Outcomes and Prognostic Factors in the Treatment of Intracanalicular Vestibular Schwannomas Using Gamma Knife Stereotactic Radiation

BACKGROUND

No gold standard has been developed for the therapy of intracanalicular vestibular schwannomas (IVS). Options for treatment include a conservative approach, microsurgery, or radiosurgery. Although the efficacy of these treatment has been well-documented, little is known about the determinants of outcome in IVSs following radiosurgery. Therefore, we examined the results in relation to age, gender, tumor volume, distance to fundus, microcyst existence, and radiosensitivity in this group. In addition, we investigated possible predictors of facial nerve function and hearing preservation.

METHODS

Ninety-four patients with unilateral IVS were included in the evaluation (52 women and 42 males). The patients were separated into younger and older age groups based on their median age (55 years). The median IVS volume was 138 mm3, microcysts were identified in 16 tumors, and 63 tumors were adjacent to the fundus. The data were analyzed using Statistica software package ver. 13.3.

RESULTS

At final follow-up, a statistically significant decrease in tumor volume and no statistically significant decline in hearing were noted, but no differences between age groups were found. The sex had no effect on overall tumor growth control, facial nerve preservation, or hearing preservation. Localization of IVS close to the fundus and the presence of tumor microcysts had no effect on the control of tumor growth, preservation of hearing, and sparing of facial nerve following radiosurgery. Cochlear dose had no influence on hearing preservation. Higher tumor volume was associated with its pseudoprogression during early follow-up and a greater risk of hearing loss.

CONCLUSIONS

Age, sex, tumor volume, proximity to the fundus, and the existence of a microcyst were not predictive of radiosensitivity nor preservation of facial nerve function and hearing, based on the findings. There was no effect of cochlear dose on hearing. Initial greater tumor volume was associated with an increased probability of tumor pseudoprogression.

The impact of Fascial Distortion Model on shoulder girdle dysfunction

Introduction: Shoulder girdle as highly specialized set of structures is particularly susceptible to overloading and injuries. In current literature USG and MRI results shows poor correlation with the function, which lead to some problems in correct diagnosis. The structure contributing to this issue might be fascia. One of the methods examination and treatment is very poorly known Fascial Distortion Model. The aim of our research was to assess the impact of the Fascial Distortion Model on shoulder girdle dysfunction. Materials and methods: The subject of research were 78 patients with shoulder dysfunction. Experimental group of 50 patients underwent six 30-minutes FDM treatments, performed every second day. The control group of 28 patients were subjected standard physiotherapy. Measurement of mobility and pain was done by: functional tests, DASH questionnaire, modified CONSTANT scale and VAS scale. Results: The experimental group obtained better results than control group. This was due to less pain (M = 0.56, SD = 1.03) vs (M = 6.71, SD = 1.88) and a greater limb function (M = 3.46, SD = 7.80) vs (M = 42.72, SD = 16.52). Participants treated with FDM improved in ROM, DASH score and VAS at the significance level (p = .000). Conclusions: 1. Fascial distortions may contribute to dysfunction of the shoulder complex. 2. Connective tissue problems can limit the range of movement 3. Fascia disorders may contribute pain.

1228 New predictors of sudden cardiac death in hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a heart disease characterized by hypertrophy of the left ventricular myocardium. HCM is the most common cause of sudden cardiac death (SCD) in young people and competitive athletes due to fatal ventricular arrhythmias. However, in most patients, HCM has a benign course. That is why it is of utmost importance to properly evaluate patients and identify those who would benefit from a cardioverter-defibrillator (ICD) implantation. The HCM SCD-Risk Calculator is a useful tool for estimating the risk of SCD. The parameters included in the model at evaluation are: age, maximum left ventricular (LV) wall thickness, left atrial (LA) dimension, maximum gradient in left ventricular outflow tract, family history of SCD, non-sustained ventricular tachycardia (nsVT) and unexplained syncope. Nevertheless, there is potential to improve and optimize the effectiveness of this tool in clinical practice. Therefore, the following new risk factors are proposed: LV global longitudinal strain (GLS), LV average strain (ASI) and LA volume index (LAVI). GLS and ASI are sensitive and noninvasive methods of assessing LV function. LAVI more accurately characterizes the size of the left atrium in comparison to the LA dimension.

METHODS

252 HCM patients (aged 20-88 years, of which 49,6% were men) treated in our Department from 2005 to 2018, were examined. The follow-up period was 0-13 years (average: 3.8 years). SCD was defined as sudden cardiac arrest (SCA) or an appropriate ICD intervention. All patients underwent an echocardiographic examination. The medical and family histories were collected and ICD examinations were performed.

RESULTS

76 patients underwent an ICD implantation during the follow-up period. 20 patients have reached an SCD end-point. 1 patient died due to SCA and 19 had an appropriate ICD intervention.

There were statistically significant differences of GLS and ASI values between SCD and non-SCD groups; p = 0.026389 and p = 0.006208, respectively. The average GLS in the SCD group was -12.4% ± 3.4%, and -15.1% ± 3.5% in the non-SCD group. The average ASI values were -9.9% ± 3.8% and -12.4% ± 3.5%, respectively. There was a statistically significant difference between LAVI values in SCD and non-SCD groups; p = 0.005343. The median LAVI value in the SCD group was 45.7 ml/m2 and 37.6 ml/m2 in the non-SCD group. The ROC curves showed the following cut-off points for GLS, ASI and LAVI: -13.8%, -13.7% and 41 ml/m2, respectively.

Cox’s proportional hazards model for the parameters used in the Calculator was at the borderline of significance; p = 0.04385. The model with new variables (GLS and LAVI instead of LA dimension) was significant; p = 0.00094. The important factors were LAVI; p = 0.000075 and nsVT; p = 0.012267.

CONCLUSIONS

The proposed new SCD risk factors were statistically significant in the study population and should be taken into account when considering ICD implantation.

P1291 Are we ready for machine learning in HCM risk stratification?

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a heart disease characterized by hypertrophy of the left ventricular myocardium. The disease is the most common cause of sudden cardiac death (SCD) in young people and competitive athletes due to fatal ventricular arrhythmias, but in most patients, however, HCM has a benign course. Therefore, it is of the utmost importance to properly evaluate patients and identify those who would benefit from a cardioverter-defibrillator (ICD) implantation. The HCM SCD-Risk Calculator is a useful tool for estimating the 5-year risk of SCD. Parameters included in the model at evaluation are: age, maximum left ventricular wall thickness, left atrial dimension, maximum gradient in left ventricular outflow tract, family history of SCD, non-sustained ventricular tachycardia and unexplained syncope. Patients’ risk of SCD is classified as low (<4%), intermediate (4-<6%) or high (≥6%). Those in the high-risk group should have an ICD implantation. It can also be considered in the intermediate-risk group. However, the calculator still needs improvement and machine learning (ML) has the potential to fulfill this task. ML algorithm creates a model for solving a specific problem without explicit programming - instead it relies only on available data - by discovering patterns and relations.

METHODS

252 HCM patients (aged 20-88 years, 49,6% were men) treated in our Department from 2005 to 2018, have been enrolled. The follow-up lasted 0-13 years (average: 3.8 years). SCD was defined as sudden cardiac arrest (SCA) or an appropriate ICD intervention. All parameters from HCM SCD-Risk Calculator have been obtained and the risk of SCD has been calculated for all patients during the first echocardiographic evaluation. ML model with variables from HCM SCD-Risk Calculator has been created. Both methods have been compared.

RESULTS

20 patients reached an SCD end-point. 1 patient died due to SCA and 19 had an appropriate ICD intervention. Among them, there were respectively 6, 7 and 7 patients in the low, intermediate and high-risk group of SCD. 1 patient, who died, had a low risk. The ML model correctly assessed the SCD event only in 1 patient. According to ML, the risk of SCD ≤2.07% was a negative predictor.

CONCLUSIONS

The study did not show an advantage of ML over HCM SCD-Risk Calculator. Because of the characteristic of the dataset (approximately the same number of features and observations), the selection of machine learning algorithms was limited. Best results (evaluated using LOOCV) were achieved with a decision tree. We expect that bigger dataset would allow improving model performance because of strong regularization need in the current setup.

P1395 New predictors of burned-out phase in hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a heart disease characterized by hypertrophy of the left ventricular myocardium. The structural and functional abnormalities cannot be explained by flow-limiting coronary artery disease or loading conditions. HCM has a benign course, however approximately 5% of these patients suffer from the end-stage of the disease. The so-called burned-out phase, characterized by systolic dysfunction with a left ventricular ejection fraction ≤50%, is often associated with wall thinning and chamber dilation. These patients should have more frequent clinic visits and have a more intensive treatment plan. They are also candidates for heart transplantation. Currently there are no risk factors of progression to burned-out phase before the onset of heart failure symptoms. Therefore, the potential risk factors: left ventricular global longitudinal strain (GLS), left ventricular average strain (ASI), right ventricular average strain (RV-ASI) and left atrial volume index (LAVI), have been examined. GLS, derived from speckle tracking echocardiography, and ASI, derived from tissue doppler imaging, are the sensitive and noninvasive methods of assessing the ventricular function. LAVI more accurately characterizes the size of the left atrium, which usually increases in the course of the disease.

METHODS

A total of 252 patients with HCM (aged 20-88 years, 49,6% were men), treated in our Department have been enrolled in the study. GLS, ASI, RV-ASI and LAVI assessment has been made in addition to standard echocardiographic examination. Burned-out was characterized as systolic dysfunction with a left ventricular ejection fraction ≤50%.

RESULTS

5.6% patients in the study population were diagnosed with burned-out phase in hypertrophic cardiomyopathy.

The t-Student test and t-Student test with Cochran-Cox adjustment showed statistically significant differences of GLS and ASI values between burned-out and non-burned-out groups; p = 0.000001 and p < 0.000001, respectively. Average and median values of GLS in burned-out group were -7.4% ± 2.9%, -7.1% and -15.3% ± 4.3%, -15.4% in non-burned-out group. For ASI those values were respectively -7.6% ± 2.2%, -7.1% and -12.9% ± 4.5%, -13.0%.

The Mann-Whitney test showed statistically significant differences of RV-ASI and LAVI values between burned-out and non-burned-out groups; p = 0.000208 and p = 0.005302, respectively. Median value of RV-ASI in burned-out group was -15.8% and -27.1% in non- burned-out group. Median value of LAVI in burned-out group was 52.6 ml/m2 and 37.8 ml/m2 in non-burned-out group.

CONCLUSIONS

Each of the proposed new risk factors of burned-out development was statistically significant in the study population. Therefore, all HCM patients should have regular echocardiographic examinations and those with deteriorating values of new parameters should become the subjects of intensified medical care.

Association of single-nucleotide polymorphisms of the tau gene with late-onset Parkinson disease

CONTEXT

The human tau gene, which promotes assembly of neuronal microtubules, has been associated with several rare neurologic diseases that clinically include parkinsonian features. We recently observed linkage in idiopathic Parkinson disease (PD) to a region on chromosome 17q21 that contains the tau gene. These factors make tau a good candidate for investigation as a susceptibility gene for idiopathic PD, the most common form of the disease.

OBJECTIVE

To investigate whether the tau gene is involved in idiopathic PD.

DESIGN, SETTING, AND PARTICIPANTS

Among a sample of 1056 individuals from 235 families selected from 13 clinical centers in the United States and Australia and from a family ascertainment core center, we tested 5 single-nucleotide polymorphisms (SNPs) within the tau gene for association with PD, using family-based tests of association. Both affected (n = 426) and unaffected (n = 579) family members were included; 51 individuals had unclear PD status. Analyses were conducted to test individual SNPs and SNP haplotypes within the tau gene.

MAIN OUTCOME MEASURE

Family-based tests of association, calculated using asymptotic distributions.

RESULTS

Analysis of association between the SNPs and PD yielded significant evidence of association for 3 of the 5 SNPs tested: SNP 3, P =.03; SNP 9i, P =.04; and SNP 11, P =.04. The 2 other SNPs did not show evidence of significant association (SNP 9ii, P =.11, and SNP 9iii, P =.87). Strong evidence of association was found with haplotype analysis, with a positive association with one haplotype (P =.009) and a negative association with another haplotype (P =.007). Substantial linkage disequilibrium (P<.001) was detected between 4 of the 5 SNPs (SNPs 3, 9i, 9ii, and 11).

CONCLUSIONS

This integrated approach of genetic linkage and positional association analyses implicates tau as a susceptibility gene for idiopathic PD.

Identification of a new autosomal dominant limb-girdle muscular dystrophy locus on chromosome 7

We report the identification of a new locus for autosomal dominant limb-girdle muscular dystrophy (LGMD1) on 7q. Two of five families (1047 and 1701) demonstrate evidence in favor of linkage to this region. The maximum two-point LOD score for family 1047 was 3.76 for D7S427, and that for family 1701 was 2.63 for D7S3058. Flanking markers place the LGMD1 locus between D7S2423 and D7S427, with multipoint analysis slightly favoring the 9-cM interval spanned by D7S2546 and D7S2423. Three of five families appear to be unlinked to this new locus on chromosome 7, thus establishing further heterogeneity within the LGMD1 diagnostic classification.

The content of free amino acids in plasma of hens of different strains

Free amino acids were estimated in the plasma of Leghorn, Cornish and White Rock hens, bred under identical conditions. It was found that the plasma of Leghorn hens had a lower content of amino acids. The differences were especially pronounced for proline, glutamic acid and glycine. It was established that a lower percentage of valine, leucine and isoleucine was typical of Leghorn hens in comparison with Cornish hens. The obtained results indicate that the level of free amino acids in blood plasma is genetically controlled.

Effect of starvation on the content of free amino acids in plasma of different breeds of hen

'Leghorn', 'Cornish' and 'White Rock' hens were subjected to starvation. Free amino acids were determined in blood samples taken after 48, 72 and 96 h of starvation. A progressive decrease in concentration of the majority of amino acids was found. Changes in amino acid concentrations during starvation were dependent on the breed of hen.

The level of free amino acids in erythrocytes of different breeds of hen

The content of free amino acids was determined in erythrocytes of adult 'Leghorn' (Lg, 'White Rock' (WR) and 'Cornish' (Cr) hens, bred under identical conditions. The concentration of total amino acids was twice as high in the erythrocytes as in plasma, amounting to 396 μm/100 ml, 424 μm/100 ml and 475μm/100 ml in 'White Rock', 'Cornish' and 'Leghorn' hens, respectively.Significant differences were found in the ratio of basic amino acids to acidic amino acids. These values were 0.76, 1.75 and 3.19 in 'White Rick', 'Leghorn' and 'Cornish' hens, respectively; in the plasma of all 3 breeds the ratio was 1. Statistically significant interbreed differences were expressed more distinctly in erythrocyte than in plasma amino acid concentrations. For absolute concentrations the differences were significant in the case of 9 amino acids.