Cochlear implants in the etiopathogenesis of glioblastoma--an interesting observation or independent finding?

Various risk factors have been implicated in the pathogenesis of glioblastomas including ionizing radiation. Recent evidence has suggested a possible association between exposure to nonionizing radiofrequency electromagnetic fields (RF-EMF) generated from mobile phones and wireless devices to cause malignant transformation of the neuroglial cells, albeit this is widely debated. In this report, we discuss the development of glioblastoma in two geopolitically unrelated patients, an elderly male from the United States and a middle-aged woman from Sweden, with long-standing cochlear implants (CI). We hypothesize that the low-frequency RF-EMF emanating from the transcutaneous link of the CI prosthesis over a long period has potentially triggered tumor development in these patients.

Microsurgical clipping following failed coiling of a giant ophthalmic aneurysm.

With the advent of endovascular modalities, endovascular coiling has become a progressively more common method of addressing intracranial aneurysms. When despite coiling, an aneurysm continues to enlarge, open microsurgical clipping is a viable, though technically demanding option. We present a unique case of failed coiling of a giant ophthalmic region aneurysm, in which the aneurysm was successfully managed via open microsurgical approach. We highlight the unique challenges faced and demonstrate the surgical process in an operative video presentation. The video can be found here: http://youtu.be/k2P4c4Lvq7g .

Technical nuances of clipping a middle cerebral artery bifurcation aneurysm.

Broad-necked middle cerebral artery aneurysms present unique challenges for the vascular neurosurgeon, who must contend with smaller vessels and often a complex clipping strategy. Due to their superficial location, these lesions are still commonly selected for microsurgical clipping. We present a case of a 42-year-old woman with significant vascular disease with a right middle cerebral artery aneurysm. We discuss the key surgical steps, demonstrate the microsurgical dissection and intraoperative rupture encountered and the final clipping strategy, as well as the postoperative course in this operative video presentation. The video can be found here: http://youtu.be/qZ2gvqz7XdQ .

Arthroscopic Primary Repair of Proximally Based Anterior Cruciate Ligament Tear With Augmentation and All-Epiphyseal Fixation.

Arthroscopic anterior cruciate ligament (ACL) reconstruction has been the gold standard of care for ACL injuries for many years. Recently, there has been growing literature and interest in arthroscopic primary ACL repair in select patients with predominantly proximally based ACL tears. This Technical Note demonstrates a surgical technique that offers an efficient minimally invasive and physeal-sparing anatomic ACL repair with all-inside internal brace augmentation that in the short term has offered good results for our patients.

Infiltrative Intramuscular Lipoma with Overlying Fascial Defect in the Anterior Thigh: A Case Report.

This case report details a unique presentation of an infiltrative intramuscular lipoma in the anterior thigh of a 51-year-old female with an overlying fascial defect. The patient reported a progressively enlarging left thigh mass associated with pain exacerbated by knee movement and exercise. MRI revealed a homogeneous intramuscular lipoma without contrast enhancement with a fascial defect. An 8 cm longitudinal incision exposed a 7 x 4 cm fascial defect overlying the lipomatous mass within the rectus femoris muscle. Pathological analysis confirmed an intramuscular lipoma without malignancy. Follow-ups at two, six, and 12 weeks demonstrated pain resolution and no soft tissue bulge. This case underscores the importance of distinguishing intramuscular lipomas from other neoplasms, such as lipomatosis and liposarcomas. The association of a fascial defect with intramuscular lipomas is unprecedented and may be due to the increased pressure on the fascia by the lipoma. The report emphasizes the role of MRI in diagnosis and appropriate surgical management, and highlights the need for further exploration into the etiology of fascial defects associated with intramuscular lipomas.

Opioid Prescribing Trends Among Workers' Compensation Patients Undergoing Foot and Ankle Surgery.

BACKGROUND: The purpose of this study was to evaluate opioid usage and prescribing trends among workers' compensation (WC) patients who underwent foot or ankle operative procedures compared with a control group. METHODS: A retrospective review was conducted for WC and non-WC patients who underwent foot or ankle procedures in a single academic orthopaedic surgery practice. Outcome measures were total morphine milligram equivalents (MME) and number of opioid prescriptions. RESULTS: A total of 118 patients were identified, including 51 patients in the WC group and 67 in the non-WC group. After index surgery, 67% (34 of 51) of WC patients had 2 or more additional opioid prescriptions compared to 39% (26 of 67) of non-WC patients (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.4-6.7; P = .003). Collectively, there were greater prescriptions of oxycodone MME (P = .002) and hydrocodone MME (P = .07) in the WC cohort. CONCLUSIONS: Workers' compensation patients seem to be prescribed and consume opioids at a higher rate postoperatively. It is important for treating physicians to be aware of these trends, and discussions with patients regarding expected opioid use when planning surgical intervention may be beneficial. Physicians may need to set expectations preoperatively and suggest there are limits on the amount of opioids that can safely be prescribed. LEVEL OF EVIDENCE: Level III, Retrospective cohort study, Prognostic.

Hyperperfusion syndrome after stent/coiling of a ruptured carotid bifurcation aneurysm.

The authors report a syndrome of regional, symptomatic cerebral hyperperfusion, and edema mimicking infarction in a 54-year-old woman following coiling of a ruptured right carotid bifurcation aneurysm and stenting of the right middle cerebral artery. The patient presented with a Hunt and Hess grade III subarachnoid hemorrhage 7 days after developing thunderclap headache. She underwent successful coiling under general anesthesia of the 1.6 × 1.5 × 1.6 cm aneurysm, but immediately after the coil was placed occlusion of the proximal M1 segment was developed. This occlusion was stented after ~5-min delay, and flow restored without angiographic evidence of distal emboli. Following the procedure, she was extubated and noted to have left hemiparesis, neglect, and mutism without a CT correlate. Cerebral infarction was suspected, but urgent repeat angiography demonstrated patent cerebral vasculature. On the following day, symptoms persisted, and non-contrast head CT now showed cerebral edema localized to the right middle cerebral artery territory mimicking subacute infarction. CT perfusion imaging and angiography showed a widely patent MCA circulation, and suggested a regional hyperperfusion syndrome. The blood pressure was incrementally lowered, with rapid and sustained neurological improvement. Hyperperfusion events following aneurysm repair and related circumstances are reviewed.

Postoperative Infection and Revision Surgery Rates in Foot and Ankle Surgery Without Routine Prescription of Prophylactic Antibiotics.

INTRODUCTION: Surgical site infections (SSIs) are associated with patient morbidity and increased healthcare costs. Limited literature in foot and ankle surgery provides guidance about routine administration of postoperative antibiotic prophylaxis. The purpose of this study was to examine the incidence and revision surgery rates of SSI in outpatient foot and ankle surgeries in patients not receiving oral postoperative antibiotic prophylaxis. METHODS: A retrospective review of all outpatient surgeries (n = 1517) conducted by a single surgeon in a tertiary referral academic center was conducted through electronic medical records. Incidence of SSI, revision surgery rate, and associated risk factors were determined. The median follow-up was 6 months. RESULTS: Postoperative infection occurred in 2.9% (n = 44) of the surgeries conducted, with 0.9% of patients (n = 14) requiring return to the operating room. Thirty patients (2.0%) were diagnosed with simple superficial infections, which resolved with local wound care and oral antibiotics. Diabetes (adjusted odds ratio, 2.09; 95% confidence interval, 1.00 to 4.38; P = 0.049) and increasing age (adjusted odds ratio, 1.02; 95% confidence interval, 1.00 to 1.04; P = 0.016) were significantly associated with postoperative infection. DISCUSSION: This study demonstrated low postoperative infection and revision surgery rates without the routine prescription of prophylactic postoperative antibiotics. Increasing age and diabetes are signficant risk factors for developing a postoperative infection.

Malignant Pineal Parenchymal Tumors in Adults: A National Cancer Database Analysis.

BACKGROUND: Limited retrospective data exist on malignant pineal parenchymal tumors (PPTs) in adults, and there are no large previous studies that review clinical outcomes across the 3 treatment arms of surgery, radiotherapy, and chemotherapy. As a result, optimal disease management has yet to be defined. OBJECTIVE: To evaluate treatment trends and perform survival analysis in adult PPT. METHODS: The National Cancer Database was queried for histologically confirmed PPT diagnosed from 2007 to 2016. Univariate and multivariate Cox regressions were used to evaluate the prognostic impact of covariates. Kaplan-Meier survival curves were generated for comparative subanalyses. RESULTS: Of the 251 patients who met inclusion criteria, 172 had PPTs of intermediate differentiation (PPTID) and 79 had pineoblastoma. A plurality of patients with pineoblastoma were treated with trimodal therapy (39.1%), whereas patients with PPTID were commonly treated with either surgery alone or surgery and radiation (33.7% each). Factors independently associated with improved overall survival include younger patient age, female sex, lower comorbidity score, lower tumor grade, and treatment with surgery or radiation (each P < .05). Subanalyses confirm the effect of radiation on survival in patients with grade III PPTID with subtotal resection; however, no survival benefit of adjuvant radiation is demonstrated in patients with grade II PPTID with subtotal resection. CONCLUSION: Although radiotherapy and surgery were found to increase survival in all patients with PPT, there was no demonstrable survival benefit of adjuvant radiation in surgically treated patients with grade II PPTID. This suggests that adjuvant radiotherapy may not add significant survival benefit in many adult patients with grade II PPTID.

Characterization of novel bovine gastrointestinal tract Treponema isolates and comparison with bovine digital dermatitis treponemes.

This study aimed to isolate and characterize treponemes present in the bovine gastrointestinal (GI) tract and compare them with bovine digital dermatitis (BDD) treponemes. Seven spirochete isolates were obtained from the bovine GI tract, which, on the basis of 16S rRNA gene comparisons, clustered within the genus Treponema as four novel phylotypes. One phylotype was isolated from several different GI tract regions, including the omasum, colon, rumen, and rectum. These four phylotypes could be divided into two phylotype pairs that clustered closest with each other and then with different, previously reported rumen treponemes. The treponemes displayed great genotypic and phenotypic diversity between phylotypes and differed considerably from named treponeme species and those recently reported by metagenomic studies of the bovine GI tract. Phylogenetic inference, based on comparisons of 16S rRNA sequences from only bovine treponemes, suggested a marked divergence between two important groups. The dendrogram formed two major clusters, with one cluster containing GI tract treponemes and the other containing BDD treponemes. This division among the bovine treponemes is likely the result of adaptation to different niches. To further differentiate the bovine GI and BDD strains, we designed a degenerate PCR for a gene encoding a putative virulence factor, tlyC, which gave a positive reaction only for treponemes from the BDD cluster.

Radiographically distinct variant of pilocytic astrocytoma: a case series.

The imaging findings of pilocytic astrocytomas are classically described as a cyst with an enhancing mural nodule. We report 2 unusual cases of multicystic cerebellar midline masses that were proven to be pilocytic astrocytomas. The uniqueness of the imaging features in these cases may represent an important variant of pilocytic astrocytomas. Recognition of this variant may prevent an unnecessary workup to exclude other etiologies such as parasitic infection (ie, cysticercosis) or cystic metastatic disease.

Association of unique, isolated treponemes with bovine digital dermatitis lesions.

This study used a PCR-based approach targeting 16S rRNA gene fragments to determine the occurrence and association of the three bovine digital dermatitis (BDD) treponeme phylogroups within lesions found in cattle from the United Kingdom. Examination of 51 BDD lesions collected from infected cattle across the United Kingdom revealed that BDD treponeme group 1 (Treponema medium/Treponema vincentii-like), group 2 (Treponema phagedenis-like), and group 3 (Treponema putidum/Treponema denticola-like) were present in 96.1%, 98%, and 76.5% of BDD lesions, respectively. The three phylogroups were present together in 74.5% of lesions. The PCR assays enabled the isolation of further treponeme strains from previously mixed primary BDD lesion cultures. Here a representative from each of the three distinct treponeme phylogroups was isolated from a single BDD lesion for the first time. These data highlight the extent to which this disease is polytreponemal. Immunohistochemistry and electron microscopy were used to investigate lesional hoof tissues, resulting in treponemes being identified copiously in hair follicles and sebaceous glands, suggesting a potential route of exit and/or entry for these pathogens. This study gives further evidence for the importance of the three treponeme groups in BDD pathogenesis and reiterates the value of molecular genetic approaches for isolating and identifying fastidious anaerobes.

Three unique groups of spirochetes isolated from digital dermatitis lesions in UK cattle.

Bovine digital dermatitis (BDD) is a severe infectious cause of lameness which has spread through dairy cattle populations worldwide, causing serious welfare and agricultural problems. Spirochetes are the main organisms implicated and have previously proven difficult to isolate. This study aimed to isolate and characterise the range of spirochetes associated with BDD in the UK. Twenty-three spirochete isolates were obtained from 30 BDD lesions, which by 16S rRNA gene and flaB2 gene analysis clustered within the genus Treponema as three phylogroups; groups 1 (Treponema medium/Treponema vincentii-like), 2 (Treponema phagedenis-like) and 3 (Treponema denticola/Treponema putidum-like). The treponemes displayed large genotypic and phenotypic diversity between phylogroups and differed from named treponeme species. A previously isolated contagious ovine digital dermatitis spirochete was located within one of the three phylogroups, group 3, and could also be identified within this group on the basis of phenotype testing, suggesting BDD and contagious ovine digital dermatitis may share the same aetiological agent. A strain isolated from a bovine interdigital dermatitis lesion, could be identified as part of BDD isolate group 2, suggesting bovine interdigital dermatitis and BDD may have the same causative agent. Two common enzyme activities, C4 esterase and C8 esterase lipase, were identified in all BDD associated treponemes suggesting common metabolic pathways for sharing this novel niche or even common virulence traits. Further studies are required to determine whether the three groups of novel treponemes are representative of new treponeme taxa and to delineate how they interact with bovine tissues to cause disease.

Nonrandom spatial clustering of spontaneous anterior fossa cerebrospinal fluid fistulas and predilection for the posterior cribriform plate.

OBJECTIVE The anterior skull base is a common site for the spontaneous development of meningoceles, encephaloceles, and meningoencephaloceles that can lead to cerebrospinal fluid (CSF) fistula formation, particularly in association with idiopathic intracranial hypertension. In some circumstances the lesions are difficult to localize. Whether all sites in the anterior skull base are equally prone to fistula formation or whether they are distributed randomly throughout the anterior skull base is unknown, although the anterior cribriform plate has been proposed as the most frequent location. The purpose of this study was to identify sites of predilection in order to provide assistance for clinicians in finding occult leaks and increase the understanding of the etiology of this pathology. METHODS The authors performed a retrospective review of a prospectively acquired surgical database of all endonasal endoscopic surgeries performed at Weill Cornell Medical College by the senior authors. Spontaneous CSF fistulas of the anterior skull base were identified. The anatomical sites of the defects were located on radiographic images and normalized to a theoretical 4 × 2 grid representing the anterior midline skull base. Data from the left and right skull base were combined to increase statistical power. This grid was then used to analyze the distribution of defects. Frequency analysis was performed by means of a chi-square test, with a subsequent Monte Carlo simulation to further strengthen the statistical support of the conclusions. RESULTS Nineteen cases of spontaneous CSF fistulas were identified. Frequency analysis using chi-square indicated a nonrandom distribution of sites (p = 0.035). Monte Carlo simulation supported this conclusion (p = 0.034). Seventy-four percent of cases occurred in the cribriform plate (p = 0.086). Moreover, 37% of all defects occurred in the posterior third of the cribriform plate. CONCLUSIONS Anterior skull base spontaneous CSF leaks are distributed in a nonrandom fashion. The most likely site of origin of the spontaneous CSF leaks of the anterior midline skull base is the cribriform plate, particularly the posterior third of the plate, likely because of the lack of significant thick bony buttressing. Clinicians searching for occult spontaneous leaks of the anterior skull base should examine the cribriform plate, especially the posterior third with particularly close scrutiny.

Clinical and Radiologic Outcome of Gamma Knife Radiosurgery on Nonfunctioning Pituitary Adenomas.

Objective To elucidate the role of Gamma Knife radiosurgery (GKRS) in the management of nonfunctioning pituitary adenomas (NFAs). Materials and Methods A retrospective review of 57 consecutive patients spanning 2000 to 2013 with NFAs was performed. Of 57 patients, 53 patients had recurrent or residual tumors after microsurgical resection. The study population was evaluated clinically and radiographically after GKRS treatment. The median follow-up time was 45.57 months. Results GKRS in pituitary adenomas showed significant variations in tumor growth control (decreased in 32 patients [56.1%], arrested growth in 21 patients [36.1%], and increased tumor size in 4 patients [7%]). Progression-free survival after GKRS at 3, 7, and 10 years was 100%, 98%, and 90%, respectively. The neurologic signs and symptoms were significantly improved after GKRS (14% versus 107%) compared with pretreated signs and symptoms (p < 0.0001). Five patients (8.8%) required additional treatment. Conclusion Recent follow-up revealed that GKRS offers a high rate of tumor control and preservation of neurologic functions in both new and recurrent patients with NFAs. Thus GKRS is an effective treatment option for recurrent and residual as well as newly diagnosed patients with NFAs.

Differential inflammatory responses of bovine foot skin fibroblasts and keratinocytes to digital dermatitis treponemes.

Bovine digital dermatitis (BDD) is a serious infectious inflammatory lameness causing pain and suffering to many cattle worldwide and which has severe economic implications. This study set out to investigate relationships between the treponemes considered causal of BDD and the local inflammatory response of the bovine host. Here we describe, for the first time, the isolation of bovine foot skin keratinocytes and fibroblasts as separate cell lineages. These cell lines were then exposed to treponeme whole-cell sonicates, and the gene expression of selected host inflammatory mediators investigated using quantitative reverse transcriptase PCR. Several genes, including those encoding RANTES/CCL5, MMP12, TNFα, TGFß and TIMP3 were significantly upregulated in fibroblasts exposed to whole-cell sonicates derived from BDD treponeme phylotypes. For each of the above genes there were similar fibroblast expression increases for all three BDD treponeme phylotypes tested, suggesting common virulence mechanisms. With bovine foot skin keratinocytes, we were unable to detect expression of RANTES/CCL5 and after incubation with BDD treponeme constituents we were unable to observe any significant changes in expression of inflammatory mediators tested. These contrasting results suggest fibroblasts rather than keratinocytes may be an important shared target of pathogenesis for BDD treponemes.

Host and environmental reservoirs of infection for bovine digital dermatitis treponemes.

Bovine digital dermatitis (BDD) is a global infectious disease causing lameness of cattle and is responsible for substantial animal welfare issues and economic losses. The causative agents are considered to be spirochetal bacteria belonging to the genus Treponema, which have consistently been identified in BDD lesions worldwide. One potential means of controlling infection is the disruption of transmission; however, the infection reservoirs and transmission routes of BDD treponemes have yet to be elucidated. To address these issues, we surveyed for evidence of BDD treponeme presence in the dairy farm environment, in bovine tissues and in bovine gastrointestinal (GI) tract contents. A total of 368 samples were tested using PCR assays specific for each of three currently recognised, isolated phylotypes of BDD treponemes. All environmental samples, together with insects and GI tract content samples were negative for BDD treponeme DNA from the three phylotypes. However, we identified BDD treponemes in two non-pedal bovine regions: the oral cavity (14.3% of cattle tested) and the rectum (14.8% of cattle tested). Whilst only single phylotypes were detected in the oral cavity, two of the rectal tissues yielded DNA from more than one phylotype, with one sample yielding all three BDD treponeme phylotypes. Whilst it might be considered that direct skin to skin contact may be a major transmission route of BDD treponemes, further studies are required to characterise and determine the potential contribution of oral and rectal carriage to BDD transmission.