Nystagmus Panayiotis Stavrou - PowerPoint Presentation

Slide1

Nystagmus

Panayiotis

Stavrou

Definition

Nystagmus

is an involuntary rhythmic shaking or wobbling of the eyes. The term

nystagmus

is derived from the Greek word ‘

nystagmos

’ which was used to describe the wobbly head movements of a sleepy individual.

Classification of

Nystagmus Doctors and researchers classify

nystagmus

by the characteristics of the eye movements like:

back and forth like a pendulum

slowly in one direction and then rapidly in another

laterally or vertically and by how much

how fast do the eyes move

Classification of

Nystagmus However there are over 45 types of

nystagmus

but traditionally

nystagmus

has been divided into two

groups

:

s

ensory

nystagmus

(congenital): that begins very early in life and is

related to vision

loss.

motor

nystagmus

(acquired): and is associated with neurological disorders and control of muscle function occurring later in life.

Congenital

NystagmusCongenital

nystagmus

occurs more frequently than acquired

nystagmus

.

It can be insular or accompany other

disorders.

Types

of congenital

nystagmus

include:

albinism,

aniridia

, optic nerve

hypoplasia

,

achromatopsia

, congenital cataracts, retinopathy.

Pendular

NystagmusThe most typical

nystagmus

related to vision loss during childhood is a

pendular

nystagmus

. The eyes rotate back and forth evenly, much like a pendulum.

Pendular

Nystagmus

Acquired

Nystagmus

Nystagmus

can be acquired later in life due to neurological

dysfunction, diseases or toxicity

such

as:

c

erebellar

ataxia

thalamic hemorrhage

a

head

injury

stroke

multiple sclerosis

brain tumors

alcohol intoxication

Acquired

Nystagmus Unlike

nystagmus

acquired from early in life, patients with late onset

nystagmus

usually notice movement in their vision related to the movement of their eyes. This is called

oscillopsia

.

Oscillopsia

causes a person to have dizziness related to the new movement they experience in their vision.

Late

onset

nystagmus

is more likely to be directional. The eye will move slowly in one direction, then quickly move back.

The

nystagmus

may change as the patient looks in different directions.

The

unexplained onset of

nystagmus

in an adult may indicate a serious neurological disorder and an immediate examination is

indicated.

Acquired

Nystagmus Acquired nystagmus

is subdivided into:

Horizontal

Pendular

Nystagmus

.

Vertical

Pendular

Nystagmus

Seesaw

nystagmus

Elliptical

nystagmus

Dissociated

Nystagmus

Horizontal

Pendular Nystagmus

Most frequently, horizontal or

pendular

nystagmus

is caused by:

central lesions involving the central

tegmental

tract

damage of the

cerebellar

nuclei

lesion near the

oculomotor

nuclei

Horizontal

Pendular Nystagmus

Vertical

Pendular Nystagmus

Vertical

nystagmus

occurs much less frequently than horizontal

nystagmus

and is often, but not necessarily, a sign of serious brain damage. T

The most common cause vertical

nystagmus

that frequently appears after:

pontine

hemorrhage related to damage to the central

tegmental

tract.

t

oluene sniffing, glue sniffing, usually in accompaniment with

cerebellar

deficits

Vertical

Pendular Nystagmus

Seesaw or jerk

nystagmus is a rare binocular disorder characterized by alternating vertical skew deviation and conjugate ocular torsion. Jerk seesaw consists of torsional

slow phases in one direction and quick phases in the opposite.

See saw

Nystagmus

See saw

Nystagmus

Fluctuations in Vision

Nystagmus

patients often experience fluctuations in their vision. A change in the speed of the

nystagmus

leading to a decrease in vision can be related

to:

s

tress

the

patient’s emotional

state

f

atigue

the

direction of

view

The Null Position

Patients with

nystagmus

often find a unique position of their head and eyes that slows the

nystagmus

allowing them to have better vision. This is called a null position and varies with each person

.

Treatment

Congenital nystagmus has traditionally been viewed as non-treatable, but medications have been discovered in recent years. Several therapeutic approaches are also proposed, such as: contact lensesdrugs

surgery

Treatment

Gabapentin

, an anticonvulsant, was found to cause improvement in about half the patients who received it to relieve symptoms of

nystagmus

.

Other drugs found to be effective against

nystagmus

in some patients include:

m

emantine

l

evetiracetam

acetazolamide

Treatment

Clinical trials of a surgery to treat nystagmus known as

tenotomy

.

Tenotomy

aims to reduce the eye shaking (oscillations), which in turn tends to improve visual acuity.