Transcript Strabismus of “obscure cause” as the only manifestation of

Chiari 1 Malformation presenting
as “Strabismus of obscure cause”
Kowal, L & Yahalom, C
OMC & CERA
RVEEH, Melbourne
Chiari 1 malformation (C1M)
Tonsillar herniation ≥ 3 - 5
mm below foramen
magnum
 Unlike many congenital
CNS malformations, C1M
patients usually
asymptomatic until late
childhood or early
adulthood
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Symptoms & Signs of C1M
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Symptoms : nonspecific headache, dizziness, neck
pain, extremity weakness,
numbness ….
Neurologic signs: ataxia,
dysarthria, nystagmus,
cranial nerve deficit ….
THIS SERIES : 12 CASES
12 cases of acquired strabismus [mostly
convergent = esotropia] as the presenting sign of
C1M.
No other credible explanation for the strabismus
Isolated acquired esotropia has been previously
described as a rare presenting sign of C1M in
several case reports - this will be the largest series
so far.
NON- STRABISMIC
FEATURES
 10/12 : ‘minor’ neurological
symptoms esp. headache
: “CHIARI PLUS” - more
serious neurological
signs/symptoms (#10 & #11)
 2/12
10 /12 patients with esotropia
 4/10
D>N ‘divergence insuff’
Some may be bilateral 6ths
 2/10
 1/10
 1/10
 2/10
N>D ‘convergence Xs’
N=D
6th nerve palsy
ET + vertical deviation
4 patients : ET D>N
# Age at
Presenting signs/
presentation symptoms.
Duration.
ET ∆
Treatment
Follow
up [y]
1 7
i/mitt diplopia 1y
N=6-22*
D=14-26
Glasses
3
4 20
i/mitt diplopia 8y
N=9
D=16
Glasses
0.1
7 18
diplopia 1y
N=35
D=40
Glasses
0.2
9 6
i/mitt ET 1mo
N=14 - 30 NSD (age 6 ½) 1
D=25 - 35
•All : Headache, no other neurological symptoms/signs.
•All : Refraction -1.50 to +1 DS
•# 9 : ET N=30, D=35 at age 7 yrs. Strab surgery planned
•NSD = Neurosurgical decompression
* Range of measurements at different examinations
2 patients : ET N>D
#
Age at
Presenting
presentation signs &
symptoms
[yrs]
ET ∆
Treatment
Follow
up [yrs]
6
19
i/mitt near
diplopia 11y
N=6-12*
D=1-4
Glasses
1.2
10
0.5
Infrequent
ET
Increasing to
constant ET N=42,
BMR in 10/04. 4
Early
orthotropia
D=36
# 10 : “ Chiari plus”.
She has developmental delay, and early closure of fontanelles.
MRI : 7 mm C1M, stable mild ventriculomegaly.
Other presentations
#
Age at
presentation
Presenting
symptoms
Manifest
deviation ∆
Refr’n
Other
F/up
yrs
12
14
Recent onset
diplopia
ET 40
N=D
R+1.25
L+1.50
L IO+
L SOMild L/R
1.2
5
16
Diplopia on
R gaze 15 mo
ET
PP: 0-14.
R gaze 1222
R&L -9
R LR-
1
2
28
Near Diplopia
18y. Pixilated
vision
XT
18=N
O=D
R-1.50
L-0.50
Convergence
insufficiency
0.5
•Patient #12: NSD 6 mo s/p dx of CM1. Little improvement in ET  Bimedial recession 2/04.
Ortho 8 mo later
•The other patients manage with glasses.
•Patients #12 and #2 presented with headache as well as diplopia
Other presentations
3
8
Age
presentation
Pres. symptoms
Signs and findings
Other
F/u
(yrs)
45
I/mitt H & V
diplopia
poor motor fusion
Myasthenia
and thyroid r/u
1.3
Upper limb
paresthesia
1.6
Nystagmus
0.2
9
11
60
AHP
diplopia
Constant H
diplopia 10 y
Oscillopsia
H: -2 to +1 V:+/-0.5
Esophoria / hyperphoria
poor motor fusion
RIO +, LSO-. Tilt R
ET 16 D=N
• # 11 is the second “Chiari plus”. His symptoms began with diplopia and balance problems.
Diplopia persisted s/p 2 neurosurgical procedures.
• # 3 and #8 manage well with glasses.
Our patients who had surgery
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#10 : Squint sx with good early results (f/u 4w)
#9 : NSD. Strab persists. BMR planned.
#11 : NSD. Strab persists. Prism working.
#12 : NSD. Strab persists. Successful squint sx
(f/u 8 mo).
NSD: neurosurgical decompression
Age at presentation
5
4
Number
of
patients
3
2
1
0
<2
2--5
6--10 11--20 21--40 >40
Patient's age
Most of the patients presented outside normal age range for strabismus
ET as only manifestation of C1M
Summary of published literature
Nunber
of cases
Age y
Squint Sx
Neurosurgery
Bixenman
J Ped Ophthal Strab 1987
1
13
Before C1M Dx
Recurrence 6 mo later
Yes with resolution of ET
Pokharel
JAAPOS 2004
1
13
PT in borderline C1M. Recurrence 6 mo
later. Second sx successful s/p neuro-sx.
Yes. ET no better
Biousse
AJO 2000
4
5 to 37
PT in 2. One successful. 2nd recurrence
s/p 2 sx.
PT=2 with resolution of ET.
F/u 2-3 y
Passo
J Clin N-Ophthal 1984
1
24
Recurrence 12 mo after surgery
Yes with resolution of ET
Weeks & Hamed
Ophthalmology1999
2
Recurrence after surgery
Yes with resolution of ET
Lewis
J N-ophthal 1996
5
17 to 37
No
Yes. PT=4 patients with
resolution of ET. > 4y f/u
*
Defoort-Dhellemmes
Amer Jnl Ophthal 2002
1
9
No
PT with resolution of ET
Imes -Ophthalmology 2001
1
14
Botox to LMR (successful after 6 mo f/u)
PT - ET no better
*One patient from Lewis’s series did not get any sx treatment
/
PT= Primary treatment
Summary of published literature : ET
as the ONLY manifestation in C1M
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16 patients ages 5 - 37
7/16 : strabismus sx as primary treatment
6/7 : recurrence of strabismus
4/5 : subsequent NSD with resolution of strab
8 patients : NSD as primary treatment
7/8 had resolution all signs/symptoms
Conclusion: Strab Sx alone usually ineffective.
NSD usually necessary & effective.
Summary
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We describe 12 cases of ‘acquired strabismus of
obscure cause’ probably caused by C1M
5/12 aged 10-20 @ presentation
10/12 had headache
Esotropia was the usual squint (10/12)
4/12 : ‘divergence insufficiency’ ET, D > N
1/12: [apparent] sixth nerve palsy
1/12: unexplained head tilt.
2/12: i/mitt diplopia with poor motor fusion
Summary
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Most patients were referred for neurosurgical
evaluation. 3/12 had NSD. It is generally felt by
neurosurgeons that strabismus alone is an
inadequate reason for NSD.
Strabismus did not resolve in these 3 cases, with
subsequent successful squint surgery in 1case.
Other patients : Most manage well with prism
glasses.
Conclusions
Isolated acquired strabismus is not a rare
presenting sign of C1M, and there might
be a good number of patients being mis /
under- diagnosed.
 Appropriate primary management of C1M
with strabismus alone [whether strabismus
surgery or NSD] is unclear.
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