, Internal*
;
Carotid Stenosis*
;
Cerebrovascular Disorders
;
Delusions
;
Female
;
Follow-Up Studies
;
Frontotemporal Dementia*
;
Humans
;
Magnetic Resonance Angiography
;
Magnetic Resonance Imaging
;
Memory, Episodic
;
Positron-Emission Tomography
;
Social Behavior
;
Stents
6.Relationship Between Left Atrial Size and Stroke in Patients With Sinus Rhythm and Preserved Systolic Function.
Bong Soo KIM ; Hyun Jik LEE ; Jae Hoon KIM ; Hee Sang JANG ; Byung Seok BAE ; Hyun Jae KANG ; Bong Ryeol LEE ; Byung Chun JUNG
The Korean Journal of Internal Medicine 2009;24(1):24-32
BACKGROUND/AIMS: Increased left atrial (LA) size has been proposed as a predictor of poor cardiovascular outcome in the elderly. In the present study, we evaluated the relationship between LA size and stroke in subjects of all ages who presented with preserved left ventricular systolic function (LVSF) and sinus rhythm (SR), and investigated the relationships between LA size and other echocardiographic parameters of diastolic function. METHODS: A total of 472 subjects were enrolled in the study (161 men, 311 women) and divided into the stroke group (n=75) and control group (n=397). A conventional echocardiographic study was then performed. Subjects with valvular heart disease, atrial fibrillation, or coronary heart disease were excluded. RESULTS: The mean subject age was 65.2+/-5.1 years in the stroke group and 65.6+/-5.9 years in the control group. Mitral inflow pattern and E & A velocity showed no significant relationship with stroke (p=NS, p=NS, respectively). Left ventricular mass index and LA dimension were significantly related to stroke (p=0.003, p=0.023, respectively), and hypertension showed a marginal relationship with stroke (p=0.050). Age was not related to stroke in the present study (p=NS). CONCLUSIONS: The LA dimension is significantly related to the incidence of stroke. Therefore, strategies for prevention of stroke in patients with preserved LVSF and SR should be considered in cases of LA enlargement.
Adult
;
Aged
;
Echocardiography, Doppler, Pulsed
;
Female
;
Heart Atria/*ultrasonography
;
Heart Rate/*physiology
;
Heart Ventricles/physiopathology/ultrasonography
;
Humans
;
Incidence
;
Korea/epidemiology
;
Male
;
Middle Aged
;
Myocardial Contraction/*physiology
;
Retrospective Studies
;
Risk Factors
;
Stroke/*epidemiology/etiology
;
Stroke Volume/*physiology
;
Systole
;
Ventricular Function, Left/*physiology
7.Long-term follow-up results and clinical manifestations of patients with a moderate to large amount of pericardial effusion.
Dae Young KIM ; Jin Hong PARK ; Jae Dae SHIN ; Bong Soo KIM ; Hyun Jik LEE ; Jae Hoon KIM ; Hee Sang JANG ; Hyun Jae KANG ; Bong Ryeol LEE ; Byung Chun JUNG
Korean Journal of Medicine 2008;74(2):154-161
BACKGROUND/AIMS: Pericardial effusion (PE), which is more than a moderate amount, is usually accompanied with various underlying illnesses. However, there have been few reports on the long-term follow-up results of these cases, and even in the studies where the etiologies were well presented. METHODS: 64 consecutive patients (mean age: 66.3 years, 23 males) with more than a moderate amount of PE, as confirmed by echocardiography, were analyzed for pericardial fluid and this was diagnosed according to ESC Executive Summary. The mean follow-up duration was 1.95+/-1.78 years and the final survival was assessed in November, 2006. RESULTS: The etiologies were composed of malignancy-related PE (MRPE: 29.7%), tuberculosis pericarditis (40.6%), idiopathic pericarditis (18.8%), hypothyroidism (7.8%), and miscellaneous (3.1%). Mortality occurred in 21 cases (32.8%), of which 15 cases were attributed to MRPE. In all patients, the mean survival duration was 372+/-247.9 days after diagnosis, and the mean survival duration was 253+/-221.5 days after pericardiocentesis. Cardiac tamponade, constrictive pericarditis and recurrent pericarditis were presented in 15 cases (23.4%), 9 cases (14.1%) and 2 cases (3.1%) respectively. The chemistry findings of PE were of no use to differentiate the etiologies. CONCLUSION: Pericardial effusion of more than a moderate amount often manifested urgent symptoms such as cardiac tamponade and intractable dyspnea, and these conditions require therapeutic pericardiocentesis more frequently than diagnostic tests. The prognosis is usually subordinate to the progression of the underlying illness, and especially in case of MRPE. The occurrence of constrictive pericarditis should be monitored carefully.
Cardiac Tamponade
;
Diagnostic Tests, Routine
;
Dyspnea
;
Echocardiography
;
Follow-Up Studies
;
Humans
;
Hypothyroidism
;
Pericardial Effusion
;
Pericardiocentesis
;
Pericarditis
;
Pericarditis, Constrictive
;
Prognosis
;
Tuberculosis
8.Age-Related Changes in Left Ventricular Torsion as Assessed by 2-Dimensional Ultrasound Speckle Tracking Imaging.
Hyun Jik LEE ; Bong Soo KIM ; Jae Hoon KIM ; Hee Sang JANG ; Byung Seok BAE ; Hyun Jae KANG ; Bong Ryeol LEE ; Byung Chun JUNG
Korean Circulation Journal 2008;38(10):529-535
BACKGROUND AND OBJECTIVES: The newly developed 2-dimensional ultrasound speckle tracking imaging (2D-STI) has enabled researchers to assess the changes of left ventricular (LV) rotation and torsion. The aims of the present study are to establish normal values and to examine the effect of advancing age on left ventricular torsion. SUBJECTS AND METHODS: We enrolled 182 healthy persons in this study. After examined the standard clinical echocardiographic parameters, we obtained the degree of the LV rotation at the basal and apical levels of the short axis view with using a customized software program EchoPAC, GE. RESULTS: Among the 182 healthy subjects, 109 healthy subjects were finally included (49 males and 60 females) due to the failure of obtaining reliable rotational patterns (feasibility: 59.8%). The basal and apical peak LV rotations during systole were 8.14+/-3.55 degrees and 8.48+/-3.70 degrees, respectively. The basal peak LV rotation and peak LV torsion had a tendency to increase with aging (r=0.277, p=0.004 and r=0.253, p=0.008, respectively). All the values of the basal LV rotation during systole tended to increase with aging. The apical LV rotation had no relationship with aging throughout the entire cardiac cycle. CONCLUSION: 2D-STI was a feasible methodology to measure the LV rotation. The peak LV torsion during systole shows statistically significant augmentation with advancing age, and this is mainly due to the increased basal LV rotation.
Age Factors
;
Aging
;
Axis, Cervical Vertebra
;
Echocardiography, Doppler
;
Heart Ventricles
;
Humans
;
Male
;
Reference Values
;
Systole
;
Track and Field
9.Methylprednisolone Pulse Therapy in Adult-Onset Minimal Change Nephrotic Syndrome.
Sook Eui OH ; Young Ki LEE ; Jin Kyung KIM ; Sung Tae CHO ; Rho Won CHUN ; Jong Woo YOON ; Ja Ryong KOO ; Hyung Jik KIM ; Jung Woo NOH ; Eun Suk NAM
Korean Journal of Nephrology 2007;26(6):677-683
PURPOSE: The incidence of complete remission is lower and the relapse is more frequent in adult-onset minimal change nephrotic syndrome (MCNS) are observed especially when compared with those in children. This study was designed to examine the effect of methylprednisolone pulse therapy in adultonset MCNS comparing to oral steroid as an initial therapeutic modality. METHODS: We have retrospectively reviewed the clinical data of 25 adult-onset MCNS patients. Twelve patients were treated with three intravenous pulses of methylprednisolone (1 g daily) followed by oral prednisolone 1 mg/kg daily for 4-8 weeks and also by low doses of oral prednisolone for 4-6 months (MP group) Thirteen patients were initially treated with oral prednisolone 1 mg/kg daily for 4-8 weeks and then with low doses of oral prednisolone (PD group). RESULTS: The response to therapy was similar between MP and PD group, with a complete remission obtained in 83.3% and 84.6%, respectively. No statistically significant difference between the two groups was observed in the rate of response at 8 weeks (58.3% versus 69.2%). The mean time to response was not different between MP group (37.9+/-28.0 days) and PD group (45.5+/-40.2 days). No difference was recognized between the two groups with respect to relapse rate. CONCLUSION: These data suggest that a short course of methylprednisolone pulse therapy followed by oral prednisolone is not superior to oral prednisolone therapy as an initial therapeutic modality in adult-onset MCNS.
Child
;
Humans
;
Incidence
;
Methylprednisolone*
;
Nephrosis, Lipoid*
;
Prednisolone
;
Recurrence
;
Retrospective Studies
10.Characteristics of QT Interval and QT Dispersion in Exercise Electrocardiogram: Healthy Persons versus Stable Angina Patients.
Jin Hong PARK ; Dae Young KIM ; Bong Soo KIM ; Hyun Jik LEE ; Jae Hoon KIM ; Hee Sang JANG ; Seung Min SHIN ; Hyun Jae KANG ; Bong Ryeol LEE ; Byung Chun JUNG
Korean Circulation Journal 2007;37(11):543-549
BACKGROUND AND OBJECTIVES: The QT interval (QTi) and QT dispersion (QTd), which represent the myocardial electrical heterogeneity of repolarization, were studied to recognize the differences between normal controls (n=32) and stable angina patients (n=78). SUBJECTS AND METHODS: During the treadmill exercise test, standard 12 lead Electrocardiogram (ECG) was obtained at every stage, with the QTi and QTd measured. The corrected QT interval (cQTi) and QT dispersion (cQTd) were calculated using Bazett's formula, with the Delta QT interval (DeltaQTi) measured on leads V5 and aVF. RESULTS: During exercise, the QTi had a reverse relationship with the heart rate in both groups, but was decreased by a lesser extent in the patient group. The QTd also had a tendency to decrease according to increasing heart rate in both groups and was significantly greater in the patient group. The corrected QTi increased during exercise in both groups, and reached maximum during the pre-peak stage, but was minimized during a 1 minute recovery stage in the patient group. The corrected QTd reached a maximum during the peak exercise stage in both groups, but the values between the two groups were significantly different. Both the QTi and cQTi had tendencies to increase according to the number of vessels with stenosis. The DeltaQTi tended to reflect a regional ischemia in a single vessel disease. CONCLUSION: The QTi, QTd, cQTi and cQTd were increased in the stable angina patients compared with the normal controls, and augmented during the exercise test.
Angina, Stable*
;
Constriction, Pathologic
;
Electrocardiography*
;
Exercise Test
;
Heart Rate
;
Humans
;
Ischemia
;
Population Characteristics

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