Nystagmus of Pelizaeus-Merzbacher disease. A magnetic search-coil study

J. D. Trobe, J. A. Sharpe, D. K. Hirsh and S. S. Gebarski
W. K. Kellogg Eye Center, Department of Ophthalmology, University of Michigan, Ann Arbor 48105.

Magnetic search-coil oculography of three brothers with clinically diagnosed Pelizaeus-Merzbacher disease disclosed the presence of binocular elliptical pendular nystagmus in two patients in whom the waveform of the nystagmus was not obvious on inspection. This study, the first reported application of high-resolution oculography to Pelizaeus-Merzbacher disease, also demonstrated primary position upbeat nystagmus in all three patients. The importance of finding this combination of elliptical pendular and upbeat nystagmus is that it is not described in any other childhood neurodegenerative states and, in combination with supportive clinical history and magnetic resonance imaging, may be so characteristic of Pelizaeus-Merzbacher disease that a strong presumptive diagnosis can be made.