1. SPONTANEOUS NYSTAGMUS

2. SPONTANEOUS NYSTAGMUS REFERS TO
NYSTAGMUS THAT OCCURS WITH THE
PATIENT SEATED, EYES IN THE PRIMARY
POSITION AND WITHOUT VISUAL OR VESTI-
BULAR STIMULATION.
RECORDING IS PERFORMED 30 SECONDS WITH
OPEN EYES AND GAZE FIXATION AND 30 SE-
CONDS WITH CLOSED EYES /ENG/ OR IN
COMPLETE DARKNESS /VNG/.

3. SPONTANEOUS NYSTAGMUS, RECORDED WITH OPEN EYES AND GAZE FIXATION IS ALWAYS PATHOLOGICAL. SPONTANEOUS NYSTAGMUS, RECORDED WITH CLOSED EYES OR IN DARKNESS IS PATHOLOGICAL IF SLOW PHASE VELOCITY /SPV/ IS = > 6 DEG/SEC.

4. SPONTANEOUS NYSTAGMUS
CENTRAL ORIGIN
PERIPHERAL ORIGIN

5. PERIPHERAL SPONTANEOUS NYSTAGMUS
HORIZONTAL COMPONENT DOMINATES

6. ------------------------------------------------------
RT LT
RT MED. RECT LT MED. RECT.
LT LAT. RECT H RT LAT. RECT.
RT SUP. RECT LT SUP. RECT.
LT INF. OBLIQUE A RT INF. OBLIQUE
RT SUP. OBLIQUE P LT SUP. OBLIQUE
LT INF. RECT RT INF. RECT.

7. PERIPHERAL SPONTANEOUS NYSTAGMUS
GAZE IN THE DIRECTION OF FAST COMPONENT INCREASES THE FREQUENCY AND AMPLITUDE OF THE NYSTAGMUS

8. PERIPHERAL SPONTANEOUS NYSTAGMUS
THE SLOW PHASE IS LINEAR

9. PERIPHERAL SPONTANEOUS NYSTAGMUS
NYSTAGMUS IS STRONGLY INHIBITED BY FIXATION

14. CENTRAL SPONTANEOUS NYSTAGMUS
IS PROMINENT WITH AND WITHOUT FIXATION

15. SLOW COMPONENT
SLOW PHASE OF SPONTANEOUS NYSTAGMUS MAY BE LINEAR, EXPONENTIALLY DECREASED OR EXPONENTIALLY INCREASED

17. Congenital nystagmus CONGENITAL NYSTAGMUS IS OF CENTRAL ORIGIN.
IT IS USUALLY PURELY HORIZONTAL.
THE WAVEFORM MAY BE PENDULAR TO SAWTOOTH.
DIFFERENT WAVEFORMS OCCUR IN THE SAME
PATIENT IN DIFFERENT EYE POSITIONS.