What should I be concerned about regarding nystagmus?

What You Should Worry About with Nystagmus

The most critical concern with nystagmus is distinguishing benign peripheral causes from life-threatening central nervous system pathology—specifically downbeat nystagmus, direction-changing nystagmus without positional triggers, gaze-evoked nystagmus, and any acquired or asymmetric nystagmus are red flags requiring urgent neuroimaging to exclude cerebellar, brainstem, or structural lesions. 1

Immediate Red Flags Requiring Urgent Evaluation

Central Nystagmus Patterns (Neurologic Emergency)

• Downbeat nystagmus is the most concerning pattern, strongly suggesting cerebellar or cervicomedullary junction disorders that do not fatigue or suppress with visual fixation 1, 2
• Direction-changing nystagmus occurring without head position changes indicates central pathology rather than benign causes 1
• Gaze-evoked nystagmus definitively indicates brainstem or cerebellar pathology and does not fatigue 1, 3
• Baseline nystagmus without provocative maneuvers suggests neurological disease requiring investigation 1

Critical Pitfall to Avoid

Do not mistake downbeat nystagmus on Dix-Hallpike testing for benign paroxysmal positional vertigo (BPPV)—downbeat nystagmus without a torsional component indicates central pathology, not BPPV. 1 True posterior canal BPPV produces torsional upbeating nystagmus, not pure downbeat 4.

Life-Threatening Conditions Associated with Nystagmus

Structural CNS Lesions

• Chiari malformation occurs in 3.4% of children with isolated nystagmus 1
• Optic pathway gliomas are found in 2% of children with isolated nystagmus 1
• Brainstem/cerebellar tumors can present with acquired nystagmus 1, 3
• Arteriovenous malformations may cause acquired nystagmus 1

Vascular Events

• Posterior circulation stroke or transient ischemic attack can cause acquired nystagmus 4, 1
• Vertebrobasilar insufficiency may present with isolated transient vertigo and central nystagmus, potentially preceding stroke by weeks or months 1

Demyelinating Disease

• Multiple sclerosis is particularly associated with convergence retraction nystagmus and can cause medial longitudinal fasciculus lesions 1

Pediatric-Specific Concerns

When to Worry in Children

• 15.5% of children with isolated nystagmus have abnormal intracranial findings on MRI, including abnormal T2 hyperintense signal in white matter, Chiari malformation, and optic pathway glioma 1, 5
• Acquired or late-onset nystagmus in children mandates urgent neuroimaging 1, 5
• Asymmetric, unilateral, or progressive nystagmus suggests neurological disease 1, 6

Spasmus Nutans Mimicry

Do not confuse spasmus nutans (nystagmus, head bobbing, torticollis appearing at 1-3 years) with benign infantile nystagmus—it requires MRI to exclude anterior visual pathway tumors. 1, 5

Distinguishing Central from Peripheral Causes

Central Nystagmus Characteristics (Worrisome)

• Does not fatigue with repeated testing 1, 2
• Not suppressed by visual fixation 1, 7
• Often accompanied by severe postural imbalance 1, 2
• May have additional neurological signs 1, 3

Peripheral Vestibular Nystagmus (Less Concerning)

• Typically has a torsional component 1
• Suppressed by visual fixation 1, 7
• Fatigues with repeated maneuvers 1
• Associated with Ménière's disease, vestibular neuritis, labyrinthitis, superior canal dehiscence syndrome 4, 1

Mandatory Neuroimaging Indications

MRI of the brain without and with IV contrast is the imaging modality of choice when any of the following are present 1, 5:

• Acquired or late-onset nystagmus 1
• Concurrent neurological symptoms 1
• Decreased visual acuity 1
• Asymmetric, unilateral, or progressive nystagmus 1
• Any central nystagmus pattern (downbeat, gaze-evoked, direction-changing without position change) 1

CT imaging has no role in nystagmus evaluation and provides inferior soft tissue detail compared to MRI. 1, 5

Underlying Systemic Conditions to Consider

Metabolic Diseases

• Leukodystrophies and mitochondrial diseases are associated with acquired nystagmus 1
• Gaucher disease type 3 can cause impaired horizontal and vertical saccades 3

Infantile Nystagmus Causes (Less Urgent but Require Evaluation)

• Albinism, retinal diseases, low vision, vision deprivation (congenital cataracts) 1, 6
• Optic nerve hypoplasia and retinal dystrophies 6
• Fusion maldevelopment syndrome in children with normal ocular development 1

Symptoms Indicating Serious Pathology

Neurologic Symptoms Requiring Urgent Evaluation

• Oscillopsia (jumping images) with acquired nystagmus 2, 8
• Permanent dizziness, postural imbalance, gait disorder (typical of downbeat/upbeat nystagmus) 2
• Acute spinning vertigo with tendency to fall (brainstem/cerebellar ischemia) 2
• Head bobbing and torticollis (spasmus nutans requiring tumor exclusion) 1

Visual Symptoms

• Blurred vision and reduced visual acuity 2, 8
• Double vision depending on eye position 2

Algorithmic Approach to Nystagmus Concerns

1. First, determine if central pattern present (downbeat, gaze-evoked, direction-changing without position change, baseline without provocation) → Urgent MRI brain 1

2. If acquired or late-onset → Urgent MRI brain 1, 5

3. If infantile/congenital with normal neurologic exam → Refer to pediatric ophthalmology for comprehensive evaluation, but maintain high suspicion as 15.5% have intracranial abnormalities 1, 5

4. If positional with torsional component and fatigability → Consider BPPV, but ensure proper differential diagnosis from central causes 4, 1

5. If asymmetric, unilateral, or progressive → Urgent MRI brain 1