China
Africa
Explore chapters and articles related to this topic
A Clinical Approach to Abnormal Eye Movements
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Acquired pendular nystagmus (APN) consists of involuntary, sinusoidal ocular oscillations typically ranging from 2 to 6 Hz that may be horizontal, vertical or a combination thereof including circular, elliptical or windmill-type. APN may arise from lesions affecting the dentate-rubro-olivary pathways (Guillain-Mollaret triangle), pontine tegmentum, inferior olivary nucleus (ION), cerebellum and MVN.6,33
Evaluation of Balance
Published in John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed, Paediatrics, The Ear, Skull Base, 2018
As mentioned under ‘Clinical examination of eye movements’ above, jerk nystagmus can be of peripheral or central origin. A jerk nystagmus of peripheral vestibular origin has a typically linear slow phase (Figure 62.4). Linear means that the velocity of the slow phase is constant and it is so because the magnitude of the velocity at rest is a direct measure of the vestibular tonus asymmetry. CNS lesions can also create a vestibular imbalance but they usually involve in addition central integrating mechanisms. This makes the slow phase of nystagmus to be non-linear, particularly during eccentric gaze, typically with an exponentially decreasing slow phase in velocity (Figure 62.5). A jerk nystagmus with a slow-phase velocity exponentially increasing (Figure 62.20), however, strongly suggests the diagnosis of congenital nystagmus, although some exceptions have been reported.43 The diagnosis of pendular nystagmus is usually easy by simple clinical inspection and confirmed with recordings but establishing whether it is acquired or congenital is not possible on simple oculographic criteria. Patients with acquired pendular nystagmus usually have clinically severe vascular or demyelinating brainstem disease whereas patients with congenital pendular nystagmus have congenital or infantile visual loss and defects.
Ocular Involvement in Muckle-Wells Syndrome
Published in Ocular Immunology and Inflammation, 2020
Sukru Cekic, Ozgur Yalcinbayir, Sara Sebnem Kilic
Mean BCVA was 0.48 ± 0.81 logMAR units in this study (range: 0.0 to 3.0). Examination of ocular motility and alignment of cases were completely normal except for the index patient who had bilateral acquired pendular nystagmus and quite low vision. Anterior segment biomicroscopy showed that band keratopathy was present in four eyes of the two patients; namely in the index patient and the patient who had cataract removal. Corneal leukoma due to corneal scarring was present in both eyes of another patient who was a 42-years-old female (patient H in Tables 1 and 2). In this patient, corneal topography demonstrated central flattening as well as surrounding steepening (Figure 2). Posterior stromal corneal opacification with edema and accompanying anterior iris snychecia was present in one eye of the index patient (Figure 3). Mild cataract was present in the other eye of the index patient that had received dexamethasone implant for uveitis. Clinical signs consistent with past uveitis (e.g. pigment on the anterior lens capsule, hyalinized keratic precipitates) were present in four eyes of three individuals. (Table 2).
Binocular, Accommodative and Oculomotor Alterations In Multiple Sclerosis: A Review
Published in Seminars in Ophthalmology, 2020
Amparo Gil-Casas, David P Piñero, Ainhoa Molina-Martin
The first cause of acquired pendular nystagmus is MS.73,74 Indeed, it has been one of the most studied nystagmus types by previous authors. The majority of patients with MS develops nystagmus later in a progressive phase of the disease.75 The amplitude, asymmetry, irregularity and mean peak velocity of nystagmus in MS are lower than in oculopalatal tremor, but the frequency is higher in MS.76 This type of nystagmus can also be associated with dissociated movements.77
Advances in pharmacotherapy of vestibular and ocular motor disorders
Published in Expert Opinion on Pharmacotherapy, 2019
Andreas Zwergal, Michael Strupp, Thomas Brandt
In the first part of this review, treatment options for peripheral and central vestibular disorders, including related cerebellar disorders, are described. The second part deals with the clinically most relevant central ocular motor disorders, in particular downbeat, upbeat, and acquired pendular nystagmus, and their current therapies. Finally, an overview of current studies in the field, including perspectives, is given.