Biomedical subjects

Moon-Chan Kim

Publications and source records attributed to Moon-Chan Kim.

12 recordsLinked to original sources

PubMed2006

Combined direct anastomosis and encephaloduroarteriogaleosynangiosis using inverted superficial temporal artery-galeal flap and superficial temporal artery-galeal pedicle in adult moyamoya disease.

BACKGROUND: We evaluated the efficacy of combined STA-MCA anastomosis and EDAGS using inverted STAGF and STAGP for the treatment of adult MMD. METHODS: This study included 8 patients with nonhemorrhagic MMD. There were 6 women and 2 men who were between 23 and 62 years old (mean = 37.8 years) in the sample. The combined surgery was performed on 12 sides in the 8 patients. The surgical results were assessed for clinical outcome, angiographic revascularization, and hemodynamic change on HMPAO brain SPECT. The follow-up period ranged from 6 to 62 months (mean = 27 months). RESULTS: Clinical symptoms and signs were improved or stabilized, and the extent of revascularization evident on external carotid angiograms was excellent in all 8 patients. The CBF on HMPAO SPECT also improved in all 12 sides that were operated on with the combined surgery, except for the preexisting infarcted area, on the basal as well as Diamox stimulation studies. One patient had a transient speech disturbance after surgery, and another patient had delayed wound healing. CONCLUSIONS: The combined STA-MCA anastomosis and EDAGS using inverted STAGF/P seems to be one of the most effective surgical modalities for the treatment of nonhemorrhagic MMD in adults.

Adult↗

PubMed2006

Diagnostic method for differentiating external hydrocephalus from simple subdural hygroma.

OBJECT: The various terms used to describe subdural fluid collection--"external hydrocephalus", "subdural hygroma", "subdural effusion", "benign subdural collection", and "extraventricular obstructive hydrocephalus"-reflect the confusion surrounding the diagnoses of these diseases. Differentiating external hydrocephalus from simple subdural hygroma may be difficult, but the former appears to be a distinct clinical entity separate from the latter. In this report, the authors present a diagnostic method for differentiating external hydrocephalus from simple subdural hygroma, based on their clinical experience in treating subdural fluid collection after mild head trauma. METHODS: Twenty patients with subdural fluid collection after mild head trauma were included in this study. Ventricle size was measured using a modified frontal horn index (mFHI); that is, the largest width of the frontal horns divided by the bicortical distance in the same plane, instead of the inner table distance. Bur hole trephination was performed on the appearance of a subdural fluid collection thicker than 15 mm on computed tomography (CT), persistent (longer than 4 weeks) or increasing in size, and accompanied by neurological symptoms (confusion or memory impairment). During the procedure, subdural pressure was measured using a manometer before opening the dura mater. Subdural pressure varied among the patients, ranging from 3 to 27.5 cm H2O. Four patients with a subdural pressure greater than 15 cm H2O had hydrocephalus after surgery (p < 0.05). Hydrocephalus developed in a pediatric patient (2 years old) with a subdural pressure of 12 cm H2O. All of the patients in whom hydrocephalus developed after bur hole trephination had had enlarged ventricles (mFHI > 33%) on preoperative CT scans. CONCLUSIONS: Monitoring subdural pressure may be a valuable tool for differentiating subdural hygroma from external hydrocephalus in patients with mild head trauma. Additionally, the mFHI reflects the nature of the subdural collection more accurately than the standard frontal horn index.

Adolescent↗

PubMed2006

Temozolomide chemotherapy in patients with recurrent malignant gliomas.

Numerous studies have demonstrated the clinical activity of temozolomide, a second-generation alkylating agent, against malignant brain tumors, however, its activity has not been reported in an Asian population. This study analyzed the efficacy and toxicity of temozolomide in 25 adult patients with recurrent or progressive malignant gliomas after surgery and standard radiation therapy with or without chemotherapy, enrolled in our institution since July 2000. Sixteen patients had glioblastoma multiforme (GBM), six with anaplastic astrocytoma, and three with anaplastic oligodendroglioma. Of the 25 patients, 3 (12%) achieved a complete response (CR), 8 (32%) achieved a partial response (PR), 6 (24%) had stable disease (SD), and 8 (32%) had progressive disease (PD). Two patients achieved a CR, 4 patients achieved a PR, 3 patients had SD and 7 patients had PD in GBM, and 1 patient achieved a CR, 4 patients achieved a PR, 3 patients had SD, 1 patient had PD in the non-GBM patients. Median progression free survival was 8 weeks in GBM and 22 weeks in the non-GBM patients. The median overall survival of each group was 17 weeks and 28 weeks. Temozolomide demonstrated moderate activity in recurrent and progressive malignant gliomas without serious toxicity.

Administration, Oral↗

PubMed2005

[The association of obesity and left colonic adenomatous polyps in Korean adult men].

OBJECTIVES: We wanted to evaluate the relationship between obesity and left colonic adenomatous polyps in Korean adult men. METHODS: This study was conducted among 575 adults men (aged between 40 and 69), who had colonoscopy done from January to December 2002 during a routine health examination at Health Promotion Center, Ulsan University Hospital. The patients' colons were examined up to splenic flexure by using fiberoptic colonoscopy. A questionnaire survey on behavioral factors and physical measurements were also done. The body mass index (BMI) and waist-hip ratio (WHR) were used as the indices of obesity. The BMI was categorized into three levels: normal (BMI < or = 22.9), overweight (23 < or = BMI < or = 24.9), and obese (BMI > or = 25.0). The WHR was categorized into four levels with cut-off points at the 30th, 60th, and 90th percentile of the control group. Age, education, smoking, alcohol use and exercise were controlled for by performing multiple logistic regression analysis. RESULTS: There were 99 cases of colonic adenomatous polyps. Four hundred seventy six subjects with normal colonoscopy findings served as the control. The BMI and WHR were associated with the adenomatous polyps (odds ratio, 1.81 [95% CI=1.02-3.19] for a BMI > or = 25.0 as compared with a BMI < or = 22.9, odds ratio, 3.94 [95% CI = 1.77-8.77] for a WHR > or = 0.95 as compared with a WHR < or = 0.86). The BMI was not associated with the risk of adenomatous polyps after additional adjustment was made for the WHR, but the association between the WHR and adenomatous polyps was still positive and independent of the BMI (odds ratio, 4.15 [95% CI=1.63-10.59]). CONCLUSIONS: The results support that obesity, and particularly abdominal obesity, can be associated with an increased risk of incurring colonic adenomatous polyps.

Adenomatous Polyps↗

PubMed2004

Development of a rapid planning technique based on heuristic target shaping for stereotactic radiosurgery.

Stereotactic radiosurgery (SRS) is a technique to delivering a high dose to a target region and a low dose to a critical organ by using only one or a few irradiations. Traditionally, SRS is performed using a Gamma knife with using 201 cobalt 60 sources or a linear accelerator with equally spaced noncoplanar arcs. Finding a specific condition that includes the target in the prescription dose while sparing the critical organ is tedious, because there are many combinations of positions and collimator sizes for each isocenter. Many methods of identifying suitable planning condition automatically have been proposed. However, there are some limitations using these methods. These include a long calculation time to obtain the final plan, and difficulties finding a unique solution due to different tumor shapes. This study uses three steps to solve these problems. (1) The dose distribution of one isocenter is modeled as a sphere. This makes it possible to reduce the time needed to obtain the result due to the absence of a dose calculation. (2) The target was constructed by piling up cylinders along a virtual axis, which was the longest line in a given target. (3) Spheres were then packed in each cylinder according to the position and diameter of each cylinder in order to cover each target divided by the height of the cylinder. The results of applying three imaginary targets were found to be satisfactory in terms of: target coverage-more than 50%, the reproducibility of the result and the calculation time-several tens of seconds. The PITV ratio was less than 2.0. However, the dose applied to normal tissue around the target must be reduced slightly. Planner or conventional optimization algorithms might easily solve this limitation.

Algorithms↗

PubMed2003

Intraspinal extradural teratoma mimicking neural sheath tumor in infant.

INTRODUCTION: An intraspinal teratoma that is located entirely extradurally is unusual both in children and in adults. CASE HISTORY: The authors present a case of an 8-month-old male infant with an extradurally arising intraspinal mature teratoma located from T-2 to T-4, who had suffered from progressive paraparesis (grade 1). The patient did not have any stigmata or anomalies suggesting spinal dysraphism. Spinal MRI showed a cystic extradural mass markedly compressing the dural sac. On operation, the only way of getting sufficient space for exposure of the whole tumor was to perform hemilaminectomies with preservation of facetal areas to prevent postoperative instability. The tumor was well encapsulated and located entirely extradurally, and the cystic portion was occupied with yellowish fluid. The site of tumor occurrence was the spinal root sheath, mimicking a neural sheath tumor. Paraparesis had improved markedly to grade 4 by the time of the neurological examination 3 months after operation.

Epidural Neoplasms↗

PubMed2003

Posteroventral pallidotomy in medically intractable postapoplectic monochorea: case report.

BACKGROUND: Posteroventral pallidotomy is a widely accepted surgical procedure for treating medically intractable Parkinson's disease and Levo-dopa induced dyskinesia. In the surgical treatment of hyperkinetic movement disorders, generalized dystonia has recently become a favorable indication of posteroventral pallidotomy. However, a commonly recognized surgical procedure for treating choreiform movement disorders has not yet been established. Here we present an unusual experience of a posteroventral pallidotomy performed to treat a medically intractable monochorea caused by a vascular insult on the basal ganglia. METHODS: A 63-year-old female presented with choreiform movement of the left upper limb that she had suffered for 5 months. She was found to have a hemorrhagic infarction in the right putaminal area. No other abnormal lesions were shown by magnetic resonance imaging except for a widening of the right cerebellopontine cistern because of an acoustic neurinoma removed 5 years previously. Despite medication with a dopamine antagonist, choreiform movement of the left limb had not improved, and the patient complained of rigidity and slowness of ambulation owing to the side effects of the medicine. A right posteroventral pallidotomy was performed with macrostimulation for a physiologic confirmation of the globus pallidus internus (GPi), which is the conventional target for Parkinson's disease. After coagulating the GPi target, the choreiform movement of the contralateral upper limb was completely abolished. RESULTS: The postoperative course was uneventful and no recurrence of chorea was observed over a follow-up period of 6 months. CONCLUSIONS: Stereotactic surgery for hyperkinetic movement disorders is not as common a procedure as that used for treating Parkinson's disease. Furthermore, there have been few reports of pallidal surgery for treating the chorea caused by an ischemic insult. However, on the basis of the current concept that varying types of hyperkinetic disorders may have a common pathophysiological mechanism, a posteroventral pallidotomy may be an alternative surgical procedure for treating medically intractable postapoplectic chorea like in an occasion of dystonia.

Chorea↗

PubMed2003

Proton MR spectroscopic changes in Parkinson's diseases after thalamotomy.

To investigate whether there are significant changes in regional brain metabolism in patients with Parkinson's disease before and after thalamotomy using proton magnetic resonance spectroscopy (1H MRS). Fifteen patients underwent 15 stereotactic thalamotomies for control of medically refractory parkinsonian tremor. Single-voxel 1H MRS was carried out on a 1.5 T unit using stimulated-echo acquisition mode (STEAM) sequence (TR/TM/TE, 2000/14/20 ms). Spectra were obtained from substantia nigra, thalamus and putamen areas with volumes of interests (7-8 ml) in patients before and after the surgery. Metabolite ratios of NAA/Cho, NAA/Cr and Cho/Cr were calculated from relative peak area measurements. We evaluated alterations of metabolite ratios in brain metabolism in Parkinson's disease patients with clinical outcome following thalamotomy. NAA/Cho ratios showed generally low levels in substantia nigra and thalamus in Parkinson's disease patients with clinical improvement following thalamotomy. In 80% (12/15) patients, decreased NAA/Cho ratios were observed from the selected voxels in substantia nigra after thalamic surgery (P<0.05). The ratios were also significantly decreased in thalamus in 67% (10/15) patients with clinical improvement (P<0.05). Our results suggest that NAA/Cho ratio may be a valuable criterion for evaluation of Parkinson's disease patients with the clinical improvement following surgery. 1H MRS may be a useful utility for the aid in better understanding the pathophysiologic process in Parkinson's disease patients on the basis of the variation of NAA/Cho ratio.

Adult↗

PubMed2003

Feasibility of proton chemical shift imaging with a stereotactic headframe.

To prove feasibility of proton chemical shift imaging ((1)H CSI) during stereotactic procedure, authors performed (1)H CSI in combination with a stereotactic headframe and selected targets according to local metabolic information, evaluated the pathologic results. The (1)H CSI directed stereotactic biopsy was performed in four patients. (1)H CSI and conventional Gd-enhancement stereotactic MRI were performed simultaneously after the fitting of a stereotactic headframe. Focal areas of increased phosphocholine(Cho)/phosphocreatine(Cr) and Lactate/Cr ratios were selected as target sites in the stereotactic MR images. (1)H CSI is possible with the stereotactic headframe in place. Pathologic samples taken from areas of increased Cho/Cr ratios and decreased NAA/Cr ratios provided information upon increased cellularity, mitoses and cellular atypism, and facilitated diagnosis. Pathologic samples taken from areas of increased Lac/Cr ratio showed predominant feature of necrosis. (1)H CSI was feasible with the stereotactic headframe in place. The final pathologic results obtained were concordant with the local metabolic information from (1)H CSI. We believe that (1)H CSI-directed stereotactic biopsy has the potential to significantly improve the accuracy of stereotactic biopsy targeting.

Adult↗

PubMed2002

Role of surgery for maintaining urological function and prevention of retethering in the treatment of lipomeningomyelocele: experience recorded in 75 lipomeningomyelocele patients.

OBJECT: The authors tried to reveal some unique features of lipomeningomyelocele (LMMC), including clinical presentation, factors precipitating onset of symptoms, pathologic entities of LMMC associated with tethered cord syndrome, and surgical outcome in LMMC patients. METHODS AND RESULTS: Seventy-five patients with LMMC were enrolled in this study. Neuro-imaging and intraoperative findings allowed classification of LMMC into three types: type I, type II, and type III. The patients were divided into two groups by age: A (51 patients), from birth to 3 years, and B (24 patients), from 3 to 24 years. For prevention of retethering of the cord, a mega-dural sac rebuilding procedure was performed in 15 patients. During a mean postoperative follow-up period of 4 years, the surgical outcome was satisfactory in terms of improved pain and motor weakness, but disappointing with reference to the resolution of bowel and bladder dysfunction. Among these 75 patients with LMMC, preoperative deficits were improved after surgery in 29 (39%), remained stable in 28 (37%), changed slightly in 13(17%), and worsened in 5 (7%). Patients in group A achieved better outcomes than those in group B. Depending on the type of lesion, patients with types I and II LMMC have better outcomes than those with type III LMMC: Finally, retethering of the cord with neurological deterioration occurred in 4 (5.3%) of the 75 patients, but no retethering was found in the 15 patients who were recently treated with a mega-dural sac rebuilding procedure. CONCLUSION: Our data continue to support the opinion that early diagnosis and optimal surgery are still essential for the treatment of patients with LMMC, since there is a high likelihood of residual neurological functions that can be preserved. Based on our surgical experience of untethering and decompression of lipomas, a mega-dural sac repair is useful to prevent retethering of the cord.

Adolescent↗

PubMed2002

Review of long-term results of stereotactic psychosurgery.

Stereotactic psychosurgery is an effective method for treating some medically intractable psychiatric illnesses. However, it is unfamiliar and the long-term clinical results have not been reported in Asia. The long-term results of psychosurgery are evaluated and the neuroanatomical basis is discussed. Twenty-one patients underwent stereotactic psychosurgery for medically intractable psychiatric illnesses since 1993. All were referred from psychiatrists for these disorders. Two patients showed aggressive behavior, 12 had obsessive-compulsive disorder (OCD), and seven had depression with anxiety disorders. Bilateral amygdalotomy and subcaudate tractotomy were performed for aggressive behavior, limbic leucotomy was performed for OCD, and subcaudate tractotomy with or without cingulotomy was performed for depression with anxiety. OCD was evaluated with the Yale-Brown Obsessive Compulsive Scale (YBOCS), the visual analogue scale, the Clinical Global Impression Scale, and the Overt Aggression Scale (OAS). The Mini-Mental State Examination and the Wechsler Adult Intelligence Scale-Revised were used for the evaluation of aggressive behavior. The 17-item Hamilton Depression Rating Scale (HAMD) was used for evaluation of depression. Ventriculography was used in the first seven patients and magnetic resonance imaging-guided stereotaxy was used in the recent 14 cases for localization of the target. The lesions were made with a radiofrequency lesion generator. OAS scores in the two patients with aggressive behavior during follow up declined from 8 to 2 with clinical improvement. All 12 patients with OCD returned to their previous life and showed the mean YBOCS scores decreased from 34 to 3. Ten patients with OCD could be followed up (mean 45 months). All patients returned to their previous social life. In seven patients with depression with anxiety, HAMD scores declined from 28.5 to 16.5. There was no operative mortality and no significant morbidity except for one case of mild transient urinary incontinence. These long-term results indicate that stereotactic psychosurgery is a safe and effective method of treating some medically intractable psychiatric illnesses.

Brain↗

PubMedDate not supplied

Assessment of malignancy in gliomas by 3T 1H MR spectroscopy .

The purpose of this study was to assess clinical 1H MR spectroscopy (MRS) as a noninvasive method for evaluating brain tumor malignancy at 3T high-field system. Using 3T MRI/MRS system, localized water-suppressed single-voxel technique in patients with brain tumor (i.e., gliomas) was employed to evaluate spectra with peaks of N-acetyl aspartate (NAA), choline-containing compounds (Cho), creatine/phosphocreatine (Cr) and lactate. On the basis of Cr, these peak areas were quantitated as a relative ratio. The variation of metabolite measurements of the designated region in 10 normal volunteers was less than 10%. Normal ranges of NAA/Cr and Cho/Cr ratios were 1.67+/-018 and 1.16+/-0.15, respectively. NAA/Cr ratio of gliomas was significantly lower than that of the normal tissues (P= .005), but Cho/Cr ratio of gliomas was significantly higher (P= .001). Cho/Cr ratio of high-grade gliomas was significantly higher than that of low-grade gliomas. The present study demonstrated that the neuronal degradation or loss was observed in all gliomas. Higher-grade glioma was correlated with higher Cho/Cr ratio, indicating a significant dependence of Cho levels on malignancy of gliomas. Our results suggest that clinical 1H MR spectroscopy could be useful to predict tumor malignancy.

Adult↗