Parinaud's syndrome

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Parinaud's Syndrome, also known as Dorsal Midbrain Syndrome or Pretectal Syndrome is named for Henri Parinaud (1844-1905), considered to be the father of French ophthalmology. It is a cluster of abnormalities of eye movements and pupil dysfunction, characterized by:

1. Paralysis of upgaze
2. Pseudo-Argyll Robertson pupils (light-near dissociation)
3. Convergence-Retraction nystagmus
4. Eyelid retraction (Collier's sign)

It is commonly associated with bilateral papilloedema. It has less commonly been associated with spasm of accommodation, pseudoabducens palsy (also known as thalamic esotropia), see-saw nystagmus and associated ocular motility deficits including skew deviation, oculomotor nerve palsy, trochlear nerve palsy and internuclear ophthalmoplegia.

Parinaud's Syndrome results from injury, either direct or compressive, to the dorsal midbrain. Specifically, compression or ischaemic damage of de superior colliculus within the mesencephalon, where the nucleus of the oculomotor nerve (cranial nerve III) and the Edinger-Westphal nucleus are located, cause dysfunction to the motor function of the eye.

Classically, it has been associated with 3 major groups:

1. Young patients with brain tumors in the Pineal Gland or midbrain
2. Women in their 20s-30s with Multiple Sclerosis
3. Older patients following stroke of the upper brainstem

However, it has also been associated with obstructive hydrocephalus, midbrain hemorrhage, cerebral arteriovenous malformation, trauma and brainstem toxoplasmosis.

When children present with Parinaud's Syndrome, physicians should strongly consider neuroimaging, as brain tumor has been reported to be the most frequent cause in children.

The eye findings of Parinaud's Syndrome generally improve slowly over months, especially with resolution of the causative factor; continued resolution after the first 3-6 months of onset is uncommon. However, rapid resolution after normalization of intracranial pressure following placement of a ventriculoperitoneal shunt has been reported.

[edit] External links

• Case report of Parinaud's syndrome
• Tumor #1 cause of Parinaud's syndrome in children
• Reversibility of Parinaud's syndrome