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Nevin Manimala Statistics

The Effect of Nonlinear Frequency Compression on Acoustic Change Complex Responses in High-Frequency Dead-Regioned Hearing Loss

J Am Acad Audiol. 2021 May 24. doi: 10.1055/s-0041-1722948. Online ahead of print.

ABSTRACT

PURPOSE: The study is concern with the distinguishing of the stimuli containing high frequency information with the frequency compression feature at the cortical level using the acoustic change complex (ACC) and the comparison of such with the ACC answers of individuals with normal hearing.

RESEARCH DESIGN: This is a case-control study.

STUDY SAMPLE: Thirty adults (21 males and nine females) with normal hearing, ranging in age between 16 and 63 years (mean: 36.7 ± 12.9 years) and 20 adults (16 males and four females) with hearing loss ranging in age between 16 and 70 years (mean:49.0 ± 19.8 years) have been included in this study.

DATA COLLECTION AND ANALYSIS: A total of 1,000 ms long stimulus containing 500 and 4,000 Hz tonal stimuli was used for ACC recording. The start frequency (SF) and compression ratio (CR) parameters of the hearing aids were programmed according to the default settings (SFd, CRd) in the device software, the optimal setting (SFo, CRo), and the extra compression (SFe, CRe) requirements and ACC has been recorded for each condition. Evaluation has been performed according to P1-N1-P2 wave complex and ACC complex wave latencies. Independent samples t-test was used to test the significance of the differences between the groups.

RESULTS: In all individuals ACC has been observed. There was a significant difference between the wave latencies in normal hearing- and hearing-impaired groups. All wave latency averages of the individuals with hearing impairment were longer than the individuals with normal hearing. There were statistically significant differences between SFd-SFo, SFd-SFe, and SFo-SFe parameters. But there was no difference between CRd, CRo, and CRe in terms of CRs.

CONCLUSION: In order to discriminate high frequency information at the cortical level we should not rely on default settings of the SF and CR of the hearing aids. Optimal bandwidth must be adjusted without performing insufficient compression or over-compression. ACC can be used besides the real ear measurement for hearing aid fitting.

PMID:34030193 | DOI:10.1055/s-0041-1722948

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Nevin Manimala Statistics

Immediate Weight Bearing of Plated Both-Bone Forearm Fractures Using Eight Cortices Proximal and Distal to the Fracture in the Polytrauma Patient Is Safe

J Am Acad Orthop Surg. 2021 May 24. doi: 10.5435/JAAOS-D-20-01252. Online ahead of print.

ABSTRACT

INTRODUCTION: Rehabilitation of trauma patients is facilitated by surgical stabilization permitting weight bearing (WB) of the fractured extremity. Both-bone forearm fracture (BBFx) plate osteosynthesis is an accepted technique with high union and low complication rates; yet, postoperative WB protocols have not been adequately investigated. There exists concern for increased complications in plated BBFx fractures for patients prescribed immediate WB. We hypothesized that immediate WB of surgically treated BBFxs results in acceptable rates of complications.

METHODS: Patients presenting to a Level-1 trauma center from 2007 to 2016 with a BBFx were identified retrospectively. Patients were skeletally mature, surgically treated with prescribed immediate WB protocol, and followed for 6 months or to fracture union. Collected data included demographics, fracture characteristics, associated injuries, and WB protocols for all extremities. Complications recorded included nonunion, hardware failure, and infection. Standard statistical comparisons were used to evaluate the risk of complication in polytrauma patients with modified lower extremity WB protocols (polytrauma group) and patients with no lower extremity WB restrictions (isolated group).

RESULTS: Two hundred thirteen patients were included with 75 (35%) females and 138 (65%) males. Mean age was 40 years and mean follow-up was 46 weeks. There were 142 (67%) patients in the poly-trauma and 71 (33%) patients in the isolated groups. In the poly-trauma group 21 (10%) patients had bilateral lower extremity WB restrictions. There were 11 (6%) complications noted: 2 non-unions, 4 hardware failures, and 5 infections. Demographics did not vary between the two groups. There was no difference in complications in the isolated (5.7%) versus poly-trauma groups (5.0%) (P = 0.75).

CONCLUSION: Immediate WB rehabilitation after BBFx plate osteosynthesis seems to be safe and associated with low nonunion and complication rates. Our results demonstrate that polytrauma patients using ambulatory aids for lower extremity injuries can immediately WB without increased risk compared with isolated BBFx patients.

PMID:34030171 | DOI:10.5435/JAAOS-D-20-01252

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Nevin Manimala Statistics

Perineurioma: A Rare Entity of Peripheral Nerve Sheath Tumors

J Neurol Surg A Cent Eur Neurosurg. 2021 May 24. doi: 10.1055/s-0041-1726110. Online ahead of print.

ABSTRACT

OBJECTIVE: Intraneural perineurioma is a rare tumor entity. It is a benign, very slow growing peripheral nerve sheath tumor that typically occurs in children and young adults. Motor deficits and muscle atrophy are classic presenting symptoms, while sensory deficits are rare at the onset of the disease. Recommended treatment strategies are lacking. We have evaluated the clinical follow-up and our experience with treatment of this rare entity.

METHODS: A total of 30 patients with intraneural perineuriomas were assessed retrospectively. Demographic data, clinical symptoms, diagnostic examinations, therapy strategies, and clinical outcome were analyzed. Descriptive statistical methods were used for evaluation.

RESULTS: The mean age was 22 years. Eleven women and 19 men were affected. The lesion occurred in the area of the upper extremity in 16 patients and in the area of the lower extremity in 14 patients. The most frequently affected nerve was the sciatic nerve, followed by the radial nerve. All patients showed a motor deficit to some extent. Seventy percent (n = 21) revealed atrophy, 43.3% (n = 13) had sensitive deficits, and 17% (n = 5) suffered of pain. Fascicle biopsies were performed in 26 patients (87%). In four patients (13%), the tumor was completely resected and then reconstructed via nerve grafts. Seventy percent of the patients (n = 21) received a magnetic resonance imaging (MRI) within 5 years postoperatively, in which no progress was shown.

CONCLUSIONS: To diagnose perineurioma, it is essential to take a biopsy of an enlarged, nonfunctional fascicle. Furthermore, a long-distance epineuriotomy to decompress the hypertrophic fascicle is reasonable. To preserve the nerves’ residual function, a complete resection is not recommended. Results after grafting are poor. One reason for this might be residual tumor cells along the nerve that cannot be visualized. Malignant transformation is not yet reported and tumor growth is stable for years.

PMID:34030186 | DOI:10.1055/s-0041-1726110

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Nevin Manimala Statistics

Censored data considerations and analytical approaches for salivary bioscience data

Psychoneuroendocrinology. 2021 May 17;129:105274. doi: 10.1016/j.psyneuen.2021.105274. Online ahead of print.

ABSTRACT

Left censoring in salivary bioscience data occurs when salivary analyte determinations fall below the lower limit of an assay’s measurement range. Conventional statistical approaches for addressing censored values (i.e., recoding as missing, substituting or extrapolating values) may introduce systematic bias. While specialized censored data statistical approaches (i.e., Maximum Likelihood Estimation, Regression on Ordered Statistics, Kaplan-Meier, and general Tobit regression) are available, these methods are rarely implemented in biobehavioral studies that examine salivary biomeasures, and their application to salivary data analysis may be hindered by their sensitivity to skewed data distributions, outliers, and sample size. This study compares descriptive statistics, correlation coefficients, and regression parameter estimates generated via conventional and specialized censored data approaches using salivary C-reactive protein data. We assess differences in statistical estimates across approach and across two levels of censoring (9% and 15%) and examine the sensitivity of our results to sample size. Overall, findings were similar across conventional and censored data approaches, but the implementation of specialized censored data approaches was more efficient (i.e., required little manipulations to the raw analyte data) and appropriate. Based on our review of the findings, we outline preliminary recommendations to enable investigators to more efficiently and effectively reduce statistical bias when working with left-censored salivary biomeasure data.

PMID:34030086 | DOI:10.1016/j.psyneuen.2021.105274

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Nevin Manimala Statistics

Efficacy of lorlatinib in lung carcinomas carrying distinct ALK translocation variants: The results of a single-center study

Transl Oncol. 2021 May 21;14(8):101121. doi: 10.1016/j.tranon.2021.101121. Online ahead of print.

ABSTRACT

BACKGROUND: Lorlatinib is a novel potent ALK inhibitor, with only a few studies reporting the results of its clinical use.

METHODS: This study describes the outcomes of lorlatinib treatment for 35 non-small cell lung cancer patients with ALK rearrangements, who had 2 (n = 5), 1 (n = 26) or none (n = 4) prior tyrosine kinase inhibitors and received lorlatinib mainly within the compassionate use program.

RESULTS: Objective tumor response (OR) and disease control (DC) were registered in 15/35 (43%) and 33/35 (94%) patients, respectively; brain metastases were particularly responsive to the treatment (OR: 22/27 (81%); DC: 27/27 (100%)). Median progression free survival (PFS) was estimated to be 21.8 months, and median overall survival (OS) approached to 70.1 months. Only 4 out of 35 patients experienced no adverse effects; two of them were the only subjects who had no clinical benefit from lorlatinib. PFS and OS in the no-adverse-events lorlatinib users were strikingly lower as compared to the remaining patients (1.1 months vs. 23.7 months and 10.5 months vs. not reached, respectively; p < 0.0001 for both comparisons). ALK translocation variants were known for 28 patients; there was no statistical difference between patients with V.1 and V.3 rearrangements with regard to the OS or PFS.

CONCLUSION: Use of lorlatinib results in excellent disease outcomes, however caution must be taken for patients experiencing no adverse effects from this drug.

PMID:34030112 | DOI:10.1016/j.tranon.2021.101121

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Tumor control probability (TCP) in hypofractionated radiotherapy as a function of total and hypoxic tumor volumes

Phys Med Biol. 2021 May 24. doi: 10.1088/1361-6560/ac047e. Online ahead of print.

ABSTRACT

Clinical studies in the hypofractionated stereotactic body radiotherapy (SBRT) have shown a reduction in the probability of local tumor control with increasing initial tumor volume. In our earlier work, we obtained and tested an analytical dependence of the TCP (tumor control probability) on the total and hypoxic tumor volumes using conventional radiotherapy model with the linear-quadratic (LQ) cell survival. In this work, this approach is further refined and tested against clinical observations for hypofractionated radiotherapy treatment schedules. Compared to radiotherapy with conventional fractionation schedules, simulations of hypofractionated radiotherapy may require different models for cell survival and the Oxygen Enhancement Ratio (OER). Our TCP simulations in hypofractionated radiotherapy are based on the LQ model and the Universal Survival Curve (USC) developed for the high doses used in SBRT. The predicted trends in local control as a function of the initial tumor volume were evaluated in SBRT for non-small cell lung cancer. Our results show, that both LQ and USC based models cannot describe the TCP reduction for larger tumor volumes observed in the clinical studies if the tumor is considered completely oxygenated. The TCP calculations are in agreement with the clinical data if the subpopulation of radio-resistant hypoxic cells is considered with the volume that increases as initial tumor volume increases. There are two conclusions which follow from our simulations. First, the extent of hypoxia is likely a primary reason of the TCP reduction with increasing the initial tumor volume in SBRT for non-small cell lung cancer. Second, the LQ model can be an acceptable approximation for the TCP calculations in hypofractionated radiotherapy if the tumor response is defined primarily by the hypoxic fraction. The larger value of OER in the hypofractionated radiotherapy compared to the conventional radiotherapy effectively extends the applicability of the LQ model to larger doses.

PMID:34030139 | DOI:10.1088/1361-6560/ac047e

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Nevin Manimala Statistics

Charlson Comorbidity Index score predicts adverse post-operative outcomes after far lateral lumbar discectomy

Clin Neurol Neurosurg. 2021 May 19;206:106697. doi: 10.1016/j.clineuro.2021.106697. Online ahead of print.

ABSTRACT

INTRODUCTION: The Charlson Comorbidity Index (CCI) score has been shown to predict 10-year all-cause mortality and post-neurosurgical complications but has never been examined in a far lateral disc herniation (FLDH) population. This study aims to correlate CCI score with adverse outcomes following FLDH repair.

PATIENTS AND METHODS: All patients (n = 144) undergoing discectomy for FLDH at a single, multihospital academic medical system (2013-2020) were retrospectively analyzed. CCI scores were determined for all patients. Univariate logistic regression was used to determine the ability of CCI score to predict adverse outcomes.

RESULTS: Mean age of the population was 61.72 ± 11.55 years, 69 (47.9%) were female, and 126 (87.5%) were non-Hispanic white. Patients underwent either open (n = 92) or endoscopic (n = 52) FLDH repair. Average CCI score among the patient population was 2.87 ± 2.42. Each additional point in CCI score was significantly associated with higher rates of readmission (p = 0.022, p = 0.014) in the 30-day and 30-90-day post-surgery window, respectively, and emergency department visits (p = 0.011) within 30-days. CCI score also predicted risk of reoperation of any kind (p = 0.013) within 30 days of the index operation. In addition, CCI score was predictive of risk of reoperation of any kind (p = 0.008, p < 0.001; respectively) and repeat neurosurgical intervention (p = 0.027, p = 0.027) within 30-days and 90-days of the index admission (either during the same admission or after discharge).

CONCLUSIONS: This study suggests that CCI score is a useful metric to predict of numerous adverse postoperative outcomes following discectomy for FLDH.

PMID:34030078 | DOI:10.1016/j.clineuro.2021.106697

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Plasma Interleukin-33 level in relapsing-remitting multiple sclerosis. Is it negatively correlated with central nervous system lesions in patients with mild disability?

Clin Neurol Neurosurg. 2021 May 20;206:106700. doi: 10.1016/j.clineuro.2021.106700. Online ahead of print.

ABSTRACT

BACKGROUND: Cytokines and chemokines are undoubtedly involved in the pathogenesis of multiple sclerosis (MS). There are many reports that suggest a significant role for Interleukin-33 (IL-33) in the course of MS development, but it is not clear whether negative or positive. We therefore investigated plasma IL-33 levels in patients with relapsing-remitting MS (RRMS).

METHODS: The study consisted of RRMS patients (n = 73) and healthy subjects (n = 54). Blood samples were taken from all and plasma IL-33 levels were then determined using an enzyme-linked immunosorbent assay method. Patients also underwent laboratory and imaging tests and their disability status was assessed.

RESULTS: Plasma IL-33 levels were marginally significantly higher in patients with RRMS (p = 0.07). Higher IL-33 levels are significantly associated with higher age (p = 0.01). There was also a statistically significant negative correlation between plasma IL-33 levels and the number of high signal intensity lesions in T2-weighted MRI (p = 0.03). After dividing the number of lesions into groups < 9 and ≥ 9 T2-weighted lesions, the Student’s t-test for unrelated variables showed a negative correlation, but not statistically significant (p = 0.22), while the Spearman’s correlation showed a marginally significant correlation (p = 0.06) between IL-33 level and number of T2-weighted lesions. IL-33 was also shown to have a significant ability to differentiate RRMS patients from healthy subjects with a sensitivity of 99% and specificity of 70% (p = 0.00).

CONCLUSIONS: Patients with RRMS have elevated plasma IL-33 levels. In RRMS patients with mild disability, high plasma levels of IL-33 may have neuroprotective effects potentially by stimulating remyelination and/or suppressing autoimmune inflammation and damage. Further studies on this matter on a larger number of patients are needed.

PMID:34030079 | DOI:10.1016/j.clineuro.2021.106700

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Nevin Manimala Statistics

Glyphosate-based herbicide exposure affects diatom community development in natural biofilms

Environ Pollut. 2021 May 12;284:117354. doi: 10.1016/j.envpol.2021.117354. Online ahead of print.

ABSTRACT

Glyphosate herbicide is ubiquitously used in agriculture and weed control. It has now been identified in aquatic ecosystems worldwide, where numerous studies have suggested that it may have both suppressive and stimulatory effects on diverse non-target organisms. We cultured natural biofilms from a hypereutrophic environment to test the effects on periphytic diatoms of exposure to a glyphosate-based herbicide formulation at concentrations from 0 to 10 mg L-1 of active ingredient. There were clear and significant differences between treatments in diatom community structure after the 15-day experiments. Diversity increased more in low glyphosate treatments relative to higher concentrations, and compositional analyses indicated statistically significant differences between glyphosate treatments. The magnitude of change observed was significantly correlated with glyphosate-based herbicide concentration. Our results show that glyphosate-based herbicides have species-selective effects on benthic diatoms that may significantly alter trajectories of community development and therefore may affect benthic habitats and whole ecosystem function.

PMID:34030084 | DOI:10.1016/j.envpol.2021.117354

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Risk models to predict late-onset seizures after stroke: A systematic review

Epilepsy Behav. 2021 May 21;121(Pt A):108003. doi: 10.1016/j.yebeh.2021.108003. Online ahead of print.

ABSTRACT

BACKGROUND AND PURPOSE: We performed a systematic review to evaluate available risk models to predict late seizure onset among stroke survivors.

METHODS: We searched major databases (PubMed, SCOPUS, and Cochrane Library) from inception to October 2020 for articles on the development and/or validation of risk models to predict late seizures after a stroke. The impact of models to predict late-onset seizures was also assessed. We included seven articles in the final analysis. For each of these studies, we evaluated the study design and scope of predictors analyzed to derive each model. We assessed the performance of the models during internal and external validation in terms of discrimination and calibration.

RESULTS: Three studies focused on ischemic stroke alone, with c-statistic values ranging from 0.73 to 0.77. The SeLECT model from Switzerland was externally validated in Italian, German, and Austrian cohorts where c-statistics ranged from 0.69 to 0.81. This model along with the PSEiCARe model, were internally validated and calibration performance was provided for both models. The CAVS and CAVE models reported on the risk of late-onset seizures in patients with hemorrhagic stroke. The CAVS model derivation cohort was racially diverse. The CAVS model’s c-statistic was 0.76, while the CAVE model had a c-statistic of 0.81. Calibration and internal validation were not performed for either study. The CAVS model, created from a Finnish population, was externally validated in American and French cohorts, with c-statistics of 0.73 and 0.69, respectively. Finally, the two studies focusing on both types of stroke came from the PoSERS and INPOSE models. Neither model provided c-statistics, calibration metrics, internal or external validation information. We found no evidence of the presence of impact studies to assess the effect of adopting late-onset seizure risk models after stroke on clinical outcomes.

CONCLUSION: The SeLECT model was the only model developed in line with proposed guidelines for appropriate model development. The model, which was externally validated in a very similar and homogeneous population, may need to be tested in a more racially/ethnic diverse and younger population; testing the SeLECT model, accounting for overall brain health is likely to improve the identification of high-risk patients for late post stroke seizures.

PMID:34029995 | DOI:10.1016/j.yebeh.2021.108003