Primary gazeCentral · refer
Pure torsional
Rotary beating with no horizontal or vertical component — central.
Primary gazeLive
The fast phase is purely rotary — the iris markings turn, but the eye does not drift horizontally or vertically. Isolated torsional nystagmus is a brainstem sign; it can be the ONLY abnormal finding in an otherwise reassuring-looking exam, so look for it deliberately.
Source: Leigh & Zee; Kattah 2009.
Other signs
Stylised teaching animations authored by NeuroDash. Not real-patient recordings, not board-certified, and not reviewed by an outside specialist. Educational only — not medical advice or a diagnosis.