OVERVIEW

What is nystagmus?

Nystagmus, also referred to as "eye tremor," primarily involves involuntary, rhythmic oscillations of the eyes when attempting to fixate on a target. It is not a disease itself but rather a common manifestation of underlying conditions, which may arise from neurological disorders, ocular diseases, or inner ear issues. The severity varies depending on the cause.

Additionally, the pattern, direction, rate, amplitude, duration, and intensity of nystagmus differ based on the location of the impairment. Even healthy individuals may exhibit nystagmus when tracking moving objects (such as a rotating striped cylinder or striped clothing).

Is nystagmus common?

Nystagmus is relatively prevalent among patients with brainstem, cerebellar, inner ear, or ocular disorders.

What are the types of nystagmus?

Nystagmus is primarily classified by its form into jerk nystagmus, pendular nystagmus, convergence nystagmus, seesaw nystagmus, and oscillopsia. It can also be categorized by etiology, such as labyrinthine (inner ear) nystagmus, brainstem/cerebellar nystagmus, and optokinetic nystagmus.

SYMPTOMS

What are the common symptoms and manifestations of nystagmus?

Nystagmus primarily manifests as involuntary, rhythmic eye movements when both eyes fixate on a target. Patients themselves cannot perceive the nystagmus, but most experience dizziness, reluctance to open their eyes or move, and in severe cases, may also suffer from nausea and vomiting, as well as other autonomic symptoms such as palpitations, cold sweats, and fatigue.

Additionally, depending on the underlying cause, other symptoms may occur, such as brainstem/cerebellar dysfunction (e.g., unsteady gait, difficulty swallowing, choking while drinking, limb weakness or numbness), inner ear involvement (e.g., tinnitus, ear fullness), or ocular symptoms (e.g., blurred vision, double vision).

What severe consequences can nystagmus cause?

Nystagmus itself can cause dizziness in patients, potentially leading to falls. Severe nausea and vomiting may result in malnutrition or electrolyte imbalances. Disease progression and prognosis largely depend on the underlying cause.

• For brainstem/cerebellar disorders, severe cases may lead to unconsciousness or even life-threatening conditions;
• For inner ear disorders, severe cases may cause hearing loss;
• For ocular diseases, severe cases may impair vision.

Nystagmus triggered by observing moving targets like rotating striped cylinders or striped clothing has no significant impact.

What should be done if nystagmus occurs in children? Can it cause blindness?

Children with nystagmus require prompt medical attention to determine the cause. Congenital nystagmus, which is more common in children, presents with complex manifestations and significant harm, often accompanied by noticeable visual impairment, with symptoms typically affecting both eyes.

How can nystagmus in young children be detected early, and what are the typical signs?

Young children exhibiting behaviors such as squinting, rapid eye movements, facial or head tilting, abnormal head positioning, or frequent blinking should raise suspicion of congenital nystagmus, necessitating immediate medical evaluation.

CAUSES

What are the common causes of nystagmus?

The causes of nystagmus include the following:

• Ocular diseases (abnormal retinal nerve impulses or absence of impulses);

• Lesions in the connection between the inner ear and vestibular nuclei or within brainstem vestibular pathways;

• Cervical spinal cord damage;

• Damage to central pathways (mainly brainstem/cerebellum) controlling eye movement and position;

• Congenital or idiopathic nystagmus;

• Toxicity (commonly caused by aminoglycoside antibiotics with ototoxic effects);

• Transient physiological responses when fixating on specific moving objects or sudden exposure to bright light after prolonged darkness.

DIAGNOSIS

How can nystagmus be detected in patients?

Nystagmus is usually discovered by a medical professional during an examination of the patient.

During the examination, the physician first checks whether both eyes are in a central position, then instructs the patient to move their eyes upward, downward, and sideways to observe if there is any rhythmic oscillation of the eyes in different gaze positions and to determine its characteristics. The causes of nystagmus vary, and so do the examination methods.

What tests do patients with nystagmus need to undergo? Why are these tests necessary?

For patients diagnosed with nystagmus, examinations mainly focus on two aspects: clarifying the characteristics of the nystagmus and identifying its underlying cause.

• Electronystagmography (ENG): Helps determine the characteristics of the nystagmus;

• Imaging tests such as head and cervical spine CT/MRI: Can assist in identifying severe lesions in areas like the brainstem, cerebellum, or cervical spinal cord;

• Inner ear MRI, audiometry, tympanometry, and otologic examinations: Can help determine if there are inner ear disorders;

• Ophthalmic examination: An ophthalmologist uses specialized instruments to assess for any eye-related conditions.

What conditions can nystagmus be easily confused with? How can they be distinguished?

Nystagmus needs to be differentiated from other spontaneous abnormal eye movements such as ocular bobbing or ocular dipping. The main method of distinction is through detailed observation by a medical professional, as the patterns of abnormal eye movements differ.

TREATMENT

Which department should I visit for nystagmus?

You can initially consult ophthalmology, neurology, or otolaryngology-head and neck surgery. If an underlying cause is identified, further treatment may be required in the relevant department.

Does nystagmus require hospitalization?

In most cases, patients with severe symptoms require hospitalization.

How is nystagmus treated?

• For cases with an underlying cause (e.g., brain disorders or systemic diseases), treatment focuses on addressing the root cause;

• Closing the eyes, resting quietly, and avoiding movement can help reduce vertigo symptoms;

• Physiological nystagmus triggered by observing rotating striped cylinders or moving patterned clothing does not require specific treatment.

Can congenital nystagmus be cured?

Congenital nystagmus is often difficult to treat. Treatment primarily aims to control or alleviate symptoms, including surgical intervention, prism glasses, and medication.

DIET & LIFESTYLE

What should patients with nystagmus pay attention to in their diet?

No special requirements, just maintain a healthy diet with low salt intake.

What should patients with nystagmus pay attention to in daily life?

Rest quietly with eyes closed and avoid moving or being moved.

PREVENTION

Can nystagmus be prevented?

For physiological nystagmus, avoid staring at moving striped targets; prevent trauma and exposure to toxic substances, and minimize the use of ototoxic medications such as aminoglycoside antibiotics.

For nystagmus related to other diseases, prevention focuses primarily on the underlying condition.