Diplopia

 

* Binocular diplopia occur only if both eyes are open and go to the occlusion of one eye.

* Monocular diplopia persists in the occlusion of the sound eye. Its causes are:

– Corneal: significant astigmatism, corneal pillowcase, keratoconus

– Iris: iridodialysis traumatic

– Cristallinienne: nuclear cataract.

* The nerve IV (trochlear nerve) innervates the superior oblique (oblique) -> moving downwards and inwards.

* Centre for laterality of verticality and convergence center (conjugated movements) -> supranuclear pathways

* Internuclear Routes: (III-VI); located in the medial longitudinal fasciculus

* Binocular vision: law of Hering (nerve impulses are sent in an amount equal to 2 agonist muscles of the eyes); Law Sherrington (when the agonist muscles contract, the antagonist muscles relax). A special case is convergence.

* If the parallelism of the two eyes disappears, an object set by the macula of an eye will be fixed by a extramaculaire area of ​​the other eye. This is the abnormal retinal match.

* Diplopia is absent in the function paralysis (supranuclear palsy)

* In case of paralytic mydriasis (paralysis III), abolition of the direct RPM seen with conservation of the consensus RPM; by against the consensus RPM to the illumination of the healthy eye is abolished.

* Ptosis providential -> masking diplopia

Diplopia

Diplopia

PARALYSIS OF IV:

– Presents a vertical diplopia and oblique marked in downwards and inwards

– This is a catastrophic diplopia in activities such as reading or descending stairs

– Compensatory head position, tilted the healthy side, lowered chin

* Paralysis VI: causes a convergence of the affected eye and a deficit of abduction;offsetting position of the head turned to one side of the oculomotor palsy.

SPECIAL SHAPES:

Supranuclear palsy:

Character: These are oculomotor paralysis without diplopia

Syndrome Foville: Paralysis of laterality

Parinaud’s syndrome:

– Paralysis of verticality + convergence paralysis

– Very evocative pinealoma; (Kernel reached III)

Internuclear ophthalmoplegia:

– Eye movements are normal the side of the lesion

– When moving the healthy side, the ipsilateral eye can be worn in supply, not exceeding the median line, while the contralateral eye naturally goes in abduction

– Etiology: multiple sclerosis

Etiologies:

* Superior orbital fissure syndrome: association of nerve damage III; IV; VI and V1.

* Syndrome apex: slot syndrome sphenoid + monocular blindness did hue of the optic nerve

* Weber’s syndrome paralysis of III + hemiplegia crossed with facial paralysis

* Disorders of colliculi (glioma) achieved kernel IV

Tumors pontomedullary (acoustic neuroma): Kernel VI

* Carotid Aneurysm suptraclinoïdien paralysis of III

* Intracavernous carotid aneurysm infraclinoïdien: syndrome of the outer wall of the cavernous sinus with involvement of III, V, VI and sometimes IV

Arteriovenous Fistula * -> pulsatile exophthalmos; conjunctival vasodilation by medusa head.

* Diabetes: incomplete paralysis of III

* A third nerve palsy with painful phenomena especially binding an urgent search for a carotid aneurysm

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