Mischaracterization of Spaceflight-Associated Neuro-ocular Syndrome

To the Editor The Viewpoint by Roberts and Petersen¹ asserts that the enlargement of the cerebral ventricles of astronauts after long-duration spaceflight is a form of normal-pressure hydrocephalus (NPH). We contend that this claim is incorrect and that it mischaracterizes a disorder affecting astronauts known as spaceflight-associated neuro-ocular syndrome (SANS).²