Transcript ppsx

CHIARI LIKE TONSILLAR HERNIA
&
A NOVEL MANAGEMENT STRATEGY
Guirish Solanki
Birmingham Children’s Hospital
Birmingham, UK
Radiological Definitions
• 1985 - Aboulezz et al.
• Tonsils tip up to 3 mm below the Foramen Magnum are normal.
• In Chiari I the hernia exceeds 5 mm.
• 1986 - Barkovich et al.
• The limit is 5 mm below the Foramen Magnum.
Asymptomatic Chiari I
14% of patients asymptomatic
Syringomyelia and osseous anomalies in
only asymptomatic patients…
Tonsillar hernia avg 11.4 mm
Incidental in 50%
22% clinical worsening
14% progressed to surgery
Craniosynostosis & Hindbrain
Risk Factors for development of
Hernia
Chronic
Hindbrain
Hernia
(a.k.a. Chiari Malformations)
 • Pfeiffer’s
50%
Prematuresyndrome
fusion of skull vault & skull base sutures
 Crouzon’s syndrome
70%
• congenital anomalies of the cerebellum & brain stem
 Oxycephaly
75%
 Kleeblattschädel deformity
100%
• Raised intracranial pressure
• Venous hypertension
 Apert’s
• Hydrocephalus
<5%
MRI Appearance of
Tonsillar Hernia in CS
 Peglike tonsils
 Effacement of CSF space





at Foramen Magnum
Flattened Occipital Bone
Steep tentorium – nearly
vertical
Venous engorgement
Cervico-medullary kink
“Standing-up” cerebellum
Normal Situation
Obtuse angle
Tent
Pons
Sitting
Cerebellum
Foramen Magnum
CSF Flow
Spinal cord
Chiari changes
Acute angle
Tent
Flattened Pons
Flat Pons
Kinking of
cervico-medullary
junction
Spinal cord
Small
Posterior Fossa
Standing
Cerebellum
Foramen Magnum
Herniation of tonsils
Chiari
with loss of CSF
Surgery in Chiari
 Current approach for Chiari I and II
 Foramen Magnum Decompression craniectomy
 With or without C1-C2 laminectomy
 With or without Dural opening
 With or without Arachnoid Opening
 With or without dural / arachnoid closure
 With or without Tonsil resection
 With or without Duroplasty
 With or without bone replacement
Paediatric Foramen Magnum Dimensions
in the Chiari malformations and
Syringomyelia: A comparative review
224 MRI Scans
R. Vemaraju D. Rodrigues, P.Davies*, N. Furtado, G. Solanki
Department of Paediatric Neurosurgery and *R&D
Diana, Princess of Wales Children’s Hospital
Birmingham Children’s Hospital NHS Foundation Trust
The Foramen Magnum in Chiari
Dimensions
Normal
Sagittal Diameter
33.0
Transverse Diameter
25.4
Surface Area
Chiari I
Chiari II
804 sq
Largest increases seen in Sagittal diameter and Surface Area in Chiari I
Introduction
Multiple Suture
Craniosynostosis
Rapid Pan-synostosis Progression
1. Progressive coronal, sagittal, metopic & lambdoid suture synostosis.
2. Progressive increase in fingerprint impressions (Copper-beaten appearance)
3. Clinical evidence of raised intracranial pressure
Crouzon’s syndrome
Age = 1 week
Crouzon’s syndrome
Age = 2 months
Crouzon’s syndrome
Age = 5 months
Rapid Approaches:
Progression with
Chiari
& ventriculomegaly
Under
1 year of age
 No fixation
Kleeblattschädel deformity
MRI age 2 months
1. Severe pansynostosis
 Supra-tentorial Augmentation
alone
2. Brachyturricephaly
 Posterior Augmentation alone
3. Small posterior fossa
4. Ventriculomegaly
 Supra-tentorial & Occipital
Augmentation
5. Hindbrain hernia
SUPRA REGIONAL CRANIOFACIAL UNIT BIRMINGHAM, UK
If the problem is at the back of the head, operate at the back of the head
Posterior
Release
1984-2003
→
Posterior
Augmentation
2003-2006
→
Posterior
Distraction
2006+
www.bch.nhs.uk/departments/craniofacial
Occipital Augmentation alone
Posterior Calvarial
Augmentation
Posterior Calvarial Augmentation
Series
Patients
Factor
No
Patients
21
Adequate Imaging
17
Gender
Boys
13
Girls
8
M:F
1.65
Age
Median
2.3 years
Range
1.5 m to 8.5 years
Follow-up:
Average
Range
25 months
7 to 45 months
%
76%
Patients
Diagnosis
Age in Months
Age in Years
20
1.7
Crouzon
19
1.6
Lambdoid synostosis
57
4.7
Pansynostosis
18
1.5
Saethre Chotzen
6
0.5
Simpson Golabi Behmel
102
8.5
Undiag. Synd.
59
5
Apert's
Bicoronal Syn
Radiological Parameters
1.
CSF DISTRIBUTION IN SULCI
2.
VENOUS HYPERTENSION
3.
TENTORIAL ANGLE
4.
BOWING OF CORPUS
CALLOSUM
5.
VENTRICULOMEGALY
6. CERVICOMEDULLARY KINK
7. “STANDING-UP “ CEREBELLUM
8. CSF FLOW AT CCJ
9. TONSILLAR DESCENT
10. SYRINX
Evaluation
PARAMETERS
CLINICAL CHANGE
Features
+ if (reduction or lack of S/S)
and – if increase in S/S
headaches, blurred vision, Papilloedema,
motor/sensory/reflex recovery;
mobility, balance;
cognitive; S&L; School performance
CSF DISTRIBUTION IN SULCI Density of Occipital lobe,
improved Sulcal & pericerebral CSF flow
VENOUS HYPERTENSION
TENTORIAL ANGLE
BOWING OF CORPUS
CALLOSUM
VENTRICULOMEGALY
Reduced engorgement of deep venous, galenic, straight sinus and or H.
Torculla
Less Acute Tentorial Angle(more horizontal tent);
occipital love above cerebellum instead of behind it
Reduction in triangular or domed (compressed) Corpus Callosum shape
Improved Evan’s Ratio;
Improved CSF flow through functional Aqueductal Stenosis
Evaluation
PARAMETERS
Features
+ if (reduction or lack of S/S)
and – if increase in S/S
CERVICOMEDULLARY KINK Reduced forward tilt of Brainstem
(as a result of posterior crowding of cerebellar and occipital lobes)
“STANDING-UP” CEREBELLUM Less upright cerebellum.
(Shallow posterior fossa forces cerebellum forwards in both upward and
downward direction making it upright)
CSF FLOW AT CCJ
TONSILLAR DESCENT
SYRINX
Visible CSF anterior and posterior to the Cervico-medullary junction at FM
and below
Reduction in chronic hindbrain hernia measured on sagittal or coronal
images
Reduction in syrinx size (or improved shape)
5 year old
with bilambdoid
synostosis,
ventriculomeg
aly and
hindbrain
hernia.
Symptomatic
with raised
ICP.
There is less tonsilar descent when compared to pre Fixed Calvarial Augmentation.
CSF is clearly seen surrounding the cord and tonsils at the cranio-vertebral
junction. No syrinx in the upper cervical cord is now noted.
Technique (CG)
Results
Pre-Op
Post-Op
•
Reduced density of the occipital cortex /
lobe
•
Despite posterior distraction frontal
expansion occurred
•
Improved CSF distribution
•
•
Improved Callosal and ventricular shape.
Reduction of raised ICP
•
Chiari malformation
•
CSF Flow?
Pre-op
1 year post-op
Reduced Chiari
Improved csf flow
2 years post-op
POST-OP
1 YEAR
PRE-OP
POST-OP
4 YEARS
PRE-OP
POST-OP
4 YEARS
PRE-OP
POST-OP
4 YEARS
PRE-OP
Diagnosis
& Chronic Hindbrain Hernia
DX
Apert's
Bicoronal Syn
Crouzon
Lambdoid synostosis
Pansynostosis
Saethre Chotzen
Simpson Golabi Behmel
Chiari
Grand Total
Hernia
+
2
1
5
3
1
1
13
62%
Hernia No
Scan
1
1
2
2
2
3
14%
5
24%
Grand
Total
3
1
3
5
5
2
1
1
21
Hindbrain Hernia cases
Diagnosis
Hernia
+
Hernia
-
Grand
Total
Apert's
2
1
3
Crouzon
1
2
3
Lambdoid synostosis
5
5
Pansynostosis
3
3
Simpson Golabi Behmel
1
1
Undiagnosed
1
1
Grand Total
13
3
16
Surgical results
Diagnosis
Not
Improved
Apert's
Crouzon
Lambdoid synostosis
Pansynostosis
Saethre Chotzen
Simpson Golabi Behmel
Undiagnosed
Grand Total
1
Improved
3
3
4
3
1
2
1
1
15
Grand
Total
3
3
5
3
1
1
1
17
Overall 88%(15/17) patients showed improvement
in the radiological criteria
Patients with
Tonsillar Hernia
DX
Not improved
Improved
Grand
Total
Apert's
2
2
Crouzon
1
1
4
5
Pansynostosis
3
3
Simpson Golabi Behmel
1
1
Undiagnosed
1
1
12
13
Lambdoid synostosis
Grand Total
1
1
92%(12/13) Patients with Tonsillar Hernia showed
improvement in radiological criteria
Follow-up & Improvement
 Overall Radiological criteria
 Improvement noted (12)
 No improvement
(1)
27 months
7.4 months
 Tonsillar Hernia
 Reduced in 9/13 cases
 Lambdoid Synostosis
 Others
69%
25 months
31 months
Complications
•
Wound complications
•
Bony non-union
•
Buckling of resorbable
plates
•
Loosening of screws and
unstable construct
Reasons for Developing Posterior
Distraction
Technique
Posterior Calvarial Distraction in Multiple Suture Synostosis
Latency
Distraction
Consolidation
Tonsillar Hernia in Craniosynostosis
Restricted Skull Expansion during rapid
brain growth
Outer cortex (lays bone) at sutures =
Ridging
Inner cortex (looses bone) remodells =
Copper beaten appearance
Volume reduction / distribution
Some compaction of brain
Reduction in Ventricular size
or
Increased ventricles / CSF space
(if obstruction to CSF e.g AS)
Transient Increase in ICP
Ocipital lobe is pushed behind tent
Posterior fossa crowding
Cerebellum pushed forwards
Brainstem kinks forwards
Tonsillar herniation
Loss of CSF at CCJ
Syrinx
Conclusion
 Fixed Posterior Calvarial Augmentation
 Is effective in management of raised ICP in CS
associated with craniocephalic mismatch
 Improves radiological appearance in a number of
features that suggest the brain has more space
around it.
 Reduction in Syrinx size
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