A 62-year-old woman with relapsing-remitting multiple sclerosis suddenly complained of diplopia associated with bilateral adduction impairment, nystagmus of the abducting eye bilaterally, and sparing of abduction, convergence, and vertical eye movements, consistent with bilateral internuclear ophthalmoplegia. Within 1 week, she had developed a complete horizontal gaze paralysis even with the oculocephalic maneuver. Vertical saccades were slow and convergence was preserved. There was a right lower motor neuron seventh cranial nerve palsy. Brain MRI showed a new enhancing lesion involving the pontine tegmentum. Clinical and MRI follow-up showed recovery after 6 months. The slowing of vertical saccades may have been due to spread of the demyelinating lesion to the adjacent paramedian pontine reticular formation, which contains omnipause neurons lying in the raphe interpositus nucleus thought to inhibit excitatory burst neurons for horizontal and vertical saccades. Our patient verifies the fact that vertical saccadic abnormalities may occur from a lesion apparently confined to the pons.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1097/WNO.0b013e318183bd26 | DOI Listing |
eNeuro
January 2025
Research Group for Brain and Cognitive Science, Shahid Beheshti Medical University, Tehran, Iran.
Visual information emerging from the extrafoveal locations is important for visual search, saccadic eye movement control, and spatial attention allocation. Our everyday sensory experience with visual object categories varies across different parts of the visual field which may result in location-contingent variations in visual object recognition. We used a body, animal body, and chair two-forced choice object category recognition task to investigate this possibility.
View Article and Find Full Text PDFBrain Sci
December 2024
Department of Neurology, The Carrick Institute, Cape Canaveral, FL 32920, USA.
Background: Eye movement research serves as a critical tool for assessing brain function, diagnosing neurological and psychiatric disorders, and understanding cognition and behavior. Sex differences have largely been under reported or ignored in neurological research. However, eye movement features provide biomarkers that are useful for disease classification with superior accuracy and robustness compared to previous classifiers for neurological diseases.
View Article and Find Full Text PDFJpn J Ophthalmol
January 2025
Department of Neurology, Yokohama Brain and Spine Center, Yokohama, Japan.
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°.
Cerebellum
December 2024
NeuroMetrology Lab, Nuffield Department of Clinical Neurosciences, Clinical Neurology, Medical Sciences Division, University of Oxford, Oxford, OX3 9DU, UK.
Whereas several studies have reported on quantitative oculomotor and vestibular measurements in spinocerebellar ataxia type 6 (SCA6), selecting the most suitable paradigms remains challenging. We aimed to address this knowledge gap through a systematic literature review and providing disease-specific recommendations for a tailored set of eye-movement recordings in SCA6. A literature search (MEDLINE, Embase) was performed focusing on studies reporting on quantitative oculomotor and/or vestibular measurements in SCA6-patients.
View Article and Find Full Text PDFEur J Pharmacol
January 2025
Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada, K7L 3N6. Electronic address:
Ketamine is widely used to probe cognitive functions relying on the properties of methyl-D-aspartate receptor (NMDAR) synaptic transmission. Numerous works have proved that cognitive performance and adjustments in the decision or perceptual domains are affected after ketamine injection in general circulation of primates. Here, we take advantage of that in the brain stem; horizontal saccade deceleration is controlled by glycine-NMDAR-gated current, while gamma-aminobutyric acid (GABA) current controls vertical deceleration to demonstrate that despite general circulation level manipulation of NMDAR synaptic transmission, the kinematic of the saccade appeared to be in the motor brainstem generator circuit differentially maintained.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!