A closer look at ping-pong gaze: an observational study and literature review

Little is known about ping-pong gaze (PPG) outside of individual case reports. We aimed to describe PPG through an observational study and literature review.

Consecutive patients with PPG at Shanghai General Hospital (SGH) from February 2016 to March 2018 were enrolled. A literature review through March 2018 was conducted.

Of the 14 patients with PPG in SGH, the median age was 60 years and 12 were males. The median Glasgow coma scale score was 7.5. The cycle of the PPG ranged from 1.5 to 6.5 s. The leading three etiologies were acute ischemic stroke in five patients, post-seizure state in three patients, and hypoxic-ischemic encephalopathy in two patients. A total of 88.9% (8/9) of the patients with consistent whole-field PPG had similar bilateral hemispheric damage, whereas 80.0% (4/5) of the patients with PPG in the hemifield had unilateral or extremely asymmetric bilateral hemispheric damage. The hemifiled side was the same side as the sole/dominant hemispheric lesion. The final clinical outcomes were neurologic remission for seven patients, vegetative state for one patient, and death for six patients.

PPG is a sign with localizing value that suggests hemispheric damage and asymmetric PPG might help to predict lateralization of the lesions. Acute ischemic stroke is the most common cause of PPG. Etiology and initial outcome are likely important prognostic factors of PPG.