Purpose: To assess the effects of modifying head position and of static ocular counter-rolling (OCR) on abduction and adduction in saccadic eye movements using a head-mounted video-oculographic device.

Study Design: A clinical observational study.

Methods: The peak velocities and amplitude gains of visually guided 12° saccades were binocularly measured in 21 healthy volunteers with their heads in the upright vertical (0°) and horizontal (± 90°, bilateral side-lying) postures, and in 6 participants with their head positions bilaterally tilted by 30°. The rotation angles of eyeballs generated via OCR in the bilateral 30° and 90° head positions were evaluated in five participants.

Results: Peak velocities and gains were significantly higher with the head in the 0° position compared to ± 90°. The decreases in peak velocities and gains at ± 90° were not affected by the apogeotropic or geotropic directions. Faster peak velocities and greater gains on abduction, rather than adduction, were observed under each test condition. The tendencies toward faster peak velocity and greater gain in the 0° head position rather than bilaterally tilted at 30° were preserved. The absolute rotation angles at ± 90° were larger than those at 30°.

Conclusions: Head position affected the peak velocities and gains of both abduction and adduction saccades. The findings suggest that modified force vectors exerted by different eye muscles recruited during OCR play a role. Our research provides valuable insights for assessing eye movements across various head positions.

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10384-024-01132-9DOI Listing

Publication Analysis

Top Keywords

peak velocities
24
velocities gains
16
abduction adduction
16
head position
16
gains abduction
12
head positions
12
adduction saccades
8
head
8
eye movements
8
bilaterally tilted
8

Similar Publications

Altered thrombin generation with prothrombin complex concentrate is not detected by viscoelastic testing: an in vitro study.

Br J Anaesth

January 2025

Ludwig Boltzmann Institute for Traumatology, The Research Center in Cooperation with AUVA, Vienna, Austria; Department of Anesthesiology and Intensive Care Medicine AUVA Trauma Center Salzburg, Academic Teaching Hospital of the Paracelsus Medical University, Salzburg, Austria.

Background: Bleeding guidelines currently recommend use of viscoelastic testing (VET) to direct haemostatic resuscitation in severe haemorrhage. However, VET-derived parameters of clot initiation, such as clotting time (CT) and activated clotting time (ACT), might not adequately reflect a clinically relevant interaction of procoagulant and anticoagulant activity, as revealed by thrombin generation assays. The aim of this study was to evaluate the ability of CT and ACT to indicate thrombin generation activity.

View Article and Find Full Text PDF

The prognostic and diagnostic significance of echocardiographic parameters on acute ischemic stroke.

J Stroke Cerebrovasc Dis

January 2025

Department of Neurology and Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou City, Jiangsu Province, China. Electronic address:

Objective: To comprehensively explore the prognostic significance of transthoracic echocardiography (TTE) and three-dimensional speckle-tracking echocardiography (3D STE) parameters in AIS and their role in distinguishing cardioembolic stroke.

Methods: 301 acute ischemic stroke (AIS) patients were enrolled. TTE and 3D STE were employed to evaluate cardiac function and structure, also left atrial strain.

View Article and Find Full Text PDF

Purpose: To assess the effects of modifying head position and of static ocular counter-rolling (OCR) on abduction and adduction in saccadic eye movements using a head-mounted video-oculographic device.

Study Design: A clinical observational study.

Methods: The peak velocities and amplitude gains of visually guided 12° saccades were binocularly measured in 21 healthy volunteers with their heads in the upright vertical (0°) and horizontal (± 90°, bilateral side-lying) postures, and in 6 participants with their head positions bilaterally tilted by 30°.

View Article and Find Full Text PDF

INCREASED CITRULLINATED HISTONE H3 LEVELS AND ACCELERATED THROMBIN KINETICS IN TRAUMA PATIENTS WHO DEVELOP VENOUS THROMBOEMBOLISM.

Shock

December 2024

Division of Trauma, Critical Care, and General Surgery, Department of Surgery, Mayo Clinic, 200 1st St. SW, Rochester, MN, United States 55905.

Background: Neutrophil extracellular traps (NETs), and its formation and release, known as NETosis, may play a role in the initiation of thrombin generation (TG) in trauma. The objective of this study was to assess whether trauma patients, who develop symptomatic venous thromboembolism (VTE), have increased levels of plasma citrullinated histone H3 (CitH3) and accelerated TG kinetics.

Methods: Patients presenting to a Level I Trauma Center as trauma activations had samples collected within 12 hours of time of injury (TOI), alongside healthy volunteers (HV).

View Article and Find Full Text PDF

High-Speed Video Blink Analysis Improves Detection of Facial Palsy in Early Guillain-Barré Syndrome.

Muscle Nerve

January 2025

Department of Medicine, St Vincent's Hospital Melbourne, The University of Melbourne, Melbourne, Victoria, Australia.

Introduction/aims: Electrophysiological investigations in early Guillain-Barré Syndrome (GBS) can be nondiagnostic. Improved testing for facial weakness in the early phase of GBS may improve diagnostic processes, as such weakness is found in approximately 50% of patients with GBS. This work pilots the utility of high-speed video analysis to complement blink reflex testing in early GBS.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!