fourth nerve / superior oblique palsy & similar / simulating conditions
DESCRIPTION
FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS. DR LIONEL KOWAL RVEEH / CERA MELBOURNE. Types of FNP / SOP used as synonyms. 1. Definite SOP 2. Possible SOP or Resolved SOP 3. Fake SOP Idiopathic oblique dysfunction & other synonyms for … - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/1.jpg)
FOURTH NERVE / SUPERIOR OBLIQUE
PALSY& SIMILAR / SIMULATING
CONDITIONS
DR LIONEL KOWALRVEEH / CERA
MELBOURNE
![Page 2: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/2.jpg)
Types of FNP / SOPused as synonyms
• 1. Definite SOP
• 2. Possible SOP or Resolved SOP
• 3. Fake SOP– Idiopathic oblique dysfunction & other
synonyms for …– “Cyclovertical dysfunction of uncertain
cause” CVD
![Page 3: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/3.jpg)
Definite/ Possible/ Fake SOP can all
– Vertical misalignment– Disrupt horizontal fusion & horizontal
misalignmentCVD can also be a consequence of loss of horizontal fusion - seen in any horizontal strab
– Head tilts– Vertical greater to one side– Apparent IO OA, SO UA CLINICAL PICTURE CAN BE THE SAME IN ALL TYPES OF SOP
![Page 4: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/4.jpg)
How to tell definite from fake: Simonsz
– GA: take off SO, inject sux & measure L-T curve– LA: take off SO; ask pt to look up / down &
measure L-T curve– When good clinicians made clinical
diagnosis of real SOP, they were wrong 50% of the time
Klin Monatsbl Augenheilkd. 1992 Length-tension measurement of oblique eye muscles in strabismus operations for differentiating trochlear paralysis and strabismus sursoadductorius [German]
![Page 5: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/5.jpg)
How to tell definite from fake : Demer
• Joe Demer– Coronal scans : can you see the muscle belly?– Upgaze to downgaze: watch SO belly move back
& increase in size
When subspecialist clinicians made clinical diagnosis of real SOP, they were wrong 50% of the time!!
Demer JL et al MRI of the functional anatomy of the sup obl muscle. IOVS. 1995 & in 1994 AAPOS / ISA joint meeting proceedings
![Page 6: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/6.jpg)
JOE DEMER
• Coming to SQUINT CLUB 2006
• MELBOURNE
• APRIL 21-22
![Page 7: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/7.jpg)
R SOP
HEAD TILT TO LEFT
![Page 8: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/8.jpg)
R IO OA
R SO UA
TIGHT RSR RIR ‘UA’
![Page 9: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/9.jpg)
SOP image
LSO OK RSO ?absent
![Page 10: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/10.jpg)
SOP image
RSO clearly smaller than LSO
![Page 11: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/11.jpg)
How to tell definite from fake : Herzau
• Is congenital SO strabismus a paretic disorder? A[n] MRI study [German] …full blown clinical picture of a congenital SOP … symmetrical muscle volumes on both sides in all coronal sections
• CLINICAL PICTURE OF REAL SOP CAN BE WRONG
Siepmann K, Herzau V Klin Monatsbl Augenheilkd. 2005 May
![Page 12: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/12.jpg)
Demer: X-sectional area of SO segregates SOP from normal SO
![Page 13: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/13.jpg)
Up gaze to down gaze: x-sectional area of SO in normals only
![Page 14: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/14.jpg)
Change in x-sectional area from up to down gaze segregates SOP from
normals
![Page 15: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/15.jpg)
Real SOP
Head injury
• ARIX gene
• Vascular disease
• Rare: SOP- specific CNS pathology [LK: 1/500]
![Page 16: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/16.jpg)
Fake SOP
Abnormal cyclovertical anatomy– Craniofacial anomalies– Posteroplaced trochlea [Bagolini]
• Abnormal physiology– Brodsky’s wild pitch
![Page 17: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/17.jpg)
Telling definite from fake does it matter?
• “Anomalous SO tendons [clinically] are nearly always associated with [radiologically] attenuated SO muscle … provides … explanation for the phenomenon of laxity of the SO tendon”
• Sato M. Magnetic resonance imaging and tendon anomaly associated with congenital superior oblique palsy. Am J Ophthalmol. 1999
![Page 18: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/18.jpg)
Telling definite from fake - does it matter?
Forewarned / forearmed• Atrophic SO on scan floppy SO
tendon on FDT : may need SO tuck • SO tuck more difficult / higher morbidity
c.f. other surgeries• Real SOP: ?less reliable long term
prognosis than ‘fake’ SOP
![Page 19: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/19.jpg)
Possible / Resolved
• Radiological changes may be too subtle for routine scans
• SOP may have resolved leaving small permanent change in L-T curve of SO
same mechanism as small ET remaining after 6th n. paresis resolves
![Page 20: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/20.jpg)
Principles of treatment
1. Make it better - don’t over correct
2. Trauma: look for bilateral SOP
3. Accurate measurements
4. Tighten floppy muscles
5. Rc tight muscles
![Page 21: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/21.jpg)
Principles of treatment
Acquired: wait 12 mo [can Rx earlier if getting worse]
Long standing: Acquired suppression makes it harder to characterise
Usually have to treat the muscular consequences of the SOP rather than the SOP itself [hence Knapp 1-7]
![Page 22: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/22.jpg)
Principles of treatment : IO OA
1. Weak SO often IO OA as a consequence, and this may dominate the clinical picture far more than the SO UA of the ‘original’ SOP
2. Fake SOP often manifests as IO OA
Parks’ IO Rc for 10-15 ∆ height in PP≈ 20 ∆ To lateral edge IR≈ 25 ∆ 2mm ant to edge IR
![Page 23: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/23.jpg)
Principles of treatmentTight SR
2. ‘Chronic hypertropia’ may tight SR, spread of comitance & [apparent] IR UA wch may come to dominate the clinical picture.
SR Rc requiredRecessing SR will increase extorsion unless it is temporally transposed
![Page 24: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/24.jpg)
Sequelae of SOP: IO OA & tight SR
![Page 25: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/25.jpg)
REAL CONG R SOP & CONG ET FIXING WITH PARETIC R EYE L HYPO NOT ‘IDIOPATHIC IR FIBROSIS’
![Page 26: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/26.jpg)
R SO atrophic
![Page 27: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/27.jpg)
R SO atrophic
![Page 28: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/28.jpg)
TREATMENT MORBIDITY
• Sup Obl – Brown’s– Ptosis
• Inf Obl– Upgaze restriction– Lid change
![Page 29: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/29.jpg)
TREATMENT MORBIDITY
• Sup Rectus–Ptosis / lid retraction
• Inf Rectus–Lid retraction–Progressive over correction
![Page 30: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/30.jpg)
TREATMENT EXPECTATIONS
• LK audit early 90’s n=450• Unilateral SOP [all sorts]:
–1.3 surgeries– 90+% VG to excellent
![Page 31: FOURTH NERVE / SUPERIOR OBLIQUE PALSY & SIMILAR / SIMULATING CONDITIONS](https://reader035.vdocuments.us/reader035/viewer/2022062517/56812f7f550346895d950181/html5/thumbnails/31.jpg)
SOP
• Difficult area of strabismus
• Imaging has been under- utilised
• Natural history of different sub types & their treatments not well defined