![]() The most common causes are pineal gland tumors and midbrain infarction 3. ![]() Parinaud’s syndrome usually presents as a sporadic condition. It has less commonly been associated with spasm of accommodation on attempted upward gaze, pseudoabducens palsy (also known as thalamic esotropia) or slower movements of the abducting eye than the adducting eye during horizontal saccades, see-saw nystagmus and associated ocular motility deficits including skew deviation, oculomotor nerve palsy, trochlear nerve palsy and internuclear ophthalmoplegia. Parinaud syndrome is also commonly associated with bilateral papilledema. The cause is thought to be due to damage to the levator inhibitory fibers at the posterior commissure. Patients may also present with lid retraction in the primary position, which is called the Collier sign. Thus they are spared in Parinaud syndrome, which is a dorsal midbrain syndrome. It is thought that the fibers for the near reflex are located more ventrally. The pupillary light reflex fibers synapse at the pretectal nucleus and the pass to the Edinger-Westphal nucleus of the same side and the contralateral side through the posterior commissure, making them susceptible to external compressive effects of mass lesions. There is poor pupillary constriction to light but preserved constriction with convergence. The third component of the Parinaud syndrome triad is pupillary involvement. Convergence retraction nystagmus is considered a highly localizing sign, pointing to a lesion of the dorsal midbrain. This results in sustained discharge from the medial rectus and other extraocular muscles. It has been postulated that convergence retraction nystagmus is caused by damage to the supranuclear fibers, which have an inhibitory effect on the midbrain convergence or divergence neurons. This is an extremely rare condition with very few reported cases.Īnother component of the triad of Parinaud syndrome is convergence- retraction nystagmus which is characterized by an irregular, jerky nystagmus, associated with convergence and retraction of both eyes, especially on attempted upgaze. In this condition, there is downgaze palsy instead of upgaze palsy, and the patient presents with the combination of downgaze palsy with convergence weakness and pupillary light-near dissociation. However, a condition called Reverse Parinaud syndrome has also been described. ![]() This makes them more susceptible to the pressure effect of space occupying lesions. It has been suggested that the pathways for downward gaze are directed medially from the rostral interstitial nucleus of the Medial Longitudinal Fasciculus whereas, the fibers for upward gaze are directed laterally from the Medial Longitudinal Fasciculus and decussate in the posterior commissure. Downgaze is classically preserved, but the reason for this is not entirely explained. ![]() It occurs because of the involvement of the vertical gaze centers, which are in proximity to the superior colliculus, with some of the main nuclei being the interstitial nuclei of Cajal and the rostral interstitial nucleus of the Medial Longitudinal Fasciculus. The characteristic symptom of Parinaud syndrome is limited conjugate upgaze. Also, it may sometimes include conjugate downgaze in primary position and rarely downgaze palsy 2. However, the definition of Parinaud syndrome has now been widened to include the triad of upgaze paralysis, convergence retraction nystagmus, and pupillary light-near dissociation. The classic triad of upgaze paly, convergence retraction nystagmus and pupillary light-near dissociation was seen in about 65% of patients with Parinaud’s syndrome. The original description by Henri Parinaud included upgaze palsy and convergence paralysis. Neurosurgeons will often see this sign most commonly in patients with failed ventriculoperitoneal shunts. ![]() Conjugate down gaze in the primary position: “setting-sun sign”.The easiest way to bring out this reaction is to ask the patient to follow down-going stripes on an optokinetic drum. On fast up-gaze, the eyes pull in and the globes retract. Convergence-Retraction nystagmus: Attemps at upward gaze often produce this phenomenon.Pseudo-Argyll Robertson pupils: Accommodative paresis ensues, and pupils become mid-dilated and show light-near dissociation.This vertical palsy is supranuclear, so doll’s head maneuver should elevate the eyes, but eventually all upward gaze mechanisms fail. Paralysis of upgaze: Downward gaze is usually preserved.Parinaud syndrome also known as Sylvian aqueduct syndrome, dorsal midbrain syndrome, pretectal syndrome, and Koerber-Salus-Elschnig syndrome is a cluster of abnormalities of eye movements and pupil dysfunction, characterized by 1: Parinaud syndrome prognosis Parinaud syndrome ![]()
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