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Neurological Sciences : Official... May 2022Eye movements serve vision in orienting gaze toward an object of interest in order to place its image simultaneously on both foveas and in stabilizing gaze relative to... (Review)
Review
Eye movements serve vision in orienting gaze toward an object of interest in order to place its image simultaneously on both foveas and in stabilizing gaze relative to the environment in order to maintain fixation on the object of interest, even in the case of body displacement. Disorders of eye movements can interfere with ocular alignment and/or monocular motility, and result in diplopia, which is the most common symptom. Eye movement disorders can also interfere with binocular motility without ocular misalignment and result in gaze palsy. Finally, disorders of eye movement can interfere with ocular stability during fixation or body displacement and result in oscillopsia, which is an illusion of an unstable visual world. A systematic examination of eye movements should be part of the neurological exam in order to detect asymptomatic manifestations that can help for the diagnosis of multiple neurological pathologies. In the case of eye movement disorders, the goals of the examination are to precisely characterize the disorder of motility, alignment, or stability, in order to finally localize anatomically the lesion among the peripheral ocular motor system or the more complex central eye movement neural network and suggest mechanisms and etiologies. In this review, we are describing the standard methods of ocular motor examination, including a "general" approach to any ocular motor assessment, and also the specific approaches to evaluating ocular misalignment, difficulty moving both eyes, and finally unstable gaze. This article will include practical tips on how to perform the tests most effectively or how to interpret the clinical signs elicited.
Topics: Eye Movements; Fixation, Ocular; Humans; Neurologic Examination; Ocular Motility Disorders; Vision Disorders
PubMed: 35239052
DOI: 10.1007/s10072-022-05981-5 -
Current Opinion in Ophthalmology Nov 2017Ocular functions can be affected in almost any type of cerebrovascular accident (CVA) creating a burden on the patient and family and limiting functionality. The present... (Review)
Review
PURPOSE OF REVIEW
Ocular functions can be affected in almost any type of cerebrovascular accident (CVA) creating a burden on the patient and family and limiting functionality. The present review summarizes the different ocular outcomes after stroke, divided into three categories: vision, ocular motility, and visual perception. We also discuss interventions that have been proposed to help restore vision and perception after CVA.
RECENT FINDINGS
Interventions that might help expand or compensate for visual field loss and visuospatial neglect include explorative saccade training, prisms, visual restoration therapy (VRT), and transcranial direct current stimulation (tDCS). VRT makes use of neuroplasticity, which has shown efficacy in animal models but remains controversial in human studies.
SUMMARY
CVAs can lead to decreased visual acuity, visual field loss, ocular motility abnormalities, and visuospatial perception deficits. Although ocular motility problems can be corrected with surgery, vision, and perception deficits are more difficult to overcome. Interventions to restore or compensate for visual field deficits are controversial despite theoretical underpinnings, animal model evidence, and case reports of their efficacies.
Topics: Animals; Disease Models, Animal; Eye Movements; Humans; Ocular Motility Disorders; Perceptual Disorders; Stroke; Transcranial Direct Current Stimulation; Vision Disorders; Visual Acuity; Visual Fields
PubMed: 28984724
DOI: 10.1097/ICU.0000000000000414 -
Neurology Oct 2017
Topics: Adult; Head Movements; Humans; Immunoglobulins, Intravenous; Male; Movement Disorders; Ocular Motility Disorders; Vision Disorders
PubMed: 29061674
DOI: 10.1212/WNL.0000000000004583 -
Current Opinion in Ophthalmology Sep 2018As the majority of our patients are spending significant time using computers and reading, it is important to understand any disease process that can affect one's near... (Review)
Review
PURPOSE OF REVIEW
As the majority of our patients are spending significant time using computers and reading, it is important to understand any disease process that can affect one's near vision. Convergence insufficiency, not an uncommon condition, is still not screened for by most eyecare professionals. This review aims to report the current screening methods and diagnostic criteria, and to summarize the current treatment of convergence insufficiency.
RECENT FINDINGS
The current literature shows that convergence insufficiency has a prevalence of 2-17% in the general population and an even higher rate, up to 49%, in patients who have suffered a traumatic brain injury. Although the measurement is still not standardized, near point of convergence and patient symptomatology appear to be an appropriate screen for convergence insufficiency. Further study is needed to establish standardization of diagnostic criteria. It is now well recognized that orthoptic/vergence therapy provides excellent improvement in the clinical measurements and symptoms associated with convergence insufficiency.
SUMMARY
Convergence insufficiency is a condition that causes a significant impact on near vision. Treatment with orthoptic/vergence therapy can reduce symptomatology and greatly improve one's quality of life. Further study is needed to provide an evidence-based definition that encompasses all cases of convergence insufficiency, research possible subtypes of the disease and establish the efficacy of home-based computer therapy as compared to office-based orthoptic/vergence therapy.
Topics: Convergence, Ocular; Disease Management; Humans; Ocular Motility Disorders; Orthoptics
PubMed: 29994854
DOI: 10.1097/ICU.0000000000000502 -
Progress in Brain Research 2019Opsoclonus/flutter (O/F) is a rare disorder of the saccadic system. Previously, we modeled O/F that developed in a patient following abuse of anabolic steroids. That...
Opsoclonus/flutter (O/F) is a rare disorder of the saccadic system. Previously, we modeled O/F that developed in a patient following abuse of anabolic steroids. That model, as in all models of the saccadic system, generates commands to make a change in eye position. Recently, we saw a patient who developed a unique form of opsoclonus following a concussion. The patient had postsaccadic ocular flutter in both directions of gaze, and opsoclonus during fixation and pursuit in the left hemifield. A new model of the saccadic system is needed to account for this gaze-position dependent O/F. We started with our prior model, which contains two key elements, mutual inhibition between inhibitory burst neurons on both sides and a prolonged reactivation time of the omnipause neurons (OPNs). We included new inputs to the OPNs from the nucleus prepositus hypoglossi and the frontal eye fields, which contain position-dependent neurons. This provides a mechanism for delaying OPN reactivation, and creating a gaze-position dependence. A simplified pursuit system was also added, the output of which inhibits the OPNs, providing a mechanism for gaze-dependence during pursuit. The rest of the model continues to generate a command to change eye position.
Topics: Brain Stem; Fixation, Ocular; Frontal Lobe; Humans; Models, Neurological; Neural Inhibition; Ocular Motility Disorders; Saccades
PubMed: 31325994
DOI: 10.1016/bs.pbr.2019.01.002 -
Journal of Clinical Neurophysiology :... Nov 2019The cerebellum works as a network hub for optimizing eye movements through its mutual connections with the brainstem and beyond. Here, we review three key areas in the... (Review)
Review
The cerebellum works as a network hub for optimizing eye movements through its mutual connections with the brainstem and beyond. Here, we review three key areas in the cerebellum that are related to the control of eye movements: (1) the flocculus/paraflocculus (tonsil) complex, primarily for high-frequency, transient vestibular responses, and also for smooth pursuit maintenance and steady gaze holding; (2) the nodulus/ventral uvula, primarily for low-frequency, sustained vestibular responses; and (3) the dorsal vermis/posterior fastigial nucleus, primarily for the accuracy of saccades. Although there is no absolute compartmentalization of function within the three major ocular motor areas in the cerebellum, the structural-functional approach provides a framework for assessing ocular motor performance in patients with disease that involves the cerebellum or the brainstem.
Topics: Animals; Cerebellum; Eye Movements; Humans; Ocular Motility Disorders
PubMed: 31688323
DOI: 10.1097/WNP.0000000000000579 -
Journal of Neurology Aug 2018
Topics: History, 19th Century; History, 20th Century; Humans; Neurology; Ocular Motility Disorders; Poland
PubMed: 29290054
DOI: 10.1007/s00415-017-8724-4 -
Journal of Neuro-ophthalmology : the... Jun 2022The opsoclonus-myoclonus-ataxia syndrome (OMAS) represents a pathophysiology and diagnostic challenge. Although the diverse etiologies likely share a common mechanism to...
BACKGROUND
The opsoclonus-myoclonus-ataxia syndrome (OMAS) represents a pathophysiology and diagnostic challenge. Although the diverse etiologies likely share a common mechanism to generate ocular, trunk, and limb movements, the underlying cause may be a paraneoplastic syndrome, as the first sign of cancer, or may be a postinfectious complication, and thus, the outcome depends on identifying the trigger mechanism. A recent hypothesis suggests increased GABAA receptor sensitivity in the olivary-oculomotor vermis-fastigial nucleus-premotor saccade burst neuron circuit in the brainstem. Therefore, OMAS management will focus on immunosuppression and modulation of GABAA hypersensitivity with benzodiazepines.
METHODS
We serially video recorded the eye movements at the bedside of 1 patient with SARS-CoV-2-specific Immunoglobulin G (IgG) serum antibodies, but twice-negative nasopharyngeal reverse transcription polymerase chain reaction (RT-PCR). We tested cerebrospinal fluid (CSF), serum, and nasopharyngeal samples. After brain MRI and chest, abdomen, and pelvis CT scans, we treated our patient with clonazepam and high-dose Solu-MEDROL, followed by a rituximab infusion after her formal eye movement analysis 10 days later.
RESULTS
The recordings throughout her acute illness demonstrated different eye movement abnormalities. While on high-dose steroids and clonazepam, she initially had macrosaccadic oscillations, followed by brief ocular flutter during convergence the next day; after 10 days, she had bursts of opsoclonus during scotopic conditions with fixation block but otherwise normal eye movements. Concern for a suboptimal response to high-dose Solu-MEDROL motivated an infusion of rituximab, which induced remission. An investigation for a paraneoplastic etiology was negative. CSF testing showed elevated neuron-specific enolase. Serum IgG to Serum SARS-CoV2 IgG was elevated with negative RT-PCR nasopharyngeal testing.
CONCLUSION
A recent simulation model of macrosaccadic oscillations and OMAS proposes a combined pathology of brainstem and cerebellar because of increased GABAA receptor sensitivity. In this case report, we report 1 patient with elevated CSF neuronal specific enolase, macrosaccadic oscillations, ocular flutter, and OMAS as a SARS-CoV-2 postinfectious complication. Opsoclonus emerged predominantly with fixation block and suppressed with fixation, providing support to modern theories on the mechanism responsible for these ocular oscillations involving cerebellar-brainstem pathogenesis.
Topics: COVID-19; Cerebellar Ataxia; Clonazepam; Female; Humans; Immunoglobulin G; Methylprednisolone Hemisuccinate; Ocular Motility Disorders; Opsoclonus-Myoclonus Syndrome; RNA, Viral; Receptors, GABA-A; Rituximab; SARS-CoV-2
PubMed: 34974489
DOI: 10.1097/WNO.0000000000001498 -
Tidsskrift For Den Norske Laegeforening... Aug 2019Multiple sclerosis can give rise to signs and symptoms from the entire nervous system, including visual impairments. Visual impairments often go unreported because they... (Review)
Review
Multiple sclerosis can give rise to signs and symptoms from the entire nervous system, including visual impairments. Visual impairments often go unreported because they are not obvious to patients, which means that doctors must ask about them specifically. Regular monitoring of vision is important, however, to provide personalised rehabilitation and assistive technologies, and thereby improve patients’ functioning and quality of life.
Topics: Cranial Nerve Diseases; Humans; Multiple Sclerosis; Nystagmus, Pathologic; Ocular Motility Disorders; Optic Neuritis; Quality of Life; Vision Disorders
PubMed: 31429247
DOI: 10.4045/tidsskr.18.0786 -
Klinische Monatsblatter Fur... Nov 2017Neuro-ophthalmological history may be very complex and difficult. This article provides 14 hints about how to construct history taking efficiently and how to avoid... (Review)
Review
Neuro-ophthalmological history may be very complex and difficult. This article provides 14 hints about how to construct history taking efficiently and how to avoid collecting unnecessary information.
Topics: Diagnosis, Differential; Eye Diseases; Humans; Medical History Taking; Nervous System Diseases; Ocular Motility Disorders; Optic Nerve Diseases; Retinal Diseases; Risk Factors; Somatoform Disorders
PubMed: 29155434
DOI: 10.1055/s-0043-120674