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Degenerative Diseases of the Nervous System
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
James A. Mastrianni, Elizabeth A. Harris
Cranial nerves: Reduced visual acuity.Optic atrophy.Eye movements: Square wave jerks at fixation.Saccadic intrusion upon smooth ocular pursuits (jerky pursuits).Gaze-evoked nystagmus.Reduced gain of vestibulo-ocular reflex.Speech: slurred, slow, staccato, and explosive (ataxic dysarthria).
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
The vestibulo-ocular reflex serves a very specific function: to stabilize gaze in space during head movements. The VOR is what allows us to see clearly when we walk, run or turn our heads. It does so by generating slow-phase eye movements of equal velocity, but opposite in direction, to head movement. This is achieved by a three-neuron, short latency, reflex: a Scarpa ganglion neuron, a vestibular nucleus neuron and an oculomotor nuclear neuron (III, IV or VI).
The Problems
Published in John Greene, Ian Bone, Understanding Neurology a problem-orientated approach, 2007
Ataxia (unsteadiness of gait) is very commonly associated with both peripheral and central vertigo, is frequent with cerebellar disease and diseases causing loss of proprioceptive input, but is uncommon in medical dizziness. Nausea and vomiting accompany dizziness and vertigo in all contexts, but tend to be more marked and dramatic in peripheral vertigo than in central vertigo. Patients may experience oscillopsia, which is an awareness of jumping of the environment. This may occur as a consequence of rapid jerking eye movements (nystagmus) or because of failure of the vestibulo-ocular reflex. The complaint of unsteadiness and imbalance (disequilibrium) may be caused by vestibular dysfunction, but may also be secondary to cerebellar disease or impaired proprioception due to large fibre peripheral nerve or spinal cord posterior column dysfunction. Presyncope is often accompanied by visual dimming, palpitation, sweating and pallor, and suggests one of the causes of the medical dizziness symptom complex. Hyperventilation may be accompanied by paraesthesiae around the mouth and in the fingers. Enquiring about the symptoms of anxiety is mandatory in the dizzy patient, but is particularly useful in a patient who may be hyperventilating.
Vestibular function in children with generalized epilepsy and treated with valproate
Published in Expert Review of Clinical Pharmacology, 2022
Sherifa Ahmed Hamed, Amira Mohamed Osiely
The vestibular system is divided into peripheral and central components. The peripheral component is composed of the semicircular canals, otolith (saccule and utricle) organs and the superior and inferior vestibular nerves. The central component begins from the point of entrance of vestibular nerves to the brainstem, the medial and lateral vestibular nuclei and the central inter-relations and connections to the thalamus and cerebral cortex. The semicircular canals sense horizontal angular head accelerations. Their afferents project to the medial vestibular nuclei via the vestibulo-ocular reflex (VOR). They provide reflexive ocular motor responses for maintenance of gaze stability. The otolith organs sense linear acceleration and static tilt in relation to gravity. Their afferents project to the lateral vestibular nucleus via the vestibulo-spinal reflex (VSR) for postural control and via connections to the cerebellar neurons, thalamus, and higher-cortical areas for balance, self-motion, and gravity direction [14].
An upper cervical spine treatment protocol for cervicogenic dizziness: a randomized controlled trial
Published in Physiotherapy Theory and Practice, 2022
Andoni Carrasco-Uribarren, Jacobo Rodríguez-Sanz, Carlos López-de-Celis, Pablo Fanlo-Mazas, Sara Cabanillas-Barea
The cervico-ocular, vestibulo-ocular, and optokinetic reflexes work together to control the extraocular muscles. These systems help to create a clear view of images during head movement (Treleaven, Jull, and Grip, 2011). Different cervical problems can alter these reflexes and give symptoms such as dizziness and headache (Treleaven, 2008, 2011). In vestibular rehabilitation, practitioners try to improve patients’ vestibulo-ocular reflex. The goal of gaze stabilization exercises is to improve the patients’ gain of the impaired vestibulo-ocular reflex. To do this, head mobility exercises are performed with the gaze fixed on an object. This tends to improve stability and decrease the feeling of dizziness in patients (Whitney and Sparto, 2011). The present study shows improvements in the cervical range of motion during the fixed gaze test for the T1 (p < .050) and T2 (p < .001) follow-ups in the intervention group. It may be that the decrease in neck pain contributes to performing this test correctly with a higher range of motion.
Effect of an oculomotor rehabilitation program for subacute brain injury patients with ophthalmoplegia: a case-control study
Published in Disability and Rehabilitation, 2022
Takayuki Watabe, Hisayoshi Suzuki, Rikitaro Sako, Marina Abe, Keiichiro Aoki, Mitsumasa Yoda
A cross-sectional study on rehabilitation interventions for external ophthalmoplegia suggested therapeutic strategies, including the use of visual devices, examining compensatory measures, and facilitative methods based on brain plasticity [3]. Three randomized controlled trials (cross-over experimental design) have verified the effects of a computer oculomotor rehabilitation (COR) program package [4–6], and a few other studies have reported the use of this program in stroke and head injury patients [7–9]. This program involves moving the eyes in synchronization with a target displayed on a computer screen and is particularly aimed at promoting pursuit, fixation, and saccade. Kawahira et al. [10] demonstrated the effects of a repetitive facilitative therapeutic program that used the vestibulo-ocular reflex in a case series. In this method, the patient is instructed to look continuously at the therapist with one eye while the therapist repeatedly performs maneuvers that cause the patient’s face to rotate by 30–45 degrees.