Cerebellar hemangioblastoma mimicking an aneurysm: A case report and literature review.

Hemangioblastomas (HBMs) are highly vascular tumors of the central nervous system. Sporadic HBMs are nearly always solitary, and solitary HBMs are similar to intracranial arteriovenous malformations due to their highly vascular characteristics. However, to the best of our knowledge, cases of HBM in the cerebellum mimicking an aneurysm have never been reported in the literature. The present study reports a case of an HBM on the right cerebellar hemisphere mimicking an aneurysm, which originated from the right posterior inferior cerebellar artery, as determined using magnetic resonance angiography and digital subtraction angiography. The patient was admitted the Department of Neurosurgery at the Tsinghua University Yuquan Hospital (Beijing, China) in January 2015 due to a 4-year history of intermittent headaches. The diagnosis of an HBM was determined during surgery and the tumor was totally resected by changing the operation technique, with no complications. In conclusion, it is difficult to distinguish between HBMs and intracranial vascular diseases, particularly aneurysms. Surgeons should consider the possibility carefully prior to surgery and careful prepare for each eventuality.

Extraventricular neurocytoma in the left temporal lobe: A case report and review of the literature.

Central neurocytoma (CNC) often develops in the ventricular system adjacent to the interventricular foramen and septum pellucidum. According to the World Health Organization, CNCs are classified as grade II tumors, and in recent years it has been reported that CNCs have occasionally occurred in rare areas of the central nervous system. The current study describes a rare case of CNC located in the left temporal lobe of a 49-year-old man, who had been experiencing headaches for 3 weeks. Computed tomography identified a round, well-demarcated, 3.3-cm tumor in the left temporal lobe. The patient underwent surgery and the tumor was totally resected. Histological analysis demonstrated that the resected tumor tissue contained clusters of small cells with regular nuclear morphology, and round nuclei with fine chromatin. Immunohistochemically, neuronal differentiation markers, including synaptophysin and neuronal nuclear antigen, were expressed in the tumor cells. Histopathological examination of the resected tissue confirmed a diagnosis of extraventricular neurocytoma. Magnetic resonance imaging was performed at 3 months post-surgery and demonstrated no evidence of tumor recurrence.

Combining task-evoked and spontaneous activity to improve pre-operative brain mapping with fMRI.

Noninvasive localization of brain function is used to understand and treat neurological disease, exemplified by pre-operative fMRI mapping prior to neurosurgical intervention. The principal approach for generating these maps relies on brain responses evoked by a task and, despite known limitations, has dominated clinical practice for over 20years. Recently, pre-operative fMRI mapping based on correlations in spontaneous brain activity has been demonstrated, however this approach has its own limitations and has not seen widespread clinical use. Here we show that spontaneous and task-based mapping can be performed together using the same pre-operative fMRI data, provide complimentary information relevant for functional localization, and can be combined to improve identification of eloquent motor cortex. Accuracy, sensitivity, and specificity of our approach are quantified through comparison with electrical cortical stimulation mapping in eight patients with intractable epilepsy. Broad applicability and reproducibility of our approach are demonstrated through prospective replication in an independent dataset of six patients from a different center. In both cohorts and every individual patient, we see a significant improvement in signal to noise and mapping accuracy independent of threshold, quantified using receiver operating characteristic curves. Collectively, our results suggest that modifying the processing of fMRI data to incorporate both task-based and spontaneous activity significantly improves functional localization in pre-operative patients. Because this method requires no additional scan time or modification to conventional pre-operative data acquisition protocols it could have widespread utility.

Sturge-Weber Syndrome Is Associated with Cortical Dysplasia ILAE Type IIIc and Excessive Hypertrophic Pyramidal Neurons in Brain Resections for Intractable Epilepsy.

Sturge-Weber syndrome (SWS) is a rare syndrome characterized by capillary-venous malformations involving skin and brain. Many patients with SWS also suffer from drug-resistant epilepsy. We retrospectively studied a series of six SWS patients with epilepsy and extensive neurosurgical resections. At time of surgery, the patients' age ranged from 11 to 35 years (with a mean of 20.2 years). All surgical specimens were well preserved, which allowed a systematic microscopical inspection utilizing the 2011 ILAE classification for focal cortical dysplasia (FCD). Neuropathology revealed dysmorphic-like neurons with hypertrophic cell bodies reminiscent to those described for FCD type IIa in all cases. However, gross architectural abnormalities of neocortical layering typical for FCD type IIa were missing, and we propose to classify this pattern as FCD ILAE type IIIc. In addition, our patients with earliest seizure onset also showed polymicrogyria (PMG; n = 4). The ictal onset zones were identified in all patients by subdural electrodes, and these areas always showed histopathological evidence for FCD type IIIc. Four out of five patients had favorable seizure control after surgery with a mean follow-up period of 1.7 years. We concluded from our study that FCD type IIIc and PMG are frequently associated findings in SWS. FCD type IIIc may play a major epileptogenic role in SWS and complete resection of the associated FCD should be considered a prognostic key factor to achieve seizure control.

Correlation between LIFG and autonomic activation during stressful tasks: a functional near-infrared spectroscopy (fNIRS) study.

It remains unclear whether language tasks in one's first (L1) or second (L2) language can cause stress responses and whether frontal, autonomic and behavioral responses to stressful tasks are correlated. In this study, we studied 22 Chinese subjects whose L2 was English and measured the cerebral blood oxygenation in their frontal lobe by using functional near-infrared spectroscopy (fNIRS) as participants engaged in a mental arithmetic task (MAT) and verbal fluency tasks (VFTs) in L1 (Chinese) and L2 (English). To examine the activated cortical areas, we estimated the channel location based on Montreal Neurological Institute (MNI) standard brain space by using a probabilistic estimation method. We evaluated heart rate (HR) changes to analyze autonomic nervous system (ANS) functioning. We found that the MAT and VFTs induced greater increases in HR than did the control (Ctrl) task. Furthermore, subjects developed greater increases in HR in the MAT and VFTL2 than they did in the VFTL1. Compared with the Ctrl task, the MAT and both VFTL1 and VFTL2 produced robust and widespread bilateral activation of the frontal cortex. Interestingly, partial correlation analysis indicated that the activity in the left inferior frontal gyrus (LIFG) [Brodmann's area (BA) 47] was consistently correlated with the increases in HR across the three tasks (MAT, VFTL2, and VFTL1), after controlling for the performance data. The present results suggested that a VFT in L2 may be more stressful than in L1. The LIFG may affect the activation of the sympathetic system induced by stressful tasks, including MATs and VFTs.

[Gamma event-related synchronization analysis: a new method for cortical function mapping].

OBJECTIVE: To localize the sensory motor cortex of human brain by analyzing the power change in Gamma band (> 60 Hz) of electrocorticography (ECoG) data. METHODS: Eight patients with intractable epilepsy underwent temporary placement of subdural electrodes. After surgery, sensory evoked potential (SEP), electrocortical stimulation (CES) and event-related synchronization analysis of Gamma band (Gamma ERS analysis) were performed to reduce the risk of complications. The results of Gamma ERS analysis were compared with those of SEP and CES. RESULTS: The results of Gamma ERS analysis had 80.7% electrodes fitting perfectly those of CES and SEP. And the percentage reached 92.3% if electrodes were superimposed or added adjacently. CONCLUSION: The Gamma ERS analysis is a new sensitive and precise method for cortical function mapping.

The regeneration of transected sciatic nerves of adult rats using chitosan nerve conduits seeded with bone marrow stromal cell-derived Schwann cells.

Autologous nerve grafts have been the 'gold standard' for treatment of peripheral nerve defects that exceed the critical gap length. To address issues of limited availability of donor nerves and donor site morbidity, we have fabricated chitosan conduits and seeded them with bone marrow stromal cell (BMSC)-derived Schwann cells as an alternative. The derived Schwann cells used were checked for fate commitment. The conduits were tested for efficacy in bridging the critical gap length of 12 mm in sciatic nerves of adult rats. By three months post-operation, mid-shank circumference, nerve conduction velocity, average regenerated myelin area, and myelinated axon count, in nerves bridged with BMSC-derived Schwann cells were similar to those treated with sciatic nerve-derived Schwann cells (p > 0.05) but significantly higher than those bridged with PBS-filled conduits (p < 0.05). Evidence is thus provided in support of the use of chitosan conduits seeded with BMSC-derived Schwann cells to treat critical defects in peripheral nerves. This provides the basis to pursue BMSC as an autologous source of Schwann cells for transplantation therapy in larger animal species.

Neuroprotective effect of piperine on primarily cultured hippocampal neurons.

It was previously reported that piperine (PIP) significantly blocks convulsions induced by intracerebroventricular injection of threshold doses of kainate, but had no or only slight effects on convulsions induced by L-glutamate, N-methyl-D-aspartate and guanidinosuccinate. In traditional Chinese medicine, black pepper has been used for epileptic treatment; however, the exact mechanism is still unclear. We reported here in that appropriate concentration of PIP effectively inhibites the synchronized oscillation of intracellular calcium in rat hippocampal neuronal networks and represses spontaneous synaptic activities in terms of spontaneous synaptic currents (SSC) and spontaneous excitatory postsynaptic currents (sEPSC). Moreover, pretreatment with PIP expects protective effect on glutamate-induced decrease of cell viability and apoptosis of hippocampal neurons. These data suggest that the neuroprotective effects of PIP might be associated with suppression of synchronization of neuronal networks, presynaptic glutamic acid release, and Ca(2+) overloading.

The use of topical intranasal fluorescein in endoscopic endonasal repair of cerebrospinal fluid rhinorrhea.

BACKGROUND: The CSF rhinorrhea is a kind of common clinical disease. The preoperative diagnosis and intraoperative localization of CSF fistulas are critical to treatment of CSF rhinorrhea. At present, intrathecal fluorescein regarding endoscopic transnasal cerebrospinal leakage repair is a common method for localization of the fistula; however, it has some disadvantages because it needs a specific endoscope, and the trauma from lumbar puncture as well as the potential complications of intrathecal fluorescein, as a result, widely limited its clinical use. Topical intranasal fluorescein can avoid the above-mentioned shortcoming. The aim of this work was to describe the use of topical fluorescein in the intraoperative localization of CSF fistulas and to screen its use in preoperative diagnosis of CSF rhinorrhea. METHODS: Fifteen patients with CSF rhinorrhea were treated with an endoscopic endonasal technique. Topical intranasal 5% fluorescein for preoperative diagnosis and intraoperative localization of the site of the leak was placed in middle turbinate meatus, the roof of the ethmoid plate, and sphenoethmoidal recesses. A change in the color of the fluorescein from brown to green fluorescence denoted the presence of CSF, and the site of the leak could be traced. The accuracy rate of diagnosis and leak site identification was made by comparison with glucose analysis, intraoperative findings, and follow-up. RESULTS: The cause of the leak was accidental trauma in 5 patients and spontaneous in 10 patients. The preoperative use of fluorescein-soaked cotton was 100% accurate in diagnosing CSF rhinorrhea. The intraoperative use of topical intranasal fluorescein was also 100% accurate in locating the site of the CSF fistula when compared with the surgical findings. It had achieved 100% success rate in sealing the CSF fistulas in our 15 patients with no recurrence detected during the follow-up period (mean, 2-24 months). No complications have been reported. CONCLUSION: In the presence of a clinically diagnosed CSF leakage and location of the leakage fistula, topical fluorescein is a very easy, sensitive, safe, and highly accurate tool in the intraoperative localization of the site and extent of CSF fistulas. It should be considered as a viable noninvasive alternative to intrathecal fluorescein.

[Application of topical intranasal fluorescein in endoscopic endonasal repair of cerebrospinal fluid leakage].

OBJECTIVE: To investigate the effects of topical fluorescein on the preoperative diagnosis of rhinorrhea of cerebrospinal fluid (CSF) and intraoperative localization of CSF fistula. METHODS: Cotton pads soaked with 5% fluorescein were placed in the middle turbinate meatus, roof of ethmoid plate, and sphenoethmoidalis recesses via endoscopic endonasal technique of 15 patients with CSF rhinorrhea, 5 caused by accidental trauma and 10 spontaneous. Change of the color of fluorescein from yellow to green fluorescence denoted the presence of CSF, and thus the site of the leak could be traced. The accuracy rates of diagnosis and leak site identification by this technique were compared with those by glucose analysis, intraoperative findings, and follow-up. RESULTS: The preoperative diagnosis rate of CSF rhinorrhea and the CSF fistula site localization rate by fluorescein-soaked cotton pad were both 100%. No recurrence was found during the follow-up for 2 - 24 months. No complication had been reported. CONCLUSIONS: Application of topical fluorescein is an easy, sensitive, safe, and highly accurate tool in the intraoperative localization of the site and extent of CSF fistulas and should be considered a viable noninvasive alternative to intrathecal fluorescein technique.

Deoxyschisandrin modulates synchronized Ca2+ oscillations and spontaneous synaptic transmission of cultured hippocampal neurons.

AIM: Deoxyschisandrin is one of the most effective composites of Schisandra chinensis, a famous Chinese medicine widely used as an antistress, anti-aging, and neurological performance-improving herb. In this study, we examined its specific mechanisms of action on cultured hippocampal neurons. METHODS: Hippocampal neurons, primarily cultured for 9-11 d in vitro, were used for this study. DS were dissolved in DMSO and applied to calcium imaging and whole-cell patch clamp. RESULTS: The application of 3 mg/L DS decreased the frequency of spontaneous and synchronous oscillations of intracellular Ca2+ to 72%+/-2% (mean+/-SEM), and the spontaneous inhibitory postsynaptic currents to 60%+/-3% (mean+/-SEM). The inhibitory concentration 50% (IC50) for the effect of DS on calcium oscillations was 3.8 mg/L. DS also depressed the high voltage-gated Ca2+ channel and the voltage-gated Na+ channel currents at the same time point. It had no effect, however, on voltage-gated K+ and spontaneous excitatory postsynaptic currents. CONCLUSION: DS inhibited the spontaneous and synchronous oscillations of intracellular Ca2+ through the depression of influx of extracellular calcium and the initiation of action potential. By repressing the spontaneous neurotransmitter release, DS modulated the neuronal network activities.

[Neurotomy of the tibial nerve for treatment of the talipes equinovarus].

OBJECTIVE: To explore indication and approaches of neurotomy of tibial nerve for the treatment of the talipes equinovarus and spastic paralysis. METHOD: A total of 25 patients including 15 patients with cerebral paralysis and other 10 patients were diagnosed with clear etiology, spastic muscles with supplied nerves were analyzed in detail, neurotomy of the tibial nerve was performed under microscope, during operation, motor nerve was lovated with electronic stimuli and monitored with induced electromyography. The surgical results were analyzed. RESULTS: A total of 36 of 37 (97%) neurotomy of the tibial nerve were improved with dorsum flex of ankle at 10 - 45 degree, and 22 of 24 (85%) talipes equinovarus improved clinically. Of 37 feet with surgery, 24 feet (65%) were in normal position and could touch ground completely, 9 feet (24%) had 10 degree with ground or could contact ground with external one third of the feet, 4 feet (11%) were abnormal. Of 25 patents, 21 (84%) had improvement of motor activity at discretion, 5 patients (20%) improved dramatically. All the 4 patients failed after the operation were cerebral paralysis, and were presumably related to disorders of spinal function, abnormal reflex and the disappearance of inhibitory reflex. CONCLUSION: Neurotomy is an effective method to treat talipes equinovarus, and can improve the motor activity of low extremity.

The design and application of DNA chips for early detection of SARS-CoV from clinical samples.

BACKGROUND: SARS coronavirus has been identified as the cause of severe acute respiratory syndrome (SARS). Few tests allow confirmation or exclusion of SARS within the first few days of infection. A gene chip is a useful tool for the study of microbial infections mainly for its capability of performing multi-target analysis in a single test. OBJECTIVES: Investigate the possibility of early detection of SARS virus from clinical samples using the gene chip-based method. STUDY DESIGN: We purified RNA from SARS-CoV obtained from routinely collected peripheral blood and sputum samples of 34 patients who had been identified as probable SARS patients by following the interim U.S. case definition. Four segments of the SARS-CoV were amplified using reverse transcription-nested PCR and the products examined using the 70-mer gene chips for SARS-CoV detection. RESULTS: A blind-test of both peripheral blood and sputum specimens lead to the positive detection of SARS-CoV in 31 out of 34 patients. SARS-CoV was not found in peripheral blood or sputum specimens from three patients. Two of the 34 patients were only 3 days post-onset of symptoms and were subsequently confirmed to be SARS positive. Our results indicate that the gene chip-based molecular test is specific for SARS-CoV and allows early detection of patients with SARS with detection rate about 8% higher than the single PCR test when the sputum sample is available.

GDNF augments survival and differentiation of TH-positive neurons in neural progenitor cells.

GDNF plays an important role in the survival and differentiation of primary dopaminergic neurons, but it requires multiple factors for its entire range of activities. This study investigated the effects of GDNF and its cofactors on the development of bFGF-responsive neural progenitor cells (NPCs), mesencephalic and cortical progenitor cells (MP and CP). Various factors were found to have significant inductive effects on the survival and maintenance of these cells in late developmental stages. MP had greater potential than CP to differentiate into dopaminergic neurons. Treatment of NPCs with GDNF and its cofactors enhanced MAP-2 and TH expression, particularly the latter. These findings suggest that NPCs, particularly MP, could develop into more specific neurons if the appropriate factors were applied during the final cell fate specification. They might thus become beneficial sources of donor cells in the treatment of neurological disorders.

Green fluorescent protein-labeled mapping of neural stem cells migrating towards damaged areas in the adult central nervous system.

Neural stem cells, which are clonogenic cells with multilineage differentiation properties from regions of the fetal brain, cortex and hippocampus, are currently considered as powerful candidates for cell replacement therapy in neurodegenerative disorders, such as Parkinson's disease. A key issue is whether stem cells can survive, migrate and differentiate following transplantation into the adult CNS. Here, enhanced green fluorescent protein plasmid electroporation-transfected neural stem cells from the fetal cortex were grafted into the striatum of a rat model of Parkinson's disease. We found most of the grafted cells could survive in the adult parkinsonian rat brain and migrated towards damaged areas, while they moved randomly in the normal brain. Several grafted cells differentiated into neurons.

[Causes of ineffectiveness of microvascular decompression for hemifacial spasm].

OBJECTIVE: To study causes of ineffectiveness of microvascular decompression (MVD) in treatment of hemifacial spasm (HFS). METHODS: Reoperative MVD was performed in 23 HFS patients with previous ineffective MVD. In the patients, the main causes of ineffectiveness included misjudgment of compressing vessels (7 patients), improper insertion of decompressing grafts (9), improper selection of grafts (5) and small grafts (2). RESULTS: Symptoms of HFS disappeared immediately after the second MVD in 21 patients and delayed in 2 patients (after 2 weeks, 6 weeks). No recurrence of HFS was noted during the follow-up period of 1.0 - 6.0 years (mean 3.4 years). CONCLUSIONS: MVD is an effective microsurgical method for treating HFS. Accurate judgement of compressing vessels and proper decompression are the key to surgical effectiveness.