Using an infrared recording system we examined the nystagmus waveforms of a pair of monozygotic twin girls and found them to be dissimilar. It is proposed that in view of the common mode of inheritance the differences are a result of environmental influences.

The objective of this study was to describe the role of electrical stimulation in controlling peripheral vertigo. In a prospective study on 13 healthy volunteers, nystagmus was induced with caloric stimulation and the interval of nystagmus disappearance was recorded. This time indicates the basal response of vestibular end-organ. After caloric irrigation, pulsed signal was applied for each...

We investigated the nystagmus of a 12-year-old boy with suspected X-linked congenital nystagmus (CN) and exophoria to determine the underlying mechanisms and component signals in the 'dual-velocity' and other slow phases of his Asymmetric (a)Periodic Alternating Nystagmus (APAN). Fast Fourier transforms (FFT) were performed on the waveforms and residual data after subtracting a sawtooth wavefor...

A 11-year-old boy with hypothyroidism developed generalized muscle hypertrophy and proximal muscular weakness. Electromyographic findings were suggestive of myopathy. He had had congenital nystagmus (CN) since early infancy. Although the association of childhood hypothyroidism and CN has been documented before, the triad of hypothyroidism, hypertrophic myopathy and CN exhibited by the patient i...

Normal visual acuity requires a stationary retinal image on the fovea. If fixation instabilities cause movement of the retinal image across the fovea for a few degrees, visual acuity is diminished. Nystagmus as the fixation instability, consequently, may impair vision. Period of foveation is the area in the wave form, i.e. a brief period of time when the eye is still and is pointed at the objec...

PURPOSE Although impaired color vision and ERG changes have been detected in carriers of blue-cone monochromatism (BCM), no eye movement abnormalities have been identified. Quantitative eye movements of three obligate carriers of BCM were analyzed. METHODS Horizontal and vertical eye movements of three obligate carriers of two families with BCM with visual acuity of 20/20 or better were recor...

Sixty-four people with pigmentary anomalies of the skin were examined in the Eastern Highlands of New Guinea. Thirty-one had a bronze-red skin colour which appears to be unique to New Guinea. Eighteen of the Red-skins had congenital nystagmus which was not associated with impairment of visual acuity. The fundi were normal. The pigmentary anomaly is recessively inherited, and the gene responsibl...

A study was made of parameters of congenital nystagmus which responded to auditory biofeedback treatment. The parameters studied included foveation time, amplitude, and frequency. The patient's right retina was observed with an infrared television fundus camera, and the fundus image was recorded on video tape. The position of the eye during nystagmus, observed via the fundus camera and recorded...

Seventy four males affected by X linked ocular albinism (XLOA) from 19 pedigrees were examined to assess phenotypic variation and visual prognosis. Nystagmus was present in all cases except one. Best visual acuity ranged from 6/9 to 6/60; 79.7% could see 6/36 or better; most could read N5. Marked iris translucency and foveal hypoplasia were present in all cases. Posterior embryotoxon was presen...

OBJECTIVES/HYPOTHESIS Periodic alternating nystagmus (PAN) is most commonly found either in its congenital form or after cerebellar/pontomedullary lesions. However, we identified PAN in 10 patients with peripheral vestibular disorders and will try to describe their characteristics to aid in the differential diagnosis between peripheral and central etiologies. STUDY DESIGN Observation of a cas...