SACCADIC PING-PONG GAZE

Ping-pong gaze (PPG), or short-cycle periodic alternating graze, consi sts of horizontal conjugate ocular deviations alternating every few se conds. This alternating gaze has been described as appearing to be smo oth. However, our electrooculographic study of four consecutive uncons cious patients with PPG showed smooth waveforms in one patient but sac cadic cog-wheeling in three patients. In one of the three patients wit h saccadic PPG, a transition from smooth to saccadic waveforms was not ed with clinical improvement. Whereas the patient with smooth PPG died immediately, the patients with saccadic PPG survived in a persistent vegetative state. These findings suggest that saccadic PPG is a clinic al variant of PPG in patients in a lighter state of consciousness, pos sibly related to less extensive brain damage.