The Poised Cannula Technique Reduces the Stereotactic Error of the Fiducial-Less Frameless DBS Procedure.

BACKGROUND: In this study, we describe a technique of optimizing the accuracy of frameless deep brain stimulation (DBS) lead placement through the use of a cannula poised at the entry to predict the location of the fully inserted device. This allows real-time correction of error prior to violation of the deep gray matter. METHODS: We prospectively gathered data on radial error during the operative placements of 40 leads in 28 patients using frameless fiducial-less DBS surgery. Once the Nexframe had been aligned to target, a cannula was inserted through the center channel of the BenGun until it traversed the pial surface and a low-dose O-arm spin was obtained. Using 2 points along the length of the imaged cannula, a trajectory line was projected to target depth. If lead location could be improved, the cannula was inserted through an alternate track in the BenGun down to target depth. After intraoperative microelectrode recording and clinical assessment, another O-arm spin was obtained to compare the location of the inserted lead with the location predicted by the poised cannula. RESULTS: The poised cannula projection and the actual implant had a mean radial discrepancy of 0.75 ± 0.64 mm. The poised cannula projection identified potentially clinically significant errors (avg 2.07 ± 0.73 mm) in 33% of cases, which were reduced to a radial error of 1.33 ± 0.66 mm (p = 0.02) after correction using an alternative BenGun track. The final target to implant error for all 40 leads was 1.20 ± 0.52 mm with only 2.5% of errors being >2.5 mm. CONCLUSION: The poised cannula technique results in a reduction of large errors (>2.5 mm), resulting in a decline in these errors to 2.5% of implants as compared to 17% in our previous publication using the fiducial-less method and 4% using fiducial-based methods of DBS lead placement.

Hyperlocal Variation in Soil Iron and the Rhizosphere Bacterial Community Determines Dollar Spot Development in Amenity Turfgrass.

Dollar spot, caused by the fungal pathogen Clarireedia spp., is an economically important foliar disease of amenity turfgrass in temperate climates worldwide. This disease often occurs in a highly variable manner, even on a local scale with relatively uniform environmental conditions. The objective of this study was to investigate mechanisms behind this local variation, focusing on contributions of the soil and rhizosphere microbiome. Turfgrass, rhizosphere, and bulk soil samples were collected from within a 256-m2 area of healthy turfgrass, transported to a controlled environment chamber, and inoculated with Clarireedia jacksonii Bacterial communities were profiled by targeting the 16S rRNA gene, and 16 different soil chemical properties were assessed. Despite their initial uniform appearance, the samples differentiated into highly susceptible and moderately susceptible groups following inoculation in the controlled environment chamber. The highly susceptible samples harbored a unique rhizosphere microbiome with suggestively lower relative abundance of putative antibiotic-producing bacterial taxa and higher predicted abundance of genes associated with xenobiotic biodegradation pathways. In addition, stepwise regression revealed that bulk soil iron content was the only significant soil characteristic that positively regressed with decreased dollar spot susceptibility during the peak disease development stage. These findings suggest that localized variation in soil iron induces the plant to select for a particular rhizosphere microbiome that alters the disease outcome. More broadly, further research in this area may indicate how plot-scale variability in soil properties can drive variable plant disease development through alterations in the rhizosphere microbiome.IMPORTANCE Dollar spot is the most economically important disease of amenity turfgrass, and more fungicides are applied targeting dollar spot than any other turfgrass disease. Dollar spot symptoms are small (3 to 5 cm), circular patches that develop in a highly variable manner within plot scale even under seemingly uniform conditions. The mechanism behind this variable development is unknown. This study observed that differences in dollar spot development over a 256-m2 area were associated with differences in bulk soil iron concentration and correlated with a particular rhizosphere microbiome. These findings provide interesting avenues for future research to further characterize the mechanisms behind the highly variable development of dollar spot, which may inform innovative control strategies. Additionally, these results suggest that small changes in soil properties can alter plant activity and hence the plant-associated microbial community, which has important implications for a broad array of agricultural and horticultural plant pathosystems.

Stereotactic MRI-guided laser interstitial thermal therapy for extratemporal lobe epilepsy.

OBJECTIVE: Magnetic resonance imaging (MRI)-guided laser interstitial thermal therapy (MRg-LITT) is an alternative to open epilepsy surgery. We assess safety and effectiveness of MRg-LITT for extratemporal lobe epilepsy (ETLE) in patients who are considered less favorable for open resection. METHODS: We retrospectively reviewed sequential cases of patients with focal ETLE who underwent MRg-LITT between 2012 and 2019. Epileptogenic zones were determined from standard clinical and imaging data ± stereoelectroencephalography (SEEG). Standard stereotactic techniques, MRI thermometry, and a commercial laser thermal therapy system were used for ablations. Anatomic MRI was used to calculate ablation volumes. Clinical outcomes were determined longitudinally. RESULTS: Thirty-five patients with mean epilepsy duration of 21.3 ± 12.2 years underwent MRg-LITT for focal ETLE at a mean age 36.4 ± 12.7 years. A mean 2.59 ± 1.45 trajectories per patient were used to obtain ablation volumes of 8.8 ± 7.5 cm3 . Mean follow-up was 27.3 ± 19.5 months. Of 32 patients with >12 months of follow-up, 17 (53%) achieved good outcomes (Engel class I + II) of whom 14 (44%) were Engel class I. Subgroup analysis revealed better outcomes for patients with lesional ETLE than for those who were nonlesional, multifocal, or who had failed prior interventions (P = .02). Of 13 patients showing favorable seizure-onset patterns (localized low voltage fast activity or rhythmic spiking on SEEG) prior to ablation, 9 (69%) achieved good outcomes, whereas only 3 of 11 (27%) who show other slower onset patterns achieved good outcomes. Minor adverse events included six patients with transient sensorimotor neurologic deficits and four patients with asymptomatic hemorrhages along the fiber tract. Major adverse events included one patient with a brain abscess that required stereotactic drainage and one patient with persistent hypothalamic obesity. Three deaths-two seizure-associated and one suicide-were unrelated to surgical procedures. SIGNIFICANCE: MRI-guided laser interstitial thermal therapy (or MRg-LITT) was well-tolerated and yielded good outcomes in a heterogeneous group of ETLE patients. Lesional epilepsy and favorable seizure-onset patterns on SEEG predicted higher likelihoods of success.

Temperature Impacts on Soil Microbial Communities and Potential Implications for the Biodegradation of Turfgrass Pesticides.

Maintaining healthy turfgrass often results in the use of pesticides to manage weed, insect, and disease pests. To identify and understand potential nontarget impacts of pesticide usage while still maintaining attractive and functional turfgrass sites, it is important to improve our understanding of how pesticides degrade in various environments throughout the growing season. Temperature heavily influences microbial community composition and activity, and the microbial community often heavily influences pesticide degradation in soil ecosystems. Pesticide transformation products generated through the action of soil microbial degradation networks can vary in their toxicity, with the potential result that a pesticide applied in the spring at 10°C could produce different transformation products with different toxicological impacts than the sample pesticide applied to the same site at 22°C. The objective of this review is to examine past research surrounding soil microbial activity related to pesticide degradation and provide a foundation for how the soil microbiome interacts with pesticides and how seasonal temperature variations may influence those interactions.

Ruptured Infantile Myofibroma of the Head Presenting in a Neonate: Case Report and Review of the Literature.

BACKGROUND: Infantile myofibroma/myofibromatosis (IM/M) is a myofibroblastic proliferative disorder often seen in infants and children. IM/M can result in congenital tumors of the head and neck and may occasionally present to the neurosurgeon. CASE DESCRIPTION: We report a case of a solitary ruptured myofibroma of the head in a newborn patient. The lesion was initially suggestive of encephalocele. We describe the presentation and management of this patient, including relevant imaging, histopathologic evaluation, and surgical technique. We subsequently review the literature of IM/M of the head and neck, highlighting the 3 forms of the condition, each requiring a distinct management strategy. CONCLUSIONS: Although this tumor rarely presents to the neurosurgeon, it may do so in the process of ruling out other more dangerous conditions. It is therefore important to consider this diagnosis in masses that occur in the head and neck of newborns.

Rotational vertebrobasilar insufficiency due to compression of a persistent first intersegmental vertebral artery variant: case report.

Rotational vertebrobasilar insufficiency, or bow hunter's syndrome, is a rare cause of posterior circulation ischemia, which, following rotation of the head, results in episodic vertigo, dizziness, nystagmus, or syncope. While typically caused by dynamic occlusion of the vertebral artery in its V2 and V3 segments, the authors here describe a patient with dynamic occlusion of the vertebral artery secondary to a persistent first intersegmental artery, a rare variant course of the vertebral artery. In this case the vertebral artery coursed under rather than over the posterior arch of the C-1. This patient was also found to have incomplete development of the posterior arch of C-1, as is often seen with this variant. The patient underwent dynamic digital subtraction angiography, which demonstrated occlusion at the variant vertebral artery with head turning. He was then taken for decompression of the vertebral artery through removal of the incomplete arch of C-1 that was causing the dynamic compression. After surgery the patient had a complete resolution of symptoms. In this report, the authors present the details of this case, describe the anatomical variants involved, and provide a discussion regarding the need for atlantoaxial fusion in these patients.

Microscopic thrombi in anaplastic astrocytoma predict worse survival?

The purpose of this study is to determine whether anaplastic astrocytoma patients with intratumoral vascular thrombi have a worse survival than anaplastic astrocytoma patients without thrombi. A retrospective review of 101 patients (60 males; mean age, 53.3 years) with anaplastic astrocytoma (World Health Organization grade III) was conducted. Thrombi were counted relative to the number of involved blood vessels in the initially resected tumor (69 biopsies, 32 subtotal resections) and were correlated with survival and development of postoperative deep venous thrombosis (DVT). Of tumors with thrombi (n = 17), the percentage of blood vessels with thrombi ranged from 1.5% to 20% (mean, 5.6%). Of these patients, 16 died of tumor (mean survival, 15.4 months), and 1 patient was alive with tumor at 180 months. Eighty-four patients with anaplastic astrocytoma had no intravascular tumor thrombi; 75 of these patients died of tumor (mean survival, 26.5 months), 4 patients were alive, and 5 patients were lost to follow-up. Evidence of DVT was found in 2 (18.2%) of 11 tested patients with thrombi vs 10 (18.5%) of 54 patients without thrombi. Patients with microscopic intratumoral thrombi (17% of anaplastic astrocytoma) had a worse survival compared with patients without thrombi; the difference did not reach statistical significance. There was no correlation between the presence of intratumoral thrombi and the development of DVT.

Tetracaine hydrochloride 0.5% versus lidocaine 2% jelly as a topical anesthetic agent in cataract surgery: comparative clinical trial.

PURPOSE: To assess the anesthetic efficacy of tetracaine hydrochloride 0.5% (TetraVisc) versus lidocaine 2% jelly in routine cataract extraction. SETTING: Private surgicenter, Warwick, Rhode Island, USA. METHODS: A prospective randomized double-blind clinical trial comprised 100 patients having routine cataract extraction by clear corneal phacoemulsification. Patients were randomized to receive TetraVisc or lidocaine 2% jelly, applied once, approximately 5 minutes before surgery. Outcomes included a self-reported postoperative pain score and the need for supplemental anesthesia. RESULTS: The mean self-reported postoperative pain scores for TetraVisc and lidocaine 2% jelly were similar (0.94 and 1.02, respectively; P = .76). A single patient in the lidocaine group required supplemental anesthesia. CONCLUSION: TetraVisc was as effective as lidocaine 2% jelly as a topical anesthetic agent for routine cataract extraction.

Interim results of the United States investigational device study of the Ophtec capsular tension ring.

PURPOSE: To evaluate the safety and efficacy of the Ophtec capsular tension ring (CTR) in providing capsular support during and/or after cataract extraction in cases of a weak or partially broken ciliary zonule. DESIGN: Phase III multicenter, nonrandomized, investigational device study. PARTICIPANTS: Twelve investigators at 9 sites enrolled 224 subjects and placed 255 CTRs. METHODS: Capsular tension rings were placed in patients who were found to have a weakened or partially broken ciliary zonule comprising <34% of the circumference of the lens capsule. Two CTR models were evaluated, with noncompressed diameters of 12 mm and 13 mm. Patients were examined preoperatively, intraoperatively, and postoperatively at day 1 and months 1, 3, 6, and 12. MAIN OUTCOME MEASURES: Rate of successful stabilization of the capsular bag and intraocular lens (IOL) centration, complications, and adverse events. RESULTS: Interim results from this ongoing study indicate that immediately after surgery 98.8% of IOLs were centered and 1.2% of the IOLs implanted (3/251) were not centered. Subsequently, the prevalence of decentered IOLs was 1.7% (4/236) 3 months after surgery, 3.8% (8/211) 6 months after surgery, and 2.3% (4/172) 12 months after surgery. The primary complication was posterior capsular opacification, which is unlikely to be a complication of CTR insertion. Neodymium:yttrium-aluminum-garnet laser capsulotomies have been performed in 12.8% of eyes by 12 months (22/172). CONCLUSIONS: Ophtec CTR models 275 and 276 safely provided capsular support during and after cataract surgery in cases where the zonule was weak or partially broken.

Phase II study of second-line gemcitabine in sensitive or refractory small cell lung cancer.

UNLABELLED: Small cell lung cancer (SCLC) is highly sensitive to chemotherapy. Despite a dramatic initial response, however, most patients relapse. Given the activity of gemcitabine in non-small cell lung cancer (NSCLC), and early clinical trials suggesting activity of gemcitabine in chemo-naive SCLC patients, we conducted a phase II study to determine the efficacy and toxicities of gemcitabine in SCLC patients who have failed first-line chemotherapy. Gemcitabine 1250 mg/m(2) was given intravenously on days 1 and 8, every 3 weeks. Eligibility criteria included prior treatment with only one chemotherapy regimen and Eastern Cooperative Oncology Group (ECOG) performance status of 0-2. Patients with brain metastases were eligible. RESULTS: Between April 1998 and October 2001, 27 patients were enrolled: 15 patients with sensitive (S) disease (recurred>3 months after first-line chemotherapy) and 12 patients with refractory (R) disease (failed<3 months after first-line chemotherapy). Median age was 61 (range 45-74). All patients had received prior platinum-based therapy involving etoposide and either cisplatin or carboplatin. There were one early death and two early withdrawals because of toxicity. No responses were observed. Of 24 patients who received at least two cycles of gemcitabine, only three achieved stable disease after six cycles while 21 progressed. The median time to progression (TTP) was 6 weeks in S group, 5.6 weeks in R group, and 6 weeks overall. After a minimum potential follow-up of almost 1 year for all patients, the median survival was 8.8 months in S group, 4.2 months in R group, and 6.4 months for the whole group. One-year survival rate was 33.3% in S group, 16.7% in R group, and 25.4% for all patients. Myelosuppression was the most commonly observed adverse effect, with grade 3/4 neutropenia in 30%, and grade 3 thrombocytopenia in 30%. One patient (3.7%) developed neutropenic fever. Respiratory failure and death, possibly related to pulmonary toxicity, was observed in one patient (3.7%). CONCLUSION: monotherapy gemcitabine as second-line agent has limited activity in previously treated SCLC.