Q: Out of the following which of the following which one is the most common cause of acquired pendular nystagmus
A) multiple sclerosis
Pendular nystagmus can occur in any direction i.e., torsional, horizontal, vertical, or any combination of these. To examiner, it can give any type of trajectory i.e., circular, oblique, or elliptical. To confuse further it can also be only monocular. It is due to abnormal brainstem feedback circuits for eye position. It can be either acquired or congenital.
MS is the most common cause and should be confirmed with electroretinogram (ERG), visual evoked potentials, and magnetic resonance imaging (MRI).
1. Gresty MA, Ell JJ, Findley LJ. Acquired pendular nystagmus: its characteristics, localising value and pathophysiology. J Neurol Neurosurg Psychiatry 1982; 45:431.
2. Tilikete C, Jasse L, Pelisson D, et al. Acquired pendular nystagmus in multiple sclerosis and oculopalatal tremor. Neurology 2011; 76:1650.