Increased brain water content in pseudotumour cerebri measured by magnetic resonance imaging of brain water self diffusion

Brain water self diffusion was investigated by magnetic resonance scanning in 7 patients fulfilling conventional diagnostic criteria for pseudotumour cerebri. Quantitative diffusion measurements were obtained using single spin echo pulse sequences with pulsed magnetic field gradients of different magnitude. In all patients the diffusion images showed an increased diffusion in various brain regions when compared with the diffusion coefficients for corresponding regions in healthy subjects. In 3 pseudotumour patients the increased self diffusion was localized to the periventricular regions, while 4 patients had increased diffusion in the whole brain. The findings indicate the presence of increased brain water content both intra- and extracellularly suggesting that patients with pseudotumour have two defects of pathogenetical significance: intracellular water accumulation and increased resistance to cerebrospinal fluid (CSF) outflow leading to an interstitial oedema.     

Supratentorial pressures: Part II: Intracerebral pulse waves

Intracerebral pulse waves were recorded in cat and monkey while intracranial pressure (ICP) manipulations were performed. The intracerebral pulse waves appeared comparable to cerebrospinal fluid (CSF) pulsations. The wave forms were divided into multiple smaller waves, designated P₁ to P₄. The P₁ component was primarily of arterial origin and was accentuated by increasing ICP unrelated to increased venous pressure, most commonly from a mass lesion. Bilateral carotid occlusion resulted in decreased amplitude of P₇. Venous hypertension from jugular venous or sagittal sinus occlusion, on the other hand, accentuated waves P₂ and P₃ more than P₇. This is consistent with a Starling resistor model of the cerebral venous system in which mass lesions may compress low-pressure veins and accentuate the arterial pressure-dependent P₁ wave, whereas venous hypertension causes increased prominence of the later P₂ and P₃ waves.     

Remote cerebellar hemorrhage following supratentorial craniotomy

Abstract

Objective: Cerebellar hemorrhage remote from the site of surgery may complicate neurosurgical procedure. The exact pathophysiology of this type of hemorrhage is poorly understood. We retrospectively compared 16 patients who had remote cerebellar hemorrhage (RCH) with a case-matched control cohort, to determine the significance of perisurgical and surgical factors that may predispose patients to such bleeding events.

Methods: From 1 June 2005 to 31 December 2008, postoperative routine head computed tomographic (CT) scan was performed in our institution and 16 patients with RCH after supratentorial neurosurgical procedure were identified. The medical charts of these 16 cases and a control cohort of 64 patients were recorded. All parameters were analyzed with regards to various variables.

Results: The incidence RCH after supratentorial craniotomy increased after postoperative computed tomographic scan. The mechanism of cerebellar hemorrhage in this series of patients is most likely multifactorial. Several variables showed a significant association with the occurrence of RCH. Multivariate analysis indicated that the following two factors independently correlated with occurrence of RCH: (1) postoperative epidural drainage amount; and (2) history of previous cerebrovascular accident (CVA) with cerebral atrophy. All cases with RCH underwent medical treatment and no neurological sequelae associated with RCH.

Conclusions: Postoperative epidural drainage amount and history of previous CVA with cerebral atrophy can reliably predict the occurrence of cerebellar hemorrhage after supratentorial craniotomy. One of the most important strategies to minimize hazardous complications is to be aware of these potential risk factors and to take action to prevent them.     

Treatment of huge hypertensive putaminal hemorrhage by surgery and cerebrospinal fluid drainage

Objective

There is limited information available regarding the treatment of huge hypertensive putaminal hemorrhage (HPH). This study aimed to evaluate our experience of 33 patients with huge HPH who were treated by open surgery (decompressive craniectomy and hematoma evacuation) and external cerebrospinal fluid (CSF) drainage.

Methods

We reviewed the records of 33 consecutive patients admitted to our hospital with huge HPH (≥60 cm³). All patients were treated by decompressive craniectomy, hematoma evacuation, and CSF drainage. Data collected included age, gender, blood pressure at admission, Glasgow Coma Scale (GCS) score, intracranial hemorrhage (ICH) location, ICH volume, degree of midline shift, presence/absence of basal cistern obliteration at admission and before surgery, and presence/absence of intraventricular hemorrhage (IVH). Outcome was assessed by the Glasgow Outcome Scale score at 30 days after surgery.

Results

The median GCS score was 5.0 at admission, and improved to 8.0 at 1 week after surgery. The median ICH volume was 95 cm³ before surgery and 4 cm³ after surgery. IVH was observed in 93.9% of patients. The overall survival rate to discharge was 75.6% (25/33), including 15.1% (4/33) with good function, 36.4% (12/33) with disability, and 24.3% (8/33) in a vegetative state. The mortality rate was 24.3% (8/33). Patients with right-sided ICH had better outcomes than those with left-sided ICH. No patients with GCS score ≤6 and ICH volume ≥90 cm³ at admission achieved good postoperative function. Operative time was significantly shorter with hematoma evacuation via the transcortical approach than via the transsylvian approach (3.41 ± 0.75 h vs. 4.14 ± 0.59 h, P < 0.001). There were no significant differences in the rates of mortality or survival with good function between the two groups.

Conclusions

Treatment of huge HPH by decompressive craniectomy, hematoma evacuation, and CSF drainage is life-saving. Patients with GCS score 7–8, ICH volume 60–90 cm³, and right-sided ICH may achieve good recovery. The transcortical approach appears to be more effective than the transsylvian approach for rapid decompression of the edematous brain.     

Vascular endothelial growth factor in the CSF of elderly patients with ventriculomegaly: Variability,periodicity and levels in drainage responders and non-responders

Objectives

The aim of this study was to examine lumbar CSF-VEGF levels from elderly patients with ventriculomegaly to evaluate the possible circadian or periodic concentration profile and relevance to the prediction of drainage response.

Methods

Lumbar CSF samples were collected in 1-h interval over 35 h from 22 patients with ventriculomegaly. CSF-VEGF levels were measured to elucidate the possible circadian or periodic concentration profiles. These VEGF levels were evaluated for correlations with clinical response to CSF drainage, ventricle size and other clinical information.

Results

The 35-h CSF-VEGF levels demonstrated a periodic concentration pattern with significant episodic fluctuation with 3–5 h intervals. CSF-VEGF levels in non-responder group in which patients did not show clinical improvement with CSF drainage were significantly higher than these in responder group.

Conclusion

VEGF variation in hydrocephalus patients suggests its possible pathophysiological role in hydrocephalus. The periodic concentration pattern of CSF-VEGF must be considered when choosing the most appropriate time for sample collection or clinical manipulation. Increased VEGF level in patients who showed no improvement with CSF drainage suggests that a possible greater ischemic or vascular injury may play a role in these patients. Pending further studies, these results suggest that high VEGF levels have a potential application in predicting non-responder patients with CSF drainage and so reducing the morbidity and cost of drainage and shunting in these patients.     

Granulocyte macrophage colony‐stimulating factor promotes regeneration of retinal ganglion cells in vitro through a mammalian target of rapamycin‐dependent mechanism

Lack of regeneration in the adult central nervous system (CNS) is a major hurdle that limits recovery from neurological ailments. Although accumulating research suggests the possibility of axon regeneration by targeting intrinsic signaling mechanisms, it remains a matter of controversy whether functional recovery can be achieved by manipulating aspects of molecular signaling. Recent studies have shown that granulocyte macrophage colony‐stimulating factor (GM‐CSF) may be an effective means of targeting repair following CNS injury; how this molecule is able to produce this effect is not known. Indeed, GM‐CSF has been shown to promote neuronal survival, potentially through activation of as yet unknown cytokine‐dependent signals and potentially through regulation of antiapoptotic mechanisms. It is well established that the loss of intrinsic regenerative ability is highly correlated with development of CNS neurons. We therefore designed experiments, using a well‐established in vitro retinal ganglion cell (RGC) culture system, to evaluate the effect of GM‐CSF on axon growth and cell survival and define possible mechanisms involved in GM‐CSF‐mediated effects in vitro. Several developmental stages were evaluated, with particular focus placed on stages at which axon growth is known to be significantly diminished. Our results reveal that GM‐CSF not only promotes axon growth in postnatal RGCs but also enhances cell survival through a mammalian target of rapamycin (mTOR)‐dependent mechanism. © 2013 Wiley Periodicals, Inc.     

SYSMEX XN-1000血球仪在脑脊液和胸腹水白细胞计数中的可行性探讨

目的：探讨SYSMEX XN-1000血液分析仪(简称SYSMEX XN-1000)的体液模式在脑脊液和胸腹水白细胞计数中应用的可行性。方法分别采用手工显微镜镜检法和SYSMEX XN-1000对183例脑脊液和胸腹水标本进行白细胞计数,将所测结果按A：(0~1000)×106/L,B：(1001~5000)×106/L,C：>5000×106/L分为三组,分别进行统计学分析。结果与手工显微镜镜检法相比,SYSMEX XN-1000所测结果差异无统计学意义(P>0.05)。A、B、C三组的相关系数分别为0.993、0.984、0.996,A组回归方程为y=1.007x-1.072,B组回归方程为y=1.003x+19.776,C组回归方程为y=1.241x-1419.365。结论 SYSMEX XN-1000血液分析仪可用于临床脑脊液和胸腹水中白细胞计数,其操作简单易行,结果稳定可靠,但如果仪器进行样品检测时报警,应当手工镜检复核,以提高结果的准确性和可靠性。     

Influence of delayed CSF storage on concentrations of phospho-tau protein (181), total tau protein and beta-amyloid (1-42)

It is generally accepted that cerebrospinal fluid (CSF) biomarkers such as tau protein, phosphorylated tau protein (threonine 181) and beta-amyloid (1-42) can facilitate early and differential diagnosis of Alzheimer's disease (AD). Since the respective concentrations can only be measured in a number of specialized centers, time to CSF specimen work-up has been considered as crucial for the stability of the respective biomarkers. When shipping of CSF samples is needed for biomarker measurement and immediate freezing of samples is not available, an overnight delay of up to 24h frequently occurs. Therefore, we investigated the potential impact of a 24h delayed freezing on CSF biomarker concentrations and compared it to 2h storage (room temperature, 20 degrees C) and an immediate freezing. First, storage at room temperature for 2h had only marginal, non-significant effects on the concentrations of CSF total tau protein and phospho-tau protein (181) compared to immediate freezing. Second, storage at room temperature for 24h did not significantly affect total tau protein or phospho-tau protein but beta-amyloid (1-42) concentrations which increased significantly compared to the samples frozen immediately. These results indicate that CSF samples for the evaluation of total tau and phospho-tau protein may be kept at room temperature for up to 24h whereas CSF samples for beta-amyloid (1-42) need to be frozen immediately.     

Role of spinal metabotropic glutamate receptors in regulation of lower urinary tract function in the decerebrate unanesthetized rat

Biomarker levels in cerebrospinal fluid (CSF) may serve as surrogate markers for treatment efficacy in clinical trials of disease-modifying drugs against Alzheimer's disease (AD). A prerequisite, however, is that the marker is sufficiently stable over time in individual patients. Here, we tested the stability of the three established CSF biomarkers for AD, total tau (T-tau), tau phosphorylated at threonine 181 (P-tau(181)) and the 42 amino acid isoform of beta-amyloid (Abeta42), over 6 months in a cohort of AD patients on stable treatment with acetylcholinesterase (AChE) inhibitors. Fifty-three patients completed the study, 29 men and 24 women, mean age (+/-S.D.) 76.1+/-7.9 years. Mean levels of CSF biomarkers were very stable between baseline and endpoint, with coefficients of variation (CVs) of 4.4-6.1%. Intra-individual biomarker levels at baseline and endpoint were also highly correlated with Pearson r-values above 0.95 (p<0.0001), for all three markers. We conclude that T-tau, P-tau and Abeta42 concentrations in CSF are remarkably stable over a 6-month period in individual AD patients. This suggest that these biomarkers may have a potential to identify and monitor very minor biochemical changes induced by treatment, and thus support their possible usefulness as surrogate markers in clinical trials with drug candidates with disease-modifying potential, such as secretase inhibitors, Abeta immunotherapy and tau phosphorylation inhibitors.