Spectral analysis of dual jerk waveforms in congenital nystagmus

✍ Scribed by R. Reccia; G. Roberti; P. Russo; G. Segré

• Book ID: 104737597
• Publisher: Springer-Verlag
• Year: 1986
• Tongue: English
• Weight: 651 KB
• Volume: 55
• Category: Article
• ISSN: 0340-1200
• DOI: 10.1007/bf00355596

✦ Synopsis

Congenital nystagmus (CN) is a disorder of the ocular motility characterized by oscillatory eye movements preventing the correct fixation of a target. Many typical waveforms of eye position recordings have been recognized and classified in the literature: in jerk CN a slow phase eye movement is followed by a fast phase, giving rise to a typical saw-tooth waveform, while in pendular CN the eyes exhibit a periodic motion, giving rise to an approximately sinusoidal waveform. Dual jerk waveforms seemed to show small, rapid oscillations superimposed on a jerk-like waveform, thus being originary classified as a mixture of jerk and pendular CN. On the contrary, a theoretical model of CN has appeared recently, which suggests a possible interpretation of the small amplitude oscillations in dual jerk waveforms as consecutive pieces of growing and decaying exponentials.

By spectral analysis of dual jerk waveforms in a number of patients with CN, we show that the oscillations are truly sinusoidal in nature, thus suggesting the possibility of a different explanation of dual jerk waveforms in CN.