-
Neurosurgery 06/2013; · 2.79 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To investigate the safe displacement range of the foramen of Monro (FM) during single burr hole rigid endoscopic third ventriculostomy (ETV) and endoscopic tumor biopsy (ETB).
Eleven patients who received ETV/ETB for third ventricular and pineal region tumor were reviewed. The burr-hole location, the size, and the virtual displacement of FM were measured using neuronavigation software.
Hydrocephalus was resolved, and no subsequent cerebrospinal fluid (CSF) shunting was required in all cases. Histological diagnosis was established in 11 patients. Ten cases received instrumental cognitive and memory assessment postoperatively. The results were within the normal range for eight cases. The mean burr-hole location was 1.7 cm anterior to coronal suture and 3 cm from the midline. The mean diameters of FM measured on the axial, coronal, sagittal, and views were 5.7, 7.8, and 5.6 mm, respectively. The mean virtual displacements of the FM were 1.9 ± 2.0 mm (range = 0-4.8) for ETV and 2.4 ± 2.1 mm (range = 0-5.5) for ETB. The maximum displacements were 4.8 mm anteriorly for ETV and 5.5 mm posteriorly for ETB.
Single burr hole rigid ETV/ETB is likely to be safe within maximum FM displacements of 4.8 mm anterior for ETV and 5.5 mm posterior for ETB. Preoperative trajectory planning using neuronavigation software is recommended.
Asian Journal of Surgery 04/2013; 36(2):74-82. · 0.57 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Background and primary objective: In recent years, the Montreal Cognitive Assessment (MoCA) has been developed to assess patients with ischemic stroke. However, it has not been validated for use on traumatic brain injury patients with intracranial haemorrhage (tICH). The aim was to evaluate the psychometric properties of the MoCA (MoCA) in such patients. Research design and method: A cross-sectional observational study was carried out on 40 controls and 48 tICH patients recruited in Hong Kong. Concurrent validity was assessed by a comprehensive battery of neuropsychological tests and the Mini-Mental State Examination (MMSE). Criterion validity was assessed by the differentiation of tICH patients from controls. Main outcome and results: In tICH patients, cognitive z-scores (β = 0.579; p < 0.001) and MMSE (β = 0.366, p = 0.012) significantly correlated with performance in the MoCA after adjustment for age, gender and total score for the Geriatric Depressive Scale. For the differentiation of tICH patients from controls, analysis of receiver operating characteristics curves in the MoCA revealed an optimal balance of sensitivity and specificity at 25/26 with an area under the curve of 0.704 (p = 0.001). MoCA is applicable to and significantly correlated with excellent neurological outcomes in tICH patients. Conclusions: MoCA is a useful and psychometrically valid tool for the assessment of gross cognitive function in tICH patients.
Brain Injury 03/2013; · 1.36 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: BACKGROUND:: Experimental evidence has indicated the benefit of simvastatin in the treatment of subarachnoid haemorrhage. However, no clinical data are available to answer whether a high-dose regimen is more effective than a normal-dosage regimen, even though the biochemical actions and related neuroprotective mechanisms are thought to be dosage-related. OBJECTIVE:: We hypothesized that eighty milligrams of simvastatin daily (high dose) over three weeks initiated within 96 hours of the ictus will reduce the incidence of delayed ischaemic deficits following subarachnoid haemorrhage when compared to 40mg of simvastatin daily (normal dose), leading to improvements in clinical outcomes and thus cost-effectiveness. METHODS:: The study design is a randomized controlled double-blinded clinical trial (ClinicalTrials.gov Identifier: NCT01077206). Two hundred and forty aneurysmal subarachnoid haemorrhage patients (presenting within 96 hours of the ictus) from six neurosurgical centers are being recruited over three years. Primary outcome measure is Presence of delayed ischaemic deficits (DIDs). Secondary outcome measures include Modified Rankin Disability Score (mRS) at six months and Cost-Effectiveness Analysis. EXPECTED OUTCOMES:: This will be the first study to clarify whether high-dose simvastatin is better than normal-dose simvastatin for patients with acute aneurysmal subarachnoid haemorrhage in terms of neurological outcomes and cost-effectiveness. DISCUSSION:: In the current trial, we compare high dose to a normal dose of Simvastatin, while we know that another ongoing phase III multi-center trial compares normal dose to no Simvastatin [http://www.stashtrial.com/home.html]. When interpreted together, the research question of possible beneficial effect of high-dose Simvastatin in acute aneurysmal subarachnoid haemorrhage could be answered.
Neurosurgery 02/2013; · 2.79 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A 45-year-old woman complained of a progressive 2-month history of bilateral hearing impairment and diplopia on upward gaze. She had a history of a recurrent pineal region ganglioglioma with repeated tumor excision, adjuvant radiotherapy, and a ventriculo-peritoneal shunt performed 12 years prior. Subsequent imaging studies 6 years ago showed a pineal region cyst with progressive increase in size and a Rickham reservoir (Codman; Johnson & Johnson, Raynham, MA) was placed for percutaneous cyst fluid aspiration. The size of the cystic lesion remained static upon follow-up CT scans for several years.
Neurology 01/2013; 80(3):e23-6. · 8.31 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Objective: We aimed to investigate the profiles and prognostic values of delayed cerebral ischemia (DCI) and delayed cerebral infarction. Methods: IMASH (Intravenous Magnesium Sulphate for Aneurysmal Subarachnoid Hemorrhage) was registered at http://www.strokecenter.org/trials , and http://www.ClinicalTrials.gov (NCT00124150). Data of 327 patients were retrieved for logistic regression analyses. Results: Seventy-one (22%) patients developed DCI, and 35 (11%) patients developed delayed cerebral infarction. Only 18 (25%) patients with DCI and 7/35 (20%) patients with delayed cerebral infarction had mean middle cerebral artery velocities (transcranial Doppler ultrasound) over 120 cm/s. Regarding the prognostic significance of the components of DCI, delayed cerebral infarction predicted unfavorable outcome in terms of Extended Glasgow Outcome Scale (OR 3.1, 95% [CI] 1.3-7.8), poor outcome in terms of modified Rankin Scale (odds ratio [OR] 3.0, 95% confidence interval CI 1.2-7.7), and dependent activity of daily living in terms of Barthel Index (OR 3.6, 95% CI 1.4-9.2) at 6 months, after adjustments for other prognostic factors. On the other hand, clinical deterioration predicted inpatient mortality (OR 8.8, 95% CI 1.6-48.8) after adjustments for other prognostic factors. Conclusions: Delayed cerebral ischemia and delayed cerebral infarction carried different prognostic values in aneurysmal subarachnoid hemorrhage.
Acta neurochirurgica. Supplement 01/2013; 115:9-11.
-
[show abstract]
[hide abstract]
ABSTRACT: The neuroprotective effect of magnesium sulphate infusion has been confirmed in experimental models. Pilot clinical trials using magnesium sulphate in patients with acute aneurysmal subarachnoid hemorrhage (SAH) have reported a trend toward a reduction in clinical deterioration due to delayed cerebral ischemia (DCI) and an improvement in clinical outcomes. However, our recent multicenter trials and systemic review failed to confirm benefit in neurological outcome. In post hoc analysis, data also did not support that a higher dose of magnesium sulphate infusion might improve clinical outcome. We here review the current literature, highlight these discrepancies, and explore alternatives.
Acta neurochirurgica. Supplement 01/2013; 115:45-8.
-
[show abstract]
[hide abstract]
ABSTRACT: Cognitive deficits are common after aneurysmal subarachnoid haemorrhage (aSAH), and clinical evaluation is important for their management. Our hypothesis was that the Montreal Cognitive Assessment (MoCa) is superior to the Mini-Mental State Examination (MMSE) in screening for cognitive domain deficit in aSAH patients.
We carried out a prospective observational and diagnostic accuracy study on Hong Kong aSAH patients aged 21 to 75 years who had been admitted within 96 hours of ictus. The domain-specific neuropsychological assessment battery, the MoCA and MMSE were administered 2-4 weeks and 1 year after ictus. A cognitive domain deficit was defined as a cognitive domain z score <-1.65 (below the fifth percentile). Cognitive impairment was defined as two or more cognitive domain deficits. The study is registered at ClinicalTrials.gov of the US National Institutes of Health (NCT01038193).
Both the MoCA and the MMSE were successful in differentiating between patients with and without cognitive domain deficits and cognitive impairment at both assessment periods. At 1 year post-ictus, the MoCA produced higher area under the curve scores for cognitive impairment than the MMSE (MoCA, 0.92; 95% CI, 0.83 to 0.97 versus MMSE, 0.77; 95% CI, 0.66 to 0.83, p = 0.009).
Cognitive domain deficits and cognitive impairment in patients with aSAH can be screened with the MoCA in both the subacute and chronic phases.
PLoS ONE 01/2013; 8(4):e59946. · 4.09 Impact Factor
-
Kay Ka-Wai Li,
Ling Yang,
Jesse Chung-Sean Pang,
Aden Ka-Yin Chan,
Liangfu Zhou,
Ying Mao,
Yin Wang,
Kin-Mang Lau, Wai Sang Poon,
Zhifeng Shi,
Ho-Keung Ng
[show abstract]
[hide abstract]
ABSTRACT: MicroRNA-137 (miR-137) expression has been reported to be decreased in astrocytic tumors in two expression profiling studies but its role in the pathogenesis of oligodendroglial tumors is still limited. In this study, we demonstrate that miR-137 expression is significantly downregulated in a cohort of 35 oligodendroglial tumors and nine glioma cell lines compared with normal brains. Lower miR-137 expression is associated with shorter progressive-free survival and overall survival. Restoration of miR-137 expression in an oligodendroglial cells TC620, and also glioblastoma cells of U87 and U373 significantly suppressed cell growth, anchorage-independent growth, as well as invasion. Demethylation and deacetylation treatments resulted in upregulation of miR-137 expression in TC620 cells. In-silico analysis showed that CSE1 chromosome segregation 1-like (yeast) (CSE1L) is a potential target gene of miR-137. Luciferase reporter assay demonstrated that miR-137 negatively regulates CSE1L by interaction between miR-137 and complementary sequences in the 3' UTR of CSE1L. Immunohistochemistry revealed that CSE1L is upregulated in oligodendroglial tumors. Knockdown of CSE1L resulted in similar outcomes as overexpressing miR-137 in oligodendroglioma cells and glioblastoma cells. Overall, our data suggest that miR-137 regulates growth of glioma cells and targets CSE1L, providing further understanding in the tumorigenesis of gliomas.
Brain Pathology 12/2012; · 3.99 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: MicroRNAs (miRNAs) are members of non-coding RNAs. They are involved in diverse biological functions. MiRNAs are precisely regulated in a tissue- and developmental-specific manner, but dysregulated in many human diseases, in particular cancers. Transcriptional regulation, post-transcriptional regulation, as well as genetic alterations, are the three major mechanisms controlling the spatial and temporal expression of miRNAs. Emerging evidence now indicates that transcriptional and epigenetic regulations play major roles in miRNA expression. This review summarizes the current knowledge and discusses the future challenges.
Cancer letters 12/2012; · 4.86 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Accumulating evidence suggests that microRNAs (miRNAs) are over or under-expressed in tumors, and abnormalities in miRNA expression may contribute to carcinogenesis. MiR-383 was previously identified as one of the under-expresssed miRNAs in medulloblastoma (MB) by miRNA expression profiling. Quantitative reverse transcription (RT)-PCR-based miRNA assays showed an enrichment of miR-383 in normal brain. Based on these data, we speculated that miR-383 is important in MB pathogenesis. In this study, we demonstrated significant downregulation of miR-383 in 23/29 (79%) MB samples and 7/7 (100%) MB cells lines. Ectopic expression of miR-383 in MB cells led to suppression of cell growth, cell accumulation at sub-G1 phase, and alteration of apoptosis related proteins. By transcriptomic analysis and computational algorithms, we identified Peroxiredoxin 3 (PRDX3) as a target gene of miR-383. Luciferase reporter assay confirmed that miR-383 negatively regulated PRDX3 by interaction between miR-383 and complementary sequences in the 3' UTR of PRDX3. MiR-383 repressed PRDX3 at transcriptional and translational levels as revealed by quantitative RT-PCR and western blot analysis. Furthermore, depletion of PRDX3 by siRNAs resulted in similar effects as observed in miR-383 transfected cells. In conclusion, miR-383 acts as a regulator controlling cell growth of MB, at least in part, through targeting PRDX3.
Brain Pathology 12/2012; · 3.99 Impact Factor
-
Xiao Hong Wang,
Gang Lu,
Xiang Hu,
Kam Sze Tsang,
Wing Hang Kwong,
Feng Xia Wu,
Hai Wei Meng,
Shu Jiang,
Shu Wei Liu,
Ho Keung Ng, Wai Sang Poon
[show abstract]
[hide abstract]
ABSTRACT: BACKGROUND: Gait deficits are important clinical symptoms of Parkinson's disease (PD). However, existing behavioral tests for the detection of motor impairments in rodents with systemic dopamine depletion only measure akinesia and dyskinesia, and data focusing on gait are scarce. We evaluated gait changes in the methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced C57BL/6 murine model of PD by using a computer-assisted CatWalk system. Correlations of gait parameters with tyrosine hydroxylase (TH) protein levels in the substantia nigra (SN) were also investigated. RESULTS: The gait readouts, including the walking duration, variation of walking speed, step cycle, duty cycle, stance, initial dual stance, terminal dual stance, three- and four-point supports, and the base of support between hind limbs was noted to increase significantly one week after MPTP injection. In contrast, values of the stride length, cadence, swing speed, and diagonal dual support decreased substantially following MPTP treatment (p < 0.05). All of these changes lasted for three weeks after the last MPTP administration. Except for the stance in the fore limbs and the swing speed in the hind limbs, the gait variability in the PD mice showed a closer correlation with the protein levels of TH in the SN than the walking distances in the conventional open field test. Coordination parameters of the regularity index and step pattern were not affected in mice treated with MPTP. CONCLUSION: Data of the study suggest that the computer-assisted CatWalk system can provide reliable and objective criteria to stratify gait changes arising from MPTP-induced bilateral lesions in C57/BL6 mice. The extent of gait changes was noted to correlate with the expression of the biomarker for dopaminergic neurons. This novel analytical method may hold promise in the study of disease progression and new drug screening in a murine PD model.
BMC Neuroscience 11/2012; 13(1):142. · 3.04 Impact Factor
-
Fengqiong Yin,
Zhenhua Xu,
Zifeng Wang,
Hong Yao,
Zan Shen,
Fang Yu,
Yiping Tang,
Dengli Fu,
Sheng Lin,
Gang Lu,
Hsiang-Fu Kung, Wai Sang Poon,
Yunchao Huang,
Marie Chia-Mi Lin
[show abstract]
[hide abstract]
ABSTRACT: Chemokine CC-motif receptor-like 2 (CCRL2) is a 7-transmembrane G protein-coupled receptor which plays a key role in lung dendritic cell trafficking to peripheral lymph nodes. The function and expression of CCRL2 in cancer is not understood at present. Here we report that CCRL2 expression level is elevated in human glioma patient samples and cell lines. The magnitude of increase is positively associated with increasing tumor grade, with the highest level observed in grade IV glioblastoma. By gain-of-function and loss-of-function studies, we further showed that CCRL2 did not regulate the growth of human glioblatoma U87 and U373 cells. Importantly, we demonstrated that over-expression of CCRL2 significantly enhanced the migration rate and invasiveness of the glioblastoma cells. Taken together, these results suggest for the first time that elevated CCRL2 in glioma promotes cell migration and invasion. The potential roles of CCRL2 as a novel therapeutic target and biomarker warrant further investigations.
Biochemical and Biophysical Research Communications 11/2012; · 2.48 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Introduction. It has been theorised that the relationship between smaller body size and smaller ruptured intracranial aneurysms in Asians indirectly supports the treatment of small, unruptured intracranial aneurysms. There has also been uncertainty regarding whether the progress that has been made in neuroimaging allows for better detection of smaller ruptured intracranial saccular aneurysms. Therefore, we conducted this systemic review of ruptured intracranial saccular aneurysm sizes according to region and time. Material and Methods. Computerised MEDLINE and PubMed searches of the literature for population-based studies of ruptured intracranial saccular aneurysms were carried out from 1 January 1980 to 1 March 2011. Statistical analyses were generated using SPSS for Windows, Version 15.0 (SPSS Inc., Chicago, IL) and Comprehensive MetaAnalysis 2.0 for Windows (Biostat, Englewood, NJ). The results of the meta-analyses are presented with 95% confidence intervals (CIs). Results. Six eligible population- or hospital-based studies were analysed. The percentage of ruptured intracranial aneurysms measuring less than 5 mm was 28.4% (95% CI: 18.1% to 41.6%, I(2) = 98%). The percentage of ruptured intracranial aneurysms measuring less than 10 mm was 76.7% (95% CI: 69.2% to 82.9%, I2 = 89%). A higher proportion of patients with ruptured intracranial aneurysms of less than 5 mm was found in Asia compared to other regions. Similarly, a higher proportion of patients with ruptured intracranial aneurysms of less than 10 mm was found in Asia compared to other regions. Conclusions. The present findings suggest that ruptured intracranial aneurysms are smaller in Asians and should be confirmed in future prospective international multi-centre registries to assess ethnicity. Whether these findings support treating smaller unruptured intracranial aneurysms in Asians should be investigated.
British Journal of Neurosurgery 08/2012; · 0.88 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The identification of aneurysmal subarachnoid hemorrhage (aSAH) patients with a decrease in health-related quality of life (HRQOL) is challenging. Failure of clinical trials has been partially attributed to lack of sensitivity in outcome measures. Stroke-specific Quality of Life (SS-QOL) is a disease-specific HRQOL tool widely applied in ischemic stroke researches, but not in aSAH.
This study aimed to validate a Chinese version of SSQOL (SS-QOL-CH) for aSAH patients and proposed summary scores for clinical application.
We carried out a prospective observational assessor-blinded multi-center study in Hong Kong. One hundred and four Chinese adults were recruited into the current study, and assessments of the outcome of aSAH patients were made 3months after ictus.
Internal consistency was good and supported convergent validity for 12 domains of the SS-QOL-CH, with Cronbach's α coefficients ranging from 0.73 to 0.98. Principal component analyses suggested a two-component solution to explain a total of 65% variance. The two-component solution showed no significant floor or ceiling effects in our aSAH population. Validity of the criteria for the physical and psychosocial subtotal scores showed relevant and distinct correlations with other outcome measures.
Dichotomization of physical and psychosocial subtotal scores is valid and can simplify applications of the scale.
Journal of the neurological sciences 07/2012; 320(1-2):97-101. · 2.32 Impact Factor
-
Neurosurgery 06/2012; 71(4):E912. · 2.79 Impact Factor
-
ANZ Journal of Surgery 06/2012; 82(6):476. · 1.25 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In this study we describe a novel polymer, mPPS-FA, synthesized as a potential gene transfer vector. To complete mPPS-FA, folic acid was conjugated to a backbone (named mPPS) consisting of a copolymer of methyl PEG-2000, PEI-600, and sebacoyl chloride. (1)H NMR, FT-IR, and UV spectroscopy were used to characterize the structure of mPPS-FA. It was revealed that mPPS-FA holds the ability to bind plasmid DNA yielding positively charged particles (polyplexes). Dynamic light scattering (DLS) and TEM techniques were used to study the size and morphology of the formed mPPS-FA/DNA nanocomplexes. The mPPS-FA/DNA nanoparticles exhibited low cytotoxicity as transfection of B16-F0, U87MG, CHO-1, and Ho-8910 cells produced >80% viability indicating low cytotoxicity of the polymer. The ability of mPPS-FA to deliver EGFP plasmid to melanoma B16-F0, U87, CHO-1, Ho-8910, and A549 cells was investigated in vitro as compared to the lipid-based transfection agent Lipofectamine2000 and Linear PEI 22 kDa (L-PEI 22 kDa). We found that mPPS-FA/DNA complexes yielded the highest GFP transfection efficiency in B16-F0, U87, CHO-1, and Ho-8910 cells, which all highly express folate receptors (FR), at an mPPS-FA/DNA ratio (w/w) of 15. Furthermore, the transfection of mPPS-FA/DNA complexes in CHO-1 cells could be competitively blocked by free folic acid molecules. In contrast, in low FR expressing A549 cells, mPPS-FA showed similar low transfection efficiency as mPPS. Taken together, mPPS-FA showed the highest efficiency in vitro and the potential to be developed as a nonviral gene carrier.
International journal of pharmaceutics 04/2012; 426(1-2):182-92. · 2.96 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: With the advanced technology of multi-slice CT scans, we explored the effectiveness of CT angiography (CTA) in place of digital subtraction angiography (DSA) in patients with acute spontaneous intracerebral hemorrhage (ICH). We performed a computerized PubMed search of the literature from inception to 27 July 2011 to find reports of similar comparative studies and performed a meta-analysis of diagnostic accuracy. The pooled sensitivity was 97.0% (95% confidence interval [CI]: 93.2-99.1%), specificity was 98.9% (95% CI: 97.0-99.7%), accuracy was 98.2% (95% CI: 96.6-99.2%), positive predictive value was 97.8% (95% CI: 94.2-99.5%) and negative predictive value was 98.5% (95% CI: 96.6-99.5%). The false negative rate was 1% (95% CI: 0.4-2.6%). We concluded that CTA with venography could replace DSA as the initial vascular investigation in patients presenting with spontaneous ICH during the acute phase. Future studies should focus on whether refinement of the techniques could preclude the false negative results.
Journal of Clinical Neuroscience 04/2012; 19(4):498-500. · 1.25 Impact Factor
-
Brain Pathology 03/2012; 22(2):255-8. · 3.99 Impact Factor
