title: Teaching Video NeuroImages: periodic alternating nystagmus evident only in darkness.
authors: Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors: Ali
authors: A
authors: Razmara
authors: Devin
authors: D
authors: Mackay
authors: Steven L
authors: SL
authors: Galetta
authors: Sashank
authors: S
authors: Prasad
mesh_terms: D000369:Aged, 80 and over; D003624:Darkness; D018450:Disease Progression; D006801:Humans; D008297:Male; D009460:Neurologic Examination / Q000379:methods; D009759:Nystagmus, Pathologic / Q000175:diagnosis*