Intracranial complications of midline nasal dermoid cysts.

BACKGROUND: Nasal dermoid cysts are common tumors in children. Due to anomalies in embryologic development of the nasal complex, sometimes an intracranial extension exists. When these cysts become infected they can lead to meningitis, brain abscess and death. METHODS: We report the case of a 1.5-year-old girl admitted to the paediatric intensive care unit after infection of a nasal dermoid cyst. RESULTS: The infant had a spiking fever and epileptic seizures. She was stabilized, intubated and a CT scan showed a subcutaneous mass with an adjacent zone of encephalitis and brain abscess formation. Neurosurgical interventions were necessary to lower intracranial pressure and control infectious spread. After a hospital stay of 69 days the child could be discharged. Due to her young age, irreversible brain damage is expected. CONCLUSION: Nasal midline dermoid cysts are considered benign swellings. When an intracranial extension exists, infection can lead to deleterious complications. It is important for health care practitioners to be aware of this imminent risk. Suspicion of a nasal midline dermoid cyst should prompt a careful clinical work-up with an ultrasound followed by CT or MRI imaging. The treatment is complete excision to avoid disastrous complications and recurrences.

Bedside Ultrasound-Guided Percutaneous Needle Aspiration of Intra- and Extra-Axial Intracranial Hemorrhage in Neonates.

Intracranial hemorrhage is an important cause of brain injury in the neonatal population and bedside percutaneous needle aspiration has emerged as an alternative due to the major risks that can be caused by standard neurosurgical decompression. We aimed to assess the effectiveness of this minimally invasive bedside technique and conducted a retrospective analysis of all newborn infants with a large extra-axial hemorrhage associated with a parenchymal hemorrhage causing a midline shift, managed at three academic centers over a 15-year period. Collected data included clinical history, laboratory results, review of all imaging studies performed, and neurodevelopmental follow-up. Eight infants (3 preterm and 5 full-term) presented on day 1 to 2 with seizures (n = 6) and apneas (n = 5), signs of increased intracranial pressure (n = 4), and coning (n = 1). Risk factors were present in six. Cranial ultrasound and computed tomography showed a midline shift in all; two infants showed status epilepticus on amplitude-integrated electroencephalography with complete resolution after the procedure. Between 7 and 34 mL could be aspirated associated with a decrease in the midline shift as seen by ultrasonography performed during the puncture. No complications were seen related to the procedure and none of the infants required further acute neurosurgical intervention. On follow-up, three had mild sequelae, including motor coordination problems (n = 1) and hemianopia (n = 2); none developed cerebral palsy or postneonatal epilepsy. Neonates, presenting with severe symptoms, can be managed successfully using ultrasound-guided needle aspiration and this minimally invasive bedside method should be kept in mind before performing neurosurgical decompression.

Hydroxyapatite cranioplasty: a retrospective evaluation of osteointegration in 17 cases.

BACKGROUND: Cranial reconstruction with autologous bone is still the gold standard although several biomaterials are available to re-establish the integrity of the cranial vault. Due to their biological and morphological characteristics, hydroxyapatite implants show promising results in small clinical cohort studies, especially within the paediatric population. Its biocompatibility and osteoconductivity should allow the formation of osseous bridging at the skull-prosthesis interface. OBJECTIVE: To examine the possible occurrence of osteointegration and to quantify it. METHODS: A retrospective study of patients with a hydroxyapatite implant from 2010 to 2014 at our neurosurgical department was conducted. Demographic, surgical and radiological data were studied. A senior neuroradiologist, a staff member neurosurgeon and a resident neurosurgeon independently performed the radiological evaluation. A new software analysis technique was developed to objectively quantify the degree of osteointegration. RESULTS: Seventeen implants were evaluated with an average patient age of 39 years and a mean follow-up of 155 weeks. Through radiologic evaluation, osseous bridging was deemed higher than 50% in six prostheses and higher than 75% in three. In five patients, no osteointegration could be seen. The remaining patients exhibited sparse signs of osteointegration, estimated between 10 and 50%. Software analysis showed an average osteointegration ratio of 37.4% with a 400-HU filter and 27.3% with a 700-HU filter. CONCLUSION: In this small retrospective study of cranial hydroxyapatite implants, osteointegration did occur and to a degree of more than 50% in 1/3 of the patients.

Diplopia as presenting sign of Turcot syndrome.

PURPOSE: To describe a patient with diplopia who was diagnosed with Turcot syndrome. METHODS: A 10-year-old boy presented with a history of left-sided sixth and seventh nerve palsy. He underwent imaging of the brain and colon, a full ophthalmological and genetic work-up. RESULTS: A 10-year-old boy was referred with combined left-sided sixth and seventh nerve palsy since 1 month without symptoms of raised intracranial pressure. BCVA was 6/6 in both eyes. Fundoscopy revealed bilateral, multiple, oval pigmented ocular fundus lesions (POFLs) in the 4 quadrants. These POFLs, together with the cranial nerve palsies raised the suspicion of Turcot syndrome, a familial neoplasia syndrome characterized by familial colorectal cancer and tumours of the central nervous system. Urgent MRI scan of the brain and stereotactic biopsy showed a primitive neuroectodermal tumour (PNET) at the pons. Coloscopy revealed multiple polyps. DNA analysis of the APC gene confirmed the clinical diagnosis of Turcot syndrome. The PNET was treated with combined radio- and chemotherapy. The patient underwent a prophylactic total colectomy as virtually all patients develop a carcinoma of the colorectal region if left untreated. CONCLUSIONS: Although strabismus is not, diplopia in childhood is rare and seldom innocuous. It requires a prompt and thorough diagnostic evaluation, including thorough, dilated fundoscopy. The presence of POFLs combined with neurological symptoms suggestive of a brain tumour should alert the clinician of the possibility of Turcot syndrome. Recognition of this rare syndrome can lead to earlier diagnosis, which is vital for appropriate surveillance and early surgical intervention of the highly frequent neoplasias in Turcot Syndrome.

The use of the trendelenburg position in the surgical treatment of extreme cerebellar slump.

BACKGROUND: State-of-the-art treatment for Chiari Malformation I (CM-I) consists of decompression by posterior fossa craniectomy. A rare but severe complication that develops over months to years after this procedure is cerebellar slump. Treatment options for this condition are limited. We present a new and promising approach to treat this rare condition. METHODS: The patients were placed in the Trendelenburg position to facilitate ascent of the cerebellum. After almost complete dissolution of neurologic symptoms, surgical reconstruction was performed by tonsillar resection and the creation of a new structural support using a bone graft. RESULTS: Both patients experienced good clinical and morphological outcomes immediately after surgery, and for two years thereafter. CONCLUSIONS: Neurological symptoms related to cerebellar or brainstem slump can be adequately reversed by placing the patient in the Trendelenburg position. After uneventful gravitational reversal of the slump, safe surgical reconstruction of the cerebellar support can be performed to securely preserve the anatomical reversal.

A novel design for steerable instruments based on laser-cut nitinol.

OBJECTIVE: Omnidirectional articulated instruments enhance dexterity. In neurosurgery, for example, the simultaneous use of 2 instruments through the same endoscopic shaft remains a difficult feat. It is, however, very challenging to manufacture steerable instruments of the requisite small diameter. We present a new technique to produce such instruments by means of laser cutting. Only 3 coaxial tubes are used. The middle tube has a cutting pattern that allows the steering forces to be transmitted from the proximal to the distal end. In this way the steering part is concealed in the wall of the tube. Large diameter articulated instruments such as for laparoscopy might benefit from the excellent tip stability provided by the same economical technology. METHOD: Coaxial nitinol tubes are laser-cut with a Rofin Stent Cutter in a specific pattern. The 3 tubes are assembled by sliding them over one another, forming a single composite tube. In a surgical simulator, the neurosurgical microinstruments and laparoscopic needle drivers were evaluated on surgical convenience. RESULTS: Simultaneous use of 2 neurosurgical instruments (1.5 mm diameter) through the same endoscopic shaft proved to be very intuitive. The tip of the steerable laparoscopic instruments (10 mm diameter) could resist a lateral force of more than 20 N. The angle of motion for either instrument was at least 70° in any direction. CONCLUSIONS: A new design for steerable endoscopic instruments is presented. It allows the construction in a range from microinstruments to 10-mm laparoscopic devices with excellent tip stability.

Outcome of early versus late primary embolization in ruptured brain arteriovenous malformations.

PURPOSE: To determine whether patients with a ruptured brain arteriovenous malformation (rBAVM) would benefit from an early embolization. METHODS: rBAVM treated first by embolization between March 2002 and May 2022 were included. Embolization was defined early (Group 1) when performed within 10 days postbleeding. If later, embolization was considered late (Group 2). Demographic and rBAVM data were compared between the groups. High-risk bleeding components and reasons for deferring embolization were retrieved. Primary endpoint was rebleeding. Secondary endpoints were good functional outcome (FO, modified Rankin Scale mRS ≤ 2) and angiographic occlusion. Predictors of rebleeding and FO were determined by multivariate analysis. RESULTS: 105 patients were recruited (N = 34 in Group 1; N = 71 in Group 2). No rebleeding was noted before, during or after the first embolization session in the early embolization group. Late embolization depended on missed diagnosis and referral pattern. Eleven patients (10.5%) suffered a rebleeding, of whom N = 3 before embolization (only in Group 2), N = 5 periembolization (N = 2 at the second embolization session in Group 1) and N = 3 spontaneous more than 30 days postembolization. More high-risk components were embolized in Group 1 (19/34; 55.9 vs 17/71; 23.9%; p = .011). Rebleeding rates, FO at last FU (90.9% vs 74.3%) and occlusion rates (80.8% vs 88.5%) did not differ between the groups. Glasgow coma scale ≤ 8 predicted rebleeding, rebleeding correlated with poor FO. CONCLUSION: Early embolization did prevent rebleeding. The overall rebleeding risk was linked to bleeding before late embolization and bleeding at the second embolization. Rebleeding predicted the final FO.

Timing of Surgery and Preoperative Predictors of Surgical Site Infections for Patients with Depressed Skull Fractures in a Sub-Saharan Tertiary Hospital: A Prospective Cohort Study.

Surgical site infections (SSIs) remain a major cause of life-threatening morbidity following surgery for depressed skull fractures (DSFs) among patients with traumatic brain injury (TBI). The timing of the surgery for DSF has been questioned as a risk of SSI without a clear cutoff. We aimed to compare the risk of SSI within 3 months between surgery done before versus after 48 h of injury and with its preoperative predictors. We conducted a prospective cohort study at Mulago Hospital, Uganda. Patients with mild-to-moderate TBI with DSF were followed up perioperatively from the operating time up to 3 months. The outcome variables were the incidence risk of SSI, types of SSI, microbial culture patterns of wound isolates, and hospital length of stay. We enrolled 127 patients with DSF, median age = 24 (interquartile range [IQR] = 17-31 years), 88.2% (112/127) male, and assault victims = 53.5%. The frontal bone involved 59%, while 50.4% had a dural tear. The incidence of SSI was 18.9%, mainly superficial incisional infection; Gram-negative microorganisms were the most common isolates (64.7%). The group of surgical intervention >48 h had an increased incidence of SSI (57.3% vs. 42.7%, p = 0.006), a longer median of postoperative hospital stay (8[IQR = 6-12] days versus 5 [IQR = 4-9], [p < 0.001]), and a higher rate of reoperation (71.4% vs. 28.6%, p = 0.05) in comparison with the group of ≤48 h. In multivariate analysis between the group of SSI and no SSI, surgical timing >48 h (95% confidence interval [CI], 1.25-6.22), pneumocranium on computed tomography [CT] scan (95% CI: 1.50-5.36), and involvement of air sinus (95% CI: 1.55-5.47) were associated with a >2.5-fold increase in the rate of SSI. The SSI group had a longer median hospital stay (p value <0.001). The SSI risk in DSF is high following a surgical intervention >48 h of injury, with predictors such as the frontal location of DSF, pneumocranium on a CT scan, and involvement of the air sinus. We recommend early surgical intervention within 48 h of injury.

Diagnosis of pediatric central nervous system tumors using methylation profiling of cfDNA from cerebrospinal fluid.

Pediatric central nervous system tumors remain challenging to diagnose. Imaging approaches do not provide sufficient detail to discriminate between different tumor types, while the histopathological examination of tumor tissue shows high inter-observer variability. Recent studies have demonstrated the accurate classification of central nervous system tumors based on the DNA methylation profile of a tumor biopsy. However, a brain biopsy holds significant risk of bleeding and damaging the surrounding tissues. Liquid biopsy approaches analyzing circulating tumor DNA show high potential as an alternative and less invasive tool to study the DNA methylation pattern of tumors. Here, we explore the potential of classifying pediatric brain tumors based on methylation profiling of the circulating cell-free DNA (cfDNA) in cerebrospinal fluid (CSF). For this proof-of-concept study, we collected cerebrospinal fluid samples from 19 pediatric brain cancer patients via a ventricular drain placed for reasons of increased intracranial pressure. Analyses on the cfDNA showed high variability of cfDNA quantities across patients ranging from levels below the limit of quantification to 40 ng cfDNA per milliliter of CSF. Classification based on methylation profiling of cfDNA from CSF was correct for 7 out of 20 samples in our cohort. Accurate results were mostly observed in samples of high quality, more specifically those with limited high molecular weight DNA contamination. Interestingly, we show that centrifugation of the CSF prior to processing increases the fraction of fragmented cfDNA to high molecular weight DNA. In addition, classification was mostly correct for samples with high tumoral cfDNA fraction as estimated by computational deconvolution (> 40%). In summary, analysis of cfDNA in the CSF shows potential as a tool for diagnosing pediatric nervous system tumors especially in patients with high levels of tumoral cfDNA in the CSF. Further optimization of the collection procedure, experimental workflow and bioinformatic approach is required to also allow classification for patients with low tumoral fractions in the CSF.

Metagenomic sequencing of the skin microbiota of the scalp predicting the risk of surgical site infections following surgery of traumatic brain injury in sub-Saharan Africa.

BACKGROUND: Surgical site infections (SSI) are a significant concern following traumatic brain injury (TBI) surgery and often stem from the skin's microbiota near the surgical site, allowing bacteria to penetrate deeper layers and potentially causing severe infections in the cranial cavity. This study investigated the relationship between scalp skin microbiota composition and the risk of SSI after TBI surgery in sub-Saharan Africa (SSA). METHODS: This was a prospective cohort study, enrolling patients scheduled for TBI surgery. Sterile skin swabs were taken from the surrounding normal skin of the head and stored for analysis at -80°Celcius. Patients were monitored postoperatively for up to three months to detect any occurrences of SSI. 16S rRNA sequencing was used to analyze the skin microbiota composition, identifying different taxonomic microorganisms at the genus level. The analysis compared two groups: those who developed SSI and those who did not. RESULTS: A total of 57 patients were included, mostly male (89.5%) with a mean age of 26.5 years, predominantly from urban areas in Uganda and victims of assault. Graphical visualization and metagenomic metrics analysis revealed differences in composition, richness, and evenness of skin microbiota within samples (α) or within the community (ß), and showed specific taxa (phylum and genera) associated with either the group of SSI or the No SSI. CONCLUSIONS: Metagenomic sequencing analysis uncovered several baseline findings and trends regarding the skin microbiome's relationship with SSI risk. There is an association between scalp microbiota composition (abundancy and diversity) and SSI occurrence following TBI surgery in SSA. We hypothesize under reserve that the scalp microbiota dysbiosis could potentially be an independent predictor of the occurrence of SSI; we advocate for further studies with larger cohorts.

Calvarial vault remodeling including pterional decompression for the treatment of nonsyndromic scaphocephaly patients: technical note and retrospective case series.

OBJECTIVE: Surgical techniques to correct scaphocephaly often rely on the implantation of foreign material and/or postoperative helmet therapy and possibly result in minimal correction of frontal bossing. Moreover, foreign material and helmet therapy are associated with extra medical care and financial costs. Frontal bossing is perceived as a prominent, disfiguring feature of scaphocephaly. Herein, authors present the results of a total cranial vault remodeling technique that corrects scaphocephaly features without relying on foreign material or postoperative helmet therapy. It includes frontal release and pterional decompression, which aim to correct frontal bossing. METHODS: All patients who had been operated on for isolated scaphocephaly at a single institution between January 2011 and December 2020 were included in this retrospective review. Operation time, transfusion volume, hospital stay, complications, cephalic index (CI), and bossing angle (BA) were analyzed. RESULTS: Sixty-five patients with nonsyndromic scaphocephaly were included in this analysis. Imaging to calculate the CI and BA preoperatively, immediately postoperatively, and 1 year postoperatively was available in 22 and 20 patients, respectively. The mean CI increased from 69.2% preoperatively to 74.6% postoperatively and 75.5% 1 year postoperatively. The mean BA decreased from 114.5° preoperatively to 111.6° postoperatively and 108.9° 1 year postoperatively. The mean operating time was 2 hours 4 minutes, and the median blood transfusion volume was 100 ml. There were no major complications or reoperations. CONCLUSIONS: The described total cranial vault remodeling technique is a safe procedure that mitigates total treatment burden, as no helmet therapy or implantation of foreign material is needed. It is effective in correcting CI and results in significant frontal bossing correction. The latter is attributed to a distinctive feature of the technique: frontal release and pterional decompression.

Cerebral Proliferative Angiopathy in a Child, Five Years after an Intraventricular Hemorrhage and Negative Catheter Angiography.

Cerebral proliferative angiopathy (CPA) is a rare cerebrovascular disease comprised of a diffuse network of blood vessels, often spread over several lobes. Due to the presence of normal brain tissue within the malformation, complete resection is not desirable. Several imaging characteristics help to distinguish CPA from brain arteriovenous malformations. We report the case of a patient diagnosed with CPA five years after a spontaneous intraventricular hemorrhage and an initial negative angiogram. Teaching Point: The radiologist should be able to differentiate CPA from brain AVM to prevent potentially harmful treatment.

Intracranial myxoid mesenchymal tumor with EWSR1-CREB1 fusion.

Myxoid mesenchymal tumor with predilection for intracranial location harboring EWSR1 fusions with CREB family transcription factors is a recently described and exceedingly rare neoplasm. While some debate still exists whether this is a true separate entity or a myxoid variant of angiomatoid fibrous histiocytoma, these tumors still deserve separate attention due to localization, fairly distinct histology and higher incidence in the pediatric population. Data regarding outcome of these neoplasms are still sparse in medical literature. We report a case of an intracranial myxoid tumor with EWSR1-CREB1 fusion in a 14-year-old girl.

Migration of pump for intrathecal drug delivery into the peritoneal cavity. Case report.

BACKGROUND: We report on a patient in whom a subfascially implanted pump for the intrathecal delivery of baclofen spontaneously migrated into the peritoneal cavity. CASE DESCRIPTION: A 54-year-old male patient presented with a refilling problem of a drug pump that had been implanted 16 months earlier subfascially through a right-sided incision 10 cm below the costal margin. Because we were unable to refill the pump even under fluoroscopy, we presumed a backward turning of the pump. At exploration, we found that the deeper part of the pocket had spontaneously eroded and had caused the migration of the pump into the peritoneal cavity. The peritoneum and the abdominal wall were closed and the pump was placed in a subcutaneous pouch. We suppose that the migration of the pump was due to its particular implantation site with the lower extent of the device at or below the level of the linea semilunaris. Below this line, the aponeuroses of all 3 lateral abdominal muscles pass in front of the rectus muscle, leaving only the transversal fascia underneath the rectus, which is not a solid layer. Not considering this anatomical detail may facilitate the inward migration of implanted material. CONCLUSION: When creating a pocket for subfascial implantation, a high subcostal incision should be used so that the lower extent of the pocket will still be above the level of the linea semilunaris, hence ensuring a strong fascial layer between the pump and the peritoneum.

A new dynamic model for in vitro evaluation of intravascular devices.

INTRODUCTION:: A dynamic model to evaluate thrombus formation on intravascular catheters in vitro is presented. The model enables fluid infusion, variation in the catheter orientation, and variable flow conditions. It was applied on a catheter used to shunt cerebrospinal fluid to a vein, a dural venous sinus, for the treatment of hydrocephalus. METHODS:: Fresh human blood-filled circuits were circulated in a non-occlusive roller pump. A catheter infused either with cerebrospinal fluid, Ringer's lactate, or no fluid (control) was inserted through each circuit's wall. Sixteen circuits (six cerebrospinal fluid, six Ringer's lactate, four control) ran for 60 min. Qualitative assessment was performed by measuring viscoelastic properties of blood at the start and end of the experiment; quantitative evaluation of clot formation by scanning electron microscope. RESULTS:: Average blood velocity was 79 mm/s, with a pressure wave between 5 and 15 mm Hg. At the experiment's end, the infused fluid represented 5.88% of the blood/infusion volume in the circuit. The control circuits showed no statistical difference between the start and end for viscoelastic testing, whereas both Ringer's lactate and cerebrospinal fluid enhanced coagulation, most pronounced for the latter. Most thrombus material was observed on catheters in the cerebrospinal fluid group. Clot formation was less pronounced on the surface of the catheter facing the blood flow. DISCUSSION:: A dynamic model for intravascular catheter testing mimics better clinical conditions when evaluating blood-material interaction. Catheter position, blood flow around the catheter, and infusion fluid all have a potential impact on the hemocompatibility of a given catheter.

Treating Hydrocephalus with Retrograde Ventriculosinus Shunt: Prospective Clinical Study.

BACKGROUND: Since the 1950s, hydrocephalus has been be treated with cerebrospinal fluid (CSF) shunts, usually to the peritoneal cavity or to the right cardiac atrium. However, because of their siphoning effect, these shunts lead to nonphysiologic CSF drainage, with possible comorbidity and high revision rates. More sophisticated shunt valve systems significantly increase costs and technical complexity and remain unsuccessful in a subgroup of patients. In an attempt to obtain physiologic CSF shunting, many neurosurgical pioneers shunted towards the dural sinuses, taking advantage of the physiologic antisiphoning effect of the internal jugular veins. Despite several promising reports, the ventriculosinus shunts have not yet become standard neurosurgical practice. METHODS: In this single-center prospective clinical study, we implanted the retrograde ventriculosinus shunt, as advocated by El-Shafei, in 10 patients. This article reports on our operation technique and long-term outcome, including 4 patients in whom this shunt was implanted as a rescue operation. RESULTS: Implantation of a ventriculosinus shunt proved to be feasible, warranting physiologic drainage of CSF. However, in only 3 of 14 patients, functionality of the retrograde ventriculosinus shunt was maintained during more than 6 years of follow-up. In our opinion, these shunts fail because present venous access devices are difficult to implant correctly and become too easily obstructed. After discussion of possible causes of this frequent obstruction, a new dural venous sinus access device is presented. CONCLUSION: An easy-to-implant and thrombogenic-resistant dural venous sinus access device needs to be developed before ventriculosinus shunting can become general practice.

A non-hydrocephalic goat experimental model to evaluate a ventriculosinus shunt.

The ventriculosinus shunt is a promising treatment for hydrocephalus. Currently, different shunt techniques exist, and it is not clear whether one is preferable. This pilot study reports on a non-hydrocephalic goat model (Saanen breed) that provides opportunities to evaluate and optimize several aspects of the ventriculosinus shunt technique. Analysis of the coagulation properties of 14 goats by a viscoelastic coagulation monitor showed that goats have a hypercoagulable state compared to humans. This property can be partially counteracted by antiplatelet drugs. During implantation of a ventriculosinus shunt, a pulsatile reflux of blood was observed. After implantation, the animals recovered to their preoperative state, and none of them developed a superior sagittal sinus thrombosis. Evaluation of the shunts after 16 days showed an obstructing luminal clot. Several model-related factors may have promoted this obstruction: the absence of hydrocephalus, the hypercoagulability of caprine blood and the smaller dimensions of the caprine superior sagittal sinus. However, the pulsatile reflux of blood, which is caused by the compliance of the shunt system distal to the valve, may have been an important factor as well. In conclusion, the non-hydrocephalic goat model limits animal suffering and simplifies the study protocol. This model allows researchers to evaluate their implantation technique and shunt hardware but not the efficacy of the treatment or shunt survival.

The influence of cerebrospinal fluid on blood coagulation and the implications for ventriculovenous shunting.

OBJECTIVE: The effect of CSF on blood coagulation is not known. Enhanced coagulation by CSF may be an issue in thrombotic complications of ventriculoatrial and ventriculosinus shunts. This study aimed to assess the effect of CSF on coagulation and its potential effect on thrombotic events affecting ventriculovenous shunts. METHODS: Two complementary experiments were performed. In a static experiment, the effect on coagulation of different CSF mixtures was evaluated using a viscoelastic coagulation monitor. A dynamic experiment confirmed the amount of clot formation on the shunt surface in a roller pump model. RESULTS: CSF concentrations of 9% and higher significantly decreased the activated clotting time (ACT; 164.9 seconds at 0% CSF, 155.6 seconds at 9% CSF, and 145.1 seconds at 32% CSF). Increased clot rates (CRs) were observed starting at a concentration of 5% (29.3 U/min at 0% CSF, 31.6 U/min at 5% CSF, and 35.3 U/min at 32% CSF). The roller pump model showed a significantly greater percentage of shunt surface covered with deposits when the shunts were infused with CSF rather than Ringer's lactate solution (90% vs 63%). The amount of clot formation at the side facing the blood flow (impact side) tended to be lower than that at the side facing away from the blood flow (wake side; 71% vs 86%). CONCLUSIONS: Addition of CSF to blood accelerates coagulation. The CSF-blood-foreign material interaction promotes clot formation, which might result in thrombotic shunt complications. Further development of the ventriculovenous shunt technique should focus on preventing CSF-blood-foreign material interaction and stagnation of CSF in wake zones.

Endoscopic Treatment of Temporal Arachnoid Cysts in 34 Patients.

INTRODUCTION: Arachnoid cysts are lesions present in 1% of the population and usually found in the temporal fossa. Clinical and radiologic presentations can differ greatly. Despite intensive research, it is still debatable which patients will benefit from surgery. OBJECTIVE: This study aims to investigate the pretreatment parameters influencing the outcome after neuroendoscopic treatment of temporal arachnoid cysts. MATERIALS AND METHODS: A retrospective analysis of 34 patients who underwent an endoscopic fenestration of a temporal arachnoid cyst between July 1991 and December 2013 was performed. RESULTS: In symptomatic patients, there was a clinical improvement in 76.4% of cases. The best results were found in treating symptoms related to intracranial hypertension, acute neurologic defects, and macrocrania. Patients with temporal lobe epilepsy improved after cyst fenestration in 33.3% of cases. Behavioral problems and psychomotor retardation remained largely unchanged. Patients with a complex neurologic presentation, often from a congenital syndrome and combined with an intellectual disability, had the least benefit from endoscopic surgery. Radiologic follow-up showed a cyst volume decrease in 91.2% of cases. Complications were present in 29.4%, but were mostly minor and transient. CONCLUSION: This study demonstrates that patients with symptoms related to intracranial hypertension, acute neurologic deficits, and macrocrania have the best postoperative outcome. Also, patients with ipsilateral temporal lobe epilepsy seem to be good candidates for endoscopic arachnoid cyst fenestrations. In complex neurologic disorders without one of the previously mentioned symptoms, endoscopy remains less successful.

Are psychotic symptoms related to vagus nerve stimulation in epilepsy patients?

Four patients with refractory epilepsy presented with psychotic symptoms following treatment with vagus nerve stimulation (VNS) to control seizures. Besides its anti-epileptic effect VNS has been shown to have an effect on various cognitive and behavioural functions. VNS is known to increase alertness and reduce sedation, which is independent from seizure control. VNS has also been shown to positively affect cognition and to exert strong antidepressant effects. Co-morbidity in epilepsy often comprises psychiatric illnesses. Increased psychiatric symptoms have mainly been described in association with successful outcome following epilepsy surgery as a result of 'forced normalisation'. Different hypotheses on the underlying aetiology of VNS-induced psychotic symptoms other than the previously described 'forced normalisation' are discussed.