L’étude des nystagmus du nourrisson est difficile pour des raisons méthodologiques. La plupart des études sont donc réalisées chez des adultes et a posteriori. Ces études chez l’adulte ont permis la révision des classifications des nystagmus infantiles, avec la consolidation des concepts de syndrome du nystagmus précoce et de nystagmus de type latent. La séméiologie et l’étiopathogénie des nystagmus du nourrisson – notamment des formes comportant un élément vertical et des formes transitoires – reste donc à étudier. Dans ce but : 1. Nous avons développé de nouvelles techniques d’enregistrement des mouvements oculaires chez les nourrissons, utilisables dans le cadre d’une consultation. Elles incluent de nouveaux stimuli, un appareil d’enregistrement des mouvements oculaires spécialement conçu pour le nourrisson et de nouvelles méthodes d’analyse statistique du signal. Nous avons vérifié la faisabilité de ces enregistrements chez 28 nourrissons atteints de nystagmus. 2. Nous avons étudié systématiquement 32 cas de nystagmus de type spasmus nutans, classiquement considéré comme une entité bénigne idiopathique, avec un examen clinique complet, une imagerie cérébrale, une électrophysiologie visuelle et des enregistrements oculo-moteurs. Dans 53,1% des cas, le spasmus nutans était le symptôme d’une autre maladie : neurologique (34,3%), notamment des gliomes du chiasma (21,9%), ou rétinienne (12,5%). Une atteinte des voies visuelles antérieures est probablement en cause dans la physiopathologie des spasmus nutans. 3. Huit cas de nystagmus ayant conduit au diagnostic de gliome des voies optiques (GVO) ont été également enregistrés et étudiés. L’âge d’apparition du nystagmus allait de 2,5 à 10 mois. Le GVO était toujours chiasmatique et constituait une sous-population spécifique. Le nystagmus était toujours de type spasmus nutans. Les enregistrements oculo-moteurs montraient : une fréquence entre 2,7 et 5 Hz, une morphologie sinusoïdale du nystagmus, une dissociation et une dysconjugaison particulière, avec une opposition de phase (180°) entre les oscillations des deux yeux dans le plan horizontal mais une correspondance de phase dans le plan vertical, à l’origine d’un mouvement semblable à un mouvement de convection. Rarement et brièvement, le rapport de phase changeait. Ces caractéristiques orientent vers des oscillations dans le système des vergences, possiblement la conséquence d’une atteinte des afférences sensorielles des centres du contrôle vergentiel dans le tronc cérébral, secondaire au GVO et survenant pendant la période sensible du développement visuel. 4. Cinq cas de nystagmus upbeat chez des nourrissons avec des rétines et une imagerie cérébrale normale ont été étudiés. Le nystagmus était observé en décubitus et électivement déclenché par des rotations de la tête en position allongée. Dans tous les cas, une résolution spontanée était observée après quelques mois d’évolution. Les caractéristiques de ce type de nystagmus suggèrent une participation du système otolithique, suivie d’une recalibration secondaire des circuits vestibulo-oculaires. En conclusion, le développement de techniques d’enregistrement des mouvements oculaires adaptées aux nourrissons aide à la compréhension de l’étiopathogénie de variétés mal décrites de nystagmus, notamment dans les cas comportant un élément vertical et dans les cas transitoires. Les processus de maturation des voies visuelles antérieures et des centres de contrôle de l’oculomotricité semblent jouer un rôle central dans les mécanismes de ces nystagmus. / Studying infantile nystagmus during infancy is difficult for methodological reasons. Most such studies have been performed in adults and a posteriori. These studies in adults allowed for an improvement in the existing classifications, with now robust knowledge about the two most frequent varieties of infantile nystagmus: infantile nystagmus syndrome and fusion maldevelopment nystagmus syndrome. The characteristics and pathophysiology of nystagmus in infants–notably varieties of nystagmus with a vertical component and transitory nystagmus– need further study. For this reason: 1. We developed new techniques for the recording of eye movements in infants in the setting of a clinic. They include new stimuli, the use of specially-designed infrared photo-oculography eyetrackers and new statistical analysis paradigms. We assessed these techniques in a population of 28 infants with a nystagmus. 2. We systematically studied 32 cases of spasmus nutans, classically considered an idiopathic entity, with comprehensive clinical examination, brain imaging, electrophysiology, nystagmus recording. In 53.1% of cases, it led to the diagnosis of another condition: a neurological disease (34.3%), including cases of chiasmal gliomas (21.9%), or a retinal dysfunction (12.5%). Anterior visual pathway dysfunction is likely involved in the pathophysiology of spasmus nutans. 3. Eight cases of nystagmus having led to a diagnosis of optic pathway glioma (OPG) were also recorded and studied. Age at nystagmus onset was 2.5-10 months. The associated OPG always involved the chiasm, and represent a specific subpopulation of OPG. Clinically, the nystagmus was always classified as spasmus nutans type. Oculographic recordings showed frequencies of 2.7-5 Hz, sinusoidal waveforms, dissociation and a special type of disconjugacy, with a 180° horizontal phase shift and no vertical phase shift, exhibiting a “convection-like” movement pattern. Rarely and for short periods of time, the phase shift could change. These characteristics point towards oscillations in the vergence system, which could possibly result from the specific disruption of the vergence centres afferences in the brainstem, induced by the OPG during the sensitive period of visual development. 4. Five cases of upbeat nystagmus in infants with normal retinas and normal brain imaging were studied. The nystagmus mostly occurred in supine position and could be triggered by head rotations in the supine position. All resolved spontaneously. The characteristics of this nystagmus suggest an involvement of the otolithic system, with a secondary recalibration of the vestibulo-ocular pathways. In conclusion, the development of infant-friendly devices for eye-movements recording helps providing new insights on the pathophysiology of poorly described varieties of nystagmus, including nystagmus with a vertical component and transitory nystagmus. The maturation process of both the anterior visual pathways and the oculomotor pathways appears to be central in the mechanisms of these nystagmus.

No description available.

Bei dieser statistischen Auswertung wurde das klinische Bild der Seiten- und Richtungsenthemmung miteinander verglichen. Die gewonnenen Daten stammten dabei ausnahmslos aus den für jeden Patienten angelegten Anamnesebogen NODEC III. Hier sind nicht nur die persönlichen Daten und subjektiven Beschwerden des Patienten dokumentiert, sondern auch die objektiven äquilibriometrischen Untersuchungswerte. Die Datenerhebung erfolgte dabei aus dem Patientenstamm der Neurootologie Würzburg. Das Gesamtkollektiv besteht in dieser Untersuchung aus 75 richtungsenthemmten und 75 seitenenthemmten Schwindelpatienten. Anhand eines PCs wurde mit dem Tabellenkalkulationsprogramm EXCEL 2000 (9.0.2812) gruppiert, sortiert und anschließend statistisch ausgewertet. Aus den gebildeten Mittel- und Prozentwerten konnte eine vergleichende Gesamtstatistik beider Hauptkollektive erstellt werden. Die so gewonnenen Vergleichsdaten konnten durch die Bildung von spezifischen, korrespondierenden Unterkollektiven nach verschiedenen Gesichtspunkten verifiziert werden. Auch wurde zusätzlich die Richtungs- und Seitenenthemmung in zwei links- und zwei rechtsenthemmte Untergruppen weiter unterteilt und konnte so kollektivintern mehrfach miteinander verglichen werden. Darüber hinaus wurden repräsentative Fälle der Richtungs- und Seitenenthemmung nach rechts beziehungsweise links in Form von einzelnen Kasuistiken vorgestellt. / In this statistical evaluation the clinical group of patients with a directional preponderance was compared with patients that showed a unileteral preponderance in the caloric electronystagmography. The analysed data based unexceptional on the anamnestic question paper NODEC III. Here are not only the personal facts and the individual medical conditions of each person but also the objective equilibriometric tests documented. The significant data collection was selected out of a patient base of the neorootology section of the Julius Maximilian University Würzburg. The overall collective exists out of 75 vertigo-patients with a directional and 75 with a unilateral preponderance. The collective was grouped and sorted with a personal computer and the chartcalculation program EXCEL 2000 (9.0.2812) bevor it was statistical analysed. The middle- and percentage value made a statistical comparison of both main collectives possible. The result of the compared data-base could be verified with the creation of specific, corresponding subcollectives with different perspectives. The directional and unilateral preponderance to the left and the directional and unilateral preponderance to the right were also subdivided in two significant soupgroups. This made a multiple collective-intern comparison possible. Four representive clinical cases of the directional and unilateral preponderance to the left and to the right are shown in 4 single casuistics.

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 368-377). Also available in electronic version.

Thesis (Ph. D.)--Johns Hopkins University, 1932. / Vita. "Pigeons were selected as subjects for this investigation."--P. 26. Published also as Comparative psychology monographs, v. 9, serial no. 45, February, 1934. Bibliography: p. 45-48.

Thesis (Ph. D.)--Johns Hopkins University, 1932. / Vita. "Pigeons were selected as subjects for this investigation."--P. 26. Published also as Comparative psychology monographs, v. 9, serial no. 45, February, 1934. Bibliography: p. 45-48.

Professional research project (Au.D.)--University of South Florida, 2002. / Title from PDF of title page. / Document formatted into pages; contains 24 pages. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: The purpose of this study was to examine the prevalence of nystagmus found in healthy individuals during the positional testing subtest of the standard vestibular test battery. Positional testing involves moving the patient's head, and sometimes the entire body, into a variety of positions while observing eye movement. The hypothesis of the current study was that a relatively low percentage of participants would display nystagmus during positional testing used routinely in clinical diagnostic procedures. The findings were then compared to those of an earlier study in which 82% of normal, healthy individuals were reported to exhibit nystagmus during this testing. Twenty-five participants were selected that had no known otologic disease and who reported normal hearing sensitivity. / ABSTRACT: In addition, the participants affirmed they had not consumed any alcohol or taken any medications that are known to affect nystagmus. They were then observed in nine different positions. Forty-eight percent of the participants experienced nystagmus in at least one position. Although this percentage was considerably lower than that reported in the earlier study, methodological differences appear to account for the discrepancy. Specifically, the criterion for determining the presence/absence of nystagmus potentially explains the difference in full. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

There have been few studies investigating the eye movement behavior of Parkinson’s disease patients during fixation. This study objectively measured the eye movements of 36 patients with Parkinson’s disease, and 20 age matched controls. Stimuli consisted of ten standardized text passages first organized by Miller and Coleman. In addition, subjects followed a randomly displaced step jump target motion. Pendular nystagmus was found in all Parkinson’s subjects, with an average frequency of 7.44 Hz. Saccadic peak velocity and duration along the main sequence were not statistically different from controls. A slower rate of reading was also noted in the Parkinson’s group in terms of characters per minute, but with no more regressions than normal. Rate of square wave jerks was also found to be normal. This suggests that the hallmark feature of eye movements in Parkinson’s disease is a pendular nystagmus during fixation, and all saccadic activity to be normal.

A MAGAZINE – A game of Chutes and Ladders – a network of pools connected by streams, rivulets, creeks and rivers. Concerns: aluminum, sculpture, film, an endless image or an image-object, cork, shoulders as the center of movement, archery, wicker, nystagmus, darkness or the penumbral near-darkness, constant movement, beer, tone, musical forms, bells, gongs, The Titanic, purple, black and white, indeterminacy, Ghostface, yodeling, John Smith, John Adams, David Hammons, Beyoncé, Honda CR-V’s, Har-khebi, Ahnighito, Hermann Doomer, Prince, Yvonne Rainer, perception, double rainbows, composers from Transylvania, Los Angeles, and chandeliers. “Everything is everything.” and “A woman is the first teacher.”

Loss of sensory input from one vestibular labyrinth by unilateral vestibular deafferentation (UVD) results in a severe ocular motor (i.e., spontaneous nystagmus (SN)) and postural syndrome (i.e., yaw head tilt, (YHT) and roll head tilt (RHT)) which compensates over time in a behavioural recovery process known as vestibular compensation. It is generally accepted that the UVD-induced neuronal imbalance in the resting activity between the two vestibular nuclear complexes (VNCs) generates the ocular motor and postural syndrome and that the restoration of the resting activity in the ipsilateral VNC plays a causal role in the compensation of the static symptoms. γ-Aminobutyric acid (GABA) and the GABAA and GABAB receptors within the VNC are involved in normal vestibulo-ocular and --spinal pathways and it has been suggested that modification of GABAergic inhibition may be a mechanism responsible for the recovery of resting activity in the ipsilateral VNC. Behavioural, western blotting, and immunoassay techniques were used to address the role of the GABAA receptor in the VNC during vestibular compensation. The first study involved the characterization of SN, YHT, and RHT compensation in guinea pigs that had been anaesthetized with isoflurane during the UVD. These animals compensated rapidly (i.e., 30 hrs) and the time to compensate was independent of the duration of the anaesthesia. Using the 30 hrs time frame, the effects of the chronic infusion of the GABAA receptor agonist (muscimol) / antagonist (gabazine) into either the ipsilateral or the contralateral VNC on the compensation of SN, YHT, and RHT, were determined. Infusion of muscimol (250, 500, and 750 ng) into the contralateral VNC and gabazine (31.25, 62.5 and 125 ng) into the ipsilateral VNC significantly affected YHT and RHT (p < 0.05), but not their rate of compensation (p > 0.05). Interestingly, the effects of muscimol and gabazine on YHT and RHT were consistent throughout the first 30 hrs post-UVD. At 30 hrs post-UVD, the pumps were disconnected. In both experimental groups, the value and direction of the YHT and RHT returned to vehicle levels. Infusion of muscimol (62.5, 125, and 250 ng) into the ipsilateral VNC and gabazine (125, 375, and 750 ng) into the contralateral VNC had little effect on YHT and RHT, or their rate of compensation. At 30 hrs post-UVD, the pumps were disconnected. In both experimental groups, the value and direction of the YHT and RHT returned to vehicle levels. These results suggest that the ipsilateral gabazine and contralateral muscimol infusions were modifying the expression of the symptoms without altering the mechanism of compensation. Furthermore, the mechanism responsible for vestibular compensation can cope with the both the GABAA receptor-mediated and the UVD-induced decrease in resting activity. Results from the western blotting study indicated that compensation of SN, YHT, and RHT is not associated with changes in the protein levels of the GABAA receptor α₁, β₂, or γ₂ subunits. Compensation of SN, YHT, and RHT is associated with an elevation in cortisol salivary levels. Overall, the results suggest that the GABAA receptors are involved in the expression of YHT and RHT, but not in the mechanism that is responsible for their compensation.