Parinaud Syndrome: Vertical Gaze Palsy Cause

Parinaud syndrome is a specific neurological condition characterized by abnormalities in eye movement, particularly involving vertical gaze.

Key Features of Parinaud Syndrome

• Vertical Gaze Palsy: Impaired ability to move the eyes upward or downward.
• Convergence Retraction Nystagmus: Rapid, involuntary jerking movements of the eyes when attempting to focus on a near object, coupled with an inward twitch of the eyeballs.
• Pupil Abnormalities: Often includes light-near dissociation (poor pupil reaction to light, but normal reaction to accommodation).
• Collier's Sign: Eyelid retraction.

This combination of symptoms, especially the marked vertical gaze palsy and convergence retraction nystagmus, is highly indicative of a lesion in the dorsal midbrain, typically affecting the pretectal region.

Differential Diagnosis of Other Syndromes

The other listed syndromes present with different primary symptoms:

• Weber syndrome: Involves ipsilateral 3rd nerve palsy and contralateral hemiparesis.
• Millard Gubler syndrome: Characterized by ipsilateral 6th nerve palsy, ipsilateral 3rd nerve palsy, and contralateral hemiparesis.
• Claude syndrome: Presents with ipsilateral 3rd nerve palsy and contralateral cerebellar ataxia.

These differ significantly from the characteristic eye movement disorders of Parinaud syndrome.