Search tips
Search criteria

Results 1-25 (26)

Clipboard (0)

Select a Filter Below

Year of Publication
1.  Cervical Spinal Epidural Hematoma Following Cervical Posterior Laminoforaminotomy 
A 65-year-old man who had lateral cervical disc herniation underwent cervical posterior laminoforaminotomy at C5-6 and C6-7 level right side. During the operation, there was no serious surgical bleeding event. After operation, he complained persistent right shoulder pain and neck pain. Repeated magnetic resonance image (MRI) showed diffuse cervical epidural hematoma (EDH) extending from C5 to T1 level right side and spinal cord compression at C5-6-7 level. He underwent exploration. There was active bleeding at muscular layer. Muscular active bleeding was controlled and intramuscular hematoma was removed. The patient's symptom was reduced after second operation. Symptomatic postoperative spinal EDH requiring reoperation is rare. Meticulous bleeding control is important before wound closure. In addition, if patient presents persistent or aggravated pain after operation, rapid evaluation using MRI and second look operation is needed as soon as possible.
PMCID: PMC3611058  PMID: 23560180
Cervical epidural hematoma; Posterior laminoforaminotomy; Cervical disc herniation; Postoperative bleeding; Reoperation
2.  Transdural Nerve Rootlet Entrapment in the Intervertebral Disc Space through Minimal Dural Tear : Report of 4 Cases 
Four patients underwent lumbar surgery. In all four patients, the dura was minimally torn during the operation. However, none exhibited signs of postoperative cerebrospinal fluid leakage. In each case, a few days after the operation, the patient suddenly experienced severe recurring pain in the leg. Repeat magnetic resonance imaging showed transdural nerve rootlets entrapped in the intervertebral disc space. On exploration, ventral dural tears and transdural nerve rootlet entrapment were confirmed. Midline durotomy, herniated rootlet repositioning, and ventral dural tear repair were performed, and patients' symptoms improved after rootlet repositioning. Even with minimal dural tearing, nerve rootlets may become entrapped, resulting in severe recurring symptoms. Therefore, the dural tear must be identified and repaired during the first operation.
PMCID: PMC3579084  PMID: 23441074
Nerve rootlet entrapment; Lumbar disc herniation; Laminectomy; Discectomy; Dura tear; Dura repair
3.  Clinical and Radiological Comparison of Femur and Fibular Allografts for the Treatment of Cervical Degenerative Disc Diseases 
This consecutive retrospective study was designed to analyze and to compare the efficacy and outcomes of anterior cervical discectomy and fusion (ACDF) using a fibular and femur allograft with anterior cervical plating.
A total of 88 consecutive patients suffering from cervical degenerative disc disease (DDD) who were treated with ACDF from September 2007 to August 2010 were enrolled in this study. Thirty-seven patients (58 segments) underwent anterior interbody fusion with a femur allograft, and 51 patients (64 segments) were treated with a fibular allograft. The mean follow-up period was 16.0 (range, 12-25) months in the femur group and 19.5 (range, 14-39) months in the fibular group. Cage fracture and breakage, subsidence rate, fusion rate, segmental angle and height and disc height were assessed by using radiography. Clinical outcomes were assessed using a visual analog scale and neck disability index.
At 12 months postoperatively, cage fracture and breakage had occurred in 3.4% (2/58) and 7.4% (4/58) of the patients in the femur group, respectively, and 21.9% (14/64) and 31.3% (20/64) of the patients in the fibular group, respectively (p<0.05). Subsidence was noted in 43.1% (25/58) of the femur group and in 50.5% (32/64) of the fibular group. No difference in improvements in the clinical outcome between the two groups was observed.
The femur allograft showed good results in subsidence and radiologic parameters, and sustained the original cage shape more effectively than the fibular allograft. The present study suggests that the femur allograft may be a good choice as a fusion substitute for the treatment of cervical DDD.
PMCID: PMC3579087  PMID: 23439721
Anterior cervical discectomy and fusion; Femur allograft; Fibular allograft; Radiological parameter
4.  Genome-wide profiles of H2AX and γ-H2AX differentiate endogenous and exogenous DNA damage hotspots in human cells 
Nucleic Acids Research  2012;40(13):5965-5974.
Phosphorylation of the histone variant H2AX forms γ-H2AX that marks DNA double-strand break (DSB). Here, we generated the sequencing-based maps of H2AX and γ-H2AX positioning in resting and proliferating cells before and after ionizing irradiation. Genome-wide locations of possible endogenous and exogenous DSBs were identified based on γ-H2AX distribution in dividing cancer cells without irradiation and that in resting cells upon irradiation, respectively. γ-H2AX-enriched regions of endogenous origin in replicating cells included sub-telomeres and active transcription start sites, apparently reflecting replication- and transcription-mediated stress during rapid cell division. Surprisingly, H2AX itself, prior to phosphorylation, was specifically located at these endogenous hotspots. This phenomenon was only observed in dividing cancer cells but not in resting cells. Endogenous H2AX was concentrated on the transcription start site of actively transcribed genes but was irrelevant to pausing of RNA polymerase II (pol II), which precisely coincided with γ-H2AX of endogenous origin. γ-H2AX enrichment upon irradiation also coincided with actively transcribed regions, but unlike endogenous γ-H2AX, it extended into the gene body and was not specifically concentrated on the pausing site of pol II. Sub-telomeres were less responsive to external DNA damage than to endogenous stress. Our findings provide insight into DNA repair programs of cancer and may have implications for cancer therapy.
PMCID: PMC3401470  PMID: 22467212
5.  Dorsal Extradural Lumbar Disc Herniation Causing Cauda Equina Syndrome : A Case Report and Review of Literature 
A 73-year-old male presented with a rare dorsally sequestrated lumbar disc herniation manifesting as severe radiating pain in both leg, progressively worsening weakness in both lower extremities, and urinary incontinence, suggesting cauda equina syndrome. Magnetic resonance imaging suggested the sequestrated disc fragment located in the extradural space at the L4-L5 level had surrounded and compressed the dural sac from the lateral to dorsal sides. A bilateral decompressive laminectomy was performed under an operating microscope. A large extruded disc was found to have migrated from the ventral aspect, around the thecal sac, and into the dorsal aspect, which compressed the sac to the right. After removal of the disc fragment, his sciatica was relieved and the patient felt strength of lower extremity improved.
PMCID: PMC2851086  PMID: 20379476
Lumbar disc herniation; Dorsal; Intradural; Migrated
6.  Dynamic Lumbar Spinal Stenosis : The Usefulness of Axial Loaded MRI in Preoperative Evaluation 
Two cases of dynamic lumbar spinal stenosis were identified by the authors using axial loaded magnetic resonance image (MRI). In both cases, the patients presented with neurogenic claudication but MRI in decumbency showed no definite pathologic condition associated with their symptoms. In contrast, axial loaded MRI demonstrated constrictive spinal stenosis and a significantly decreased dural sac caused by epidural fat buckling and thickening of the ligamentum flavum in both cases. In the second case, a more prominent disc protrusion was also demonstrated compared with decumbent MRI. After decompressive surgery, both patients had satisfactory outcomes. Axial loaded MRI can therefore give decisive information in dynamic spinal disorders by allowing simulation of an upright position.
PMCID: PMC2764028  PMID: 19844630
Axial loaded MRI; Dynamic lumbar spinal stenosis; Neurogenic claudication
7.  Spontaneous Spinal Subarachnoid Hemorrhage with Spontaneous Resolution 
Spontaneous spinal subarachnoid hematoma (SSH) is a rare entity to cause spinal cord or nerve root compression and is usually managed as surgical emergencies. We report a case of spontaneous SSH manifesting as severe lumbago, which demonstrated nearly complete clinical resolution with conservative treatment. A 58-year-old female patient developed a large SSH, which was not related to blood dyscrasia, anticoagulation, lumbar puncture, or trauma. Patient had severe lumbago but no neurologic deficits. Because of absence of neurologicl deficits, she was treated conservatively. Follow-up magnetic resonance (MR) image showed complete resolution. Conservative treatment of SSH may be considered if the patient with spontaneous SSH has no neurologic deficits.
PMCID: PMC2682125  PMID: 19444355
Spinal subarachnoid hematoma; Spinal cord; Spontaneous
8.  Comparison between Instrumented Mini-TLIF and Instrumented Circumferential Fusion in Adult Low-Grade Lytic Spondylolisthesis : Can Mini-TLIF with PPF Replace Circumferential Fusion? 
To evaluate clinical and radiological results of two different fusion techniques in adult low-grade isthmic spondylolisthesis.
Between November 2003 and December 2004, 46 consecutive patients underwent instrumented mini-transforaminal lumbar interbody fusion (mini-TLIF) (group I) at Wooridul Spine Hospital, Seoul, Korea. Between February 2003 and October 2006, 32 consecutive patients underwent instrumented circumferential fusion (group II) at Leon Wiltse Memorial Hospital, Suwon, Korea. The mean follow-up periods were 29.7 and 26.1 months, respectively.
Mean visual analog scale (VAS) scores for back and leg pain decreased, respectively, from 6.98 and 6.33 to 2.3 and 2.2 in group I and from 7.38 and 6.00 to 1.7 and 1.0 in group II. Mean Oswestry disability index (ODI) improved from 51.85% to 14.4% in group I and from 60% to 9.1% in group II. In both groups, VAS and ODI scores significantly changed from pre- to postoperatively (p<0.001), but postoperative outcome between groups was statistically not significant. Radiologic evidence of fusion was noted in 95.7% and 100% of the patients in group I and II, respectively. In both groups, changes in disc height, segmental lordosis, degree of listhesis, and whole lumbar lordosis between the pre- and postoperative periods were significant except whole lumbar lordosis in both groups.
Clinical and functional outcomes demonstrate no significant differences between groups in treating back and leg pain of adult patients with low-grade isthmic spondylolisthesis. However, in terms of operative data (i.e. operation time and hospital stay), instrumented mini-TLIF demonstrated better results.
PMCID: PMC2651550  PMID: 19274115
Low-grade isthmic spondylolisthesis; Instrumented transforaminal lumbar interbody fusion; Instrumented circumferential
9.  Minimally invasive posterior cervical decompression using tubular retractor: The technical note and early clinical outcome 
The aim of this work is to present a novel decompression technique that approaches cervical spine posteriorly, but through minimal invasive method using tubular retractor avoiding detachment of posterior musculature.
Six patients underwent minimally invasive posterior cervical decompression using the tubular retractor system and surgical microscope. Minimally invasive access to the posterior cervical spine was performed with exposure through a paramedian muscle-splitting approach. With the assistance of a specialized tubular retraction system and deep soft tissue expansion mechanism, multilevel posterior cervical decompression could be accomplished. This approach also allows safe docking of the retractor system on the lateral mass, thus avoiding the cervical spinal canal during exposure. A standard operating microscope was used with ×10 magnification and 400 mm focal length. The hospital charts, magnetic resonance imaging studies, and follow-up records of all the patients were reviewed. Outcome was assessed by neurological status and visual analog scale (VAS) for neck and arm pain.
There was no significant complication related to operation. The follow-up time was 4-12 months (mean, 9 months). Muscle weakness improved in all patients; sensory deficits resolved in four patients and improved in two patients. Analysis of the mean VAS for radicular pain and VAS for neck pain showed significant improvement.
The preliminary experiences with good clinical outcome seem to promise that this minimally invasive technique is a valid alternative option for the treatment of cervical spondylotic myelopathy.
PMCID: PMC3994691  PMID: 24778922
Cervical spondylotic myelopathy; cervical spine; minimal invasive technique; tubular retractor
10.  Neurocognitive Function Differentiation from the Effect of Psychopathologic Symptoms in the Disability Evaluation of Patients with Mild Traumatic Brain Injury 
We determined whether the relationship between the neuropsychological performance of patients with mild traumatic brain injury (TBI) and their psychopathological characteristics measured by disability evaluation are interrelated. In addition, we assessed which psychopathological variable was most influential on neuropsychological performance via statistical clustering of the same characteristics of mild TBI.
A total of 219 disability evaluation participants with mild brain injury were selected. All participants were classified into three groups, based on their psychopathological characteristics, via a two-step cluster analysis using validity and clinical scales from the Minnesota Multiphasic Personality Inventory (MMPI) and Symptom Checklist-90-revised (SCL-90-R). The Korean Wechsler Adult Intelligence Scale (K-WAIS), Korean Memory Assessment Scale (K-MAS) and the Korean Boston Naming Test (K-BNT) were used to evaluate the neurocognitive functions of mild TBI patients.
Over a quarter (26.9%) experienced severe psychopathological symptoms and 43.4% experienced mild or moderate psychopathological symptoms, and all of the mild TBI patients showed a significant relationship between neurocognitive functions and subjective and/or objective psychopathic symptoms, but the degree of this relationship was moderate. Variances of neurocognitive function were explained by neurotic and psychotic symptoms, but the role of these factors were different to each other and participants did not show intelligence and other cognitive domain decrement except for global memory abilities compared to the non-psychopathology group.
Certain patients with mild TBI showed psychopathological symptoms, but these were not directly related to cognitive decrement. Psychopathology and cognitive decrement are discrete aspects in patients with mild TBI. Furthermore, the neurotic symptoms of mild TBI patients made positive complements to decrements or impairments of neurocognitive functions, but the psychotic symptoms had a negative effect on neurocognitive functions.
PMCID: PMC3873351  PMID: 24379945
Disability evaluation; Mild traumatic brain injury; Neuropsychological performance; Post-concussion syndrome
11.  Cystic Giant Sacral Schwannoma Mimicking Aneurysmal Bone Cyst : A Case Report and Review of Literatures 
To present a rare case of a cystic giant schwannoma of the sacrum mimicking aneurysmal bone cyst (ABC). A 54-year-old man visited our institute complaining left leg weakness and sensory change for several years. Magnetic resonance imaging revealed a large multilocular cystic mass with canal invasion and bone erosion confined to left S1 body. The lesion showed multiple septal enhancement without definite solid component. Initially the tumor was considered as ABC. The patient underwent grossly-total tumor resection with lumbosacral reconstruction via posterior approach. The tumor was proved to be a cystic schwannoma. The postoperative course was uneventful and the patient was relieved from preoperative symptoms. We present a rare case of pure cystic giant schwannoma confined to sacrum mimicking ABC. The surgical treatment is challenging due to the complex anatomy of the sacrum. Schwannoma should be considered in the differential diagnosis of osteolytic sacral cysts.
PMCID: PMC3841281  PMID: 24294462
Giant schwannoma; Sacrum; Cystic degeneration; Aneurysmal bone cyst
12.  Synthesis of desformylflustrabromine and its evaluation as an α4β2 and α7 nACh receptor modulator 
Desformylflustrabromine (dFBr; 1) and desformylflustrabromine-B (dFBr-B; 2) have been previously isolated from natural sources, and the former has been demonstrated to be a novel and selective positive allosteric modulator of α4β2 nicotinic acetylcholine (nACh) receptors. The present study describes the synthesis of water-soluble salts of 1 and 2, and confirms and further investigates the actions of 1 and 2 using two-electrode voltage clamp recordings.
PMCID: PMC3633077  PMID: 17604168
Nicotinic cholinergic receptors; Allosteric modulators
13.  Changes of the liver volume and the Child-Pugh score after high dose hypofractionated radiotherapy in patients with small hepatocellular carcinoma 
Radiation Oncology Journal  2012;30(4):189-196.
To investigate the safety of high dose hypofractionated radiotherapy (RT) in patients with small hepatocellular carcinoma (HCC) in terms of liver volumetric changes and clinical liver function.
Materials and Methods
We retrospectively reviewed 16 patients with small HCC who were treated with high dose hypofractionated RT between 2006 and 2009. The serial changes of the liver volumetric parameter were analyzed from pre-RT and follow-up (FU) computed tomography (CT) scans. We estimated linear time trends of whole liver volume using a linear mixed model. The serial changes of the Child-Pugh (CP) scores were also analyzed in relation to the volumetric changes.
Mean pre-RT volume of entire liver was 1,192.2 mL (range, 502.6 to 1,310.2 mL) and mean clinical target volume was 14.7 mL (range, 1.56 to 70.07 mL). Fourteen (87.5%) patients had 4 FU CT sets and 2 (12.5%) patients had 3 FU CT sets. Mean interval between FU CT acquisition was 2.5 months. After considering age, gender and the irradiated liver volume as a fixed effects, the mixed model analysis confirmed that the change in liver volume is not significant throughout the time course of FU periods. Majority of patients had a CP score change less than 2 except in 1 patient who had CP score change more than 3.
The high dose hypofractionated RT for small HCC is relatively safe and feasible in terms of liver volumetric changes and clinical liver function.
PMCID: PMC3546287  PMID: 23346538
Radiotherapy; Hepatocellular carcinoma
14.  Deconstruction of the α4β2 Nicotinic Acetylchloine (nACh) Receptor Positive Allosteric Modulator des-Formylflustrabromine (dFBr) 
Journal of medicinal chemistry  2011;54(20):7259-7267.
des -Formylflustrabromine (dFBr; 1), perhaps the first selective positive allosteric modulator of α4β2 neuronal nicotinic acetylcholine (nACh) receptors, was deconstructed to determine which structural features contribute to its actions on receptors expressed in Xenopus ooycytes using 2-electrode voltage clamp techniques. Although the intact structure of 1 was found optimal, several deconstructed analogs retained activity. Neither the 6-bromo substituent nor the entire 2-position chain is required for activity. In particular, reduction of the olefinic side chain of 1, as seen with 6, not only resulted in retention of activity/potency but in enhanced selectivity for α4β2 versus α7 nACh receptors. Pharmacophoric features for the allosteric modulation of α4β2 nACh receptors by 1 were identified.
PMCID: PMC3200116  PMID: 21905680
15.  Different effects of bladder distention on point A-based and 3D-conformal intracavitary brachytherapy planning for cervical cancer 
Journal of Radiation Research  2012;54(2):349-356.
This study sought to evaluate the differential effects of bladder distention on point A-based (AICBT) and three-dimensional conformal intracavitary brachytherapy (3D-ICBT) planning for cervical cancer. Two sets of CT scans were obtained for ten patients to evaluate the effect of bladder distention. After the first CT scan, with an empty bladder, a second set of CT scans was obtained with the bladder filled. The clinical target volume (CTV), bladder, rectum, and small bowel were delineated on each image set. The AICBT and 3D-ICBT plans were generated, and we compared the different planning techniques with respect to the dose characteristics of CTV and organs at risk. As a result of bladder distention, the mean dose (D50) was decreased significantly and geometrical variations were observed in the bladder and small bowel, with acceptable minor changes in the CTV and rectum. The average D2 cm3and D1 cm3showed a significant change in the bladder and small bowel with AICBT; however, no change was detected with the 3D-ICBT planning. No significant dose change in the CTV or rectum was observed with either the AICBT or the 3D-ICBT plan. The effect of bladder distention on dosimetrical change in 3D-ICBT planning appears to be minimal, in comparison with AICBT planning.
PMCID: PMC3589929  PMID: 23104899
intracavitary brachytherapy; bladder distention; 3D-conformal intracavitary brachytherapy; cervical cancer
16.  Modified transcorporeal anterior cervical microforaminotomy assisted by O-arm-based navigation: a technical case report 
European Spine Journal  2010;20(Suppl 2):147-152.
This study was done to present our surgical experience of modified transcorporeal anterior cervical microforaminotomy (MTACM) assisted by the O-arm-based navigation system for the treatment of cervical disc herniation. We present eight patients with foraminal disc herniations at the C5–C6, C6–C7, and C7–T1 levels. All patients had unilateral radicular arm pain and motor weakness. The inclusion criteria for the patients were the presence of single-level unilateral foraminal cervical disc herniation manifesting persistent radiculopathy despite conservative treatment. Hard disc herniation, down-migrated disc herniation, concomitant moderate to severe bony spur and foraminal stenosis were excluded. We performed MTACM to expose the foraminal area of the cervical disc and removed the herniated disc fragments successfully using O-arm-based navigation. Postoperatively, the patients’ symptoms improved and there was no instability during the follow-up period. MTACM assisted by O-arm-based navigation is an effective, safe, and precise minimally invasive procedure that tends to preserve non-degenerated structures as much as possible while providing a complete removal of ruptured disc fragments in the cervical spine.
PMCID: PMC3111514  PMID: 20490870
Cervical disc herniation; Modified transcorporeal anterior cervical microforaminotomy; Minimally invasive; Navigation; O-arm
17.  Effects of Kimchi Extract and Temperature on Embryostasis of Ascaris suum Eggs 
To determine the effects of kimchi extracts at different temperatures on larval development, Ascaris suum eggs were mixed with soluble part of 7 different brands of commercially available kimchi and preserved at either 5℃ or 25℃ for up to 60 days. A. suum eggs incubated at 25℃ showed marked differences in larval development between kimchi extract and control group. While all eggs in the control group completed embryonation by day 21, only 30% of the eggs in the kimchi extract group became embryonated by day 36 and about 25% never became larvated even at day 60. At 5℃, however, none of the eggs showed larval development regardless of the incubation period or type of mixture group. To determine the survival rate of A. suum eggs that showed no embryonation after being preserved at 5℃, eggs preserved in kimchi extracts for 14, 28, and 60 at 5℃ were re-incubated at 25℃ for 3 weeks in distilled water. While all eggs in the control group became larvated, eggs in the kimchi extract group showed differences in their embryonation rates by the incubation period; 87.4 % and 41.7% of the eggs became embryonated after being refrigerated for 14 days and 28 days, respectively. When refrigerated for 60 days, however, no eggs mixed in kimchi extract showed larval development. Our results indicate that embryogenesis of A. suum eggs in kimchi extract was affected by duration of refrigeration, and that all eggs stopped larval development completely in kimchi kept at 5℃ for up to 60 days.
PMCID: PMC3309058  PMID: 22451740
Ascaris suum; embryonation; kimchi; temperature; embryostasis
18.  Analysis of changes in dose distribution due to respiration during IMRT 
Radiation Oncology Journal  2011;29(3):206-213.
Intensity modulated radiation therapy (IMRT) is a high precision therapy technique that can achieve a conformal dose distribution on a given target. However, organ motion induced by respiration can result in significant dosimetric error. Therefore, this study explores the dosimetric error that result from various patterns of respiration.
Materials and Methods
Experiments were designed to deliver a treatment plan made for a real patient to an in-house developed motion phantom. The motion pattern; the amplitude and period as well as inhale-exhale period, could be controlled by in-house developed software. Dose distribution was measured using EDR2 film and analysis was performed by RIT113 software. Three respiratory patterns were generated for the purpose of this study; first the 'even inhale-exhale pattern', second the slightly long exhale pattern (0.35 seconds longer than inhale period) named 'general signal pattern', and third a 'long exhale pattern' (0.7 seconds longer than inhale period). One dimensional dose profile comparisons and gamma index analysis on 2 dimensions were performed
In one-dimensional dose profile comparisons, 5% in the target and 30% dose difference at the boundary were observed in the long exhale pattern. The center of high dose region in the profile was shifted 1 mm to inhale (caudal) direction for the 'even inhale-exhale pattern', 2 mm and 5 mm shifts to exhale (cranial) direction were observed for 'slightly long exhale pattern' and 'long exhale pattern', respectively. The areas of gamma index >1 were 11.88%, 15.11%, and 24.33% for 'even inhale-exhale pattern', 'general pattern', and 'long exhale pattern', respectively. The long exhale pattern showed largest errors.
To reduce the dosimetric error due to respiratory motions, controlling patient's breathing to be closer to even inhaleexhale period is helpful with minimizing the motion amplitude.
PMCID: PMC3429904  PMID: 22984672
Intensity modulated radiation therapy; Respiratory patterns; Dosimetric error
19.  Impairment of Concept Formation Ability in Children with ADHD: Comparisons between Lower Grades and Higher Grades 
Psychiatry Investigation  2010;7(3):177-188.
We investigated executive functions (EFs), as evaluated by the Wisconsin Card Sorting Test (WCST), and other EF between lower grades (LG) and higher grades (HG) in elementary-school-age attention deficit hyperactivity disorder (ADHD) children.
We classified a sample of 112 ADHD children into 4 groups (composed of 28 each) based on age (LG vs. HG) and WCST performance [lower vs. higher performance on WCST, defined by the number of completed categories (CC)] Participants in each group were matched according to age, gender, ADHD subtype, and intelligence. We used the Wechsler intelligence Scale for Children 3rd edition to test intelligence and the Computerized Neurocognitive Function Test-IV, which included the WCST, to test EF.
Comparisons of EFs scores in LG ADHD children showed statistically significant differences in performing digit spans backward, some verbal learning scores, including all memory scores, and Stroop test scores. However, comparisons of EF scores in HG ADHD children did not show any statistically significant differences. Correlation analyses of the CC and EF variables and stepwise multiple regression analysis in LG ADHD children showed a combination of the backward form of the Digit span test and Visual span test in lower-performance ADHD participants significantly predicted the number of CC (R2=0.273, p<0.001).
This study suggests that the design of any battery of neuropsychological tests for measuring EF in ADHD children should first consider age before interpreting developmental variations and neuropsychological test results. Researchers should consider the dynamics of relationships within EF, as measured by neuropsychological tests.
PMCID: PMC2947805  PMID: 20927306
Attention deficit hyperactivity disorder; Wisconsin Card Sorting Test; Concept formation ability; Age; Developmental variation; Working memory
20.  Polymer Microring Resonators for High-Frequency Ultrasound Detection and Imaging 
Polymer microring resonators fabricated by nanoimprinting are presented as a means of ultrasound detection. Acoustic waves impinging on a ring-shaped optical resonator cause strain in the ring dimensions, modulating optical output. Basic acoustic and optical characteristics of the microring sensor are presented. Measurements at several frequencies show a high sensitivity and low noise-equivalent pressure. The angular response is determined by sensing the optoacoustic excitation of a 49 μm polyester microsphere and shows wide-angle sensitivity. A 1-D array consisting of 4 microrings is demonstrated using wavelength multiplexing for addressing each element. The high sensitivity, bandwidth, and angular response make it a potentially useful sensor platform for many applications including high-frequency ultrasonic and photoacoustic imaging.
PMCID: PMC2917845  PMID: 20700482
Ultrasound detector; Acoustic detectors; acoustic devices; microresonators; optical resonance; optical resonators; optical waveguide components; optical strip waveguides; optical waveguides
21.  Removal of discal cyst using percutaneous working channel endoscope via transforaminal route 
European Spine Journal  2008;18(Suppl 2):201-205.
Discal cyst is a very rare lesion that can cause refractory low back pain and radiating leg pain. Although there are some reports to remove this lesion, there has been no report of discal cyst removed by percutaneous endoscopic transforaminal approach. Two young patients manifested left gluteal and leg pain due to a discal cyst at L5–S1 level and L4–5 level, respectively. Percutaneous endoscopic transforaminal approach was performed to remove the discal cyst, achieving complete decompression of the nerve root. The symptom was relieved and the patient was discharged the next day. Percutaneous endoscopic transforaminal approach could be a good alternative option in selected cases for the treatment of lumbar discal cyst.
PMCID: PMC2899551  PMID: 19034535
Lumbar; Discal cyst; Percutaneous; Endoscopic transforaminal approach
22.  Memory Dysfunctions after Mild and Moderate Traumatic Brain Injury : Comparison between Patients with and without Frontal Lobe Injury 
The purpose of this study was to assess memory dysfunction in patients with mild and moderate traumatic brain injury (TBI) with and without frontal lobe injury (FLI).
The subjects were 110 TBI patients, who had recovered from the acute clinical phase, and comprised 20 (18.2%) mild TBI (MTBI) patients with FLI, 16 (14.5%) MTBI patients without FLI, 51 (46.4%) moderate TBI (MOTBI) patients with FLI and 23 (20.9%) MTBI patients without FLI. All patients were administrated the Korean version of the Memory Assessment Scale (K-MAS).
Almost all the Summary Scale scores on the K-MAS failed to show any differences between TBI patients with and without FLI, but differences did emerge by types at severities. TBI patients with FLI showed higher Global Memory ability than TBI patients without FLI if their TBI was only mild, but when their TBI was more severe, this finding was reversed, and TBI patients with FLI showed lower Verbal and Global Memory abilities than TBI patients without FLI.
Different kinds of assessment tools are needed for the measurement of memory abilities in TBI patients with FLI, and that the selection of the appropriate tool depends on the severity of the TBI.
PMCID: PMC2796352  PMID: 20041056
Frontal lobe injury; Memory; Severity
23.  Characterization of a Broadband All-Optical Ultrasound Transducer—From Optical and Acoustical Properties to Imaging 
A broadband all-optical ultrasound transducer has been designed, fabricated, and evaluated for high-frequency ultrasound imaging. The device consists of a 2-D gold nanostructure imprinted on top of a glass substrate, followed by a 3 μm PDMS layer and a 30 nm gold layer. A laser pulse at the resonance wavelength of the gold nanostructure is focused onto the surface for ultrasound generation, while the gold nanostructure, together with the 30 nm thick gold layer and the PDMS layer in between, forms an etalon for ultrasound detection, which uses a CW laser at a wavelength far from resonance as the probing beam. The center frequency of a pulse-echo signal recorded in the far field of the transducer is 40 MHz with -6 dB bandwidth of 57 MHz. The signal to noise ratio (SNR) from a 70 μm diameter transmit element combined with a 20 μm diameter receive element probing a near perfect reflector positioned 1.5 mm from the transducer surface is more than 10 dB and has the potential to be improved by at least another 40 dB. A high-frequency ultrasound array has been emulated using multiple measurements from the transducer while mechanically scanning an imaging target. Characterization of the device’s optical and acoustical properties, as well as preliminary imaging results, strongly suggest that all-optical ultrasound transducers can be used to build high-frequency arrays for real-time high-resolution ultrasound imaging.
PMCID: PMC2760086  PMID: 18986929
24.  Thrombosis of Left Common Iliac Artery Following Anterior Lumbar Interbody Fusion: Case Report and Review of Literatures 
We report on a case of thrombosis of the left common iliac artery following anterior lumbar interbody fusion (ALIF) of L4-5 in a 79-year-old man with no previous medical problems, including peripheral vascular disease. After completing the ALIF procedure, the surgeon could not feel the pulsation of the left dorsalis pedis artery, and the oxygen saturation (SaO2) had fallen below 90% from pulse oxymetry on the left great toe. Thrombectomy was successfully performed after confirming the thrombus in the left common iliac artery using Computed Tomography (CT) angiography. Thrombosis of the common iliac artery is very rare following ALIF. However, delayed diagnosis can lead to disastrous outcome. Although elderly patients have no cardio-vascular disease or vessel calcification in pre-op evaluation, the possibility of a complication involving L4-5 should be considered.
PMCID: PMC2682124  PMID: 19444354
Thrombosis; Common iliac artery; Anterior lumbar interbody fusion
25.  CT-Guided Percutaneous Vertebroplasty in the Treatment of an Upper Thoracic Compression Fracture 
Korean Journal of Radiology  2009;10(2):185-189.
Percutaneous vertebroplasty (PVP) has been used to relieve pain and to prevent further collapse of the vertebral body in patients with an osteoporotic compression fracture. The most commonly affected site for the use of PVP is the thoracolumbar junction. There are few reports that have described on the usefulness of PVP in the treatment of a high thoracic compression fracture. We report a case of an upper thoracic compression fracture that was treated with computed tomography (CT)-guided PVP. It was possible to obtain easy access to the narrow thoracic pedicle and it was also possible to monitor continuously the proper volume of polymethylmethacrylate employed, under CT guidance.
PMCID: PMC2651434  PMID: 19270865
Compression fracture; Computed tomography (CT)-guided PVP; High thoracic; Polymethylmethacrylate

Results 1-25 (26)