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o and m > Marcus gunne syndrome , aberrant generation and double elevator palsy > Flashcards

Marcus gunne syndrome , aberrant generation and double elevator palsy Flashcards

1
Q

what is double elevator palsy

A

monocular elevation deficiency(one eye)

unilateral (bilateral)

limitation elevation

abduction and adduction

no manifest deviation in pp or hypotonia

pseudo potsis

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2
Q

what are some features of double elevator palsy

A

intact bells phenomenon

ahp - chin elevation

+ve fdt

if mechanical restriction

associated Marcus gunn jaw winking ptosis

dvd

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3
Q

what is the aetiology of double elevator palsy

A

congenital

supra nuclear defect

+ve bells

full passive moment

_ve fdt and full elevation under ga

contracture of ir

mechanical

primary/ secondary

abnormality of ir (thickened)

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4
Q

what is the aetiology of double elevator palsy if its not congenital

A

SR paresis
Approx 50%
reduced SR volume shown on MRI
Absent Bells
sup div 3rd N palsy c spread of concomitance
Acquired upgaze palsy
suspect dorsal midbrain lesion

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5
Q

what things need to be done in a orthoptic investigation

A

va , app , ct , bsv , om

true v pseudo ptosis

jaw wink

bells phenomena

lower lid crease

pct

hess

field of bsv

filed of funicular fixation

upward saccadic velocity

if reduced indicates sr weakness

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6
Q

what is the differential diagnosis for double elevator palsy

A

congenital fibrosis

contracted / firbortic inferior rectus

blow out fracture

graves orbitopoathy

browns syndrome

superior divison 3rd nerve palsy

absent superior rectus - congenital

orbital mass/ cellulitis

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7
Q

what is the management of double elevator palsy

A

conservative where possible

refraction

treat amblyopia

strabismic

stimulus deprivation

meridional

aniesmetropic

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8
Q

where is surgery indicated

A

marked ahp

poor cosemesis

hypertrophic and pseudo ptosis
which is significant in primary position

ptosis that is significantly obscuring the visual axis

cosmetically poor

? Marcus gunn present

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9
Q

is surgery done before or after ptosis surgery

A

surgery is done before ptosis surgery

choice of surgery is dependent on force duction test

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10
Q

if the force duction test is negative what surgery will be done

A

FDT -ve
Knapp procedure
transpose LR & MR up to borders of SR
may have an increased effect over time
can be graded

minimal restriction of elevation

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11
Q

what surgery what would be done if there is a positive force duction test

A

indicates contracture of IR
IR weakening
+/- Knapp procedure
usually perform bot

marked restriction of elevation

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12
Q

what are the key points of double elevator palsy

A

very rare and congenital

differentiate inferior rectus palsy and absent inferior rectus

spread of concomitance

limited depression

force diction test +ve determine contracture of the superior rectus

surgery

inverse knapp

superior rectus revession if fat is positive for superior rectus contracture

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13
Q

what is Marcus gunne

A

jaw winking phenomenon

jaw winkin ptosis

Trigemino-oculomotor synkinesis

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14
Q

what are the features of Marcus gunne

A

Congenital & unilateral
Misdirection of nerve supply
branch of mandibular divison of Vth CN
supplies pterygoid muscles
misdirected into superior division 3rd CN
supplying the levator
Supported by MRI evidence (Conte et al, 2012)
Structural abnormality in brainstem (midbrain tegmentum)
Neural misdirection happens in brainstem
? supranuclear synkinesis
can be familial

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15
Q

what are the features of ptosis in Marcus gunne syndrome

A

partial ptosis
variable in different patients
2-13% congenital ptosis
upper lid position changes with jaw movement
increase ptosis (lid lowers)
move jaw to affected side
close mouth
decrease ptosis (lid lifts)
move jaw to unaffected side
open mouth
project mandible forwards

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16
Q

what are the features of lids in Marcus gunne syndrome

A

lid may change position on:
chewing
sucking
jaw protrusion
smiling

commonly noticed in infancy
feeding / sucking / eating

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17
Q

what are the associated features of Marcus gunne

A

strabismus
amblyopia
anisometropia
OM defect
DEP
SR palsy
Hypotropia
Hypertropia

AHP
maintain BSV
avoid ptosis
other developmental abnormalities
rarely - other synkineses
OBSERVE!

18
Q

what are the associated features of Marcus gunne

A

strabismus
amblyopia
anisometropia
OM defect
DEP
SR palsy
Hypotropia
Hypertropia

AHP
maintain BSV
avoid ptosis
other developmental abnormalities
rarely - other synkineses
OBSERVE!

19
Q

what investigations need to be done

A

VA
AHP
CT
BSV
Conv
PCT

Hess
Field of BSV
Field of Uniocular Fixation
20
Q

what needs to be noted on ocular movements q

A

lid position
lid crease & brow position
? pupil covered - at worst & at best
? normal situation
lid movement
anomalous movement
observe during OM
lid closure

ptosis
true V pseudo
measurement
levator function
variability

21
Q

what is the differential diagnosis for Marcus gunne

A

aberrant regeneration
SR palsy
superior division 3rd NP
double elevator palsy

HoT & pseudoptosis
Ptosis
MG

22
Q

what are the management options for Marcus gunne

A

refraction
occlusion
AHP
may learn to disguise / minimise jaw wink
Sx
strabismus before ptosis
leave ptosis alone if possible

23
Q

is surgery indicated in Marcus gunne

A

suregery is only indicated if cosmoses is extremely poor

patient and parents must be aware of limited prognosis for improvement

24
Q

what surgery is done for Marcus gunne

A

Unilateral levator excision & frontalis suspension
can perform this Sx bilaterally to try & gain a more symmetrical result
Levator resection
Fasenella-Servat procedure
Levator myectomy
Removal of levator aponeurosis & muscle

25
Q

what are postoperative complications of Marcus gunne syndrome

A

lagopthalmos on downsize

eyelash malipositon

loss of eyelid crease

eyelid contour abnormality

entropian

residual ptosis

recurrence of ptosis (10%)

recurrence of ptosis (10%)

residual jaw winking cosmetically unacceptable

26
Q

what is aberrant regeneration

A

Aberrant regeneration refers to a medical condition where a damaged or injured nerve in the body tries to repair itself, but instead of reconnecting to its original target muscle or organ, it ends up connecting to a different muscle or organ that is nearby. This results in a misdirected nerve signal that causes the wrong muscle or organ to move or function.

One common example of aberrant regeneration is in patients with third nerve palsy, where the muscles responsible for moving the eye are affected. When the damaged nerve tries to repair itself, it may end up connecting to the muscle responsible for elevating the eyelid, resulting in a phenomenon known as “lid retraction” where the eyelid lifts up when the patient tries to look down.

27
Q

following a 3rd nerve plays what are some examples of abberent regeneration

A

lid elevates on adduction or downsize

adduction on attempted upgazr

globe retraction on uptake or downsize

pupil constriction on adduction

28
Q

when is abberent regeneration likely to take place

A

not all signs present in every case
lid elevation most common
abnormal movements due to co-contraction of muscles supplied by 3rd CN
8-12 weeks after onset of 3rd N palsy
6 weeks
cosmetically upsetting

29
Q

what needs to be done on investigation for a 3rd nerve palsy

A

3rd N palsy
particular attention to OM
aberrant features
document as accurately as possible
descriptions
drawing OM
video
photographs

30
Q

what is the ateiology of abbereant regeneration

A

TRAUMA
usually significant head injury
? loss of consciousness
? other neurological deficits
Compressive lesion – aneurysm
Damage to the structure of the nerve

31
Q

what are other known aetiologies of third nerve palsies

A

congenital 3rd N palsy
migraine
following neuroSx
cavernous sinus
inflammatory conditions
Guillain-Barre syndrome
Miller Fisher syndrome
primary aberrant regeneration syndrome
? without acute 3rd N palsy
? without any 3rd N palsy

32
Q

what type of cause of a 3rd nerve palsy would cause abberent regeneration

A

almost never (?) occurs in diabetic or microvascular 3rd N palsy
structure of the nerve remains intact
If you see aberrant regeneration features in a 3rd nerve palsy previously assumed to be ‘microvascular’ aetiology → imaging & further investigation

33
Q

what are theories of abberent regeneration

A

misdirection theory
central synaptic reorganisation
ephaptic transmission

34
Q

what is the misdirection theory of abberent regeneration

A

traumatic damage to 3rd CN
fibres regrow but innervate different muscles
‘misrouting of axons’
confirmed by some EMG evidence
doesn’t explain mechanism in every case
experimental evidence in rats
fibres regenerate along the length of the nerve
not just at the site of the lesion

35
Q

what is the central synaptic reorganisation theory of abberent regeneration

A

disruption of synapses of 3rd CN nuclei
central mechanism
axonal injury > changes then affect & disrupt:
organisation of cell bodies
synapses
supported by cases of primary regeneration without 3rd N palsy

36
Q

what is the ephaptic transmission of abberent regeneration

A

neuronal transmission between nerve axons instead of at the synapse
slow growing lesion
destruction & regeneration of 3rd CN fibres
? allows electrical cross talk between individual 3rd CN fibres
especially if myelin sheaths have been damaged by slow compression

37
Q

what is management for a abberent regernation occurring for a 3rd nerve plays

A

allow for recovery
conservative
prisms
occlusion
total
sector
AHP & head movements
6/12
dependent on symptoms & BSV

38
Q

what are patient symptoms for abberent regeneration.

A

Diplopia
aberrant features
lid
abnormal eye mm
pupil

39
Q

if a patient has no bsv then what would you do for abberent regeneration

A

potential for BSV
prisms in free space
Synoptophore
If potential BSV - plan Sx to achieve this
If no potential for BSV
? traumatic loss of fusion
improve eye alignment
occlusion if necessary

40
Q

if a patient has bsv then what would you do

A

Field of BSV important
expand Field of BSV
move it to a more useful area
primary position
downgaze

Pt needs to have realistic aims

41
Q

what would you do if a patient needed to have surgery

A

Contralateral eye
may worsen aberrant signs if operate on affected eye
Weaken overacting muscles
Faden
Adjustable sutures
Strabismus Sx before ptosis Sx
ptosis Sx more unpredictable
Can involve >1 Sx procedure
Occlusion

o and m (30 decks)

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