Common Cases: Nystagmus

1. Dr. Riyad Banayot

2.  Remember to describe the nystagmus as
follow:
 Position: Primary position or gaze-related
(only in eccentric gaze)
 Type: Pendular (equal velocity in both
directions) or jerky (possessing a fast and
slow phase). The direction of the nystagmus
refers to the fast phase
 Rate: Rapid or slow
 Plane: Horizontal, vertical or rotary
 Null zone: Nystagmus is minimal in this field
of gaze (this may be left or right or on
convergence)
 Binocular or monocular / dissociated

3.  Cerebellar jerk nystagmus
 Congenital pendular nystagmus
 Down-beat nystagmus
 See-saw nystagmus

4.  The nystagmus is jerky with large amplitude
and low frequency.
 It may be present in the primary position.
 The nystagmus increases when the eyes look in
the direction of the fast phase.
Other additional examination:
 Examine for other cerebellar signs such as
scanning speech, intention tremor, past-
pointing, disdianochokinesia and wide-based
gaits
 Test the hearing and corneal sensation for
possible cerebello-pontine lesion
 Examine the fundus for optic atrophy (as
cerebellar signs and optic neuritis are common
in multiple sclerosis)

5.  See-saw nystagmus (lesion in chiasm and
third ventricle)
 Convergence-retraction (dorsal mid-brain)
 Upbeat nystagmus (ponto-medullary
junction, fourth ventricle and cerebellar
vermis)
 Dissociated nystagmus (as in internuclear
ophthalmoplegia, lesion in the medial
longitudinal fasciculus)
 Down-beat nystagmus (cranio-cervical
junction)

6. There is pendular nystagmus in the primary position. This may be horizontal,
vertical or rotary. The nystagmus decreases on convergence but increases on
covering one eye. There may be abnormal eye posture in an attempt to keep the
eyes in the null point.

7. Anterior segment:
 Congenital cataract
 Aphakia from previous cataract operation
 Albinism
 Aniridia
 Corneal abnormalities
Posterior segment:
 Optic nerve hypoplasia
 Dragged discs from retinopathy of prematurity
and foveal hypoplasia

8.  Establish and treat the underlying cause
if possible (e.g. cataract)
 Improve visual acuity by
 Conservative treatment such as placing the
child in front of the class or anywhere where
he can maintain his null point and therefore
maximize his vision
 Refractive correction
 Prisms for null point and convergence
 Surgery such as liberal recession to reduce
the nystagmus

9. There is nystagmus in the primary position with the fast phase beating downward.
The nystagmus remains down-beating in different directions of gaze. Lateral gaze
usually accentuates the nystagmus. The nystagmus is associated with cervico-
medullary lesion such as Arnold-Chiari malformation (Examine the back of the
neck for any surgical scar).

10.  Arnold-Chiari malformation
 Spinocerebellar degeneration
 Brain stem stroke
 Multiple sclerosis
 Drugs such as alcohol or anticonvulsant
such as phenytoin

11. There is torsional nystagmus in the primary position. When one eye elevates and
intorts the other depresses and extorts and vice-versa. This typical of lesion in
chiasmal region. Examine the visual field for bitemporal hemianopia