Electronystagmographic findings in motor neuron disease

The electronystagmogram (ENG) was abnormal in 94 percent of 88 consecutive patients with motor neuron disease (MND). The most common ENG abnormalities were dysrhythmic caloric responses (64 percent), active random eye movements with eyes closed (25 percent), caloric directional preponderance (24 percent), and caloric vestibular preponderance (20 percent). Torsional preponderance, poor fixation suppression (of induced vestibular nystagmus), spontaneous nystagmus, square waves, tracking and optokinetic abnormalities were also frequent. Most of these ENG findings are considered to be of central nervous system origin. Although these findings are not considered specific for MND, they appear to have clinical significance.