• Investigative Magnetic Resonance Imaging
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• 제19권2호
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• pp.117-121
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• 2015

Chordoid glioma is a rare, low-grade brain neoplasm typically located in the third ventricle. Herein, we report an unusual case of histologically confirmed chordoid glioma located in the pituitary fossa and suprasellar region, not attached to the third ventricle. A 57-year-old woman presented with a 2-month history of headache and visual disturbance. Magnetic resonance imaging revealed an ovoid mass in the pituitary fossa and suprasellar region, compressing the optic chiasm without involvement of the third ventricle. The tumor showed low signal intensity on T1-weighted images and iso- to high signal intensity on T2-weighted images, with strong and homogenous contrast enhancement. Subtotal resection was performed via the transcranial approach, and the patient subsequently received adjuvant gamma knife radiosurgery. However, the residual mass showed disease progression 5 months after the initial surgery.

• 대한두경부종양학회지
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• 제36권1호
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• pp.27-31
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• 2020

The midline nasal dermoid cysts are rare congenital neoplasms, which are diagnosed frequently in childhood. Masses are often noticeable at birth gaining size over time with recurrent infections and usually arise from the nasal cavity or lower 1/3 of the nasal dorsum. CT scan as the primary investigation is helpful to determine accurately the size and extent of the lesion as well as the integrity of adjacent bony structures. MRI scan is recommended to rule out an intracranial extension or sinus tracts. Treatment of choice is the complete surgical excision preserving the cyst wall. Here in, we present an unusual case of nasofrontal dermoid cyst in a 19-year-old boy without radiographic evidence of transcranial extension. In this case, we surgically removed nasofrontal dermoid cyst via transcolumellar approach. We also corrected saddle nose deformity after mass removal. Therefore, in this case, we experienced a successful case in which the nasofrontal dermoid cyst was totally removed without facial scar and deformity.

• Journal of Korean Neurosurgical Society
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• 제63권4호
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• pp.495-503
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• 2020

Objective : Thyroid-stimulating hormone (TSH)-secreting pituitary adenoma (PA) is an extremely rare functioning form of PA that accounts for 0.7-2% of all such cases. The previously reported outcomes of the surgical removal of TSH-PA are poor. Owing to its extremely low incidence, most available reports on TSH-PA are case reports or small case series. Thus, we investigated the clinical and endocrinological outcomes of surgically treated TSH-PA through our institutional series. Methods : We retrospectively reviewed 14 consecutive cases of surgically treated TSH-PA, focusing on the clinical, radiological, surgical, and endocrinological data. Results : There were seven male (50%) and seven female (50%) patients. The mean age was 42.5 years (range, 19-63). The mean tumor size was 16.6 mm (range, 4-30). Optic chiasm compression was noted in six patients (42.9%), and no patient showed cavernous sinus invasion. Thirteen of 14 patients (92.8%) underwent transnasal transsphenoidal approach (TSA), and one patient underwent TSA followed by transcranial approach for residual tumor removal. Thirteen of 14 patients (92.8%) showed endocrinological remission; all patients who experienced remission showed subnormal levels of TSH (<0.4 μU/mL) on postoperative day 2. Recurrence occurred in two patients (14.2%). One patient underwent subsequent revision transnasal TSA for recurrent tumor removal, and the other patient underwent gamma knife radiosurgery for recurrence. Conclusion : Surgical treatment showed excellent surgical outcomes. The TSH level in the immediate postoperative period may be a predictor for endocrinological remission.

• Journal of Korean Neurosurgical Society
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• 제37권4호
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• pp.275-281
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• 2005

Objective: The prolactinoma is the most common pituitary tumor and sometimes shows severe invasiveness to the adjacent cavernous sinus, especially in the male patient. The dopamine agonist can be used as an alternative treatment modality to surgery. But, the transsphenoidal or transcranial approach for tumor removal has been more preferred treatment option of neurosurgeons in invasive prolactinoma. Especially rapid decompression of mass effect and resolution of the neurologic deficit is demanded. The prospective study is done in order to identify the therapeutic efficacy of bromocriptine as an initial treatment option for the invasive prolactionomas. Methods: Twenty patients with invasive prolactinoma were studied. Preoperative neurological and endocrinological evaluations were done, and size and invasiveness of the tumor was estimated on MRI. Bromocriptine was administrated by increasing dose planning reaching maximum dose at 1 month of treatment, with close neurological and endocrinological monitoring. At 3months after treatment, MRI was taken and decision was made whether to continue bromocriptine or to have surgical intervention. Results: Thirteen patients showed excellent result with only bromocriptine treatment. These patients showed not only marked reduction of tumor volume and prolactin level, but also, improving clinical symptoms and other hormonal deficits. 13patients who had visual field defect and decreased visual acuity had all improved visual symptoms. But, the remaining 4patients required surgical treatment due to insufficient reduction of tumor size inspite of normalized prolactin level within 3months. Remaining 2patients had $20{\sim}30%$ of tumor size reduction, but prolactin level was not normalized. One patient required radiation therapy. Conclusion: Bromociptine can be used as initial treatment for the invasive prolactinomas with careful monitoring of the neurological and endocrinological status. It should be carefully followed up for tumor size reduction within 3 months after initiation of treatment.

• 대한의용생체공학회:의공학회지
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• 제45권2호
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• pp.101-107
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• 2024

Steady-state visual evoked potential-based brain-computer interface (SSVEP-BCI) is one of the promising systems that can serve as an alternative input device due to its stable and fast performance. However, one of the major bottlenecks is that some individuals exhibit no or very low SSVEP responses to flickering stimulation, known as SSVEP illiteracy, resulting in low performance on SSVEP-BCIs. However, a lengthy duration is required to enhance multiple SSVEP responses using traditional single-frequency transcranial alternating current stimulation (tACS). This research proposes a novel approach using dual-frequency tACS (df-tACS) to potentially enhance SSVEP by targeting the two frequencies with the lowest signal-to-noise ratio (SNR) for each participant. Seven participants (five males, average age: 24.42) were exposed to flickering checkerboard stimuli at six frequencies to determine the weakest SNR frequencies. These frequencies were then simultaneously stimulated using df-tACS for 20 minutes, and the experiment was repeated to evaluate changes in SSVEP responses. The results showed that df-tACS effectively enhances the SNR at each targeted frequency, suggesting it can selectively improve target frequency responses. The study supports df-tACS as a more efficient solution for SSVEP illiteracy, proposing further exploration into multi-frequency tACS that could stimulate more than two frequencies, thereby expanding the potential of SSVEP-BCIs.

• 인지과학
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• 제26권4호
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• pp.393-433
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• 2015

창의성은 독창적이고 유용한 아이디어를 산출할 수 있는 능력을 말한다. 현대 사회의 많은 문제들을 해결하고 인류의 복지를 증진시키기 위해 창의성의 기전을 이해하고 이를 증진할 수 있는 방안에 대한 연구는 매우 중요하다. 창의성은 매우 이질적이고 복합적인 능력으로서 이를 하나의 능력으로 개념화하는 것은 적절하지 않다. 따라서 학계에서는 창의성의 개별 구성 요소를 중심으로 창의성의 기전에 대한 연구가 활발하게 이루어지고 있다. 본 개관 연구에서는 창의성의 주요한 구성 요소인 확산적 사고, 통찰, 관계적 사고 그리고 예술적 창의성에 대한 인지신경과학 연구들을 소개한다. 여러 연구 결과를 종합적으로 고려한 결과, 창의성의 인지신경학적 기전과 관련하여 우반구가 좌반구보다 우세하다는 가설은 실험적 증거에 의해 지지되지 않았다. 또한, 창의성과 관련하여 특정 뇌 영역의 중요성이 일관되게 보고되고 있지 않으며, 다양한 뇌 영역의 활동성이 창의성과 관계된다는 연구 결과가 혼재하고 있다. 이러한 상이한 연구 결과가 관찰되는 이유는 창의성의 각 구성 요소의 이질성 뿐 아니라, 연구에 사용된 과제의 특수성과 과제에 의해 유발된 인지적 전략의 차이에 의해 뇌 활동이 달라지기 때문인 것으로 해석할 수 있다. 본 개관 연구에서는 창의성의 요소 별 뇌기반과 창의성의 증진에 대하여 우수한 연구 방법을 사용하여 탁월한 연구 성과를 이룬 대표적인 사례들을 소개하고 현행 연구들의 제한점과 후속 연구의 방향을 제시한다.