Publications by authors named "Dan Valsky"

During Deep Brain Stimulation (DBS) surgery for treating Parkinson's disease, detecting the Subthalamic Nucleus (STN) and its sub-territory called the Dorsolateral Oscillatory Region (DLOR) is crucial for adequate clinical outcomes. Currently, the detection is based on human experts, often guided by supervised machine learning detection algorithms. This procedure depends on the knowledge and experience of particular experts and on the amount and quality of the labeled data used for training the machine learning algorithms.

View Article and Find Full Text PDF

The yield of chromosomal microarray analysis (CMA) is well established in structurally normal fetuses (0.4-1.4%).

View Article and Find Full Text PDF

Tremor is a core feature of Parkinson's disease and the most easily recognized Parkinsonian sign. Nonetheless, its pathophysiology remains poorly understood. Here, we show that multispectral spiking activity in the posterior-dorso-lateral oscillatory (motor) region of the subthalamic nucleus distinguishes resting tremor from the other Parkinsonian motor signs and strongly correlates with its severity.

View Article and Find Full Text PDF

Dopamine and striatal dysfunctions play a key role in the pathophysiology of Parkinson's disease (PD) and Dystonia, but our understanding of the changes in the discharge rate and pattern of striatal projection neurons (SPNs) remains limited. Here, we recorded and examined multi-unit signals from the striatum of PD and dystonic patients undergoing deep brain stimulation surgeries. Contrary to earlier human findings, we found no drastic changes in the spontaneous discharge of the well-isolated and stationary SPNs of the PD patients compared to the dystonic patients or to the normal levels of striatal activity reported in healthy animals.

View Article and Find Full Text PDF

Objective:  To evaluate the outcome of twin pregnancies that were complicated by rupture of membranes at 13-20 weeks of gestation and were managed by expectant management or by selective termination.

Methods:  A retrospective cohort study of all bichorionic twin pregnancies that were referred to three fetal medicine units between 2001 and 2016, due to rupture of membranes of one sac at 13-20 weeks of gestation. Women without clinical signs of infection who opted for expectant management or selective termination were included.

View Article and Find Full Text PDF

The subthalamic nucleus (STN), a preferred target for treating movement disorders, has a crucial role in inhibition and execution of movement. To better understand the mechanism of movement regulation in the STN of Parkinson's disease patients, we compared the same movement with different context, facilitation vs. inhibition context.

View Article and Find Full Text PDF

Background: Therapeutic outcomes of STN-DBS for movement and psychiatric disorders depend on electrode location within the STN. Electrophysiological and functional mapping of the STN has progressed considerably in the past years, identifying beta-band oscillatory activity in the dorsal STN as a motor biomarker. It also has been suggested that STN theta-alpha oscillations, involved in impulse control and action inhibition, have a ventral source.

View Article and Find Full Text PDF

Objective: Deep brain stimulation (DBS) of the internal segment of the globus pallidus (GPi) in patients with Parkinson's disease and dystonia improves motor symptoms and quality of life. Traditionally, pallidal borders have been demarcated by electrophysiological microelectrode recordings (MERs) during DBS surgery. However, detection of pallidal borders can be challenging due to the variability of the firing characteristics of neurons encountered along the trajectory.

View Article and Find Full Text PDF

Introduction: : Minimally invasive fetal therapeutic procedures reduce the morbidity and mortality in monochorionic (MC) twins and in fetuses with congenital diaphragmatic hernia (CDH). MC pregnancies share their blood systems due to communicating vessels over their single placenta and may develop specific complications: Twin-to-Twin transfusion syndrome (TTTS), Selective intrauterine growth restriction (sIUGR), Twin Anemia-Polycythemia Sequence (TAPS), Twin Reverse Arterial Perfusion Syndrome (TRAP) or anomalies in one. Half of complicated MC require intrauterine interventions.

View Article and Find Full Text PDF

Background: Persistently high rates of cesarean deliveries are cause for concern for physicians, patients, and health systems. Prelabor assessment might be refined by identifying factors that help predict an individual patient's risk of cesarean delivery. Such factors may contribute to patient safety and satisfaction as well as health system planning and resource allocation.

View Article and Find Full Text PDF

Subthalamic nucleus field potentials have attracted growing research and clinical interest over the last few decades. However, it is unclear whether subthalamic field potentials represent locally generated neuronal subthreshold activity or volume conductance of the organized neuronal activity generated in the cortex. This study aimed at understanding of the physiological origin of subthalamic field potentials and determining the most accurate method for recording them.

View Article and Find Full Text PDF

Objectives: We evaluated primiparous women with clinically diagnosed third- and fourth-degree and anal sphincter tears, to evaluate the rate of levator ani muscle injury compared to primiparous women without sphincter tears.

Methods: Primiparous women delivering in our maternity ward with intrapartum diagnoses of third- or fourth-degree anal sphincter tears, repaired by the overlapping technique, were recruited to undergo 3-dimensional transperineal sonography of the pelvic floor anatomy, including the anterior and posterior compartments. Primiparas with uncomplicated vaginal deliveries were recruited as a comparison group.

View Article and Find Full Text PDF

Background: Microelectrode recordings along preplanned trajectories are often used for accurate definition of the subthalamic nucleus (STN) borders during deep brain stimulation (DBS) surgery for Parkinson's disease. Usually, the demarcation of the STN borders is performed manually by a neurophysiologist. The exact detection of the borders is difficult, especially detecting the transition between the STN and the substantia nigra pars reticulata.

View Article and Find Full Text PDF
Article Synopsis
  • The study assessed primiparous women with severe anal sphincter tears to determine the prevalence of levator ani muscle injuries compared to those without such tears.
  • Out of 94 women with anal sphincter tears, 40.4% had levator ani defects, significantly higher than the 16.2% in the control group of 464 women with normal deliveries.
  • The findings highlight a correlation between severe sphincter tears and levator ani muscle damage, suggesting the need for better awareness and preventive strategies for pelvic floor disorders.
View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the impact of fetal head circumference (HC) on obstetric outcomes compared to birthweight (BW) during term singleton births.
  • The research analyzes data from over 24,000 births to assess risks of unplanned cesarean sections and other complications for infants with large HC versus high BW.
  • Results indicate that infants with large HC have significantly higher odds of unplanned cesarean and instrumental deliveries compared to those with normal HC, while high BW has a less pronounced effect on delivery mode.
View Article and Find Full Text PDF

Objectives: To compare visualization rates for early targeted organ scanning at gestational ages ranging from 11 weeks 3 days to 13 weeks 2 days versus 14 weeks 3 days to 16 weeks 2 days.

Methods: We conducted a prospective longitudinal study of patients who presented for nuchal translucency (NT) screening and targeted organ scanning. Extended targeted organ scanning, including the central nervous system, face and neck, chest, heart (including complete echocardiography), digestive system, abdominal wall, urinary system, skeleton, and umbilical cord with its insertion and placenta, was performed on gravidas in 2 age ranges.

View Article and Find Full Text PDF

Objective: The aim of this study is to evaluate the independent and combined value of gestational age, fetal weight, fetoplacental Doppler, and myocardial performance index for the prediction of individual risk of early (≤7 days) intrauterine fetal death (IUFD) after laser therapy in twin-to-twin transfusion syndrome (TTTS).

Material And Methods: A consecutive series of 215 cases of TTTS treated with laser therapy in three centers was prospectively studied. Ultrasound evaluation within 24 h of surgery included estimated fetal weight discordance, umbilical artery, pulsatility index (PI) and diastolic flow evaluation, middle cerebral artery PI and middle cerebral artery peak systolic velocity, ductus venosus PI and atrial flow assessment, and modified myocardial performance index.

View Article and Find Full Text PDF

Objective: To compare the outcomes of twin-to-twin transfusion syndrome (TTTS) cases treated with fetoscopic laser coagulation of vascular anastomoses before 25 + 6 weeks of gestation and between 26 and 28 weeks of gestation.

Material And Methods: 28 consecutive cases of TTTS at Quintero stages II-IV treated with laser therapy between 26 + 0 and 28 + 6 weeks of gestation were compared with 324 cases treated between 15 + 0 and 25 + 6 weeks during a 3-year period in two centers. The following data were recorded and compared: duration of the fetoscopy, rate of complications (preterm labor before 28 weeks and before 32 weeks, chorioamnionitis, twin anemia-polycythemia syndrome and recurrent TTTS), gestational age at delivery and neonatal survival rate.

View Article and Find Full Text PDF

Prenatal imaging of the fetal cerebellar vermis is challenging even for experienced examiners. We found that by aiming the ultrasound beam through the mastoid fontanel and then rotating the data set in a multiplanar reconstruction and applying volume contrast imaging in the C plane, we were consistently able to obtain images of the vermis in the standard midsagittal plane. Images of the fetal vermis suitable for morphologic evaluation were obtained in 408 of 414 cases (98.

View Article and Find Full Text PDF

Twin-to-twin transfusion syndrome (TTTS) is a severe complication of monochorionic (MC) twin pregnancies, characterized by the development of unbalanced chronic blood transfer from one twin, defined as donor twin, to the other, defined as recipient, through placental anastomoses. If left untreated, TTTS is associated with very high perinatal mortality and morbidity rates, due to a combination of fetal and/or obstetric complications. The reported prevalence is 10-15% of all MC twins, or about 1 in 2000 pregnancies.

View Article and Find Full Text PDF

Selective intrauterine growth restriction (sIUGR) in monochorionic twins is associated with a substantial increase in perinatal mortality and morbidity for both twins. Clinical evolution depends on the combination of the effects of placental insufficiency in the IUGR twin with inter-twin blood transfer through placental anastomoses. Classification of sIUGR into types according to the characteristics of umbilical artery diastolic flow in the IUGR twin permits the differentiation of clinical and prognostic groups.

View Article and Find Full Text PDF

Selective intrauterine growth restriction (sIUGR) occurs in 10 to 15% of monochorionic (MC) twins, and it is associated with a substantial increase in perinatal mortality and morbidity. Clinical evolution is largely influenced by the existence of intertwin placental anastomoses: pregnancies with similar degrees of fetal weight discordance are associated with remarkable differences in clinical behavior and outcome. We have proposed a classification of sIUGR into three types according to umbilical artery (UA) Doppler findings (I-normal, II-absent/reverse end-diastolic flow, III-intermittent absent/reverse end-diastolic flow), which correlates with distinct clinical behavior, placental features and may assist in counseling and management.

View Article and Find Full Text PDF

Objective: Ultrasonography has been applied previously to the assessment of the fetal anal canal. We aimed to examine the potential of 3-dimensional ultrasonography (3DUS) in the evaluation of the fetal anal canal and to obtain normal fetal anal canal measurements.

Methods: Patients were recruited from an unselected population of gravidas with known gestational age (by dates or first-trimester ultrasonography) and without known fetal anomalies presenting for fetal evaluation in the ultrasound units of 2 tertiary care centers between 16 and 39 gestational weeks.

View Article and Find Full Text PDF

Purpose Of Review: To describe the state of the science of three-dimensional/four-dimensional ultrasound (3D/4DUS) applications to fetal medicine.

Recent Findings: 3D/4DUS applications are many and varied. Their use in fetal medicine varies with the nature of the tissue to be imaged and the challenges each organ system presents, versus the advantages of each ultrasound application.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessiondituf2300nf8al9dkjk2hbljm8r2kirt): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once