John D. Pickard and Alonso Pena
Zengpanpan Ye, Xiaolin Ai and Chao You
Hakseung Kim, Eun-Jin Jeong, Dae-Hyeon Park, Zofia Czosnyka, Byung C. Yoon, Keewon Kim, Marek Czosnyka and Dong-Joo Kim
Periventricular lucency (PVL) is often observed in the hydrocephalic brain on CT or MRI. Earlier studies have proposed the extravasation of ventricular CSF into the periventricular white matter or transependymal CSF absorption as possible causes of PVL in hydrocephalus. However, there is insufficient evidence for either theory to be conclusive.
A finite element (FE) model of the hydrocephalic brain with detailed anatomical geometry was constructed to investigate the possible mechanism of PVL in hydrocephalus. The initiation of hydrocephalus was modeled by applying a transmantle pressure gradient (TPG). The model was exposed to varying TPGs to investigate the effects of different geometrical characteristics on the distribution of PVL. The edema map was derived based on the interstitial pore pressure.
The model simulated the main radiological features of hydrocephalus, i.e., ventriculomegaly and PVL. The degree of PVL, assessed by the pore pressure, was prominent in mild to moderate ventriculomegaly. As the degree of ventriculomegaly exceeded certain values, the pore pressure across the cerebrum became positive, thus inducing the disappearance of PVL.
The results are in accordance with common clinical findings of PVL. The degree of ventriculomegaly significantly influences the development of PVL, but two factors were not linearly correlated. The results are indicative of the transependymal CSF absorption as a possible cause of PVL, but the extravasation theory cannot be formally rejected.
Jeong Eun Kim, Jeong Hoon Kim, Oh Lyong Kim, Sun Ha Paek, Dong Gyu Kim, Je G. Chi and Hee-Won Jung
Object. Rathke cleft cysts (RCCs) are rarely symptomatic. The purpose of this study was to clarify the clinical, neuroimaging, surgical, and pathological features of symptomatic RCCs with special attention to their recurrence.
Methods. This retrospective study involved 53 patients with pathologically confirmed symptomatic RCCs. There were 28 female and 25 male patients, ranging in age from 11 to 68 years (mean 37 years). Common clinical presentations included headache, visual impairment, and endocrine disturbance. The most common endocrine disturbances were hyperprolactinemia and diabetes insipidus. Most of these improved or were resolved after surgery, with the exception of diabetes insipidus and panhypopituitarism. The cysts were intrasellar with suprasellar extension in 33 patients, and ranged in size from 5 to 40 mm (mean 17 mm). In the 50 magnetic resonance (MR) images that were reviewed, the signal intensities were quite variable. Fourteen MR images demonstrated enhancement after an injection of Gd. Intraoperatively, the cyst contents were found to be yellowish (18 patients [37%]) and mucoid (25 patients [51%]). Pathological examinations revealed a pseudostratified columnar epithelium in 26 patients (49%). Abundant squamous metaplasia and a stratified squamous epithelium were also found in 12 patients (23%). Follow-up MR images revealed cyst recurrences that required a repeated operation in six patients. Statistically significant risk factors for a recurrence included enhancement of the lesion on MR images (p = 0.017), the extent of cyst removal (p = 0.012), and the presence of squamous epithelium (p = 0.008).
Conclusions. Rathke cleft cysts are associated with a variety of clinical presentations and sometimes confusing intraoperative and pathological findings. Close postoperative observation with neuroimaging and neuroophthalmological assessment is necessary, especially after a partial removal, as in cases with squamous metaplasia.
Jung Ho Han, Dong Gyu Kim, Hyun-Tai Chung, Chul-Kee Park, Sun Ha Paek, Jeong Eun Kim, Hee-Won Jung and Dae Hee Han
In this paper the authors analyzed the clinical and neuroimaging outcomes of patients with cerebral arteriovenous malformations (AVMs) after Gamma Knife surgery (GKS), focusing on the analysis of the radiation injury rate depending on the AVM volume.
Between 1997 and 2004, 277 consecutive patients with cerebral AVMs were treated with GKS. Of these patients, 218 were followed up for ≥ 2 years. The mean age was 31 ± 15 years, the median AVM volume was 3.4 cm3 (range 0.17–35.2 cm3), the median marginal dose was 18.0 Gy (range 10.0–25.0 Gy), and the mean follow-up duration was 44 ± 20 months. The authors reduced the prescription dose by various amounts, depending on the AVM volume and location as prescribed in the classic guideline to avoid irreversible radiation injuries.
The angiographic obliteration rate was 66.4% overall, and it was 81.7, 53.1, and 12.5% for small, medium, and large AVMs, respectively. The overall annual bleeding rate was 1.9%. The annual bleeding rate was 0.44 and 4.64% for small and large AVMs, respectively. Approximately 20% of the patients showed severe postradiosurgery imaging (PRI) changes. The rate of PRI change was 11.4, 33.3, and 9.5% for small, medium, and large AVM volume groups, respectively, and a permanent radiation injury developed in 5.1% of patients.
By using the reduced dose from what is usually prescribed, the authors were able to obtain outcomes in small AVMs that were comparable to the outcomes described in previous reports. However, medium AVMs appear to still be at risk for adverse radiation effects. Last, in large AVMs, the authors were able to attain a tolerable rate of radiation injury; however, the clinical outcomes were quite disappointing following administration of a reduced dose of GKS for large AVMs.
Jae Hyo Park, Seung-Yeob Yang, You-Nam Chung, Jeong Eun Kim, Seung-Ki Kim, Dae Hee Han and Byung-Kyu Cho
✓The authors describe a modified technique of encephaloduroarteriosynangiosis (EDAS) with bifrontal encephalogaleoperiosteal synangiosis (EGPS) and present the preliminary results of the procedure. Between January 2004 and June 2005 the authors performed modified EDAS with bifrontal EGPS in 17 patients with moyamoya disease. Surgical results were evaluated in terms of clinical outcomes, changes visible on neuroimages, extent of revascularization noted on angiograms, and hemodynamic changes demonstrated on single-photon emission computed tomography (SPECT) scans. The follow-up period ranged from 6 to 21 months (mean 11.5 months). The overall clinical outcomes were excellent or good in 15 patients (88.2%) and poor in two (11.8%). The overall morbidity rate was 5.9% (one of 17 patients). Based on changes in the anterior cerebral artery (ACA) and middle cerebral artery (MCA) territories after surgery, as shown on SPECT scans following administration of acetazolamide, 14 patients (82.4%) exhibited an improved vascular reserve capacity in both the ACA and MCA territories. It is the authors' opinion that wide covering of the cortex is necessary for sufficient revascularization. In the present study they demonstrate that modified EDAS with bifrontal EGPS is a safe and efficient surgical approach that covers not only the MCA territory but also the ACA territory.
Eun Jung Lee, Jeong Hoon Kim, Eun Suk Park, Young-Hoon Kim, Jae Koo Lee, Seok Ho Hong, Young Hyun Cho and Chang Jin Kim
Advances in neuroimaging techniques have led to the increased detection of asymptomatic intracranial meningiomas (IMs). Despite several studies on the natural history of IMs, a comprehensive evaluation method for estimating the growth potential of these tumors, based on the relative weight of each risk factor, has not been developed. The aim of this study was to develop a weighted scoring system that estimates the risk of rapid tumor growth to aid treatment decision making.
The authors performed a retrospective analysis of 232 patients with presumed IM who had been prospectively followed up in the absence of treatment from 1997 to 2013. Tumor volume was measured by imaging at each follow-up visit, and the growth rate was determined by regression analysis. Predictors of rapid tumor growth (defined as ≥ 2 cm3/year) were identified using a logistic regression model; each factor was awarded a score based on its own coefficient value. The probability (P) of rapid tumor growth was estimated using the following formula:
Fifty-nine tumors (25.4%) showed rapid growth. Tumor size (OR per cm3 1.07, p = 0.000), absence of calcification (OR 3.87, p = 0.004), peritumoral edema (OR 2.74, p = 0.025), and hyperintense or isointense signal on T2-weighted MRI (OR 3.76, p = 0.049) were predictors of tumor growth rate. In the Asan Intracranial Meningioma Scoring System (AIMSS), tumor size was categorized into 3 groups of < 2.5 cm, ≥ 2.5 to < 4.0 cm, and ≥ 4.0 cm in diameter and awarded a score of 0, 3, and 6, respectively; the parameters of calcification and peritumoral edema were categorized into 2 groups based on their presence or absence and given a score of 0 or 2 and 1 or 0, respectively; and the signal on T2-weighted MRI was categorized into 2 groups of hypointense and hyperintense/isointense and given a score of 0 or 2, respectively. The risk of rapid tumor growth was estimated to be < 10% when the total score was 0–2, 10%–50% when the total score was 3–6, and ≥ 50% when the total score was 7–11 (Hosmer-Lemeshow goodness-of-fit test, p = 0.9958). The area under the receiver operating characteristic curve was 0.86.
The authors suggest a weighted scoring system (AIMSS) that predicts the specific probability of rapid tumor growth for patients with untreated IM. This scoring system will aid treatment decision making in clinical settings by screening out patients at high risk for rapid tumor growth.
Jin Pyeong Jeon, Jeong Eun Kim, Won-Sang Cho, Jae Seung Bang, Young-Je Son and Chang Wan Oh
The purpose of this study was to evaluate treatment outcomes of future stroke prevention, perioperative complications, and angiographic revascularization in adults with symptomatic moyamoya disease (MMD) according to treatment modalities and surgical techniques.
A systemic literature review was performed based on searches of the PubMed, Embase, and Cochrane Central databases. A fixed-effects model was used in cases of heterogeneity less than 50%. Publication bias was determined by Begg’s funnel plot, Egger’s test of the intercept, and the Begg and Mazumdar rank correlation test.
Eleven articles were included in the meta-analysis. Bypass surgery significantly decreased the future stroke events compared with conservative treatments in adult MMD (odds ratio [OR] 0.301, p < 0.001). Direct bypass showed better future stroke prevention than indirect bypass (OR 0.494, p = 0.028). There was no meaningful difference in perioperative complications between direct and indirect bypass (OR 0.665, p = 0.176). Direct bypass was associated with better angiographic outcomes than indirect bypass (OR 6.832, p < 0.001).
Bypass surgery can be effective in preventing future stoke events in adults with MMD. Direct bypass seems to provide better risk reduction with respect to stroke than indirect bypass in these patients.
New prognostic factors for adjacent-segment degeneration after one-stage 360° fixation for spondylolytic spondylolisthesis: special reference to the usefulness of pelvic incidence angle
Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2007
Jeong Yoon Park, Yong Eun Cho, Sung Uk Kuh, Jun Hyung Cho, Dong Kyu Chin, Byung Ho Jin and Keun Su Kim
The purpose of this study was to evaluate the correlation between adjacent-segment degeneration (ASD) and pelvic parameters in the patients with spondylolytic spondylolisthesis. Sagittal balance is the most important risk and prognostic factor in the development of ASD. The pelvic incidence angle (PIA) is an important anatomical parameter in determining the sagittal curvature of the spine and in the individual variability of the sacral slope and the lordotic curve. Thus, the authors evaluated the relationship between the pelvic parameters and the ASD.
Among 132 patients with spondylolytic spondylolisthesis who underwent surgery at their institution, the authors selected patients in whom a one-stage, single-level, 360° fixation procedure was performed for Grade I spondylolisthesis and who underwent follow-up for more than 1 year. Parameters in 34 patients satisfied these conditions. Of the 34 patients, seven had ASD (Group 1) and 27 patients did not have ASD (Group 2). The investigators measured degree of spondylolisthesis, lordotic angle, sacral slope angle (SSA), pelvic tilt angle (PTA), PIA, and additional parameters pre-and postoperatively. The radiographic data were reviewed retrospectively.
The population consisted of nine men and 25 women whose mean age was 48.9 ± 9 years (± standard deviation) (range 28–65 years). Seven patients developed ASD after undergoing fusion. Of all the parameters, pre-and postoperative degree of spondylolisthesis, segmental lordosis, lordotic angle, SSA, preoperative PTA, and pre-operative PIA did not differ significantly between the two groups; only postoperative PTA and PIA were significantly different.
The development of ASD is closely related to postoperative PIA and PTA, not preoperative PIA and PTA. The measurement of postoperative PIA can be used as a new indirect method to predict the ASD.
Hyun-Seung Kang, Youn-Joo Moon, Young-Yim Kim, Woong-Yang Park, Ae Kyung Park, Kyu-Chang Wang, Jeong Eun Kim, Ji Hoon Phi, Ji Yeoun Lee and Seung-Ki Kim
Moyamoya disease (MMD) is a cerebrovascular occlusive disease affecting bilateral internal carotid termini. Smooth-muscle cells are one of the major cell types involved in this disease process. The characteristics of circulating smooth-muscle progenitor cells (SPCs) in MMD are poorly understood. The authors purified SPCs from the peripheral blood of patients with MMD and sought to identify differentially expressed genes (DEGs) in SPCs from these patients.
The authors cultured and isolated SPCs from the peripheral blood of patients with MMD (n = 25) and healthy control volunteers (n = 22). After confirmation of the cellular phenotype, RNA was extracted from the cells and DEGs were identified using a commercially available gene chip. Real-time quantitative reverse transcription polymerase chain reaction was performed to confirm the putative pathogenetic DEGs.
The SPC-type outgrowth cells in patients with MMD invariably showed a hill-and-valley appearance under microscopic examination, and demonstrated high α–smooth muscle actin, myosin heavy chain, and calponin expression (96.5% ± 2.1%, 42.8% ± 18.6%, and 87.1% ± 8.2%, respectively), and minimal CD31 expression (less than 1%) on fluorescence-activated cell sorter analysis. The SPCs in the MMD group tended to make more irregularly arranged and thickened tubules on the tube formation assay. In the SPCs from patients with MMD, 286 genes (124 upregulated and 162 downregulated) were differentially expressed; they were related to cell adhesion, cell migration, immune response, and vascular development.
With adequate culture conditions, SPCs could be established from the peripheral blood of patients with MMD. These cells showed specific DEGs compared with healthy control volunteers. This study provides a novel experimental cell model for further research of MMD.