Endoscopic management of a low-grade thalamic glioma: a safe alternative to open microsurgery?

Background

Despite considerable advances in preoperative and intraoperative imaging and neuronavigation, resection of thalamic gliomas remains challenging. Although both endoscopic biopsy and third ventriculostomy (ETV) for the treatment of secondary hydrocephalus are commonly performed, endoscopic resection of thalamic gliomas has been very sparsely described.

Method

We report and illustrate the surgical procedure and patient’s outcome after full endoscopic resection of a thalamic glioma and to discuss this approach as an alternative to open microsurgery.

Results

In 2016, a 56-year-old woman presented with disorientation, dysphasia and right facial hypaesthesia in our department. Cranial magnetic resonance imaging revealed a left thalamic lesion and subsequent hydrocephalus. Initially, hydrocephalus was treated by ETV but forceps biopsy was not diagnostic. However, metabolism in ¹⁸F-fluoroethyl-L-tyrosine positron emission tomography indicated glioma. Subsequently, endoscopic and neuronavigation-guided tumour resection was performed using a <1 cm², trans-sulcal approach through the left posterior horn of the lateral ventricle. While visibility was poor using the intraoperative microscope, neuroendoscopy provided excellent visualisation and allowed safe tumour debulking. Neither haemorrhage from the tumour or collapse of the cavity compromised endoscopic resection.

Conclusions

In accordance with one previously published case of endoscopic resection of a thalamic glioma, no surgery-related complications were observed. Although this remains to be determined in larger series, endoscopic resection of these lesions might be a safe and feasible alternative to biopsy or open surgery. Future studies should also aim to identify patients specifically eligible for these approaches.

     

Effect of long term caffeine treatment on A1 and A2 adenosine receptor binding and on mRNA levels in rat brain

Summary The effect of long-term oral treatment with caffeine on A₁ and A₂ receptors in the rat brain was studied. Caffeine was added to the drinking water and the animals were sacrificed after a 12 day treatment period. The plasma caffeine concentration was close to 100 M. A₁ receptors were studied using quantitative autoradiography with [³H]cyclohexyladenosine (CHA). Caffeine treatment increased the number of A₁ receptors in the CA3 subfield of the hippocampus from 337 to 393 fmol/mg with no change in K_D (0.692 vs. 0.675 nM). A₁ mRNA was measured using Northern blots and quantitative in situ hybridization. There was no increase in A₁ mRNA. A_2a receptors, located in dopamine rich regions of the rat brain, were studied with quantitative autoradiography using [³H]CGS 21680 as the ligand, and the A_2a mRNA was determined using quantitative in situ hybridization. Caffeine treatment produced no significant change in either receptor number or mRNA, even though the apparent B_max tended to increase from 322±8 to 352±8 fmol/mg. The results show that treatment with caffeine in a dose that causes tolerance to several effects of caffeine and increases some effects of adenosine analogues increases the number of A₁ receptors without any change in A₁ mRNA, suggesting that the adaptive changes are at a post-translational level. There were no significant changes in A₂ receptors indicating that the two types are regulated differently and/or that the amount of endogenous agonist is sufficient to regulate A₁, but not A₂ receptors.Correspondence to B. Johansson at the above address     

Impact of pigment dispersion on trabecular meshwork cells

Graefe's Archive for Clinical and Experimental Ophthalmology - Dysfunction of the trabecular meshwork (TM) in pigmentary glaucoma contributes to increased aqueous humor outflow resistance and...     

RKI-1447, a Rho kinase inhibitor,causes ocular hypotension,actin stress fiber disruption,and increased phagocytosis

Graefe's Archive for Clinical and Experimental Ophthalmology - This study investigated the hypotensive effect of RKI-1447, a Rho kinase inhibitor, in a porcine ex vivo pigmentary glaucoma...     

Reproducibility of transpulmonary thermodilution cardiac output measurements in clinical practice: a systematic review

Measuring cardiac output (CO) is an integral part of the diagnostic and therapeutic strategy in critically ill patients. During the last decade, the single transpulmonary thermodilution (TPTD) technique was implemented in clinical practice. The purpose of this paper was to systematically review and critically assess the existing data concerning the reproducibility of CO measured using TPTD (COTPTD). A total of 16 studies were identified to potentially be included in our study because these studies had the required information that allowed for calculating the reproducibility of COTPTD measurements. 14 adult studies and 2 pediatric studies were analyzed. In total, 3432 averaged CO values in the adult population and 78 averaged CO values in the pediatric population were analyzed. The overall reproducibility of COTPTD measurements was 6.1 ± 2.0 % in the adult studies and 3.9 ± 2.9 % in the pediatric studies. An average of 3 boluses was necessary for obtaining a mean CO value. Achieving more than 3 boluses did not improve reproducibility; however, achieving less than 3 boluses significantly affects the reproducibility of this technique. The present results emphasize that TPTD is a highly reproducible technique for monitoring CO in critically ill patients, especially in the pediatric population. Our findings suggest that obtaining a mean of 3 measurements for determining CO values is recommended.     

Population Pharmacodynamic Modeling of Exenatide After 2-Week Treatment in STZ/NA Diabetic Rats

The purpose of this study is to investigate the effect of exenatide on glycemic control following two administration routes in a streptozotocin/nicotinamide (STZ/NA)-induced diabetic rat model, and to develop a pharmacodynamic model to better understand the disease progression and the action of exenatide in this experimental system. Two groups of STZ/NA-induced diabetic rats were treated for 2 weeks with 20 (μg/kg/day) of exenatide, either by continuous subcutaneous (SC) infusion or two SC injections daily. Disease progression was associated with slower glucose utilization. Fasting blood glucose was significantly reduced by 30 mg/dL in both treatment groups at the end of 2 weeks. A subsequent intravenous glucose tolerance test (IVGTT) confirmed an improved glucose tolerance in both treatment groups; however, overall glycemic control was similar between groups, likely due to the relatively low and short-term drug exposure. A population indirect response model was successfully developed to simultaneously describe the STZ/NA-induced disease progression, responses to an IVGTT, and exenatide effects on these systemic challenges. The unified model includes a single set of parameters, and the cumulative area under the drug–receptor concentration curve was used as a unique driving force to account for systemic effects long after drug elimination.     

A practical approach to diode based in vivo dosimetry for intensity modulated radiotherapy

A method for in vivo entrance dosimetry, using point detectors, in intensity modulated radiotherapy has been clinically evaluated. Diode dosimetry was performed for treatments of the head and neck and prostate regions. The results were good; 92.2% of the measurements showed deviations within ±5% of the expected values.