Spectral analysis of pendular waveforms in congenital nystagmus.
We analyzed quantitatively electronystagmographic recordings of pendular waveforms via spectral analysis methods. We found (1) symmetrical pendular oscillations in orbital positions spanning a range as wide as 40 degrees, with frequencies between 2 and 8 Hz; (2) stable and small pendular oscillations in patients without a null zone and unstable and large pendular oscillations in patients with a neutral zone; (3) a non-decreasing relationship between the amplitude and the frequency of the eye oscillations, and (4) pendular components in orbital positions at the two sides of a neutral zone. It is argued that pendular nystagmus can be generated independently of normal (jerk) nystagmus in the same orbital position.
Reccia
R
R
Clinica Oculistica, II Facoltà di Medicina e Chirurgia, Università di Napoli, Italia.
Roberti
G
G
Russo
P
P
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D001330:Electronic Data Processing; D004584:Electronystagmography / Q000379:methods*; D005133:Eye Movements; D005260:Female; D006801:Humans; D008297:Male; D009759:Nystagmus, Pathologic / Q000151:congenital*; D009915:Orbit; D009991:Oscillometry; D014792:Visual Acuity