Neuro-ophthalmology of type 1 Chiari malformation

Abstract

Chiari malformation is a congenital deformity leading to herniation of cerebellar tonsils. Headache is a typical symptom of this condition, but patients with Chiari malformation often present with double vision and vertigo. Examination of eye movements in such patients often reveals nystagmus and strabismus. Eye movement deficits in the context of typical symptomatic presentation are critical clinical markers for the diagnosis of Chiari malformation. We will review eye movement deficits that are seen in patients with type 1 Chiari malformation. We will then discuss the underlying pathophysiology and therapeutic options for such deficits.

Keywords:

• brainstem
• cerebellum
• eye movement
• nystagmus
• strabismus

Financial & competing interests disclosure

Part of the contents of this review was acquired with support from NIH grant R01EY06717. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Key issues

• Type 1 Chiari malformation is a common deformity of the nervous system.

• Patients with Type 1 Chiari malformation commonly present with eye movement deficits, such as nystagmus and strabismus.

• Gaze-evoked nystagmus is commonly seen, but it does not warrant treatment in most cases.

• Downbeat nystagmus is also common. The effects on the quality of life may justify treatment with GABAergic pharmacotherapy.

• Strabismus commonly leads to diplopia in patients with Chiari malformation.

• Rare eye movement deficits in patients with Chiari malformation include shifted null of gaze-evoked nystagmus, seesaw nystagmus and periodic alternating nystagmus.

Notes