scholarly journals Impaired ‘fixation suppression’ of horizontal vestibular nystagmus during smooth pursuit: Pathophysiology and clinical implications

2021 ◽  
Author(s):  
Athanasia Korda ◽  
David S. Zee ◽  
Thomas Wyss ◽  
Ewa Zamaro ◽  
Marco D. Caversaccio ◽  
...  
Keyword(s):  
Smooth Pursuit ◽  
Clinical Implications ◽  
Vestibular Nystagmus

Quantitative Analysis of Abducens Neuron Discharge Dynamics During Saccadic and Slow Eye Movements

1999 ◽  
Vol 82 (5) ◽  
pp. 2612-2632 ◽  
Author(s):  
Pierre A. Sylvestre ◽  
Kathleen E. Cullen
Keyword(s):  
Eye Movements ◽  
Firing Rate ◽  
Eye Movement ◽  
Neuronal Activity ◽  
Smooth Pursuit ◽  
Slow Phase ◽  
Vestibular Nystagmus ◽  
Firing Rates ◽  
Rapid Eye Movements ◽  
Eye Velocity

The mechanics of the eyeball and its surrounding tissues, which together form the oculomotor plant, have been shown to be the same for smooth pursuit and saccadic eye movements. Hence it was postulated that similar signals would be carried by motoneurons during slow and rapid eye movements. In the present study, we directly addressed this proposal by determining which eye movement–based models best describe the discharge dynamics of primate abducens neurons during a variety of eye movement behaviors. We first characterized abducens neuron spike trains, as has been classically done, during fixation and sinusoidal smooth pursuit. We then systematically analyzed the discharge dynamics of abducens neurons during and following saccades, during step-ramp pursuit and during high velocity slow-phase vestibular nystagmus. We found that the commonly utilized first-order description of abducens neuron firing rates (FR = b + kE + rE˙, where FR is firing rate, E and E˙ are eye position and velocity, respectively, and b, k, and r are constants) provided an adequate model of neuronal activity during saccades, smooth pursuit, and slow phase vestibular nystagmus. However, the use of a second-order model, which included an exponentially decaying term or “slide” (FR = b + kE + rE˙ + uË − c[Formula: see text]), notably improved our ability to describe neuronal activity when the eye was moving and also enabled us to model abducens neuron discharges during the postsaccadic interval. We also found that, for a given model, a single set of parameters could not be used to describe neuronal firing rates during both slow and rapid eye movements. Specifically, the eye velocity and position coefficients ( r and k in the above models, respectively) consistently decreased as a function of the mean (and peak) eye velocity that was generated. In contrast, the bias ( b, firing rate when looking straight ahead) invariably increased with eye velocity. Although these trends are likely to reflect, in part, nonlinearities that are intrinsic to the extraocular muscles, we propose that these results can also be explained by considering the time-varying resistance to movement that is generated by the antagonist muscle. We conclude that to create realistic and meaningful models of the neural control of horizontal eye movements, it is essential to consider the activation of the antagonist, as well as agonist motoneuron pools.

Eye Movements in Cerebellar and Combined Cerebellobrainstem Diseases

1983 ◽  
Vol 92 (2) ◽  
pp. 165-171 ◽  
Author(s):  
Carsten Wennmo ◽  
Bengt Hindfelt ◽  
Ilmari Pyykkö
Keyword(s):  
Quantitative Analysis ◽  
Eye Movements ◽  
Eye Movement ◽  
Smooth Pursuit ◽  
Optokinetic Nystagmus ◽  
Vestibular Nystagmus ◽  
Full Field ◽  
Eye Velocity ◽  
Voluntary Saccades ◽  
Cerebellar Disorders

We report a quantitative analysis of eye movement disturbances in patients with isolated cerebellar disorders and patients with cerebellar disorders and concomitant brainstem involvement. The most characteristic abnormalities in the exclusively cerebellar patients were increased velocities of the slow phases of vestibular nystagmus induced by rotation in the dark and increased peak velocities of the fast phases of optokinetic nystagmus induced by full-field optokinetic stimuli. Dysmetria of saccades was found in three of six cerebellar patients and gaze nystagmus in all six patients. The typical findings in the combined cerebellobrainstem group were reduced peak velocities of voluntary saccades, defective smooth pursuit and reduced peak velocities of the fast component of nystagmus during rotation in both the dark and light. All patients with combined cerebellobrainstem disorder had dysmetric voluntary saccades and gaze nystagmus. The numbers of superimposed saccades during smooth pursuit were uniformly increased. Release of inhibition in cerebellar disorders may explain the hyperresponsiveness and inaccuracy of eye movements found in this study. In addition, when lesions also involve the brainstem, however, integrative centers coding eye velocity are affected, leading to slow and inaccurate eye movements. These features elicited clinically may be useful in the diagnosis of cerebellar and brainstem disorders.

Effects of Selected Rhinologic Disorders on the Perception of Nasal Resonance in Children

1984 ◽  
Vol 15 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Michael P. Rastatter ◽  
Melvin Hyman
Keyword(s):  
Allergic Rhinitis ◽  
Clinical Implications ◽  
Normal Children ◽  
Nasal Resonance

A group of sophisticated listeners judged the nasal resonance characteristics of normal children versus children evidencing selected rhinologic disorders under three speaking conditions. Results showed that perceptions of denasality are influenced by both speakers and speaking tasks. That is, children with allergic rhinitis and edemic adenoids were perceived as being denasal when they produced VCV utterances and recited sentences. However, their resonance characteristics were deemed normal for vowel productions. Interestingly, children with severely deviated septums were judged to have normal nasal resonance under all speaking conditions. Clinical implications are discussed.

Perceptions of Stuttering of Different Age Groups

2019 ◽  
Vol 4 (6) ◽  
pp. 1311-1315
Author(s):  
Sergey M. Kondrashov ◽  
John A. Tetnowski
Keyword(s):  
Age Groups ◽  
School Age Children ◽  
Clinical Implications ◽  
School Age ◽  
Fourth Edition ◽  
Self Perception ◽  
Behavioral Measures ◽  
Self Rating ◽  
Comparison Results ◽  
Subject Pool

Purpose The purpose of this study was to assess the perceptions of stuttering of school-age children who stutter and those of adults who stutter through the use of the same tools that could be commonly used by clinicians. Method Twenty-three participants across various ages and stuttering severity were administered both the Stuttering Severity Instrument–Fourth Edition (SSI-4; Riley, 2009 ) and the Wright & Ayre Stuttering Self-Rating Profile ( Wright & Ayre, 2000 ). Comparisons were made between severity of behavioral measures of stuttering made by the SSI-4 and by age (child/adult). Results Significant differences were obtained for the age comparison but not for the severity comparison. Results are explained in terms of the correlation between severity equivalents of the SSI-4 and the Wright & Ayre Stuttering Self-Rating Profile scores, with clinical implications justifying multi-aspect assessment. Conclusions Clinical implications indicate that self-perception and impact of stuttering must not be assumed and should be evaluated for individual participants. Research implications include further study with a larger subject pool and various levels of stuttering severity.

Treatment Considerations for Adolescents Who Exhibit Cognitive/Communication Problems: A Neuroscience Perspective

2020 ◽  
Vol 5 (6) ◽  
pp. 1767-1775
Author(s):  
Martha S. Burns
Keyword(s):  
Social Communication ◽  
Transition Period ◽  
Clinical Intervention ◽  
Review Article ◽  
Sensitive Period ◽  
Clinical Implications ◽  
Evidence Based ◽  
Communication Problems ◽  
Treatment Considerations ◽  
Behavioral Growth

Purpose Adolescence is a period of substantial neurophysiological and behavioral growth, representing a second sensitive period of brain development. It is a psychological and social transition period between childhood and adulthood with many beneficial changes occurring, especially with respect to potential responsiveness to clinical intervention. However, adolescent behavioral complexities introduce clinical challenges as well. The purpose of this review article is to review the current neuroimaging research on neurophysiological changes observed during adolescence and the cognitive and social behavioral counterparts, with specific attention to the clinical implications. The review article will then summarize currently available intervention tools that can be utilized by speech-language pathologists working with this population. It will conclude with available evidence-based social-communication approaches that may be applicable as well as available evidence-based supplemental technological cognitive interventions that may be useful in working with adolescents who exhibit language and communication issues. Conclusion As a transition period between childhood and adulthood, adolescence represents a second sensitive period during which there is opportunity for clinically derived beneficial cognitive and communication growth.

Laryngeal Manifestations of Autoimmune Diseases

2020 ◽  
Vol 5 (2) ◽  
pp. 439-456
Author(s):  
Jenny L. Pierce
Keyword(s):  
Autoimmune Disease ◽  
Autoimmune Diseases ◽  
Patient Outcomes ◽  
Correct Diagnosis ◽  
Upper Airway ◽  
Clinical Implications ◽  
Laryngeal Function ◽  
The Past ◽  
Referral Practices ◽  
Timely Referral

Purpose This review article provides an overview of autoimmune diseases and their effects on voice and laryngeal function. Method A literature review was conducted in PubMed. Combinations of the following keywords were used: “autoimmune disease and upper airway,” “larynx,” “cough,” “voice,” “dysphonia,” and “dyspnea.” Precedence was given to articles published in the past 10 years due to recent advances in this area and to review articles. Ultimately, 115 articles were included for review. Results Approximately 81 autoimmune diseases exist, with 18 of those highlighted in the literature as having laryngeal involvement. The general and laryngeal manifestations of these 18 are discussed in detail, in addition to the clinical implications for a laryngeal expert. Conclusions Voice, breathing, and cough symptoms may be an indication of underlying autoimmune disease. However, these symptoms are often similar to those in the general population. Appropriate differential diagnosis and timely referral practices maximize patient outcomes. Guidelines are provided to facilitate correct diagnosis when an autoimmune disease is suspected.

The Nature of Deviant Articulation

1973 ◽  
Vol 38 (2) ◽  
pp. 156-161 ◽  
Author(s):  
Laurence B. Leonard
Keyword(s):  
Clinical Implications ◽  
Phonological System

This paper examines the credibility of deviant articulation as a less mature phonological system and as an individual phonological system with its own rules. Evidence is presented suggesting that both types of deviant phonological systems may occur in the articulatory defective population. The clinical implications of each type of deviant system are presented.

Communicative Performance of Adolescents with Severe Speech Impairment

1989 ◽  
Vol 54 (3) ◽  
pp. 403-421 ◽  
Author(s):  
Beth M. Dalton ◽  
Jan L. Bedrosian
Keyword(s):  
Data Analysis ◽  
Peer Interactions ◽  
Consistent Pattern ◽  
Clinical Implications ◽  
Speech Impairment ◽  
Communication Mode ◽  
Mode Function ◽  
Communicative Performance ◽  
Therapy Room ◽  
Communication Board

The communicative performance of 4 preoperational-level adolescents, using limited speech, gestures, and communication board techniques, was examined in a two-part investigation. In Part 1, each subject participated in an academic interaction with a teacher in a therapy room. Data were transcribed and coded for communication mode, function, and role. Two subjects were found to predominantly use the speech mode, while the remaining 2 predominantly used board and one other mode. The majority of productions consisted of responses to requests, and the initiator role was infrequently occupied. These findings were similar to those reported in previous investigations conducted in classroom settings. In Part 2, another examination of the communicative performance of these subjects was conducted in spontaneous interactions involving speaking and nonspeaking peers in a therapy room. Using the same data analysis procedures, gesture and speech modes predominated for 3 of the subjects in the nonspeaking peer interactions. The remaining subject exhibited minimal interaction. No consistent pattern of mode usage was exhibited across the speaking peer interactions. In the nonspeaking peer interactions, requests predominated. In contrast, a variety of communication functions was exhibited in the speaking peer interactions. Both the initiator and the maintainer roles were occupied in the majority of interactions. Pertinent variables and clinical implications are discussed.

The Occlusion Effect in Unilateral Functional Hearing Loss

1970 ◽  
Vol 13 (1) ◽  
pp. 37-40
Author(s):  
Gary Thompson ◽  
Marie Denman
Keyword(s):  
Hearing Loss ◽  
Bone Conduction ◽  
Low Frequency ◽  
Clinical Implications ◽  
The Right ◽  
Occlusion Effect

Bone-conduction tests were administered to subjects who feigned a hearing loss in the right ear. The tests were conducted under two conditions: With and without occlusion of the non-test ear. It was anticipated that the occlusion effect, a well-known audiological principle, would operate to draw low frequency bone-conducted signals to the occluded side in a predictable manner. Results supported this expectation and are discussed in terms of their clinical implications.

Complex Trauma and Prenatal Alcohol Exposure: Clinical Implications

2012 ◽  
Vol 13 (2) ◽  
pp. 32-42 ◽  
Author(s):  
Yvette D. Hyter
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Child Development ◽  
Academic Outcomes ◽  
Complex Trauma ◽  
Prenatal Alcohol Exposure ◽  
Alcohol Exposure ◽  
Clinical Implications ◽  
Prenatal Alcohol ◽  
The Brain

Abstract Complex trauma resulting from chronic maltreatment and prenatal alcohol exposure can significantly affect child development and academic outcomes. Children with histories of maltreatment and those with prenatal alcohol exposure exhibit remarkably similar central nervous system impairments. In this article, I will review the effects of each on the brain and discuss clinical implications for these populations of children.

Sign in / Sign up

Export Citation Format

Share Document