This diagnostic image displays electronystagmography (ENG) or videonystagmography (VNG) tracings recorded during an ophthalmological or vestibular examination. The figure is divided into three sections evaluating eye movement dynamics. The top panel depicts 'Horizontal Eye Position [°]', showing a classic sawtooth wave pattern of spontaneous left-beating nystagmus characterized by a slow rightward drift and a rapid leftward corrective phase. The middle panel shows stable 'Vertical Eye Position [°]' with minimal deviation. The bottom panel illustrates 'Horizontal Eye Position' during a smooth pursuit task, featuring a green sinusoidal target line superimposed with red and blue eye-tracking lines. These tracings exhibit significant saccadic intrusions and oscillations, indicating broken or fragmented pursuit movements where the patient employs catch-up saccades to track the target. The data demonstrates a congenital-type horizontal conjugate nystagmus that intensifies during tracking, relevant for neuro-otological and vestibular diagnostics.

Diagnostic diagnostic traces and charts showing results of a caloric vestibular test, used to assess peripheral vestibular function. The top four panels display Electronystagmography (ENG) or Videonystagmography (VNG) recordings of slow phase velocity (SPV) in degrees per second (°/s) during bithermal caloric irrigation (30°C cold and 44°C hot) for both the left and right ears. The left ear panels demonstrate characteristic nystagmus responses with fluctuating SPV values. In contrast, the right ear panels ('Right; cold' and 'Right; hot') show flat traces with SPV peak values ≤ 5°/s, indicating a diagnosis of right vestibular areflexia. The bottom left quadrant contains a composite scatter plot of nystagmus velocity over time, with red and blue data points representing the fast and slow phases of nystagmus. The bottom right graph provides a summary caloric chart plotting peak velocities to quantify vestibular paresis or directional preponderance. This material is essential for neurology and otolaryngology students studying the diagnostic workup of vertigo, balance disorders, and unilateral vestibular loss.

This diagnostic image displays four electronystagmography (ENG) or videonystagmography (VNG) recordings of vertical eye motion in a patient undergoing a motorized rotation chair test. The traces correspond to four different head rotation velocities: 10°/s, 20°/s, 30°/s, and 40°/s. Each recording depicts paroxysmal downbeat nystagmus (DBN) induced during a positioning phase, indicated by shaded pink rectangular areas. There is a direct correlation between rotation velocity and nystagmus intensity; as the velocity increases from 10 to 40°/s, both the amplitude and frequency of the downward deflections (downbeat nystagmus) increase significantly. Following the cessation of positioning, the paroxysmal downbeat nystagmus typically transitions into a lower-amplitude upward deflection, representing a brief upbeat nystagmus. A scale bar at the bottom right indicates 10° for vertical displacement and 1 second for time. This visual aids in understanding the velocity-dependent nature of central positional nystagmus (CPN) and its diagnostic patterns in neuro-otology.

A compilation of three-dimensional videonystagmography (VNG) recordings illustrating stimulus-evoked vestibular-induced nystagmus (SVIN) in a patient with left superior semicircular canal dehiscence (uSCD). The panels display horizontal (H, red), vertical (V, green), and torsional (T, blue) ocular motor components across four bone conduction frequencies: 60 Hz, 100 Hz, 200 Hz, and 300 Hz. The recordings compare different stimulation sites including the left mastoid (LM), right mastoid (RM), vertex (Vx), and baseline no stimulation (N). Key findings demonstrate that the horizontal and torsional components remain consistently left-beating across all frequencies, particularly during vertex stimulation. In contrast, the vertical component exhibits frequency-dependent directionality: it is up-beating (indicated by upward arrows) at 60, 100, and 200 Hz, but reverses to a down-beating pattern (indicated by downward arrows) at 300 Hz. This clinical diagnostic image illustrates the use of high-frequency vibration to evaluate vestibular hypersensitivity and identify semicircular canal pathology.