Marcus gunne syndrome , aberrant generation and double elevator palsy Flashcards
what is double elevator palsy
monocular elevation deficiency(one eye)
unilateral (bilateral)
limitation elevation
abduction and adduction
no manifest deviation in pp or hypotonia
pseudo potsis
what are some features of double elevator palsy
intact bells phenomenon
ahp - chin elevation
+ve fdt
if mechanical restriction
associated Marcus gunn jaw winking ptosis
dvd
what is the aetiology of double elevator palsy
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)
what is the aetiology of double elevator palsy if its not congenital
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
what things need to be done in a orthoptic investigation
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
what is the differential diagnosis for double elevator palsy
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
what is the management of double elevator palsy
conservative where possible
refraction
treat amblyopia
strabismic
stimulus deprivation
meridional
aniesmetropic
where is surgery indicated
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
is surgery done before or after ptosis surgery
surgery is done before ptosis surgery
choice of surgery is dependent on force duction test
if the force duction test is negative what surgery will be done
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
what surgery what would be done if there is a positive force duction test
indicates contracture of IR
IR weakening
+/- Knapp procedure
usually perform bot
marked restriction of elevation
what are the key points of double elevator palsy
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
what is Marcus gunne
jaw winking phenomenon
jaw winkin ptosis
Trigemino-oculomotor synkinesis
what are the features of Marcus gunne
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
what are the features of ptosis in Marcus gunne syndrome
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
what are the features of lids in Marcus gunne syndrome
lid may change position on:
chewing
sucking
jaw protrusion
smiling
commonly noticed in infancy
feeding / sucking / eating
what are the associated features of Marcus gunne
strabismus
amblyopia
anisometropia
OM defect
DEP
SR palsy
Hypotropia
Hypertropia
AHP
maintain BSV
avoid ptosis
other developmental abnormalities
rarely - other synkineses
OBSERVE!
what are the associated features of Marcus gunne
strabismus
amblyopia
anisometropia
OM defect
DEP
SR palsy
Hypotropia
Hypertropia
AHP
maintain BSV
avoid ptosis
other developmental abnormalities
rarely - other synkineses
OBSERVE!
what investigations need to be done
VA
AHP
CT
BSV
Conv
PCT
Hess Field of BSV Field of Uniocular Fixation
what needs to be noted on ocular movements q
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
what is the differential diagnosis for Marcus gunne
aberrant regeneration
SR palsy
superior division 3rd NP
double elevator palsy
HoT & pseudoptosis
Ptosis
MG
what are the management options for Marcus gunne
refraction
occlusion
AHP
may learn to disguise / minimise jaw wink
Sx
strabismus before ptosis
leave ptosis alone if possible
is surgery indicated in Marcus gunne
suregery is only indicated if cosmoses is extremely poor
patient and parents must be aware of limited prognosis for improvement
what surgery is done for Marcus gunne
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
what are postoperative complications of Marcus gunne syndrome
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
what is aberrant regeneration
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.
following a 3rd nerve plays what are some examples of abberent regeneration
lid elevates on adduction or downsize
adduction on attempted upgazr
globe retraction on uptake or downsize
pupil constriction on adduction
when is abberent regeneration likely to take place
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
what needs to be done on investigation for a 3rd nerve palsy
3rd N palsy
particular attention to OM
aberrant features
document as accurately as possible
descriptions
drawing OM
video
photographs
what is the ateiology of abbereant regeneration
TRAUMA
usually significant head injury
? loss of consciousness
? other neurological deficits
Compressive lesion – aneurysm
Damage to the structure of the nerve
what are other known aetiologies of third nerve palsies
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
what type of cause of a 3rd nerve palsy would cause abberent regeneration
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
what are theories of abberent regeneration
misdirection theory
central synaptic reorganisation
ephaptic transmission
what is the misdirection theory of abberent regeneration
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
what is the central synaptic reorganisation theory of abberent regeneration
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
what is the ephaptic transmission of abberent regeneration
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
what is management for a abberent regernation occurring for a 3rd nerve plays
allow for recovery
conservative
prisms
occlusion
total
sector
AHP & head movements
6/12
dependent on symptoms & BSV
what are patient symptoms for abberent regeneration.
Diplopia
aberrant features
lid
abnormal eye mm
pupil
if a patient has no bsv then what would you do for abberent regeneration
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
if a patient has bsv then what would you do
Field of BSV important
expand Field of BSV
move it to a more useful area
primary position
downgaze
Pt needs to have realistic aims
what would you do if a patient needed to have surgery
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
