• 10 SECTION Nystagmus

Monocular Pendular Nystagmus of Childhood

Key Facts

•Monocular pendular nystagmus, usually vertical, present in childhood

•Subnormal vision in oscillating eye

•Common causes:

•anterior visual pathway tumor (glioma, craniopharyngioma)

•optic nerve hypoplasia

•amblyopia

•MRI to rule out anterior visual pathway tumor unless there is a predisposing cause for amblyopia and pupil reactions are normal

Clinical Findings

•Monocular pendular nystagmus, more commonly vertical

•Subnormal visual acuity in oscillating eye

•Anisometropia, strabismus, and media opacity may be causes of amblyopia in oscillating eye

•Afferent pupil defect and pale and/or small optic disc are signs of optic neuropathy in oscillating eye

Ancillary Testing

• MRI may show anterior visual pathway tumor

Differential Diagnosis

•Spasmus nutans

•Congenital motor or sensory nystagmus

•Acquired binocular pendular nystagmus

Treatment

•Monocular occlusion for amblyopia

•Chemotherapy, radiotherapy, surgery, or observation for anterior visual pathway tumor

Prognosis

•Depends on underlying lesion

•Nystagmus may resolve if vision improves

Fig. 10.5 Monocular pendular nystagmus of childhood. In all positions of gaze, the right eye displays a vertical pendular nystagmus.

Fig. 10.6 Glioma of optic nerve and chiasm. Axial FLAIR MRI shows high signal mass in the optic chiasm and left optic nerve (arrow). The patient displayed monocular pendular nystagmus in the left eye.

Childhood of Nystagmus Pendular Monocular

Nystagmus

Spasmus Nutans

Key Facts

•Idiopathic triad of low-amplitude binocular pendular nystagmus, torticollis, and head nodding

•Torticollis and nodding often absent

•Appears with first 3 years of life, usually within first year

•Disappears spontaneously within 36 months, leaving no after-effects

•Cannot be distinguished easily from congenital nystagmus, monocular pendular nystagmus of childhood, or ocular flutter or opsoclonus

Clinical Findings

•Low-amplitude binocular pendular (shimmery) nystagmus, sometimes accompanied by torticollis and/or head nodding

•Nystagmus amplitude may be so low in one eye that it escapes notice

•Ophthalmologic and neurologic examinations otherwise normal

•No systemic abnormalities

• 10 SECTION

Ancillary Testing

•Evaluate for:

•retinal photoreceptor dystrophies (electroretinogram)

•anterior visual pathway tumors (brain MRI)

•meningoencephalitis (brain MRI, lumbar puncture, electroencephalogram)

•occult neuroblastoma (chest and abdomen MRI, nuclear scan, urine catecholamines)

Differential Diagnosis

•Congenital motor or sensory nystagmus

•Monocular pendular nystagmus of childhood

•Ocular flutter or opsoclonus

Treatment

• None

Prognosis

• All findings disappear completely within 36 months and leave no after-effects