Parinauds, INO and DUanes retraction syndrome revision Flashcards
(14 cards)
Parinauds syndrome
Loss of upward saccadic movement with normal vertical pursuit.
Very uncommon but when present mainly in children than adults.
Lesion in upper mid brain and is caused by a tumour or cyst on the pinel gland.
Px will have covergance retraction nystagmus, this will best be seen on downwards roatational movements.
Px will have light / near dissociation- meaning they will have usually dilated pupils that will only react to accomodation and not to light.
Parinauds aetiology
Aetiology of parinauds includes- Pineal gland tumours, Stroke, and assocaited hydrocephalus due to increased ICP.
Parinauds signs
Other signs of the disease include:-
1. Colliers signs which is Bilateral upper eyelid retraction with a Lid Lag
2. Papilloedema can be seen in children espically of they have hydrocephalus, can also be seen in adults.
3. Convergence insufficiency
4. accomodation insuffiency
5. skew devition
6. progressive lesion, INO and 3rd, 4th and 5th nerve palsies
INO
Is a lesion of the medial longtitudual
fasciculus (MLF) adn will result in the pasly of the medial rectus muscle, and will also cause dissociated gaze evoked nystagmus of the abducting eye (ataxia nystagmus), this is due to increased innervation convergence. this however can remain unaffected if the lesion in question is small.
In INO there is no dammage to the MLF therefore causing a adduction defect, convergence in most cases is still intact
Unilateral INO
Unilateral:-
- Affects the internerurons of only 1 6th nerve nucleus.
- Saccadic, pursuit and VOR movements are all affected
- Milder cases may only show a reduction in peak saccadic velocity of the affected medial rectus.
- Abducting nystagmus will then be seen in the unaffected eye.
- If lesion is located in the lower MLF then convergence may remain intact.
- If convergence and adduction are both affected then lesion is likely to be higher in the MLF, this will be closer to the third nerve nucleus.
- Skew deviations may also be seen in unilateral INO & the hypertropic eye is on the same side as the INO.
Bilateral INO
Bilateral:-
- Larger lesions that affect the eye interneurons rinning in both MLF
- Bilateral addustiob loss with Bilateral ataxia nystagmus of the abducting eye
- PX may be assymptomatic, and convergence may still be intact
- Px will present wiyh Upbeat nystagmus and Vertical gaze defects
- WEBINO - wall eyed bilateral internuclear opthalmoplegia
- Large angled exotropia if the patient has a previous EXO deviation
- Common in neurological disorders
INO presenting aetioogy
Aetiology includes; MS, Stroke- Bilateral artery occlusion and tumours (Rare).
INO presenting signs
Persenting signs:-
- EOP/EOT on cover test
- Will increase on attempted adduction
- Impaired/slow saccades are useful when differenciating a clionical INO from an assymetrical Bilateral INO
- Ataxia nystagmus on lateral gaze
INO ataxia nystagmus
- this is thoght to be due to addaptive changes to the MR
- Central changes cause an increased innervation to the affected MR plus equal to excessive innervation to the contralateral MR
- Will cause an initial overshoot and then drift back to the target.
DUANES retraction syndrome
Classed as a mechanical disease that causes congenital developmental errors in innervation
Tyyical ocular motility findings of pxs suffering from this include:-
- Limitations of right abduction
- Overreaction of contralateral MR (Synergist)
- Globe reataction on adduction
- Narrowing of palpebral fissure on adduction and widening on adduction
Duanes retraction syndrme classifications
type 1- limited abduction and adduction
type 2- limited abduction
type 3- limited adduction and abduction
Duanes Retraction syndrome aetiology
Aetiology;-
- Innervation of the lateral rectus by extra branches of the 3rd Nerve instead of absent or deficient 6th nerve fibers
- autopsy will show an absent 6th nerve and nucleus and as a result the inferior division of the 3rd nerve will supply the Lateral rectus
- will also be other nerve deficiencies present
Duanes retraction syndrome ocular features
Ocular features include:-
- Limited horizontal motility
- Unilateral or Bilateral
- AHP- face turn to affected side
- Mostly esodeviations and usually a esophoria
- Normal Binocular single vision
- up/down shoots on adduction
- A + V patterns
- Globe retraction on adduction and therefore narrowing of palpebral apperture
- Widening of palpebral fissure on attempted abduction
- Diplopia is very rare and only present in the absenct of binocular single vision.
Duanes retraction syndrome management
Management:-
- Refer to HES
- No treatment often due to BSV, small degree of suppression, CHP
- Amblyopia therapy if required
- Surgery
