Min Soo Kim, Kyu Hong Kim, Eun Hee Lee, Young Min Lee, Sung-Hun Lee, Hyung Dong Kim and Young Zoon Kim
The aim of this study was to evaluate the role of certain cell-cycle regulatory proteins in the recurrence of atypical meningiomas. These proteins were analyzed with immunohistochemical staining to identify predisposing factors for the recurrence of atypical meningiomas.
The authors retrospectively reviewed the medical records of patients with atypical meningiomas diagnosed in the period from January 2000 to June 2012 at the Department of Neurosurgery at Samsung Changwon Hospital and Dong-A University Medical Center. Clinical data included patient sex and age at the time of surgery, presenting symptoms at diagnosis, location and size of tumor, extent of surgery, use of postoperative radiotherapy, duration of follow-up, and recurrence. Immunohistochemical staining for cell-cycle regulatory proteins (p16, p15, p21, p27, cyclin-dependent kinase [CDK] 4 and 6, phosphorylated retinoblastoma [pRB] protein, and cyclin D1) and proliferative markers (MIB-1 antigen, mitosis, and p53) was performed on archived paraffin-embedded tissues obtained during resection. The recurrence rate and time to recurrence were assessed using Kaplan-Meier analysis.
Of the 67 atypical meningiomas eligible for analysis, 26 (38.8%) recurred during the follow-up period (mean duration 47.7 months, range 8.4–132.1 months). Immunohistochemically, there was overstaining for p16 in 44 samples (65.7%), for p15 in 21 samples (31.3%), for p21 in 25 samples (37.3%), for p27 in 32 samples (47.8%), for CDK4 in 38 samples (56.7%), for CDK6 in 26 samples (38.8%), for pRB protein in 42 samples (62.7%), and for cyclin D1 in 49 samples (73.1%). Multivariate analysis using the Cox proportional-hazards regression model showed that incomplete resection (HR 4.513, p < 0.001); immunohistochemical understaining for p16 (HR 3.214, p < 0.001); immunohistochemical overstaining for CDK6 (HR 3.427, p < 0.001), pRB protein (HR 2.854, p = 0.008), and p53 (HR 2.296, p = 0.040); and increased MIB-1 labeling index (HR 2.665, p = 0.013) and mitotic index (HR 2.438, p = 0.024) predicted the recurrence of atypical meningiomas after resection.
Findings in this study indicated that p16, CDK6, and pRB protein were associated with the recurrence of atypical meningiomas.
Eun Ju Lee, Hyun Joo Lee, Min Kyung Hyun, Ji Eun Choi, Jong Hee Kim, Na Rae Lee, Jin Seub Hwang and Jin-Won Kwon
The authors investigated the rupture rate among patients with untreated unruptured intracranial aneurysms (UIAs) in South Korea during 2006–2009.
A longitudinal study using national representative health-claim data, including all hospital records for every Korean citizen, was used. Patients with a UIA who were 18–80 years old in 2006 were identified using the I67.1 ICD-10 code. To select eligible patients, a historical period of 1 year prior to the first diagnosis of a UIA in 2006 was utilized. Patients with a previous UIA diagnosis, subarachnoid hemorrhage (SAH), or treatments, such as clipping or coiling, during the historical period were excluded from analysis. Patients with head trauma or a brain tumor during the historical period were also excluded. Eligible patients were followed up for at least 3 years from the index date. Rupture was defined as SAH events with at least 14 days of hospitalization, using the I60 ICD-10 code and excluding the I60.8 code, or death within 14 days of hospitalization.
Seven thousand four hundred four patients with UIAs were identified, including 1441 treated patients (20%) and 5963 untreated patients (80%), with a median follow-up of 3.3 years. Rupture events occurred in 163 (0.9 cases/100 person-years) of the 5963 untreated patients. The rupture rate was highest in the 1st year after UIA diagnosis. An older age was a risk factor for rupture among patients with UIAs.
The overview of the incidence of rupture indicates the need for a preventive strategy and future studies to prevent rupture in Asian patients with UIAs.
Min-Hee Lee, Nolan B. O’Hara, Yasuo Nakai, Aimee F. Luat, Csaba Juhasz, Sandeep Sood, Eishi Asano and Jeong-Won Jeong
This study is aimed at improving the clinical utility of diffusion-weighted imaging maximum a posteriori probability (DWI-MAP) analysis, which has been reported to be useful for predicting postoperative motor, language, and visual field deficits in pediatric epilepsy surgery. The authors determined the additive value of a new clustering mapping method in which average direct-flip distance (ADFD) reclassifies the outliers of original DWI-MAP streamlines by referring to their minimum distances to the exemplar streamlines (i.e., medoids).
The authors studied 40 children with drug-resistant focal epilepsy (mean age 8.7 ± 4.8 years) who had undergone resection of the presumed epileptogenic zone and had five categories of postoperative deficits (i.e., hemiparesis involving the face, hand, and/or leg; dysphasia requiring speech therapy; and/or visual field cut). In pre- and postoperative images of the resected hemisphere, DWI-MAP identified a total of nine streamline pathways: C1 = face motor area, C2 = hand motor area, C3 = leg motor area, C4 = Broca’s area–Wernicke’s area, C5 = premotor area–Broca’s area, C6 = premotor area–Wernicke’s area, C7 = parietal area–Wernicke’s area, C8 = premotor area–parietal area, and C9 = occipital lobe–lateral geniculate nucleus. For each streamline of the identified pathway, the minimal ADFD to the nine exemplars corrected the pathway membership. Binary logistic regression analysis was employed to determine how accurately two fractional predictors, Δ1–9 (postoperative volume change of C1–9) and γ1–9 (preoperatively planned volume of C1–9 resected), predicted postoperative motor, language, and visual deficits.
The addition of ADFD to DWI-MAP analysis improved the sensitivity and specificity of regression models for predicting postoperative motor, language, and visual deficits by 28% for Δ1–3 (from 0.62 to 0.79), 13% for Δ4–8 (from 0.69 to 0.78), 13% for Δ9 (from 0.77 to 0.87), 7% for γ1–3 (from 0.81 to 0.87), 1% for γ4–8 (from 0.86 to 0.87), and 24% for γ9 (from 0.75 to 0.93). Preservation of the eloquent pathways defined by preoperative DWI-MAP analysis with ADFD (up to 97% of C1–4,9) prevented postoperative motor, language, and visual deficits with sensitivity and specificity ranging from 88% to 100%.
The present study suggests that postoperative functional outcome substantially differs according to the extent of resected white matter encompassing eloquent cortex as determined by preoperative DWI-MAP analysis. The preservation of preoperative DWI-MAP–defined pathways may be crucial to prevent postoperative deficits. The improved DWI-MAP analysis may provide a complementary noninvasive tool capable of guiding the surgical margin to minimize the risk of postoperative deficits for children.
Hun Ho Park, Min Chul Oh, Eui Hyun Kim, Chan Yun Kim, Sun Ho Kim, Kyu-Sung Lee and Jong Hee Chang
The authors investigated the value of retinal nerve fiber layer (RNFL) thickness in predicting visual outcome after surgery for parachiasmal meningioma.
Forty-nine eyes of 25 patients who underwent craniotomy and resection of a parachiasmal meningioma were analyzed retrospectively. Visual parameters including visual field (VF) (recorded as the mean deviation [MD]), visual acuity (VA), and RNFL thickness (via optical coherence tomography) were measured before and 1 week, 6 months, and 1 year after surgery. Postoperative visual outcome was compared among the patients with a thin or normal RNFL. A separate analysis of data pertaining to 22 eyes of 13 patients with severe VF defects (MD ≤ −10 dB) was performed to compare visual outcome for those with a thin or normal RNFL.
Of the 23 eyes that showed VF improvement, 22 (95.7%) had normal RNFL thickness. The positive predictive value of normal RNFL thickness for VF improvement was 78.6%. The VF of patients with normal RNFL thickness improved in 6 months and continued improving 1 year after surgery (MD −5.9 dB before surgery, −5.5 dB 1 week after surgery, −2.8 dB 6 months after surgery [p < 0.01], and −1.1 dB 1 year after surgery [p < 0.01]). In contrast, those with a thin preoperative RNFL showed deterioration at first and then slower, worse visual recovery after surgery (MD −18.1 dB before surgery, −22.4 dB 1 week after surgery, −21.2 dB 6 months after surgery, and −19.1 dB 1 year after surgery). VA also showed significant progress 6 months after surgery in patients with normal RNFL thickness (0.6 before surgery, 0.7 one week after surgery, 0.9 six months after surgery [p = 0.025], and 0.9 one year after surgery [p = 0.050]) compared to those with a thin RNFL (0.3 before surgery, 0.2 one week after surgery, 0.3 six months after surgery, and 0.4 one year after surgery). Preoperative differences in VF MD and VA were noted between the 2 groups (p < 0.01). Even patients with severe VF defects and normal RNFL thickness improved by 11.1 dB by 1 year after surgery compared with patients with a thin RNFL (−0.01 dB) (p < 0.01). Patients with normal RNFL thickness also did better in VA improvement (from 0.7 to 1.1) than those with a thin RNFL (from 0.2 to 0.3), but these results were not statistically significant.
RNFL thickness measured by optical coherence tomography has significant value as a prognostic factor of postoperative visual recovery for parachiasmal meningioma. Patients with normal RNFL thickness before surgery are more likely to have visual improvement after surgery than patients with a thin RNFL.
Min-Hee Lee, Nolan B. O’Hara, Hirotaka Motoi, Aimee F. Luat, Csaba Juhász, Sandeep Sood, Eishi Asano and Jeong-Won Jeong
In this study the authors investigated the clinical reliability of diffusion weighted imaging maximum a posteriori probability (DWI-MAP) analysis with Kalman filter prediction in pediatric epilepsy surgery. This approach can yield a suggested resection margin as a dynamic variable based on preoperative DWI-MAP pathways. The authors sought to determine how well the suggested margin would have maximized occurrence of postoperative seizure freedom (benefit) and minimized occurrence of postoperative neurological deficits (risk).
The study included 77 pediatric patients with drug-resistant focal epilepsy (age 10.0 ± 4.9 years) who underwent resection of their presumed epileptogenic zone. In preoperative DWI tractography from the resected hemisphere, 9 axonal pathways, Ci=1–9, were identified using DWI-MAP as follows: C1–3 supporting face, hand, and leg motor areas; C4 connecting Broca’s and Wernicke’s areas; C5–8 connecting Broca’s, Wernicke’s, parietal, and premotor areas; and C9 connecting the occipital lobe and lateral geniculate nucleus. For each Ci, the resection margin, di, was measured by the minimal Euclidean distance between the voxels of Ci and the resection boundary determined by spatially coregistered postoperative MRI. If Ci was resected, di was assumed to be negative (calculated as –1 × average Euclidean distance between every voxel inside the resected Ci volume, ri). Kalman filter prediction was then used to estimate an optimal resection margin, d*i, to balance benefit and risk by approximating the relationship between di and ri. Finally, the authors defined the preservation zone of Ci that can balance the probability of benefit and risk by expanding the cortical area of Ci up to d*i on the 3D cortical surface.
In the whole group (n = 77), nonresection of the preoperative preservation zone (i.e., actual resection margin d*i greater than the Kalman filter–defined d*i) accurately predicted the absence of postoperative motor (d*1–3: 0.93 at seizure-free probability of 0.80), language (d*4–8: 0.91 at seizure-free probability of 0.81), and visual deficits (d*9: 0.90 at seizure-free probability of 0.75), suggesting that the preservation of preoperative Ci within d*i supports a balance between postoperative functional deficit and seizure freedom. The subsequent subgroup analyses found that preservation of preoperative Ci
=1–4,9 within d*i
=1–4,9 may provide accurate deficit predictions independent of age and seizure frequency, suggesting that the DWI-based surgical margin can be effective for surgical planning even in young children and across a range of epilepsy severity.
Integrating DWI-MAP analysis with Kalman filter prediction may help guide epilepsy surgery by visualizing the margins of the eloquent white matter pathways to be preserved.
Zang-Hee Cho, Hoon-Ki Min, Se-Hong Oh, Jae-Yong Han, Chan-Woong Park, Je-Geun Chi, Young-Bo Kim, Sun Ha Paek, Andres M. Lozano and Kendall H. Lee
A challenge associated with deep brain stimulation (DBS) in treating advanced Parkinson disease (PD) is the direct visualization of brain nuclei, which often involves indirect approximations of stereotactic targets. In the present study, the authors compared T2*-weighted images obtained using 7-T MR imaging with those obtained using 1.5- and 3-T MR imaging to ascertain whether 7-T imaging enables better visualization of targets for DBS in PD.
The authors compared 1.5-, 3-, and 7-T MR images obtained in 11 healthy volunteers and 1 patient with PD.
With 7-T imaging, distinct images of the brain were obtained, including the subthalamic nucleus (STN) and internal globus pallidus (GPi). Compared with the 1.5- and 3-T MR images of the STN and GPi, the 7-T MR images showed marked improvements in spatial resolution, tissue contrast, and signal-to-noise ratio.
Data in this study reveal the superiority of 7-T MR imaging for visualizing structures targeted for DBS in the management of PD. This finding suggests that by enabling the direct visualization of neural structures of interest, 7-T MR imaging could be a valuable aid in neurosurgical procedures.