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68 A.V. Ciurea et al Intracranian arahnoid cysts in children (ACs)
Intracranian arahnoid cysts in children (ACs)
A.V. Ciurea1, A. Tascu1, A. Iliescu1, C. Mihalache2, F. Brehar1, C. Palade1,
A. Spatariu1
1I-st Neurosurgical Clinic, Clinic Hospital “Bagdasar-Arseni”
2Sf. Andrei Emergency County Hosp. Galati Neurosurg Departament, Galati
Abstract
Intracranial arachnoid cysts (ACs)
represent an extremely common condition
in pediatric pathology. With the
development of CT Scan and especially
MRI these cysts could be find more
constantly.
ACs are congenital lesions with
maximum frequency in middle cranial
fossa, followed by supraselar aria , ponto-
cerebelar angle and cranial posterior fossa.
These cysts are often incidentally
uncovered during a routine neuroimaging
investigations for cranio-cerebral trauma or
other diseases.
The authors present a series of 317 cases
in children with ACs over a period of 10
years.
The authors avocate over the MRI
evaluation of Acs and refering to
therapeutic approach it is recomanded only
in compresive forms with focal neurologica
sings or seizures.
Are rewiewed therapeutical procedures
as: microsurgical fenestration with cystwall
excision, endoscopic approach, stereotaxic
suction, cyst shunting by cysto-peritoneal
procedures. A number of cases remain
under observation the surgical treatment
beeing unnecesary. The surgical treatment
must be carfuly chosen, there is non
therapeutical priority. It remains that
improved neuroendoscopic methods to
improve operator prognosis in Acs.
Keywords: Intracranial arachnoid cyst,
MRI, microsurgical fenestration,
endoscopic approach, cyst shunting,
increased intracranial pressure, seizures
Introduction
Intracranial arachnoid cysts(ACs) also
known as leptomeningeal cysts, are
congenital, benign, nonneoplasic, extraxial
lesions. ACs arise during development from
splitting of arachnoid membrane, and are
distinct from posttraumatic cysts and
unrelated to infection.
Bright (1831) describe the
intraarahnoidian origin of these lesion as
“serous cysts forming in connection with
the arachnoid and apparently lying between
its layers.”, Starkman et all (1958) proposed
that the asociated temporal hypoplasia is
secandary to cyst expansion and pressure on
the temporal operculum. Also Robinson
(1961) the primary source of the problem
lay in a congenital failure of temporal lobe
development.
Acording to Di Rocco et all(2010), Acs
are developmental defect, that occurs
within the first three months of gestational
life, in the duplication or splitting of the
arachnoid layers, and are related to
abnormalities of CSF flow. This theory
cover the whole development of
intracranial arachnoidian cysts. Acs are
Romanian Neurosurgery (2011) XVIII 1: 68 – 76 69
associeted with other developmental
abnormalities of the brain, such as
heterotopias. Incidence of Acs in 5 per 1000
in autopsy series and represent 1% of all
intracranial masses. The male: female rate is
4:1, Di Rocco et all.( 2010). Multiple or
bilateral arachnoid cysts are unusual, and
familial occurrence has been reported in
only a few cases.
Location
In 50% intracranian araschnoid cyst
involve the Sylvian fissure/middle cerebral
fossa . Rengachary&Watanabe (1980)
(Table I). Acording to Gallasi et all. (1980)
Sylvian Acs can be classified into three
subgoups in connection with cysts
dimensions and extensions.
Gallasi type I: small, biconvex, located in
anterior temporal tip, no mass effect,
communicates with subarachnoid
space.(Figure 1).
In Gallasi type II: involves proximal and
intermediate segments of Sylvian fissure,
completely open insula gives rectangular
shape,partial communication with
subarachnoidian space (Figure 2).
Figure 1 MRI-aspect of Gallasi I left temporal
arachnoid cyst
In Gallasi type III: involves entire
Sylvian fissure, midline shift, bony
expansion, minimal communication with
the subarahnoidian space and surgical
treatment usually does not result in
efficient expansion of brain (Figure 3).
Figure 2 MRI – aspect of Gallasi II left temporo-
insular arachnoid cyst
Figure 3 MRI- aspect of Gallasi III left cerebral
hemisfere arachnoid cyst with middle line shift
70 A.V. Ciurea et al Intracranian arahnoid cysts in children (ACs)
Other common locations are: CP angle,
the quadrigeminal cistern, the retrocerebelar
area and the sellar/supraselar region. Less
commonly ACs can develope within the
interhemisferic fissure and cerebral
convexity (Tabel I).
Clinical findings
ACs become symptomatic mainly during
childhood and adolescence, depending on
the location of the cyst not to it’s
dimension. Asymmetrical macrocranian or
a focal bulging of the skull in the temporal
region is the most common symptom,
headaches, focal neurological symptoms,
epilepsy and sings of increased intracranial
pressure.
In suprasellar ACs endocrine
disfunctions (60% of cases), hydrocephalus
(40% of cases - probably due to
compression of the third ventricle) and
visual impairment are the most common
presenting symptoms.
Natural evolution occuring without
sings of: inflammation, trauma or
hemorrhage. May be associated with other
congenital anomalies (agenesis of the
corpus callosum). Often do not expand and
rarely may spontaneously regress or
disappear
Terapeutical options
Observation - Many authors
recommend not treating arachnoid cysts
that do not cause mass effect or symptoms,
regardless of their size and location. Fatih E,
Burkan B, Pinar O (2003)
Multimodal surgical treatment
consisting of shunting the cyst into
peritoneum, craniotomy (microsurgery)
with fenestration and cystwall excision,
endoscopic fenestration or stereotactic
suction.Ciurea et all.( 2010)
Nowadays endoscopic fenestration
represent the main therapeutical option in
arachnoid cyst for decompression and
restoration of CSF circulation.
Each procedures has advantages and
disadvantages as described in table II.
TABEL I
Localization of
ACs(Rengachary&Watanabe 1981)
Location %
Sylvian fissure 49%
CPA 11%
Supracollicular 10%
Pineal aria 9%
Sellar & suprasellar 9%
Interhemispheric 5%
Cerebral convexity 4%
Clival 3%
TABEL II
Surgical treatment options for arachnoid cysts (Keyvan Abtin and Marion L 2010)
PROCEDURE ADVANTAGES DISADVANTAGES
Drainage by needle
aspiration or bur hole
evacuation
• siple
• quik
• high rate of recurrence
of cyst and neurologic deficit
Craniotomy, excising cyst
wall and fenestrating into
basal cistern
• permits direct inspection
of cyst
• loculated cysts treated
more effectively
• avoid permanent shunt
• allows visualization of
bridging vessels
• subsequent scarring may
block fenestration allowing
reaccumulation
• signifiant morbidity and
mortality
Romanian Neurosurgery (2011) XVIII 1: 68 – 76 71
Endoscopic cyst
fenestration
• minimal invasive
• avoid permanent shunt
• no visualization of
bridging vesseles- hemoragic
risk
• fenestration may close
Shunting of cyst into
peritoneum
• low morbidity/mortality
• low rate of recurrence
• patient “shunt dependent”-
risk of shunt infection
Patients and methods
The authors study 317 cases of
arachnoid cysts, admited in 1st
neurosurgical clinic, pediatric neurosurgical
departament Bagdasar-Arseni Hospital
betweem January 2002-January 2010 (8
years). Admission criteria was: age betwenn
0 to 16 years old and patients diagnosed,
treated and fallowed in 1st Neurosurgical
clinic.
There were excluded all patients over 16
years old or treated in other neurosurgical
services.
Results
Localisation of ACs: Sylvian fissure 172
cases(54%), CP angle 38 cases(12%), sellar
and suprasellar region 32 cases(10%), pineal
area 28 cases(9%), retrocerebelar 28 cases
(9%) and interhemisferic 19 cases(6%).
(table III)
TABLE III
Location of intracranial Acs current study
Location Number
of cases
Percentage
%
Sylvian fissure 172 54
CPA 38 12
Sellar &
suprasellar area
32 10
Pineal area 28 9
Retrocerebelar 28 9
Interhemisferic 19 6
Total 317 100
The most common clinical finding was
the focal bulging of the skull 62% (196
cases), irritability 51%(162 cases), epilepsy
32%(101 cases) minor focal neurological
symptoms 18%(57 cases), cranial nerves
palsy 11%(35 cases) and increased
intracranial pressure syndrome in 13%
(41cases) (tabel IV).
TABLE IV
Clinical findings in current study
Elected treatment was: (table V)
TABLE V
Elected treatment in current study
Type of
intervention
Number
of cases
Percentage
%
Observation 40 12,6
Unishunt cysto-
peritoneal dr.
162 51,4
Low pressure valv
CPS
20 6,3
Endoscopic
procedure
31 9,7
Mycrosurgery 64 20,1
Total 317 100
72 A.V. Ciurea et al Intracranian arahnoid cysts in children (ACs)
- observation in 40 de cases(12,6%)
Case presentation I
A 16 years old girl presenting with
migrenal syndrome . The MRI
investigation show a Gallasi tip I cyst of the
left middle fossa. The elected treatment was
observation with MRI reevaluation
annually.
Figure 4 MRI- Gallasi I left temporal pole ACs-
observational treatment
- unishunt cysto-peritoneal drainage
162 cases (51,4%) & low pressure valv
cysto-peritoneal shunt in 20 cases (6,3%).
Case presentation II
A 4 years old girl presenting with
epileptic seizures. The preoperative
investigation show a Gallasi tip II left
middle fossa cyst. The elected treatment
was a unishunt cysto-peritoneal shunt.
Figure 5 MRI preoperative aspect of a Gallasi II left
temporal ACs
Figure 6 CT scan postoperative aspect of the same
cyst as figure 5 after cysto-peritoneal shunting, and
the pacient
- microsurgucal approach with cystwall
excision and fenestration in 64 cases
(20,1%).
Case presentation III
A 3 yers old boy presenting with seizures
unresponsive to medical treatment. The
MRI evaluation show a Gallasi III
arachnoidian cyst of left cerebral
hemisphere. The elected treatment was
mycrosurgical approach with cyst wall
excision and fenestration. The outcome was
a good recovery.
Romanian Neurosurgery (2011) XVIII 1: 68 – 76 73
Figure 7 preoperative MRI aspect of a Gallasi III
left cerebral hemisphere ACs
Microsurgucal approach with cystwall
excision and fenestration is recommended
as an initial approach to avoid shunting
Shunt independence an important
surgical goal. Keyvan Abtin & Marion l.
Walker (2007)
- endoscopic procedure in 31 cases
(9,7%)
Figure 8 postoperative CT scan aspect of the same
cyst as in figure7 after microneurosurgical treatment
Figure 9 preoperative MRIaspect of a
supracollicular giant ACs
Case presentation IV
A 1 year old girl presenting with
hypotonic syndrome and psymotor
retardation. The MRI examination show a
supracollicular giant ACs, The elected
treatment was endoscopic fenestration.
74 A.V. Ciurea et al Intracranian arahnoid cysts in children (ACs)
Figure 10 postoperative CT scan aspect of the same
cyst as in figure 9, after endoscopic fenestration, and
the pacient
Discution
Intracranial arahnoid cysts are
mentioned throughout the specialised
literature. The discovery of such cysts in
almost all cases is done when is made an
CT scan or MRI exam of the brain for
other diseaze of nervous sistem. Once the
intracranial arachnoidian cyst is fount, one
has to establish very careffuly the clinical
findings, neuroimaging evaluation and after
that we may proceed to a posible surgical
treatment.
There are 2 histological types of ACs:
1. “simple arachnoid cysts”: arachnoid
lining with cell that appear to be capable of
active CSF secretion. Middle fossa cysts
seem to be excusively of this type.
2. cysts with more complex lining which
may also contain neuroglia, ependyma and
other tissue types. Mayr U. Aicher F, Bauer
G et all (1982)
Many authors recommend observation
and monitoring of these cysts on MRI. The
rarity of expanding arachnoid cysts makes
frequent serial neuroimaging unnecessary
and cost ineffective. The recommended
follow-up neuroimaging is at one year.
In case of a simptomatic cyst by
neurologica focal deficit, epilepsy or reised
ICP the best surgical solution to release
pressure on the cerebral structure has to be
found.
For a long time shunting mettods were
prefered. But with the apperence of shunt
complication this mettods where
abandoned. Microneurosurgycal approach
of fenestration are very effective but they
require latge opening of basal cistern.
Nowadays as miminaly invasic
procedure the endoscopic procedures has
become increasingly popular ”the
procedure of choice” and has been used to
decrease the number of shunts. Hopf N J,
Perneczky A (1998)
As effective and safe and less invasive but
great care in needed to avoid bleeding -ACs
are associated with large bridging veins. F.
di Rocco et all (2010)
Intraoperative ultrasound or frameless
Romanian Neurosurgery (2011) XVIII 1: 68 – 76 75
stereotaxy, especially with intravenous
contrast enhanced CT or MR imaging
guidance, is helpful in choosing the
trajectory of the bridging veins. Main
limitation is anatomical: due to the relation
of the cyst with the basal cisterns and the
temporal lobe displacement. C di Rocco et
all (2010)
Conclusions
ACs are very frequent congenital
intracranial malformation.
More than 80% of ACs are incidental
findings being completely asymptomatic.
Treatment is recommended only in
symptomatic ACs by focal neurological
deficits, skull deformities, signs/symptoms
related to increased ICP and seizures not
responsive to medical treatment.
Current series of 317 cases constitute a
uniform cohort because cases are
diagnosed, treated and followed in a single
pediatric neurosurgical service. Choice of
treatment was performed very carefully to
obtain the best clinical outcome and
imaging properly, reducing the size of the
cyst. Ciurea at all (2010)
All cases requiring follow predominantly
by MRI to monitor the possible expansion
of the cerebrale structures.In a significant
number of cases the expected expansion did
not occur because of the cyst membranes
were not enough fenestrated into basal
cisterns and CSF cisculatia not restored
properly. In these cases depending on
clinical aspects the therapeutical process can
be repeated, minimally invasive by
endoscopy.
Basically we can say that there is no
“Best Treatment” in ACs, and each case
must be analyzed separately. Ciurea et all
(2010)
Abbreviations:
ACs - intracranial arachnoid cysts
CSF - cerebro spinal fluid
CPA - cerebro-pontine angle
CPD - cisto-peritoneal drenage
MRI - magnetic resonance imaging
CT - computer tomography
ICP - intracranian pressure
References
1. Anne G. Osborn: Arachnoid Cyst, Prymary
Nonneoplastic Cysts. Osborn (2010) 7: 6-9
2. Barbara Spacca, Jothy Kandasamy et all : Endoscopic
treatment of middle fossa arachnoid cysts: a series of 40
patient treated endoscopically in two centres. in Childs
Nerv Syst(2010) 26: 163-172
3. Bright R: Serous cysts of the arachnoid.Report of
Medical cases vol 2, part 1, London: Longmans (1831)
4. Catala M, Poirier J. Arachnoid cysts: histologic,
embryologic and physiopathologicreview. Rev Neurol
Paris (1998) 154:489–501.
5. Ciurea A.V et all: Treatment options in intracranial
arachnoid cysts: 7th National Congres of Romanian
Society of Neurosurgery, October 2010 Cluj Napoca
Romania pub in Romanian Neurosurgery (2010) 4
6. C. di Rocco, L. D’Angelo,L. Massimi –Arachnoid
cysts in Esential practice of neurosurgery Access
Publishing Co. Ltd (2010) 1235-1244
7. Concezio Di Rocco : Sylvian fissure arachnoid cysts:
we do operate on them but should it be done? in Childs
Nerv Syst (2010) 26: 163-172
8. Fatih Ersay Deniz, Burkan Bilginer, Pinar Ozirik:
Araknoid Kist He Birlikte Eozinofilik Graniilom: Vaka
Sunumu Turkish Neurosurgery (2003) 13: 118-121,
9. Federico Di Rocco, Syril R. James, Thomas Roujeau,
Stephanie Puget, Christian Sainte-Rose , Michel Zerah:
Limits of endoscopic treatment of sylvian arachnoid
cysts in children. Childs Nerv Syst (2010) 26: 155-162
10. Gallasi E, Tohnetti F, Gaist G. et al,:CT scan and
metrizamide CT cisternography in arachnoid cysts of
the middle fossa: classification and pathophysiological
aspects. Suerg Neurol. (1982) 17:363-369
11. Hopf N J, Perneczky A: Endoscopic neurosurgery
and endoscope assisted microneurosurgery for the
treatmetn of intracranial cyst. Neurosurgery (1998) 43
1330-7.
12. Keyvan Abtin and Marion l. Walker: Congenital
arachnoid cysts and Dandy Walker complex. In
Albright Principles and Practice of Pediatric
Neurosurgery (2007) 7:125- 141
76 A.V. Ciurea et al Intracranian arahnoid cysts in children (ACs)
13. Rengachary SS, Watanabe I. Ultrastructure and
pathogenesis of intracranial arachnoid cysts. J
Neuropathol Exp Neurol. (1981) 40:61-83.
14. Pierre-Kahn A, Capelle L, Brauner R, et al:
Presentation and management of suprasellar arachnoid
cysts: Rewiew of 20 cases. J Neurosurg (1990) 73:355-9
15. Mayr U. Aicher F, Bauer G et all: Supratentorial
extracerebral cyst of the middle cranial fossa: A report of
23 consecutive cases of so colled temporal lobe agenesis
syndrome. Neurochirurgia(1982) 25: 51-6.
16.Rao G. et all Expansion of arachnoid cysts in
children Report of two cases and review of the
literature. J Neurosurg (Pediatrics 3) (2005)102:314–
317.
17. Robinson R.G: Congenital cysts of the brain:
arachnoid malformations.Prog Neurol Surg( 1971)
4:133–174.
18. Robinson R. G: The temporal lobe agenesis
syndrome. Brain (1964) 88:87–106.
19. Russon. et all: Spontaneous reduction of intracranial
arachnoid cysts: a complete review British Journal of
Neurosurgery, October (2008), 22(5): 626–629
20. Tamburrini G. et all: Sylvian fissure arachnoid cysts:
a survey on their diagnostic workout and practical
management; Childs Nerv Syst (2008) 24:593–604
21. W. N. Al-Halou, C.O. Maher et all. The natural
history of pineal cysts in children and young adults. in
Jurnal Neurosurg Pediatrics(2010) 5: 162-166