Parinaud's syndrome

A neurological condition affecting eye movement

Parinaud's Syndrome

Diagram of the human brain showing the location of the midbrain, where Parinaud's syndrome originates.

Parinaud's syndrome, also known as dorsal midbrain syndrome, is a neurological condition characterized by a group of eye movement abnormalities. It is named after the French ophthalmologist Henri Parinaud, who first described the condition. This syndrome is primarily caused by lesions in the dorsal midbrain, particularly affecting the superior colliculus and the pretectal area.

Clinical Features

Parinaud's syndrome is marked by several distinct clinical features:

• Vertical Gaze Palsy: Patients exhibit difficulty in moving their eyes vertically, especially upwards. This is due to the involvement of the vertical gaze centers in the midbrain.

• Convergence-Retraction Nystagmus: This is a jerky eye movement that occurs when the patient attempts to look upwards. The eyes appear to converge and retract into the orbit.

• Light-Near Dissociation: The pupils react poorly to light but constrict normally during accommodation (focusing on a near object).

• Eyelid Retraction (Collier's Sign): The upper eyelids are abnormally elevated, giving the appearance of a "staring" look.

Causes

Parinaud's syndrome can result from various causes, including:

• Pinealoma: Tumors of the pineal gland can compress the dorsal midbrain.
• Multiple sclerosis: Demyelinating lesions can affect the midbrain.
• Stroke: Vascular events can lead to ischemia in the midbrain region.
• Trauma: Head injuries can damage the midbrain structures.

Diagnosis

The diagnosis of Parinaud's syndrome is primarily clinical, based on the characteristic eye movement abnormalities. Neuroimaging, such as MRI or CT scan, is used to identify the underlying cause, such as a tumor or lesion.

Treatment

Treatment of Parinaud's syndrome focuses on addressing the underlying cause. For instance, surgical removal of a pineal tumor or medical management of multiple sclerosis may alleviate symptoms. Symptomatic treatment for eye movement disorders may include prism glasses or botulinum toxin injections.

Related Pages

• Ophthalmology
• Neurology
• Midbrain
• Pineal gland