IV Nerve Palsy

1
IV Nerve Palsy

• A presentation

2
IV Nerve Palsy

• Add description as an introduction?

3
Case History

• Initial Orthoptists Observations(aspects to
  look out for)
• Head tilt/turn to opposite side of affected eye
• Facial asymmetry
• Affected eye-hypertropia

4
Case History

• General Health
• Any illness/meds
• Diabetes, Myasthenia Gravis, hypertension,
• Intracranial tumour
• Any injury/trauma-recent bump to the head
• Family History
• For suspected congenital fourth nerve palsy,
  there is evidence that it can be inherited in an
  autosomal dominant form (Botelho Giangiacomo,
  1996)

5
Case History

• Previous Ocular History
• Treatment for diplopia or other eye related
  problems, glasses
• With congenital fourth nerve palsy, patient may
  report always having had a head posture or may be
  unaware of it but on looking through old
  photographs notice that it was there in
  childhood

6
Case History

• Questions to ask further as a basis for
  investigation
• Reason for visit-diplopia?
• Vertical/horizontal?
• How far apart images are?
• Any torsion?
• How long they have had it
• When does it occur? Constant/ intermittent?
• Worse when reading?
• Neck pain?

7
Case History

• 74 Year old male presented with a three day
  history of sudden onset vertical diplopia. This
  was worse when reading. He had had a mild left
  CVA one week previously resulting in hand
  weakness which later resolved (Fiona Rowe,
  Clinical Orthoptics, 2nd edition, page 344)

8
Case History

• A 36-year-old woman has been bothered by a
  deviating right eye since early childhood. She
  has had diplopia for as long as she can remember
  but was able to tilt her head to relieve it. She
  has worn prism glasses for many years. Her
  friends and associates at work comment on the
  fact that she tilts her head constantly.
  (http//telemedicine.orbis.org)

9
Aetiology-Nerve pathway (Origin)

• The trochlear nerve is the smallest (in diameter)
  of the 12 cranial nerves. It is the only nerve to
  originate in the brainstem (medulla).

10
Aetiology-Nerve pathway (Intracranial)

• From its origin it decussates and exits the
  brainstem dorsally before passing temporally
  around the brainstem and projecting superiorly
  through the arachnoidal space. The trochlear
  pierces the arachnoid and enters the subdural
  space of the cavernous sinus. The trochlear then
  passes through the superior orbital fissure

11
Aetiology-Nerve pathway (Intraorbital)

• The trochlear does not traverse through the
  Common Tendonous ring (annulus of Zinn). It
  projects anteriorly superiorly and medially to
  the Common Tendonous ring, traveling inferiorly
  and temporally to the superior oblique. The
  Trochlear finally pierces the belly of the
  superior oblique.

12
Aetiology-Eye Movements
13
Aetiology-Children

• Leading cause would be a congenital superior
  oblique palsy
• Will usually develop an abnormal head posture

14
Aetiology-Adults

• Leading cause of isolated 4th nerve palsy is
  trauma, specifically CHI
• CHI Closed head injury blunt force damage that
  doesnt cause a break in the scalp or mucous
  membranes
• 4th nerve palsies are rarely due to aneurism and
  it is unlikely that a cavernous sinus fistula
  would cause an isolated 4th nerve palsy as it is
  much more likely that various palsies would
  occur, due to the proximity of the cranial nerves
  in the cavernous sinus.

15
References

• http//www.google.co.uk/imgres?qTrochlearorigin
  num10hlenbiw1241bih606tbmischtbnidOZD7_
  21RoHwOQMimgrefurlhttp//www.sgul.ac.uk/depts/h
  istopathology/ssm_archive/ssmpteresh/trochlear2.ht
  mdocidmpIaZKRmO2Qe9Mimgurlhttp//www.sgul.ac.u
  k/depts/histopathology/ssm_archive/ssmpteresh/troc
  hlear1.JPGw443h453einB1PULafJPS00QXXpIGwBQz
  oom1iactrcdur3sig117787785741486807606page
  1tbnh128tbnw126start0ndsp23ved1t429,r
  2,s0,i79tx54ty50

http//www.google.co.uk/imgres?qCavernoussinusn
um10hlenbiw1241bih606tbmischtbnidnu0IYz
PJuAgcTMimgrefurlhttp//persiapbba0611.blogspot
.com/2010/07/infranuclear-opthalmoplegia.htmldoci
dA1oe2pLXU_3dqMimgurlhttp//3.bp.blogspot.com/_
plbJ03T5zBk/TD8NawBKuzI/AAAAAAAAAAM/t_tRFOrFiy4/s1
600/cavernoussinusthumb2.jpgw421h431eiKiBPUM
ezN8vK0AWYmYCwBgzoom1iactrcdur480sig117787
785741486807606page1tbnh117tbnw112start0n
dsp22ved1t429,r4,s0,i88tx53ty36
http//www.google.co.uk/imgres?qcavernoussinusn
um10hlenbiw1241bih606tbmischtbnidnu0IYz
PJuAgcTMimgrefurlhttp//persiapbba0611.blogspot
.com/2010/07/infranuclear-opthalmoplegia.htmldoci
dA1oe2pLXU_3dqMimgurlhttp//3.bp.blogspot.com/_
plbJ03T5zBk/TD8NawBKuzI/AAAAAAAAAAM/t_tRFOrFiy4/s1
600/cavernoussinusthumb2.jpgw421h431eiux9PUK
a3HsfY0QX82oHQBAzoom1iacthcvpx749vpy138du
r195hovh130hovw128tx108ty104sig11778778
5741486807606page1tbnh130tbnw126start0nds
p20ved1t429,r4,s0,i85
http//medical-dictionary.thefreedictionary.com/cl
osedheadinjury
16
Clinical Characteristics

• When first presenting to the clinic the following
  information should be gained by simple
  observation
• The type of deviation present
• Any abnormal head posture

17
Clinical Characteristics cont.

• Observed deviation
• http//www.pedseye.com/strabismus_hypertropia.htm
  LSO palsy RSO palsy

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Clinical Characteristics cont.

• Abnormal Head Posture
• The patient may present with chin depression and
  a face turn or head tilt away from the affected
  side, to reduce their diplopia.
• (Ansons and Davis 2001)
• http//www.aao.org/publications/eyenet/200409/am_r
  ounds.cfm

Asymmetry of the face may be observed in cases of
congenital IV nerve palsies. Typically a
reduction in distance between the lateral canthus
and the corner of the mouth on the side of the
head tilt.
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Clinical Characteristics cont.

• Diplopia
• Patients with a IV nerve palsy typically
  experience vertical diplopia and in some cases
  may be aware of cyclotorsion.
• http//galeri.uludagsozluk.com/r/vertical-diplopia
  -143415/ http//www.freakingnews.com/Double-Visi
  on-Pictures--1762-0.asp

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Expected Findings from Investigations

• Visual Acuity appropriate test for near and
  distance
• -usually normal, exceptional cases previously
  reduced VA (old amblyopia), traumatic mydriasis,
  decompensation of longstanding palsy, related to
  neurogenic condition, co-incidental pathological
  cause.-note presence of abnormal head posture
  which is frequent, subjective awareness more
  common in acquired.

21
Expected Findings from Investigations

• Investigating Cyclotorsion Using Synoptophore and
  Double Maddox Rod (affected eye will be
  extorted) Image tilt will only be appreciated in
  fields of gaze where diplopia is present.
  Subjective measurement made in cardinal positions
  of gaze, using synoptophore. Can be observed on
  fundus examination if absent of symptoms.
• -Increases on down-gaze, least on up-gaze.
• -very rarely reported in congenital cases,
  torsion is usual in acquired.

Bielschowsky Head Tilt Test -positive for both
congenital and acquired.
22
Expected Findings from Investigations

• Prism Fusion Range
• -Vertical Fusion Range in acquired norm is 2-4
  dioptres, in congenital is much greater, 10
  dioptres or more.Ocular Movements
• Version, duction and vergence movements?? noting
  any anomaly of globe position

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Expected Findings from Investigations

• Hess Chart Using Lees Screen
• -For congenital palsy fields will be equal in
  size, primary and secondary deviations equal,
  will be relatively concomitant
• Primary underaction of superior oblique
• Overaction of the contralateral inferior rectus
• Overaction of the ipsilateral inferior oblique
• Secondary inhibitional palsy of the contralateral
  superior rectus
• -Muscle sequelae will not have developed in
  acquired, secondary deviation will be larger than
  the primary and hess chart of affected eye will
  be smaller
• Primary underaction of superior oblique
• Overaction of the contralateral inferior rectus
•  

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Expected Findings from Investigations

• Past-pointing
• -Present in acquired palsies but very quickly
  lost
•  
• BSV
• -For congenital, most the suppression is
  intermittent.
• -For acquired, suppression occurs in young
  children and is rare in adults

25
Expected Findings from Investigations

• Cover Test for near and distance, with and
  without abnormal head posture-convergent/
  divergent horizontal deviation. Large hyperphoria
  that can exceed 20 dioptres with abnormal head
  posture, manifest vertical deviation often
  present with head straight-vertical deviation
  increases for near-position of gaze in which
  deviation is at maximum is with affected eye
  looking in and down.-Diplopia may be
  appreciated, non-specific symptoms common when
  manifest??, may suppress. Recent onset of
  diplopia common in acquired.

26
Congenital

• Patient frequently presents with an abnormal head
  posture. A full ophthalmic examination should be
  performed to exclude any nonocular cause.
• If ahp due to nerve palsy and not nonocular
  causes, there will be a stabismus present when
  the head is straightened.
• Components of the head posture should be analysed
  (what position will the head be in?). Straighten
  head and allow it to resume to comfortable
  position.
• Large hyperphoria with ahp and vertical deviation
  with head straight and will increase on near
  fixation. Diplopia may be appreciated or
  suppression mau occur .

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Congenital cont.

• Intermittent diplopia can occur later in
  childhood or in adult life as first symptom on
  decmpensating palsy. AHP can be observed and
  compared to old photos as patient often unaware.
  Vertical diplopia will be seen in a 4th nerve
  palsy.
• The diplopia can be measured by a prism cover
  test and can be relived by incorporating prisms
  into the patients glasses.
• Absence of symptomatic excyclotorsion. Objective
  excyclotorsion can be seen objectively on fundus
  examination. This can be measured using double
  maddox rod or by using a major amblyoscope.
• Positive response to bielschowsky head tilt test
  (need to go into detail)

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Acquired

• Recent onset of symptoms diplopia
• No evidence of enlarged vertical fusion reserves
• Subjective awareness of head posture
• History of significant head trauma
• Cover test should be performed with ahp and
  compared with the head straight. Noting the
  difference and whether BSV is restored with ahp
• Same respone to bielschowsky test
• May be aware of cyclotorsion.

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References

• Ansons, A. M. and Davis, H. (2001) Diagnosis and
  Management of Ocular Motility Disorders.
  Blackwell Publishing Oxford.

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