Assessment of Vestibular Function in Children
Kenneth J Ottenbacher, Margaret A Short Degraft in Vestibular Processing Dysfunction in Children, 2013
Methodological Considerations Types of Nystagmus. A spontaneous nystagmus (direction fixed and beating with similar intensity in all head positions) with the eyes closed is normally detected in a significant proportion of the normal population, 2 however, this type of nystagmus is strongly suppressed by visual fixation. When the eyes are open in light, a spontaneous nystagmus is almost always pathologic, although it is often the result of deficits in visual fixation reflexes, rather than the result of vestibular deficits. Congenital nystagmus (high frequency horizontal oscillations of the eyes during attempted fixation of stationary targets) is an ocular motor disorder which is the result of defective fixational reflexes. 3 Positional nystagmus refers to nystagmus which occurs in certain head positions only and this information is useful as a diagnostic tool in determining central versus peripheral etiology. Nystagmus can be elicited in a variety of manners. An optokinetic nystagmus (OKN) is elicited via a visual stimulus such as a rotating drum with black and white stripes. A filmstrip of cartoon characters or animals which is moved across the visual field can be used to elicit an OKN in children. Another approach is to study vestibular-visual interaction by rotating the individual while he is surrounded by a visual environment designed to elicit an OKN (i.e., white curtain with black design). Thermal stimulation to the ear using air or water (caloric tests) will
Neurology
Fazal-I-Akbar Danish in Essential Lists of Differential Diagnoses for MRCP with diagnostic hints, 2017
Nystagmus:1 Congenital.2 Acquired: a Vestibular pathology (fast phase away from the side of the lesion).b Cerebellar pathology (fast phase towards the side of the lesion).c Drug-induced (alcohol; amitriptyline; phenytoin; phenobarbitone).
Ocular oscillation and visually dependent postural control in congenital nystagmus
Jan-Tjeerd de Faber in 28th European Strabismological Association Meeting, 2020
Particularly significant is the difference observed when comparing the group of patients placed in a position of maximum nystagmus to the control group of patients when the Bangerter filters were applied to the latter. The postural behaviour of the two groups did not differ for any of the variables considered except for the visual afferences. In fact, in these positions of gaze, the latter are reduced in both groups of patients, but more markedly in the group of patients suffering from congenital nystagmus. Such an observation may be attributed to the conditions of reduced vision, which is presumably lower in patient with maximus nystagmus, infact the binocular visus of the control group with filter applied was similar to the mean binocular visus of the nystagmic patients in block gaze position. Nevertheless we could not exclude that also plays an important role the nystagmic ocular motion. The ocular motion, infact, causes oscillopsia and consequent attempts to compensate it.
Evaluating the impact of information and support for people with nystagmus in the digital age: A patient and carer questionnaire study
Published in Current Eye Research, 2020
S. L. Gummer, M. Evans, A. Cygan, D. Osborne, H. J. Griffiths, H. Lee, J. E. Self
Nystagmus is a disorder of rhythmic involuntary oscillations of the eyes1,2 and can either be infantile or acquired. Infantile nystagmus can be idiopathic or be associated with other eye diseases, neurological syndromes or low vision.3–5 Nystagmus is thought to affect 24 people per 10,000 in the UK, and treatment options are currently limited for the vast majority.1 A range of visual impairments are seen in children, extending from driving standard vision to severe visual impairment.6 Importantly, visual impairment can be underestimated by using static visual acuity tests alone as ‘real-world vision’ relies on the ‘speed of seeing’7 and various other factors for people with nystagmus. For example, static visual acuity tests do not take into account moving targets, judgement of speed, real-world lighting conditions or complex visual scenes. Furthermore, real-world vision in nystagmus is known to be affected by factors such as changes in vision due to head position, tiredness and stress.7,8 For these reasons, inconstant levels of support and information are often reported by patients.9
Two-muscle surgical treatment of a compensatory head tilt in an adult with acquired downbeat nystagmus
Published in Baylor University Medical Center Proceedings, 2023
Daniel Vinson, Jonathan Kopel, Caezaan Keshvani, James Lee, Kenn Freedman
Nystagmus in children and adults is an involuntary oscillatory eye movement disorder that can vary in intensity in different gaze positions. If there is a certain gaze position where the nystagmus is least active, this is known as a null point (or zone), and often the patients’ symptoms and vision improve when the eyes are deviated toward that null point/zone. Patients with an eccentric null point/zone will often assume a compensatory head tilt to set their eyes in that null zone and optimize their vision. This forms the basis of the Kestenbaum-Anderson–like operations, which have proven beneficial in treatment of compensatory head tilt in patients with infantile nystagmus. The Kestenbaum-Anderson procedures involve shifting the eyes in the direction of the abnormal head turn/tilt and away from the preferred direction of gaze. The Kestenbaum procedure involves bilateral recession of the yoke muscles opposite to the head turn, combined with bilateral resection of their antagonists. Anderson’s procedure only involves recession of the yoke muscles. However, the procedure’s use in acquired vertical nystagmus in adults with head tilt has rarely been reported.
The challenges faced by clinicians diagnosing and treating infantile nystagmus Part II: treatment
Published in Expert Review of Ophthalmology, 2021
Eleni Papageorgiou, Katerina Lazari, Irene Gottlob
Children with nystagmus are common in pediatric ophthalmic practice. Due to the variability in clinical presentation, complexity of pathophysiologic mechanisms and possibility of serious underlying disorders, clinicians often face diagnostic and therapeutic challenges when dealing with affected children. The first step in choosing the appropriate treatment for a child with nystagmus is the correct diagnosis. Hence, the identification of INS in the clinical practice signals the beginning of a diagnostic pathway, in order to accurately characterize the underlying cause. Recent advances in pediatric retinal imaging and genetic testing in combination with eye movement recordings allow the early and exact diagnosis of nystagmus. Brain neuroimaging and electrodiagnostic testing are also necessary in some children to determine the underlying etiology. The recent development of next-generation sequencing panels will enable the identification of a genetic cause and the characterization of phenotype-genotype correlations in order to guide further individualized treatment [155]. However, the limited availability of these genetic panels in the clinical setting across different countries is a potential difficulty that has to be addressed, as gene replacement treatments are arising.
Related Knowledge Centers
- Birth Defect
- Caloric Reflex Test
- Eye Movement
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- Semicircular Canals
- Visual Impairment
- Pathology
- Head
- Vestibule of The Ear
- Extraocular Muscles