Nystagmus

Question 1

Vestibular Nystagmus

Answer 1

Nystagmus due to disturbance of the labyrinth or of the vestibular nuclei

Question 2

Optokinetic Nystagmus

Answer 2

Nystagmus induced by looking at objects moving across the visual field; including strobe lights, or passing vehicles.

Nystagmus that occurs in response to a rotation movement. It is present normally. The optokinetic reflex allows the eye to follow objects in motion when the head remains stationary.

Question 3

Caloric Nystagmus

Answer 3

Rotatory nystagmus in response to caloric stimuli in the ear. Typically caused by a drastic temperature difference in either ear.

Question 4

Positional Nystagmus

Answer 4

Nystagmus that which occurs, or is altered in form or intensity, on assumption of certain positions of the head.

Question 5

Fixation Nystagmus

Answer 5

Nystagmus only present when gazing fixedly at an object.

Question 6

Rotatory Nystagmus

Answer 6

Involuntary rotation of the eyes about the visual axis.

Question 7

Secondary Nystagmus

Answer 7

Nystagmus occurring after the abrupt cessation of rotation of the head, caused by the labyrinthine fluid continuing to move.

Question 8

Positional Alcohol Nystagmus

Answer 8

Nystagmus produced when the head is placed in a sideways position. PAN occurs when the specific gravity of the membrane space of the semicircular canals in the ear differs from the specific gravity of the fluid in the canals because of the presence of alcohol.

Question 9

PAN I

Answer 9

the alcohol concentration is higher in the blood than in the vestibular system fluid and occurs when a person’s blood alcohol content (BAC) is increasing.

Question 10

PAN II

Answer 10

In PAN II, the alcohol concentration is lower in the blood than in the vestibular system fluid and occurs when a person’s BAC is decreasing.

Question 11

Postrotatory Nystagmus

Answer 11

If one spins in a chair continuously and stops suddenly, the fast phase of nystagmus is in the opposite direction of rotation, known as the “post-rotatory nystagmus”, while slow phase is in the direction of rotation.

Question 12

Latent Nystagmus

Answer 12

Nystagmus only occurring when one eye is covered.

Question 13

Downbeat Nystagmus

Answer 13

Refers to the irregular downward jerking of the eggs during downward gaze. It can signal lower medullary damage.

Question 14

Seesaw Nystagmus

Answer 14

Is the rapid, seesaw movement of the eyes; one eye appears to rise while the other appears to fall. It suggests an optic chiasm lesion.

Question 15

Congenital Nystagmus

Answer 15

Most often develops by 2 to 3 months of age, but sometimes in the first couple of years of their life. The eyes tend to move in a horizontal swinging fashion.

Question 16

Acquired Nystagmus

Answer 16

Nystagmus that develops later, generally in adults. A sign of another condition such as stroke, multiple sclerosis, brain tumor, the effect of a drug or head injury. Anything that damages the parts of the brain that control eye movements can result in nystagmus.