Chiari 1 Malformation presenting Chiari 1 Malformation presenting as as ““Strabismus of obscure cause”Strabismus of obscure cause”

  Kowal, L & Yahalom, CKowal, L & Yahalom, C

OMC & CERAOMC & CERARVEEH, MelbourneRVEEH, Melbourne

Chiari 1 malformation (C1M)Chiari 1 malformation (C1M)

Tonsillar herniation ≥ 3 - 5 Tonsillar herniation ≥ 3 - 5 mm below foramen mm below foramen magnummagnum

Unlike many congenital Unlike many congenital CNS malformations, C1M CNS malformations, C1M patients usually patients usually asymptomatic until late asymptomatic until late childhood or early childhood or early adulthoodadulthood

Symptoms & Signs of C1MSymptoms & Signs of C1M

Symptoms : nonspecific - Symptoms : nonspecific - headache, dizziness, neck headache, dizziness, neck pain, extremity weakness, pain, extremity weakness, numbness …. numbness ….

Neurologic signs: ataxia, Neurologic signs: ataxia, dysarthria, nystagmus, dysarthria, nystagmus, cranial nerve deficit ….cranial nerve deficit ….

THIS SERIES : 12 CASESTHIS SERIES : 12 CASES

12 cases of acquired strabismus [mostly 12 cases of acquired strabismus [mostly convergent = esotropia] as the presenting sign of convergent = esotropia] as the presenting sign of C1M.C1M.

No other credible explanation for the strabismusNo other credible explanation for the strabismus

Isolated acquired esotropia has been previously Isolated acquired esotropia has been previously described as a rare presenting sign of C1M in described as a rare presenting sign of C1M in several case reports - this will be the largest series several case reports - this will be the largest series so far.so far.

NON- STRABISMIC NON- STRABISMIC FEATURESFEATURES

10/12 : ‘minor’ neurological 10/12 : ‘minor’ neurological symptoms esp. headachesymptoms esp. headache

2/12 : “CHIARI PLUS” - more 2/12 : “CHIARI PLUS” - more serious neurological serious neurological signs/symptoms (#10 & #11)signs/symptoms (#10 & #11)

10 /12 patients with esotropia10 /12 patients with esotropia

4/10 D>N ‘divergence insuff’4/10 D>N ‘divergence insuff’Some may be bilateral 6thsSome may be bilateral 6ths

2/10 N>D ‘convergence Xs’2/10 N>D ‘convergence Xs’1/10 N=D1/10 N=D1/10 6th nerve palsy1/10 6th nerve palsy2/10 ET + vertical deviation2/10 ET + vertical deviation

4 patients : ET D>N4 patients : ET D>N##Age at Age at

presentationpresentationPresenting signs/ Presenting signs/ symptoms. symptoms. Duration. Duration.

ET ∆ET ∆TreatmentTreatmentFollow Follow up [y]up [y]

1177i/mitt diplopia 1yi/mitt diplopia 1yN=6-22*N=6-22*

D=14-26D=14-26

GlassesGlasses33

442020i/mitt diplopia 8yi/mitt diplopia 8yN=9N=9

D=16D=16

GlassesGlasses0.10.1

771818diplopia 1ydiplopia 1yN=35N=35

D=40D=40

Glasses Glasses 0.20.2

9966i/mitt ET 1moi/mitt ET 1moN=14 - 30N=14 - 30

D=25 - 35D=25 - 35

NSD NSD (age 6 ½)(age 6 ½)11

•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>D2 patients : ET N>D

##Age at Age at presentation presentation

[yrs][yrs]

Presenting Presenting signs & signs & symptomssymptoms

ET ∆ET ∆TreatmentTreatmentFollow Follow up [yrs]up [yrs]

661919i/mitt near i/mitt near diplopia 11ydiplopia 11y

N=6-12*N=6-12*

D=1-4D=1-4

GlassesGlasses1.21.2

10100.50.5Infrequent Infrequent ETET

Increasing to Increasing to constant constant ET N=42, ET N=42,

D=36D=36

BMR in 10/04. BMR in 10/04. Early Early orthotropiaorthotropia

44

# 10 : “ Chiari plus”.She has developmental delay, and early closure of fontanelles. MRI : 7 mm C1M, stable mild ventriculomegaly.

Other presentationsOther presentations##Age at Age at

presentationpresentationPresenting Presenting symptomssymptoms

Manifest Manifest deviation ∆deviation ∆

Refr’nRefr’nOtherOtherF/upF/up

yrsyrs

12121414Recent onset Recent onset diplopiadiplopia

ET 40 ET 40 N=DN=D

R+1.25R+1.25

L+1.50L+1.50

L IO+L IO+

L SO-L SO-

Mild L/RMild L/R

1.21.2

551616Diplopia on Diplopia on R gaze 15 moR gaze 15 mo

ET ET

PP: 0-14. PP: 0-14.

R gaze 12-R gaze 12-2222

R&L -9R&L -9R LR-R LR-11

222828Near Diplopia Near Diplopia 18y. Pixilated 18y. Pixilated

visionvision

XT XT

18=N18=N

O=DO=D

R-1.50R-1.50

L-0.50L-0.50

Convergence Convergence insufficiencyinsufficiency

0.50.5

•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 presentationsOther presentationsAge Age

presentationpresentationPres. symptomsPres. symptomsSigns and findingsSigns and findingsOtherOtherF/uF/u

(yrs)(yrs)

334545I/mitt H & V I/mitt H & V diplopiadiplopia

poor motor fusionpoor motor fusion

H: -2 to +1 V:+/-0.5H: -2 to +1 V:+/-0.5

Esophoria / hyperphoriaEsophoria / hyperphoria

Myasthenia Myasthenia and thyroid r/uand thyroid r/u

1.31.3

8899AHPAHP

diplopiadiplopiapoor motor fusionpoor motor fusion

RIO +, LSO-. Tilt RRIO +, LSO-. Tilt R

Upper limb Upper limb paresthesiaparesthesia

1.61.6

11116060Constant H Constant H diplopia 10 ydiplopia 10 y

OscillopsiaOscillopsia

ET 16 D=NET 16 D=NNystagmusNystagmus0.20.2

• # 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 surgeryOur patients who had surgery

#10 : Squint sx with good early results (f/u 4w)#10 : Squint sx with good early results (f/u 4w) #9 : NSD. Strab persists. BMR planned.#9 : NSD. Strab persists. BMR planned. #11 : NSD. Strab persists. Prism working.#11 : NSD. Strab persists. Prism working. #12 : NSD. Strab persists. Successful squint sx #12 : NSD. Strab persists. Successful squint sx

(f/u 8 mo).(f/u 8 mo).

NSD: neurosurgical decompression

Age at presentationAge at presentation

0

1

2

3

4

5

<2 2--5 6--10 11--20 21--40 >40

Number of

patients

Patient's age

Most of the patients presented outside normal age range for strabismus

ET as only manifestation of C1MET as only manifestation of C1MSummary of published literatureSummary of published literature

Nunber Nunber of casesof cases

Age yAge ySquint SxSquint SxNeurosurgeryNeurosurgery

BixenmanBixenman

J Ped Ophthal Strab 1987J Ped Ophthal Strab 1987

111313Before C1M DxBefore C1M Dx

Recurrence 6 mo laterRecurrence 6 mo later

Yes with resolution of ETYes with resolution of ET

PokharelPokharel

JAAPOS 2004JAAPOS 2004

111313PT in borderline C1M. Recurrence 6 mo PT in borderline C1M. Recurrence 6 mo later. Second sx successful s/p neuro-sx.later. Second sx successful s/p neuro-sx.

Yes. ET no betterYes. ET no better

BiousseBiousse

AJO 2000AJO 2000

445 to 375 to 37PT in 2. One successful. 2nd recurrence PT in 2. One successful. 2nd recurrence s/p 2 sx.s/p 2 sx.

PT=2 with resolution of ET. PT=2 with resolution of ET. F/u 2-3 yF/u 2-3 y

PassoPasso

J Clin N-Ophthal 1984J Clin N-Ophthal 1984

112424Recurrence 12 mo after surgeryRecurrence 12 mo after surgeryYes with resolution of ETYes with resolution of ET

Weeks & HamedWeeks & Hamed

Ophthalmology1999Ophthalmology1999

22Recurrence after surgeryRecurrence after surgeryYes with resolution of ETYes with resolution of ET

LewisLewis

J N-ophthal 1996J N-ophthal 1996

5517 to 3717 to 37NoNoYes. PT=4 patients with Yes. PT=4 patients with resolution of ET. > 4y f/u resolution of ET. > 4y f/u **

Defoort-DhellemmesDefoort-Dhellemmes

Amer Jnl Ophthal 2002Amer Jnl Ophthal 2002

1199NoNoPT with resolution of ETPT with resolution of ET

ImesImes -Ophthalmology 2001 -Ophthalmology 2001111414Botox to LMR (successful after 6 mo f/u)Botox to LMR (successful after 6 mo f/u)PT - ET no betterPT - ET no better

*One patient from Lewis’s series did not get any sx treatment / PT= Primary treatment

Summary of published literature : ET Summary of published literature : ET as the ONLY manifestation in C1Mas the ONLY manifestation in C1M

16 patients ages 5 - 3716 patients ages 5 - 37 7/16 : strabismus sx as primary treatment7/16 : strabismus sx as primary treatment 6/7 : recurrence of strabismus6/7 : recurrence of strabismus 4/5 : subsequent NSD with resolution of strab4/5 : subsequent NSD with resolution of strab 8 patients : NSD as primary treatment8 patients : NSD as primary treatment 7/8 had resolution all signs/symptoms7/8 had resolution all signs/symptoms

Conclusion: Strab Sx alone usually ineffective. Conclusion: Strab Sx alone usually ineffective. NSD usually necessary & effective. NSD usually necessary & effective.

Summary Summary We describe 12 cases of ‘acquired strabismus of We describe 12 cases of ‘acquired strabismus of

obscure cause’ probably caused by C1Mobscure cause’ probably caused by C1M 5/12 aged 10-20 @ presentation5/12 aged 10-20 @ presentation 10/12 had headache10/12 had headache Esotropia was the usual squint (10/12)Esotropia was the usual squint (10/12) 4/12 : ‘divergence insufficiency’ ET, D > N 4/12 : ‘divergence insufficiency’ ET, D > N 1/12: [apparent] sixth nerve palsy1/12: [apparent] sixth nerve palsy 1/12: unexplained head tilt.1/12: unexplained head tilt. 2/12: i/mitt diplopia with poor motor fusion 2/12: i/mitt diplopia with poor motor fusion

SummarySummary

Most patients were referred for neurosurgical Most patients were referred for neurosurgical evaluation. 3/12 had NSD. It is generally felt by evaluation. 3/12 had NSD. It is generally felt by neurosurgeons that strabismus alone is an neurosurgeons that strabismus alone is an inadequate reason for NSD.inadequate reason for NSD.

Strabismus did not resolve in these 3 cases, with Strabismus did not resolve in these 3 cases, with subsequent successful squint surgery in 1case.subsequent successful squint surgery in 1case.

Other patients : Most manage well with prism Other patients : Most manage well with prism glasses.glasses.

ConclusionsConclusions

Isolated acquired strabismus is not a rare Isolated acquired strabismus is not a rare presenting sign of C1Mpresenting sign of C1M, and there might , and there might be a good number of patients being mis / be a good number of patients being mis / under- diagnosed.under- diagnosed.

Appropriate primary management of C1M Appropriate primary management of C1M with strabismus alone [whether strabismus with strabismus alone [whether strabismus surgery or NSD] is unclear.surgery or NSD] is unclear.