Nystagmus

1. NYSTAGMUS
Neil Bailie
ENT Postgraduate Class 18/05/01

2. Definition
‘nmstagmos’ (Greek) the head nodding
seen with alcohol or
drowsiness
Nystagmus may be defined as:
“a periodic rhythmical ocular oscillation that is
initiated by a slow phase(drift)”

3. Control of Gaze
1)Gaze Stabilisation system
2)Gaze alignment system

4. Gaze Stabilisation System
Compensates for self-motion stabilising
visual world on the retina
-Vestibulo-ocular system
-Optokinetic System

5. Gaze Alignment System
Keeps object of interest within the visual
world centred on fovea
-Saccades
-Smooth pursuit

6. Classification of Nystagmus
1)Pendular Vs Jerk
2)Physiological Vs Pathological
3)Congenital Vs Acquired
4)Peripheral Vs Central
5)Spontaneous Vs Gaze-evoked

7. Pendular Nystagmus
Slow oscillations with approximately equal
velocity and amplitude in both directions
May be horizontal, vertical or rotatory
Commonly congenital or caused by poor
visual fixation
Rarely occurs in ‘neurological’ disease

8. Jerk Nystagmus
Slow phase in one direction followed by a
rapid phase in the opposite direction
Slow phase – pathological
Rapid phase – corrective response
Named after the direction of the fast
phase

9. Physiological Nystagmus
1)‘End-point’ nystagmus
3)Optokinetic nystagmus
5)Vestibular Caloric – ‘COWS’

10. Pathological Nystagmus
1)Labyrinthine nystagmus
2)Central Nystagmus
3)Positional Nystagmus
4)Disconjugate Nystagmus

11. Labyrinthine Nystagmus
•Horizontal-rotatory or horizontal jerk
nystagmus
•Unidirectional with fast phase away
from affected side
•Intensity maximal looking in direction of
fast phase (Alexander’s Law)
•Tend to fall away from direction of fast
phase

12. Central Nystagmus

13. Positional Nystagmus
•Peripheral BPPV
•Central
•Atypical

14. Disconjugate Nystagmus
•Ataxic Nystagmus
•See-Saw Nystagmus

15. Clinical Assessment
•Ask patient to fix and follow on your
finger (about 1m away)
•Move slowly to 12, 3, 6 and 9 o’clock
waiting 5 seconds at each position
•Do not move more than 30 degrees
from midline
•Nystagmus must be sustained for more
than a few beats to be significant