Parinaud's syndrome is a constellation of neurological signs indicating injury to the dorsal midbrain. More specifically, compression of the vertical gaze center at the rostral interstitial nucleus of medial longitudinal fasciculus (riMLF). It is a group of abnormalities of eye movement and pupil dysfunction and is named for Henri Parinaud (1844–1905), considered to be the father of French

ophthalmology Ophthalmology (, ) is the branch of medicine that deals with the diagnosis, treatment, and surgery of eye diseases and disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a ...

Signs and symptoms

Parinaud's syndrome is a cluster of abnormalities of eye movement and pupil dysfunction, characterized by: * Paralysis of upwards gaze: Downward gaze is usually preserved. This vertical palsy is supranuclear, so doll's head maneuver should elevate the eyes, but eventually all upward gaze mechanisms fail. In the extreme form, conjugate down gaze in the primary position, or the "setting-sun sign" is observed. Neurosurgeons see this sign most commonly in patients with hydrocephalus. * Pseudo- Argyll Robertson pupils: Accommodative paresis ensues, and pupils become mid-dilated and show light-near dissociation. * Convergence-retraction nystagmus: Attempts at upward gaze often produce this phenomenon. On fast up-gaze, the eyes pull in and the globes retract. The easiest way to bring out this reaction is to ask the patient to follow down-going stripes on an optokinetic drum. * Eyelid retraction ( Collier's sign) It is also commonly associated with bilateral papilledema. It has less commonly been associated with spasm of accommodation on attempted upward gaze, pseudoabducens palsy (also known as thalamic

esotropia Esotropia () is a form of strabismus in which one or both eyes turn inward. The condition can be constantly present, or occur intermittently, and can give the affected individual a "cross-eyed" appearance. It is the opposite of exotropia and us ...

) 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 The oculomotor nerve, also known as the third cranial nerve, cranial nerve III, or simply CN III, is a cranial nerve that enters the orbit through the superior orbital fissure and innervates extraocular muscles that enable most movements o ...

palsy, trochlear nerve palsy and internuclear ophthalmoplegia.

Causes

400px, Cross section of midbrain. The area affected in Parinaud's syndrome is indicated by the striped region. Parinaud's syndrome results from injury, either direct or compressive, to the dorsal

midbrain The midbrain or mesencephalon is the uppermost portion of the brainstem connecting the diencephalon and cerebrum with the pons. It consists of the cerebral peduncles, tegmentum, and tectum. It is functionally associated with vision, hearing, mo ...

. Specifically, compression or ischemic damage of the mesencephalic tectum, including the

superior colliculus In neuroanatomy, the superior colliculus () is a structure lying on the tectum, roof of the mammalian midbrain. In non-mammalian vertebrates, the Homology (biology), homologous structure is known as the optic tectum or optic lobe. The adjective f ...

adjacent oculomotor (origin of cranial nerve III) and Edinger-Westphal nuclei, causing dysfunction to the motor function of the eye. Classically, it has been associated with three major groups: * Young patients with brain tumors in the

pineal gland The pineal gland (also known as the pineal body or epiphysis cerebri) is a small endocrine gland in the brain of most vertebrates. It produces melatonin, a serotonin-derived hormone, which modulates sleep, sleep patterns following the diurnal c ...

, causing hydrocephalus * Women in their 20s-30s with

multiple sclerosis Multiple sclerosis (MS) is an autoimmune disease resulting in damage to myelinthe insulating covers of nerve cellsin the brain and spinal cord. As a demyelinating disease, MS disrupts the nervous system's ability to Action potential, transmit ...

* Older patients following

stroke Stroke is a medical condition in which poor cerebral circulation, blood flow to a part of the brain causes cell death. There are two main types of stroke: brain ischemia, ischemic, due to lack of blood flow, and intracranial hemorrhage, hemor ...

of the upper brainstem However, any other compression, ischemia or damage to this region can produce these phenomena:

hydrocephalus Hydrocephalus is a condition in which cerebrospinal fluid (CSF) builds up within the brain, which can cause pressure to increase in the skull. Symptoms may vary according to age. Headaches and double vision are common. Elderly adults with n ...

, midbrain hemorrhage, cerebral arteriovenous malformation, trauma and brainstem

toxoplasmosis Toxoplasmosis is a parasitic disease caused by ''Toxoplasma gondii'', an apicomplexan. Infections with toxoplasmosis are associated with a variety of neuropsychiatric and behavioral conditions. Occasionally, people may have a few weeks or month ...

infection. Neoplasms and giant aneurysms of the posterior fossa have also been associated with the midbrain syndrome. Vertical supranuclear ophthalmoplegia has also been associated with metabolic disorders, such as Niemann-Pick disease, Wilson's disease,

kernicterus Kernicterus is a bilirubin-induced brain dysfunction. The term was coined in 1904 by Christian Georg Schmorl. Bilirubin is a naturally occurring substance in the body of humans and many other animals, but it is neurotoxic when its concentration ...

, and barbiturate overdose.

Diagnosis

Diagnosis can be made via combination of physical exam, particularly deficits of the relevant cranial nerves. Confirmation can be made via imaging, such as CT scan or MRI.

Treatment

Treatment is primarily directed towards etiology of the dorsal midbrain syndrome. A thorough workup, including

neuroimaging Neuroimaging is the use of quantitative (computational) techniques to study the neuroanatomy, structure and function of the central nervous system, developed as an objective way of scientifically studying the healthy human brain in a non-invasive ...

is essential to rule out anatomic lesions or other causes of this syndrome. Visually significant upgaze palsy can be relieved with bilateral inferior rectus recessions. Retraction nystagmus and convergence movement are usually improved with this procedure as well.

Prognosis

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.

References

External links

{{Lesions of spinal cord and brainstem Medical signs Disorders of ocular muscles, binocular movement, accommodation and refraction Syndromes affecting the nervous system