Technical report: surgical preparation of human brain tissue for clinical and basic research.

BACKGROUND: The study of the distinct structure and function of the human central nervous system, both in healthy and diseased states, is becoming increasingly significant in the field of neuroscience. Typically, cortical and subcortical tissue is discarded during surgeries for tumors and epilepsy. Yet, there is a strong encouragement to utilize this tissue for clinical and basic research in humans. Here, we describe the technical aspects of the microdissection and immediate handling of viable human cortical access tissue for basic and clinical research, highlighting the measures needed to be taken in the operating room to ensure standardized procedures and optimal experimental results. METHODS: In multiple rounds of experiments (n = 36), we developed and refined surgical principles for the removal of cortical access tissue. The specimens were immediately immersed in cold carbogenated N-methyl-D-glucamine-based artificial cerebrospinal fluid for electrophysiology and electron microscopy experiments or specialized hibernation medium for organotypic slice cultures. RESULTS: The surgical principles of brain tissue microdissection were (1) rapid preparation (<1 min), (2) maintenance of the cortical axis, (3) minimization of mechanical trauma to sample, (4) use of pointed scalpel blade, (5) avoidance of cauterization and blunt preparation, (6) constant irrigation, and (7) retrieval of the sample without the use of forceps or suction. After a single round of introduction to these principles, multiple surgeons adopted the technique for samples with a minimal dimension of 5 mm spanning all cortical layers and subcortical white matter. Small samples (5-7 mm) were ideal for acute slice preparation and electrophysiology. No adverse events from sample resection were observed. CONCLUSION: The microdissection technique of human cortical access tissue is safe and easily adoptable into the routine of neurosurgical procedures. The standardized and reliable surgical extraction of human brain tissue lays the foundation for human-to-human translational research on human brain tissue.

Gray-White Matter Blurring of the Temporal Pole Associated With Hippocampal Sclerosis: A Microstructural Study Involving 3 T MRI and Ultrastructural Histopathology.

Hippocampal sclerosis (HS) is often associated with gray-white matter blurring (GMB) of the anterior temporal lobe. In this study, twenty patients with unilateral temporal lobe epilepsy and HS were studied with 3 T MRI including T1 MP2RAGE and DTI/DMI sequences. Anterior temporal lobe white matter T1 relaxation times and diffusion measures were analyzed on the HS side, on the contralateral side, and in 10 normal controls. Resected brain tissue of three patients without GMB and four patients with GMB was evaluated ultrastructurally regarding axon density and diameter, the relation of the axon diameter to the total fiber diameter (G-ratio), and the thickness of the myelin sheath. Hippocampal sclerosis GMB of the anterior temporal lobe was related to prolonged T1 relaxation and axonal loss. A less pronounced reduction in axonal fraction was also found on imaging in GMB-negative temporal poles compared with normal controls. Contralateral values did not differ significantly between patients and normal controls. Reduced axonal density and axonal diameter were histopathologically confirmed in the temporopolar white matter with GMB compared to temporal poles without. These results confirm that GMB can be considered an imaging correlate for disturbed axonal maturation that can be quantified with advanced diffusion imaging.

Piezosurgery for safe and efficient petrous bone cutting in cerebellopontine angle and petroclival meningioma surgery.

Intradural petrous bone drilling has become a widespread practice, providing extended exposure in the removal of cerebellopontine angle (CPA) or petroclival tumors. Adjacent neurovascular structures are at risk, however, when drilling is performed in this deep and narrow area. Hence, this study evaluates the use of Piezosurgery (PS) as a non-rotating tool for selective bone cutting in CPA surgery. A Piezosurgery® device was used in 36 patients who underwent microsurgery for extra-axial CPA or petroclival tumors in our Neurosurgical Department between 2013 and 2019. The clinical and radiological data were retrospectively analyzed. The use of PS was evaluated with respect to the intraoperative applicability and limitations as well as efficacy and safety of the procedure. Piezosurgical petrous bone cutting was successfully performed in the removal of meningiomas or extra-axial metastases arising from the dura of the petroclival region (21 patients) or petrous bone (15 patients). PS proved to be very helpful in the deep and narrow CPA region, considerably reducing the surgeon's distress toward bone removal in close proximity to cranial nerves and vessels in comparison to common rotating drills. The use of PS was safe without injuries to neurovascular structures. Gross total resection was achieved in 67% of petroclival and 100% of petrous bone tumors. Piezosurgery proved to be an effective and safe method for selective petrous bone cutting in CPA surgery avoiding rotating power and associated risks. This technique can particularly be recommended for bone cutting in close vicinity to critical neurovascular structures.

High-Resolution Gadolinium-Enhanced MR Cisternography Using Compressed-Sensing T1 SPACE Technique for Detection of Intracranial CSF Leaks.

In patients with CSF rhinorrhea, accurate identification of the CSF leakage site is crucial for surgical planning. We describe the application of a novel gadolinium-enhanced high-resolution 3D compressed-sensing T1 SPACE technique for MR cisternography and compare findings with CT cisternography and intraoperative results. In our pilot experience with 7 patients, precise detection of CSF leaks was feasible using compressed-sensing T1 SPACE, which appeared to be superior to CT cisternography.

Colonic volvulus after laparoscopic left colectomy.

Volvulus of the mobilized colon after laparoscopic left colectomy is rare. Contributing factors seem to be excessive length of the mobilized colon, absence of peritonization and absence of adhesions due to laparoscopy. Onset of colonic volvulus after laparoscopic left colectomy should lead to routine computerized tomography (CT), searching for an image suggestive of small intestinal incarceration under the neo-mesocolon, which might be an additional risk factor. Treatment consists of disincarceration of the small intestines while closing the mesocolic defect remains a subject of controversy.

Antimicrobial resistance in N'Djamena (Chad): Four-year experience of the French Forward Medical and Surgical Team engaged in the "Barkhane Operation".

OBJECTIVES: Knowledge of local antimicrobial resistance (AMR) patterns is required for effective empirical treatment of bacterial diseases. Very little is known about current resistance patterns of common pathogenic bacteria in the African region and particularly in the Sahel region. We aimed to describe the local bacterial epidemiology and to determine whether French recommendations for empirical treatment could be implemented. PATIENTS AND METHODS: We performed a single-center observational study. Data was collected retrospectively from the Forward Medical and Surgical Center (FFMSC) bacterial database from January 2015 to December 2018. All bacteriological analyses, negative or positive, were included. RESULTS: A total of 2194 samples were analyzed. Infectious diseases were urinary tract infections (20.8%), bone and joint infections (20.4%), skin infections of chronic wounds (13.4%), soft tissue abscesses (13%), and gastroenteritis (10.8%). The most frequent infections were enterobacterial infections (43.6%) and staphylococcal infections (31.1%). The prevalence of AMR was 32.1%. Significantly more ESBL-producing bacteria (41.3%) were observed in the Chadian population than in the French population in N'djamena (6.3%) (P<0.001). CONCLUSIONS: We reported a high rate of ESBL-producing bacteria in N'Djamena. The use of empirical antibiotic therapies in the FFMSC may thus be questioned: French recommendations cannot be implemented in such setting and the use of carbapenems or new anti-ESBL antibiotics should be considered. Prospective studies are required to conclude.

A rare Foreign Body in the bladder: a surgical dressing as a bladder stone.

We report an unusual case of a foreign body removed from the urinary bladder of an 11-year-old boy, which had mimicked a recurrent bladder stone. The diagnosis was suspected by ultrasound. As the clinical presentation appeared typical, no other examination was performed. Open surgery revealed that this foreign body was a surgical dressing forgotten during the first surgery eight years earlier. The absence of clinical evidence or infectious complications related to this foreign body over such a long period was surprising.

Neurophysiological Evaluation of a Customizable µECoG-based Wireless Brain Implant.

The number of implantable bidirectional neural interfaces available for neuroscientific research applications is still limited, despite the rapidly increasing number of customized components. We previously reported on how to translate available components into "ready-to-use" wireless implantable systems utilizing components off-the-shelf (COTS). The aim of the present study was to verify the viability of a micro-electrocorticographic ($\mu $ECoG) device built by this approach. Functionality for both neural recording and stimulation was evaluated in an ovine animal model using acoustic stimuli and cortical electrical stimulation, respectively. We show that auditory evoked responses were reliably recorded in both time and frequency domain and present data that demonstrates the cortical electrical stimulation functionality. The successful recording of neuronal activity suggests that the device can compete with existing implantable systems as a neurotechnological research tool.

Xanthogranulomatous cholecystitis: a rare cause of digestive hemorrhage.

Xanthogranulomatous cholecystitis is a rare affection with non-specific symptoms. It is essential to differentiate it from gall bladder adenocarcinoma. Presentation signs include hemorrhage or fistula. This report concerns a patient with pseudotumoral xanthogranulomatous cholecystitis who presented with gastrointestinal hemorrhage.

First experience using navigation-guided radiofrequency kyphoplasty for sacroplasty in sacral insufficiency fractures.

PURPOSE: To evaluate the efficacy and safety of navigation-guided radiofrequency kyphoplasty for sacroplasty in patients with sacral insufficiency fractures. METHODS: In this single-center retrospective observational study, four consecutive patients with sacral insufficiency fractures were treated with navigation-guided radiofrequency kyphoplasty for sacroplasty between April 2010 and May 2012. Symptom characteristics, pain duration and pain intensity were recorded for each patient. Cement extravasation was evaluated in thin-sliced and triplanar reconstructed CT scans of the sacrum. RESULTS: Four female patients with painful sacral insufficiency fractures and extensive osteopenic areas significantly improved from an average pre-treatment VAS score of 8.3 ± 0.5 to 2.3 ± 1.0 (p < 0.001) on the first postoperative day and to 1.3 ± 1.9 (p < 0.004) at follow-up (mean, 20.1 weeks). Slight cement extravasations were observed without evidence of being symptomatic. No major complications or procedure-related morbidity were noted. CONCLUSION: From the limited experience in four patients, navigation-guided radiofrequency kyphoplasty appears to be a safe and effective treatment option for sacral insufficiency fractures even though asymptomatic cement extravasation was noted. The use of navigation based on intraoperative 3 D images simplifies the positioning of the navigated bone needles via the long axis approach. The radiofrequency kyphoplasty system provides the possibility to administer a sufficient amount of bone cement with a well-defined viscosity over the entire period of the procedure leading to high security and low cement extravasation. Sacroplasty provides rapid and enduring pain relief and facilitates prompt mobilization.

Vesselplasty: a new minimally invasive approach to treat pathological vertebral fractures in selected tumor patients - preliminary results.

PURPOSE: To evaluate the effectiveness and safety of percutaneous vesselplasty in pathological vertebral fractures of the thoracolumbar spine in selected tumor patients. MATERIALS AND METHODS: Eleven pathological vertebral fractures in nine patients were treated with vesselplasty (Vessel-X®, MAXXSPINE). Nine of eleven vertebras (81.8 %) had major posterior wall deficiency (> 30 %). Clinical and radiological (CT) measures were obtained before and 3 months after the procedure. RESULTS: The mean VAS improved significantly from preoperative to postoperative (6.9 ± 2.2 to 3.7 ± 2.3; p < 0.05), as did the ODI (59.7 %± 19.2 % to 40.3 %± 24.0 %; p < 0.05). The physical component summary of the SF-36 was significantly improved by the operation (19.2 ± 8.0 to 31.0 ± 16.5; p < 0.05). Symptomatic cement leakage or other operation-associated complications were not observed. Three patients were primarily treated with concomitant minimally invasive stabilization via fixateur interne. One patient had to undergo minimally invasive stabilization via fixateur interne 4 months after vesselplasty due to further collapse of the treated vertebral body. CONCLUSION: From these preliminary results, vesselplasty appears to be a treatment option worth considering in pathological vertebral fractures, even in the case of posterior wall deficiency. Selected tumor patients might benefit from vesselplasty as a minimally invasive procedure for stabilization of the fractured vertebra, pain control, and improvement in body function and quality of life. Long-term prospective studies with a larger sample size are required to validate these results.

Late bacterial granuloma at an intrathecal drug delivery catheter.

In the case reported, neurological complaints were pain and dysaesthesiae in the lower back and thigh, as well as paresis of the ileopsoas muscle. MRI of the lumbar spine showed an intradural-extramedullary mass at the level of L1 homogeneously enhancing with gadolinium. This mass was situated at the tip of an intrathecal catheter implanted 11 years before for a morphine trial infusion as therapy for phantom pain after amputation of the right arm. Now, removal of the catheter was performed. Cultures of lumbar CSF and the catheter tip demonstrated coagulase negative staphylococcus. Antibiotic medication with cephalosporines was given for 6 weeks. After removal of the catheter, the patient was free of pain and he progressively regained full neurological function. Although most catheter-associated granulomas reported so far were sterile in nature, bacterial infection should still be considered even years after catheter placement.

Temporal lobe epilepsy associated up-regulation of metabotropic glutamate receptors: correlated changes in mGluR1 mRNA and protein expression in experimental animals and human patients.

Aberrant axonal reorganization and altered distribution of neurotransmitter receptor subtypes have been proposed as major pathogenic mechanisms for hippocampal hyperexcitability in chronic temporal lobe epilepsies (TLE). Recent data point to excitatory class I metabotropic glutamate receptors (mGluR1 and mGluR5) as interesting candidates. Here, we have analyzed the hippocampal distribution and mRNA expression of mGluR1 and mGluR5 in two rat models of limbic seizures, i.e. electrical kindling and intraperitoneal kainate injections, as well as in human TLE. Quantitative RT-PCR analysis detected a significant increase of hippocampal mGluR1 gene transcript levels in kainate treated and kindled rats. In addition, microdissected hippocampal tissue samples localized this increase to the dentate gyrus. Using immunohistochemistry with mGluR1alpha subtype specific antibodies, increased labeling was observed within the dentate gyrus molecular layer (DG-ML). A similar pattern of increased mGluR1alpha neuropil staining was found within the DG-ML of epilepsy patients (n = 42) compared with peritumoral hippocampus specimens obtained from nonepileptic patients (biopsy controls, n = 3). This increase was detected in TLE patients with segmental hippocampal cell loss, as well as in TLE patients with focal lesions but no histopathological alterations of the hippocampus. In contrast, mGluR5 immunoreactivity and mRNA expression were not significantly altered in the DG-ML. Our data demonstrate a striking regional induction of mGluR1alpha in the hippocampal dentate gyrus of experimental animals with limbic seizures as well as in human patients with chronic, intractable TLE. This increase corresponds to functional alterations of class I mGluRs observed in seizure models and may significantly contribute to hippocampal hyperexcitability in focal human epilepsies.

The apolipoprotein E epsilon 4 allele is not associated with early onset temporal lobe epilepsy.

A polymorphism of the apolipoprotein E gene, in particular the epsilon 4 allele (ApoE4), has been associated with impaired neuronal phospholipid metabolism and synapse reorganization and has been implicated in several neurodegenerative disorders. Since selective neuronal cell lose and aberrant axonal reorganization represent hall-marks of Ammon's horn sclerosis (AHS) in patients with chronic temporal lobe epilepsy (TLE), the ApoE polymorphism was studied in 125 patients with TLE. The genotype analysis revealed a frequency of 15.5% for epsilon 4, and 74.8% and 9.8% for epsilon 3 and epsilon 2, respectively. These figures were not significantly different from those reported in the normal European population. In addition, no correlation was found between the ApoE4 allelotype and the age of epilepsy onset, seizure type, febrile seizures, family history of epilepsy, surgical outcome and neuropathological findings in patients with TLE. These data virtually exclude ApoE as a susceptibility gene involved in the pathogenesis of early onset TLE or AHS.