[Rebound nystagmus: a new cerebellar sign (author's transl)].

Rebound nystagmus is a special type of nystagmus provoked by excentration of gaze of a sight (gaze nystagmus). Gaze nystagmus is absent when looking straight ahead, and is already clearly evident after excentration of gaze of less than 20 degrees. It beats in the direction of the excentration. The first special feature of rebound nystagmus is the fact that it disappears in 10 to 20 seconds. Its diagnostic significance could be based upon this feature alone, as was though up to now. However, its second original feature is fundamental. After excentration, gaze is brought back to the primary position (straight ahead). As confirmed by all the literature its value is of being pathognomic of a lesion of the cerebellar pathways. It is of the greatest simplicity, and it is sough by asking the subject to follow the finger of the examiner.