Assessing the risk of magnetic interaction between auditory implants and programmable ventriculoperitoneal shunts.

PURPOSE: This study investigated whether the magnetic field of the internal magnet of cochlear implants and bone-anchored hearing aids (BAHA) would be sufficient to affect a programmable ventriculoperitoneal (VP) shunt. Current guidelines suggest against implanting these hearing devices ipsilateral to a programmable VP shunt, but the exact nature of the interaction has not been quantified. METHODS: The magnetic field strength (mT) was measured at 0 and 10 mm from the edge of both the Cochlear Implant CI512 (Cochlear Corporation) magnet and BAHA Attract magnet. Next, the hearing devices were placed into their anatomical positions in a 3-D clay model, along with three different types of programmable VP shunts. The valve setting was measured before and after exposure. RESULTS: At 10 mm, neither device generated a magnetic field sufficient to adjust the VP shunt valve. In the clay model, the valve settings were not affected by the presence of any device. CONCLUSION: Neither the cochlear implant nor the BAHA subcutaneous internal magnets generated sufficient magnetic field to reprogramme the valves of commonly used programmable VP shunts. The magnetic field from each device decreases dramatically at 10 mm. Further clinical studies to help mitigate the current restrictive guidance should consider involvement of VP shunt manufacturers to inform future shunt development and design.

Endovascular and surgical obliteration rates of spinal dural arteriovenous fistulae: a single UK Centre experience.

OBJECTIVE: Endovascular treatment (EVT) of spinal dural arteriovenous fistulae (SDAVF) has become increasingly popular given its less invasive nature. This study aims to assess radiological obliteration rates after surgery and EVT for SDAVF in a major tertiary referral centre serving a population of 2.2 million. METHOD: A retrospective review of all patients diagnosed with SDAVF between February 2010 and February 2018 was undertaken, identifying baseline demographics, treatment modality and the final radiological outcome (i.e., persistence of the SDAVF). Patients were identified from the departmental neurovascular database, clinical notes and imaging reports. RESULTS: Twenty patients were identified with an angiographically confirmed SDAVF. Two (10%) were managed conservatively. Nine patients (45%) underwent EVT. Obliteration was achieved in one patient (11%) after a single procedure, while one patient required two sessions. Further surgery was required in five patients (56%) to achieve complete obliteration. Nine patients (45%) underwent surgical disconnection as first treatment. Obliteration was radiologically confirmed in eight patients (89%). No radiological (MRI or angiographic) follow-up data was available for two patients (one from each group) and these were excluded from analysis. In this study, the obliteration rate of SDAVF after surgery was superior compared to EVT (p <0.01). CONCLUSION: Complete obliteration and recurrence rates after single treatment with EVT were inferior compared to surgical intervention. EVT may be better suited for specific presentations of SDAVF either in isolation or as an adjunct in multi-modality treatment. A national registry of outcomes may aid ongoing refinement of patient selection for EVT.

Malignant vestibular schwannoma with intracerebral metastasis.

BACKGROUND: Malignant change in vestibular schwannoma is rare and intracranial metastatic deposits have not been reported. CLINICAL PRESENTATION: We report the case of a 64 year old woman with a benign vestibular schwannoma who underwent translabyrinthine excision in 1996 and Gamma Knife® radiosurgery (Elekta AB, Stockholm, Sweden) (GKRS) in 2006. She presents 10 years after GKRS with progressive neurological deterioration. Histopathologic analysis confirms a malignant peripheral nerve sheath tumour, WHO grade IV with subsequent metastatic spread to the left thalamus confirmed on biopsy. CONCLUSION: We report a rare case of a vestibular schwannoma metastasizing with histological confirmation. It also reminds us of malignant conversion of a benign vestibular schwannoma following GKRS and subsequent aggressive behaviour, with poor prognosis.

Management of Chronic Subdural Hematoma: A Systematic Review and Component Network Meta-analysis of 455 Studies With 103 645 Cases.

BACKGROUND: Chronic subdural hematoma (CSDH) is a common neurosurgical condition with a high risk of recurrence after treatment. OBJECTIVE: To assess and compare the risk of recurrence, morbidity, and mortality across various treatments for CSDH. METHODS: A systematic review and meta-analysis was performed. PubMed/MEDLINE, EMBASE, SCOPUS, and Web of Science were searched from January 01, 2000, to July 07, 2021. The primary outcome was recurrence, and secondary outcomes were morbidity and mortality. Component network meta-analyses (CNMAs) were performed for surgical and medical treatments, assessing recurrence and morbidity. Incremental risk ratios (iRRs) with 95% CIs were estimated for each component. RESULTS: In total, 12 526 citations were identified, and 455 studies with 103 645 cases were included. Recurrence occurred in 11 491/93 525 (10.8%, 95% CI 10.2-11.5, 418 studies) cases after surgery. The use of a postoperative drain (iRR 0.53, 95% CI 0.44-0.63) and middle meningeal artery embolization (iRR 0.19, 95% CI 0.05-0.83) reduced recurrence in the surgical CNMA. In the pharmacological CNMA, corticosteroids (iRR 0.47, 95% CI 0.36-0.61) and surgical intervention (iRR 0.11, 95% CI 0.07-0.15) were associated with lower risk. Corticosteroids were associated with increased morbidity (iRR 1.34, 95% CI 1.05-1.70). The risk of morbidity was equivalent across surgical treatments. CONCLUSION: Recurrence after evacuation occurs in approximately 10% of cSDHs, and the various surgical interventions are approximately equivalent. Corticosteroids are associated with reduced recurrence but also increased morbidity. Drains reduce the risk of recurrence, but the position of drain (subdural vs subgaleal) did not influence recurrence. Middle meningeal artery embolization is a promising treatment warranting further evaluation in randomized trials.

Effect of audiological testing on programmable ventriculoperitoneal shunts.

OBJECTIVE: This study aimed at measuring the magnetic field strength of commonly used types of audiological testing equipment and determine their effects on the three most commonly used programmable ventriculoperitoneal (VP) shunts to try and quantify the risk of a VP shunt being reprogrammed during audiological testing. DESIGN: In this in vitro study, magnetic field strength was measured for TDH 39 supra-aural earphones, B71 bone vibrator, ALGO 3i probe, Bio-logic Nav Pro probe, Otodynamics otoport insert earphone and Madsen Zodiac tympanometry probe. STUDY SAMPLE: Magnetic field strength associated with transducers placed on a model of a skulls having implanted Miethke ProGAV 2.0, Medtronic Strata II and Codman Hakim programmable VP shunts was measured. RESULTS: The supra-aural earphones had a magnetic field strength of 14 mT at 0 mm, which dropped to 0 mT at 10 mm away from the transducer. All other equipment had a magnetic field strength of 3.5 mT or less at 0 mm. There was no instance of reprogramming of the shunts by the transducers. CONCLUSIONS: The findings suggest that the risk of inadvertent valve-reprogramming by the transducers is extremely small. However, care should be taken to avoid placing any of the transducers directly over the shunt.

Meningioma with rhabdoid features combined with meningioangiomatosis in infancy: a novel combination.

Meningioangiomatosis is a rare histologically distinct abnormality that is occasionally associated with intracranial meningioma. The rhabdoid variant of meningioma is also uncommon and is classified as a World Health Organization Grade III tumour. We report a case of meningioangiomatosis in conjunction with a meningioma with prominent rhabdoid features, in an infant male who underwent complete surgical resection of the lesion. The patient has been followed up for 6 years with no disease recurrence. To our knowledge, this is the first report in the literature describing meningioangiomatosis combined with a meningioma with rhabdoid features.

Assessing the safety and learning curve of a neurosurgical trainee in performing a microvascular decompression (MVD).

Purpose: MVD is complex procedure when done safely can be effective in managing Trigeminal Neuralgia. Here we assess the safety and learning curve of a surgical trainee in performing a MVD. Methods: A retrospective analysis of patients who have undergone MVD by the trainee (07/2014-07/2017) and by the senior neurosurgeon (03/2011-04/2015). Data such as surgery time, length of stay, outcomes and complications were collected. Results: Out of the 18 cases of MVD were performed by the trainee, 10 were supervisor trainer unscrubbed (STU) or performed (P) and 8 were supervisor trainer scrubbed (STS). Mean surgical time was 2:30 hrs and mean length of stay was 6.33 days. The mean outcome score was 2.33/3 with 89% cases a positive outcome. The complication rate was 16.7%, of which one had meningitis, one had CSF leak and one developed a pseudomeningocele. The trainee's surgery time, outcomes and complication rates were comparable to trainer and the literature. There was a statistically significant correlation between number MVD performed and operative time (R = -0.50, p < .05), intervals between MVDs and complication rates (R = 0.64, p < .05), and interval between MVDs and outcome scores (R = -0.66, p < .05). We estimate the time between cases should be below 40 days. Conclusions: Training a trainee is safe and does not add much burden to the hospital. A trainee will benefit the most if they have the same supervisor at least for the first eight cases and that each case should be done within 40 days of each other.

Unexplained paraparesis following subarachnoid haemorrhage.

Spinal arachnoid cysts (SAC) are rare in isolation and the exact aetiology is still debated. Primary (congenital) cysts are caused by structural abnormalities in the arachnoid layer and largely affect the thoracic region. Secondary cysts are induced by a multitude of factors, infection, trauma or iatrogenic response, and can affect any level of the spinal cord. While subarachnoid haemorrhage (SAH) is a relatively common condition with significant repercussions, it is extremely uncommonly associated with SAC. When present, it may develop in the months and years after the original bleed, giving rise to new neurological symptoms. Prompt treatment is needed to halt or reverse the worsening of symptoms and questions are still being asked about how best to approach this condition. A 42-year-old man presented with chronic back pain, severe worsening ataxia and numbness below the umbilicus, 7 months after treatment for a World Federation of Neurosurgical Societies grade five (WFNS V) SAH. Imaging revealed a SAC extending from T12 to L4 and causing thecal compression. This was treated with a L3 laminectomy andmarsupialisation. An improvement in neurological function was observed at 6 months. Aetiology of the SAC and its association with SAH are discussed and a review of the relevant literature is provided.

Assessment of Trace Metals in Consumer Chickens in Bangladesh.

BACKGROUND: Bangladesh is a densely populated country with a high demand for non-vegetable protein. Poultry meat is an important source of protein due to its affordability. Trace metals are persistent in the environment and are subject to bioaccumulation in the food chain. Contaminated poultry feed can pose a risk to human health as it biomagnifies and bioconcentrates toxic metals up the food chain, which can enter the human body and cause adverse and toxic health effects. OBJECTIVES: The aim of the current study was to assess the concentration and distribution of metals such as arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu) and nickel (Ni) in different types and parts of poultry in markets in Dhaka, Bangladesh. METHODS: A total of 15 chickens were collected from five commercial markets of Dhaka city. Three types of poultry were selected, broiler, layer and cock. Altogether, 45 chicken samples were analyzed for toxic metals concentrations using inductively coupled plasma optical emission spectroscopy. RESULTS: The concentrations of As, Cd, Co, Cr, Cu and Ni obtained in the broiler, layer and cock chickens were 0.728, 0.232, 0.392; 0.595, 0.245, 0.271; 0.058, 0.016, 0.096; 5.275, 1.562, 22.180; 3.571, 2.269, 4.241, and 0.332, 0.211, 0.433 mg/kg (wet weight), respectively. The results indicate that the concentrations of As, Cr, and Cu in the analyzed samples exceeded the maximum permissible levels, whereas the concentrations of Cd and Ni were within acceptable limits. Metal concentrations decreased in the order of Cr > Cu > As > Cd > Ni > Co. The target hazard quotient and cancer risk values were estimated for each metal due to consumption of the different types of chicken. CONCLUSIONS: The estimated metal concentrations of As, Cr and Cu were higher than the permissible levels of international standards, indicating a health risk. Groundwater in many parts of the country is contaminated with As and is a probable source of As contamination in poultry. High concentrations of Cr and Cu in chicken may be caused by contaminated poultry feed. In the present study, layer chickens were comparatively less contaminated with metals than other types of chicken. The estimated target hazard quotient and cancer risk values of the analyzed chicken samples were lower than acceptable limits for all individual trace metals in the three types of chicken, indicating no non-carcinogenic and cancer health risk from ingestion of a single trace metal through consumption of these chickens. ETHICAL APPROVAL: This study was approved by the Academic Committee of the Institute of Leather Engineering and Technology, University of Dhaka, Bangladesh. COMPETING INTERESTS: The authors declare no competing financial interests.

Orbitocerebral mucormycosis and intracranial haemorrhage: a role for caution with steroids in suspected giant cell arteritis.

A 75-year-old man with type 2 diabetes mellitus presented with complete loss of vision in his right eye and severe headaches for the past 24 hours. He had been treated for suspected giant cell arteritis (GCA) with high-dose corticosteroids which were being tapered to stop after an inconclusive right temporal artery biopsy and an erythrocyte sedimentation rate (ESR) value of 8. His current acute presentation, however, raised further concern for partially treated GCA and precipitated treatment with pulsed methylprednisolone. The patient, taking metformin, developed diabetic ketoacidosis and was transferred to the intensive care unit where a swollen, painful right eye with chemosis and complete ophthalmoplegia was subsequently revealed to be secondary to cavernous sinus thrombosis. Rhino-orbital skin necrosis with positive samples for the organism Rhizopus on eventual orbital exenteration revealed angioinvasive fungal infection, mucormycosis, to be the cause. We discuss here the lessons learnt, and how best to treat a susceptible cohort within our ageing western population.

Genome-wide association study of intracranial aneurysm identifies three new risk loci.

Saccular intracranial aneurysms are balloon-like dilations of the intracranial arterial wall; their hemorrhage commonly results in severe neurologic impairment and death. We report a second genome-wide association study with discovery and replication cohorts from Europe and Japan comprising 5,891 cases and 14,181 controls with approximately 832,000 genotyped and imputed SNPs across discovery cohorts. We identified three new loci showing strong evidence for association with intracranial aneurysms in the combined dataset, including intervals near RBBP8 on 18q11.2 (odds ratio (OR) = 1.22, P = 1.1 x 10(-12)), STARD13-KL on 13q13.1 (OR = 1.20, P = 2.5 x 10(-9)) and a gene-rich region on 10q24.32 (OR = 1.29, P = 1.2 x 10(-9)). We also confirmed prior associations near SOX17 (8q11.23-q12.1; OR = 1.28, P = 1.3 x 10(-12)) and CDKN2A-CDKN2B (9p21.3; OR = 1.31, P = 1.5 x 10(-22)). It is noteworthy that several putative risk genes play a role in cell-cycle progression, potentially affecting the proliferation and senescence of progenitor-cell populations that are responsible for vascular formation and repair.