1/208. Disorders in cerebellar ocular motor control. II. Macrosaccadic oscillation. An oculographic, control system and clinico-anatomical analysis.A distinctive cerebellar ocular motor disorder, macrosaccadic oscillation, evolved simultaneously with an acute cerebellar syndrome in 4 patients, 2 with haemorrhagic metastatic melanoma deep in the vermis, a third with a presumed cerebellar haematoma and a fourth with focal demyelinating disease. Ocular oscillations were conjugate, horizontal, symmetrical, occurred in bursts of several seconds duration, had amplitudes of 30 degrees to 50 degrees, and were evoked whenever the patient attempted to shift visual fixation or pursue a moving target. Photo-electric recordings in one patient with tumour defined features of this disorder of saccadic eye movement: (i) oscillation was composed of saccades, (ii) frequency was 2 Hz, (iii) bursts occurred with amplitude first increasing and then decreasing, (iv) intervals between beginnings of saccades averaged 260 ms and (v) eye position did not exhibit systematic drift during the intersaccadic period. These features documented the inreased gain and instability of the visually guided saccadic system. By using increased feed-forward gain in a sampled-data control model we simulated the pattern of macrosaccadic oscillation. We belive that the acute loss of the calibrator function of the cerebellum accounts for the gain abnormality underlying macrosaccadic oscillation.- - - - - - - - - - ranking = 1keywords = ocular (Clic here for more details about this article) |
2/208. Neuro-ophthalmic, radiographic, and pathologic manifestations of adult-onset alexander disease.A 61-year-old woman had a 3-year history of imbalance. eye movement studies revealed square-wave jerks, gaze paretic nystagmus, rebound nystagmus, impaired smooth pursuit, impaired optokinetic nystagmus, and abnormal fixation suppression of vestibular nystagmus. A brain magnetic resonance imaging study showed extensive areas of increased signal from the middle cerebellar peduncles and dentate nuclei, which enhanced with gadolinium. Histopathological analysis of a needle biopsy specimen of the left cerebellar peduncle revealed diffuse gliosis in the presence of symmetrically distributed areas of demyelination. There were associated Rosenthal fibers. Clinicopathologic correlation supported a diagnosis of alexander disease. An adult patient with a history of progressive imbalance, ocular motility abnormalities consistent with cerebellar and/or brainstem dysfunction, and diffuse, symmetric hyperintense magnetic resonance imaging signals in brainstem and cerebellar white matter should suggest a diagnosis of adult-onset alexander disease.- - - - - - - - - - ranking = 0.2keywords = ocular (Clic here for more details about this article) |
3/208. Vestibulo-ocular reflex pathways in internuclear ophthalmoplegia.We measured the vestibulo-ocular reflex (VOR) during head impulses in a patient with right-sided internuclear ophthalmoplegia. head impulses are rapid, passive, high-acceleration, low-amplitude head rotations in the direction of a particular semicircular canal (SCC). Adduction of the right eye was abnormally slow during right lateral SCC head impulses. The VOR during left posterior SCC impulses was severely deficient in both eyes, but the VOR during left anterior SCC impulses was only slightly deficient. We suggest that the vertical vestibulo-ocular pathways in humans are connected in SCC-plane coordinates, not the traditional roll and pitch coordinates, and that anterior SCC signals do not travel exclusively in the medial longitudinal fasciculus.- - - - - - - - - - ranking = 3.1586084304522keywords = ophthalmoplegia, ocular (Clic here for more details about this article) |
4/208. Anti-labyrinthine antibodies in a patient with relapsing polychondritis.Relapsing polychondritis is a rare inflammatory disease that causes destruction of cartilaginous tissue in various anatomical regions. We report here about a 55-year-old female patient with relapsing polychondritis that involved the right auricle, both audiovestibular organs and both eyes. The patient presented with persisting inflammation of the right auricle, sudden lower-frequency hearing loss, acute moderate vertigo with nausea and mild ocular symptoms. Immunofluorescence assays were used for the detection of antibodies against the cochlea and the vestibular organ and demonstrated the presence of circulating antibodies against the audiovestibular organ. No staining for anti-corneal IgG was detected. Improvement of clinical disease was achieved by treatment with systemic steroids and vasodilator drugs, and long-term medication with low-dose corticosteroids.- - - - - - - - - - ranking = 0.2keywords = ocular (Clic here for more details about this article) |
5/208. The incidence and waveform characteristics of periodic alternating nystagmus in congenital nystagmus.PURPOSE: To investigate the incidence and waveform characteristics of periodic alternating nystagmus, (PAN) in congenital nystagmus (CN). methods: In a prospective study, 18 patients with CN without associated sensory defects agreed to undergo eye movement documentation using binocular infrared oculography. Two of the 18 had a diagnosis of suspected PAN before entering the study. The patients sat in a dimly lit room and viewed an LED (4 min in diameter) located in the primary position, at a distance of 100 cm. During an 8-minute recording, patients were read a story of neutral interest to hold attention at a constant level. PAN was defined as a left-beating nystagmus, a transition phase, a right-beating nystagmus, and a final transition phase; the sequence was then repeated. RESULTS: Seven of the 18 patients had PAN (median cycle: 223 seconds, range 180-307 seconds). The periodicity of the cycles for each adult patient was regular, although the phases within a cycle were often asymmetric. Six of the seven patients had an anomalous head posture (AHP), and in five the AHP was in only one direction. Except for one patient, the PAN waveforms had an increasing slow-phase velocity in at least one phase of the cycle; in the other phase they were linear. CONCLUSIONS: The occurrence of PAN in CN is not as rare as previously thought and can be missed because of the long cycles and the use of only one AHP. The AHP was dependent on, and could be predicted from, the waveforms containing the longest foveation times. Although the waveforms and foveation times may differ among the phases of the PAN cycle, the periodicity of the cycle was usually regular and therefore predictable. Identification of PAN is essential in cases in which surgical treatment is considered for correction of AHPs.- - - - - - - - - - ranking = 0.2keywords = ocular (Clic here for more details about this article) |
6/208. Posterior semicircular canal nystagmus is conjugate and its axis is parallel to that of the canal.A patient with a postoperative fistula of the left posterior semicircular canal is presented. Negative pressure in the external ear canal produced upbeat-torsional nystagmus, which was recorded in three dimensions using binocular scleral search coils. The nystagmus was conjugate, without skew deviation, and its trajectory corresponded to the anatomic axis of the left posterior canal. The current study helps validate Ewald's first law in humans: the axis of nystagmus should match the anatomic axis of the semicircular canal that generated it. This law is clinically useful in diagnosing pathology of the vestibular end-organ, such as benign paroxysmal positional vertigo or the superior semicircular canal dehiscence syndrome.- - - - - - - - - - ranking = 0.2keywords = ocular (Clic here for more details about this article) |
7/208. Nystagmus: benign or significant?Nystagmus is a broad symptom describing unusual ocular movements. The peri-anesthesia nurse may identify nystagmus as a preoperative condition, as an event during recovery from general anesthesia, or as a pathological finding. Understanding the physiology of nystagmus provides a basis for nursing assessment and intervention.- - - - - - - - - - ranking = 0.2keywords = ocular (Clic here for more details about this article) |
8/208. Periodic alternating nystagmus and vestibulo-spinal system facilitating activity.OBJECTIVE: Periodic alternating nystagmus has been associated with the instability of the velocity storage mechanism, which is known to play an important role in both the vestibulo-oculomotor and the optokinetic systems. In the present study we looked for a possible spinal equivalent to PAN. methods AND RESULTS: In 3 PAN patients, the h-reflex amplitude proved to be slightly but significantly influenced by nystagmus direction, in that it was greater when the nystagmus was beating toward the stimulation side. CONCLUSIONS: This finding suggests that projections from velocity storage may play a role not only in the ocular motor but also in assisting postural stability through the vestibulo-spinal system.- - - - - - - - - - ranking = 0.2keywords = ocular (Clic here for more details about this article) |
9/208. Ocular motor signs in an infant with carbohydrate-deficient glycoprotein syndrome type Ia.PURPOSE: To document the evolution of ocular motor abnormalities in an infant with carbohydrate-deficient glycoprotein syndrome. methods: Case report. An infant with carbohydrate-deficient glycoprotein syndrome type 1a underwent magnetic resonance imaging and infrared eye movement recording. RESULTS: A 10-month-old male with carbohydrate-deficient glycoprotein syndrome type Ia had rapid horizontal oscillations of the eyes when startled or awakened from sleep. Clinical examination confirmed this finding and disclosed congenital ocular motor apraxia with a reduced vestibulo-ocular reflex. Infrared eye movement recording showed ocular flutter and square wave jerks superimposed on a horizontal pendular nystagmus. magnetic resonance imaging showed diffuse cerebellar hypoplasia. CONCLUSION: Carbohydrate-deficient glycoprotein syndrome type Ia can be associated with multiple cerebellar eye signs including ocular flutter, square-wave jerks, and congenital ocular motor apraxia.- - - - - - - - - - ranking = 1.2keywords = ocular (Clic here for more details about this article) |
10/208. Bilateral papillomacular retinal folds and posterior microphthalmus: new features of a recently established disease.Clinical findings of a 2.5-year-old girl presenting with barely detectable horizontal nystagmus and high hypermetropia are described. Despite the normal appearing anterior segments, the child had posterior microphthalmus and bilateral papillomacular retinal folds, conforming to a recently described, rare congenital disease. The patient also had significant posterior pole excyclorotation and avascular zones at the extreme temporal periphery without ridge formation or neovascularization. These findings were not reported previously. Other remarkable features include mildly depressed photopic and scotopic electroretinogram amplitudes and a short axial length of the vitreous cavity compared to age-matched normals, measured by ultrasonography. The present case adds new elements to this relatively rare ocular developmental abnormality.- - - - - - - - - - ranking = 0.2keywords = ocular (Clic here for more details about this article) |
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