1. Cerebro Spinal Fluid (CSF)
Intracranial Hypotension
Idiopathic Intracranial Hypertension
JL Sarrazin
Hôpital Américain de Paris, Hôpital de Bicêtre
2. Cerebro Spinal Fluid (CSF)
Locating CSF
Extra axial
In the Ventricles
In the sub ararachnoid space (SAS) between the
arachnoid membran and the pia mater
25 cm3
In the cistern
(encephalic and spinal)
125 cm3
150 cm3
4. CSF
Extra axial :
— Sub arachnoid space
— Cisterns
— Cisterna Magna
— Interpeduncular cistern
— Ambient citern
—
—
Peripontine cistern
Pontocerebellar cistern
5. CSF
The ventricles
— V1 and V2 (lateral
ventricles) are linked to V3
through the foramen of
Monroe
— V3 is linked to V4 through
the mesencephalic aqueduct
— V4 is linked with the cisterns
through
— the Luschka foramens lateraly
— The Magendie foramen
medialy
— Only meninx : pia mater
6. Production of CSF
20 cm3/h or 500 à 600 cm3 every 24
hours
CSF is produced:
Mainly in the choroid plexus area
A lesser amount is produced in the
capillaries of the spinal and
encephalic sub arachnoid space
A small amount starts from the
intraparenchymal vessels to join the
encephalic sub arachnoid space
through the Virchow-Robin
perivascular spaces
7. roduction du LCR
Acétazolamine
AC
HCOHCO-
actif
Cl-
CO2
H2CO3
Cl-
H+
H2O
H2O
H2O
3 Na+
H2O
2 K+
2 Na+
ATP
actif
+
2K
Na/K
ATPase
3 Na+
H+
2 Na+
3’-5’ AMPc
Fibres -adrénergiques
passif
Ouabaïne
Choroid epithelium : brush border
10
epithelial cells spread on a basement
10
membrane
The junction between the cells is not
a100 % tight and the capillaries are
fenestrated : exchanges between blood
and interstitial fluid are free
8. Composition of CSF
— Maintains the physico-chemical environment constant in the
brain
— Fluid
— Clear, pH = 7,3
— 3 à 5 lymphocytes/cm3
— The CSF composition is different from that of the plasma.
Plasma
CSF
Na+
150 mmol/l
147 mmol/l
K+
4,6 mmol/l
2,8 mol/l
Ca++
1,8 mmol/l
1,1mmol/l
Cl-
115 mmol/l
130 mmol/l
HCO 3-
26 mmol/l
22 mmol/l
pH
7,4
7,3
PCO2
45 mmHg
50 mmHg
Proteins
8g/100ml
0,02 g/100ml
10. Resorption of CSF
— Passive flow from production area to clearance
area.
— Flowrate: 20 cm3/h.
— Renewal: 3 times a day.
— The CSF flows through the dural sinuses, the spinal
veins, and in a lesser part in the lymph along the
nerves 4/5 of the CSF
— 1/5 is eliminated in the spinal area
11. Dural Sinuses and Arachnoid granulations (Pacchioni’s granulations)
Hernias of the arachnoid in the dural sinuses
Small « safety valves » responds passively by hydrostatic or osmotic pressure
difference
ICP>ISP
ICP<ISP
13. Role of CSF
— Mechanical protection of the brain and the spinal
cord
— +++ Role in cerebral homeostasis by holding a ionic
equilibrium, allowing the flow of active molecules
and the removal of catabolite
18. Intracranial hypotension
— CSF leak, with volume loss of that fluid
— Monroe Kelly principle :
— Brain vol + Blood vol + CSF vol = constant
— Decreasing of CSF = Increasing of blood volume
Cerebral and spinal venous congestion
20. Idiopathic Hypotension
— Defined 20 years ago. Scarce, but its frequency is under
estimated. Prevalence: 1/500000
— Slim, tall, young woman
— F/M ratio : 3/1
— Average age: 37-42 y.o (extreme: from15 to 76) y.o
— Aetiologies
— Minor trauma (sneezing, coughs, violent sport moves )
— Pre-existing anomalies: Tarlov cysts, meningeal diverticula
— Disease of the connective tissue (Marfan type).
21. The main symptom
ORTHOSTATIC headaches
— Orthostatism : the Headache appears within less than 15
minutes
— Decubitus : the headache disappears within 30 minutes
Uninterrupted, not pulsating, growing along with
orthostatism, with neck pains and feelings of neck and
shoulder tensions headaches
Intensifying with head moves, coughing and sneezing
shocks . ….Valsalva maneuver
Variable ways to start, mostly in a progressive way,
sometimes in a brutal way
Downward shift of cerebral structures
causing headaches by the pulling on
anchoring structures in brain’s dura mater
22. Other clinical symptoms
— Neck stiffness
— Nausea and vomiting 30%
— Visual troubles : diplopia mostly through VI (Abducens nerve)
— Hearing and vestibulary troubles : tinnitus, dizziness (less frequent)
23. CSF Analysis
— Decreased pressure < 60 mm of water…
sometimes normal
— Hyper proteinorachia, important sometimes
— Lymphoticpleocytocis
— Normal Glycorrhachia
— this set offers less interest since MRI
26. Thickening of dura mater
— Thickening and enhancement of dura mater, equally
spread, supra and infra tentorial areas
— Leptomeninges untouched
— Might be due to dilation of dura mater veins
31. Collections and sub-dural hematoma
SDHematoma caused by ripping
off of arachnoid granulations
(«Pacchioni’s granulations »)
32. brain. In paompensate for
henomenon is
ts in a characThis contour
verse sinus on
s of the brain.
inary fashion.
agittal images
ansverse sinus
include the following: diffuse headache that worsens within 15 minutes
after sitting or standing; evidence of low CSF pressure on MR imaging;
and spontaneous headache resolution or within several days after epidural blood patch (EBP). Fifteen IH patients (IHPs) with complete MR
imaging at presentation were identified and included 13 women and 2
men with an overall average age of 46 years. Of the 15 patients with
confirmed IH, 12 presented with primary SIH, 2 presented after lumbar
puncture, and 1 after a spinal anesthetic procedure. All 15 of the IHPs
provided the typical clinical presentation of orthostatic headaches, as well
as characteristic findings at gadolinium-enhanced MR imaging of the
brain. Nine of the 15 went on to have EBP treatment, 4 had spontaneous
resolution of their symptoms, and 2 were lost to follow-up. Follow-up
MR imaging of the brain was available in 10 of the 15 IHPs.
Congestion of veins
7.
Division of Neurontario, Canada; and
uebec, Canada.
niversity of Toronto.
Pituitary gland and stalk
Retroclival veins
Control Patients
Eighty consecutive potential control patients (CPs) were recruited
from the population of cancer patients at our institution who were
undergoing screening for intracranial metastatic
Venous Distension Sign: A DiagnosticofSigndisease. These
of
patients had no clinical signs or symptoms neurologic disease.
logy, Department of
New East Wing 3MC
.farb@utoronto.ca
The
Intracranial Hypotension at MR Imaging of the
AJNR Am J Neuroradiol 28:1489 –93 ͉ Sep 2007 ͉ www.ajnr.org
Brain
1489
BACKGROUND AND PURPOSE: Patients with intracranial hypotension (IH) demonstrate intracranial venous
enlargement with a characteristic change in contour of the transverse sinus seen on routine T1-weighted
sagittal imaging. In IH, the inferior margin of the midportion of the dominant transverse sinus acquires a
distended convex appearance; we have termed this the venous distension sign (VDS). This is distinct from
the normal appearance of this segment, which usually has a slightly concave or straight lower margin. This
sign is introduced, and its performance as a test for the presence of this disease is evaluated.
MATERIALS AND METHODS: The transverse sinuses on T1-weighted sagittal imaging of 15 patients
with IH and 15 control patients were independently assessed in a blinded fashion by 3 readers for the
presence of a VDS. A present or absent VDS was determined for each patient by each reader, and a
consensus result for each patient was determined by unanimity or majority rule.
RESULTS: Using the VDS, the readers correctly identified 93% (14 of 15) of the IH patients and
similarly 93% (14 of 15) of the control patients. There was a high rate of agreement among the readers
for the interpretation of the VDS (multirater ϭ 0.82). The overall sensitivity of the VDS for the
diagnosis of intracranial hypotension was 94%. Specificity was also 94%.
3D Flair +++
Shifting downward of
structures
CONCLUSION: The VDS appears to be an accurate test for the presence or absence of IH and may be
helpful in the evaluation of these patients.
normally has a concave or straight inferior border (Fig 1). In cases
of IH, the inferior border acquires a distended appearance with a
convex bulging of its inferior border (a VDS, as in Figs 2 and 3).
The purpose of this paper is to report this sign and evaluate its
performance in a controlled trial for identifying patients with IH
and differentiating them from normal age- and sex-matched
control subjects.
Chiasma
BRAIN
(IH) is a syndrome of variable etiions, and MR imaging appearances
e of CSF volume depletion and retic pressure.1-7 The syndrome of
ypically presents with orthostatic
MR findings and most commonly
leak of CSF from the spinal thecal
include “over shunting” associated
ures, as well as continued leaks after
mbar punctures. Many characterisassociated with IH regardless of its
Cerebellar tonsils
Materials and Methods
Patients with IH
Less frequent
maging of patients presenting to our
identified a highly reliable novel imof IH. We have termed this sign the
VDS) and evaluated for it on routine
eighted imaging of the brain. In pauses enlarge as they compensate for
volume.2,7,13,14 This phenomenon is
A retrospective review of clinical and imaging records was carried out to
identify patients evaluated for IH at our institution from February 2001
to September 2005. Criteria used in this study to firmly establish the
diagnosis of IH were similar to those reported previously for SIH2,15 and
include the following: diffuse headache that worsens within 15 minutes
after sitting or standing; evidence of low CSF pressure on MR imaging;
ORIGINAL RESEARCH
Institutional review board approval was obtained for this project.
33. MRI
o Global enhancement of dura mater
o Sub dural collection
o Venous congestion
Ø Pituitary gland and pituitary stalk
Ø Retroclival veins
o Cranio caudal shift
Ø Chiasma, Cerebellar tonsils
34. Causative investigation
— Cause identified
Lumbar punction, surgical operation
— « Idiopathic » process
•
Minor trauma, sneezing, violent cough, sudden
sports effort
• «Anatomical « fragility » of meninges:
peri radicular cysts , meningeal diverticula,Tarlov cysts,
meningocele
• Inherited/genetic: Marfan, NF1, Ehlers-Danlos…
— Never (or very scarce) at level of skull base
J Neurosurg 116:749–754, 2012
35. graded as “classic” if both pachymeningeal enhanc
of the brain were present (Fig 1). Brain MR ima
From the Department of Neuroradiology, Mayo Clinic, Rochester, Minnesota.
“equivocal” if pachymeningeal enhancement with
Paper previously presented at: 49th Annual Meeting of the American Society of Neurora“brain sag” without pachymeningeal enhancemen
diology, June 4 –9, 2011; Seattle, Washington.
MR imaging was graded as negative if neither p
Please address correspondence to Patrick H. Luetmer, MD, Department of Neuroradiology,
IsotopicSttransit MN 55905; e-mail: luetmer.patrick@mayo.edu
Mayo Clinic, 200 1st SW, Rochester,
The Role ofhancement nor sagging brain was present. For ea
MR Myelography with Intrathecal
Neuroradiology (2012) 54:1367–1373
http://dx.doi.org/10.3174/ajnr.A2815
Gadolinium in the presence of Spinal CSF Leaks
DOI 10.1007/s00234-012-1055-3ing,Localizationor absence of extradural fluid was
Received May 10, 2011; accepted after revision June 25.
Causative investigation = Spinal cord exploration
—
— Myelo CT
ORIGINAL
RESEARCH
— Spinal cord MRI
in Patients with Spontaneous Intracranial
Hypotension AJNR Am J Neuroradiol 33:535– 40 ͉ Mar 2012 ͉ w
INTERVENTIONAL NEURORADIOLOGY
Detection and treatment of spinal CSF leaks in idiopathic
intracranial hypotension
J.J. Akbar
BACKGROUND AND PURPOSE: Localization of spinal CSF leaks in CSF hypovolemia is critical in
directing focal therapy. In this retrospective review, our aim was to determine whether GdM was
P.H. Luetmer
helpful in confirming and localizing spinal CSF leaks in patients in whom no leak was identified on a
Neuroradiology (2012) 54:1367–1373
K.M. Schwartz
prior CTM.
DOI 10.1007/s00234-012-1055-3
C.H. Hunt
MATERIALS AND METHODS: & C. Musahl &
G.
F.E. Diehn Albes & H. Weng & D. Horvath Forty-one symptomatic patients with clinical suspicion of SIH were
referred Henkes
H. Bäzner & H. for GdM after undergoing at least 1 CTM between February 2002 and August 2010. A
L.J. Eckel
retrospective review of the imaging and electronic medical records was performed on each patient.
Ø Myelo MR
Ø Axial +/- T2 weighted sequence
ü Spin echo sat fat
ü « T2 » High resolution (Fiesta, CISS, drive)
ü 3D FSE T2 Sat Fat
INTERVENTIONAL NEURORAD
RESULTS: In 17 of the 41 patients (41%), GdM was performed for follow-up of a previously docu-
mented leak at CTM. In the remaining 24 patients (59%), in whom GdM was performed for a
suspected CSF leak, which was not identified on CTM, GdM localized the CSF leak in 5 of 24 patients
(21%). In 1 of these 5 patients, GdM detected the site of leak despite negative findings on brain MR
Received: 11 March 2012 MR imaging,June 2012 / Published online: 6 JulySixteen of 17 patients with previously
imaging, spine / Accepted: 8 and CTM of the entire spine. 2012
# Springer-Verlag leaks underwent interval treatment, and leaks were again identified in 12 of 17 (71%).
identified 2012
Detection and treatm
intracranial hypotens
CONCLUSIONS: GdM is a useful technique in the highly select group of patients who have debilitating
symptoms of SIH, a high clinical index of suspicion of spinalAdjacent to the level(s) of theleak on
CSF leak, and no demonstrated detected CSF le
Abstract
conventional CTM. aimed to injection the diagnostic
Introduction This study Intrathecal evaluate of gadolinium contrast remains an off-label useof fresh venous blood w
the nerve roots, 20 cc and should be
reserved for those patients who of patients with idiimaging findings and treatment resultsfail conventional CTM.
Gadovist was injected epidurally (blood patch
opathic intracranial hypotension (IIH) due to cerebrospinal
distribution of the BP was visualized by MRI th
ABBREVIATIONS: CTM ϭ CT myelography; GdM ϭ intrathecal gadolinium MR myelography; In111fluid (CSF) leaks.
day. Treatment results were evaluated clinica
DTPA ϭ indium-111 diethylene triamine pentaacetic acid; SIH ϭ spontaneous intracranial hypotenMethods Between February 2009 and April 2012, 26 IIH
myelography 2 weeks after the application
&
&
&
sion; SPGR ϭ spoiled gradient-recalled-echo
patients (15 men, median age 49 years) presenting with
Retreatment was offered to patients with persis
&
orthostatic headache (n020) and/or with spontaneous subtoms and continued CSF leakage.
dural effusions or subarachnoid hemorrhage (n019) were
Results CSF leaks were detected at the cervic
Materials and CT
IH is a debilitating syndromeTwenty-three patients underwent a whole spine Methods
enrolled. classically characterized by
thoracic (n025), or lumbar (n021) spine. In 2
orthostatic headaches, low CSF pressure, starting 45 min after the intrathecal
Approval of the institutional review board with waived consent was affected. O
and MRI myelography, and diffuse
more than one spinal segment was
pachymeningeal gadolinium enhancement on MR imaging.1 300 M) and 1this Health refused treatment. BP were applied in one (n09
Insurance Portability and Accountability
injection of 9 cc of iomeprol (Imeron obtained for cc of
First-line treatment for patients with this condition is conserAct— compliant retrospective research study. A searchand/orradiolgadobutrolum (Gadovist). Three patients only underwent
(n016) levels. Clinical of the radiological im
2
vative therapy or large-volume lumbar epidural blood patch.gadobutrolum injection. between Februaryafter one August 2010 reogy information system was achieved 2002 and (n016), two (n05), thre
MR myelography after intrathecal
Further treatment, however, including targeted epidural
trieved a total of 164 patients who were referred for myelography for
five (n01) BPs.
blood patches, fibrin glue injections, and open surgical repairs the Deutsche Gesellschaft these, 41 patients underwent GdM after under- allow the
evaluation of SIH. Of
Conclusion CT and MRI myelography
Presented in part at the Annual Meeting of
may be necessary. Each of these focal therapies requires precise
least 1 CTM. If 11 March 2012 on a single patient, 8 June 2
für Neuroradiologie (DGNR) Cologne 2011. going at Received: Ͼ1 GdM of spinal CSF leaks. The targeted and eventu
tection was performed / Accepted:
localization of the CSF leak. Current standard radiologic techonly the# examination ed epidural BP procedure Noaother casesefficacious
first Springer-Verlag 2012 study. is safe and
was evaluated in our
G. Albes : D. Horvath : H. Henkes (*)
niques used to evaluate Klinik für Neuroradiologie, Klinikum Stuttgart, were excluded.
spinal CSF leaks in these patients include conventional CTM, dynamic CT 60,
Kriegsbergstrasse myelography, radioImaging examinationsKeywords Idiopathic intracranial hypotension . O
reviewed included prior brain MR imag70174 Stuttgart, Germany
nuclide cisternography, and conventional spine MR imaging.
ing, spine MR imaging, CTM (standard or dynamic16), nuclear medheadache . SAH . Spinal CSF leak . Epidural bloo
e-mail: hhhenkes@aol.com
GdM has been reported in small series and case reports to be a
icine In111-DTPA cisternography, and GdM. All imaging studies and
useful adjunct in localization of CSF leaks in the difficult sub-
SPINE
G. Albes H. Weng D. Horvath C.
H. Bäzner H. Henkes
S
ORIGINAL RESEARCH
3D FSE T2 sat fat
Abstract
36. Spinal cord MRI
Causative investigation
Meningeal diverticula . ..
Level of leakage
Congestion of venous plexuses
Fluid collection in the epidural space
Collapsing of dural sac
AJNR Am J Neuroradiol 23:618–621, April 2002
38. TREATMENT
Decubitus, hydratation, abdominal strapping
Blood patch
Standard practice : in L3L4 or L4L5
Or at the breach level if location of breach can be seen or
known
Injection of 10 to 40 ml (incurring low back pain)
Decubitus for two hours, no forceful exercise for 3 weeks
Way of working
Initial mass effect (immediate effect), vasoconstrictor effect
Fibrin clot plugs up the breach
Results
56% success rate after 2 blood patches
MG Bousser 33 patients
90% immediate efficiency: , 57% sustainable effect for 1
BP 77% for 2 BP
,
.s’
39.
40. Empty sella
Thin Ventricles
Tortuous optic nerves
41 y.o woman. Headache. Bilateral pulsatile tinnitus.
Enlargement
of
peri optic sub archnoid spaces
Tortuous optic nerves
Enlargement
of
peri optic sub archnoid spaces
41. Empty sella
Thin Ventricles
Tortuous optic nerves
Idiopathic intra cranial Hypertension
Enlargement
of
peri optic sub archnoid spaces
Tortuous optic nerves
Enlargement
of
peri optic sub archnoid spaces
43. Idiopathic intracranial Hypertension
Dandy (1937) Pseudo tumor cerebri
ü Rise of intracranial pressure
ü Normal composition of CSF
ü No tumor
Current criteria
—
1 patient fully aware
ü with a normal neurological examination
or
ü Papilledema
ü Widening of blind spot
ü Decreasing of visual field
ü Paralysis of VI
—
2 Rise of pressure of CSF > 200 mmH2O (205 in obese patients). Normal (lateral
decubitus) 100 à 200 mmH2O
—
3 Normal composition of CSF (minor hyperproteinorachia may happen)
—
4 No intracranial or medullar (tumoral) pathology
—
5 No metabolic, toxic, or hormonal cause
44. Epidemiology
— Sex ratio: Female >>> Male
— Frequency
ü 0,034/100.000 men/year
ü 2,7/100.000 women/year
ü 21,4/100.000 obese women/year
— May happen but scarce in children
46. Clinical features
Not always conclusive
Unspecified headaches (90-94%)
Sometimes with nausea and vomiting
Ophtalmological clues (68-85%)
Weakening of visual acuity (Edema of
Impairments of visual field
Dizziness, pulsatile tinnitus (60%)
Obesity: risk factor
optic disk, edema of fundus)
47. MRI
Ruling out tumor
pathology
Confirming diagnosis:
etiologic investigation
— Median line: sagittal T1
— Flair
— T2*
— Diffusion
— +/- injection
— Ventricles: axial or frontal T2/
Flair
— Orbits : optic nerves : T2W
sequence HR or 3D FSE T2
— Veins : venous MR Angiography
48. de pain, pulsatile tinnitus, and vin lead to blindness.2,5 Treatment
n, acetazolamide, and surgical inhunt surgery.6-8
l diagnosis based on normal CSF
d opening pressure (Ͼ20 cm H2O
25 cm H2O in obese patients with
pportive neuroimaging findings
the Chiari I Malformation
with tonsillar ectopia, such as Chiari I malformation and
RESEARCH
spontaneous intracranial hypotension.
Chiari I malformation is characterized by caudal protrusion of “peg-shaped” cerebellar tonsils below the foramen.11,12
A.H. Aiken
BACKGROUND
Chiari I malformation is defined radiographically AND infeas an PURPOSE: IIH is a syndrome of elevated intracranial pressure without hydrocep
alus, mass,Ն5 mm below
or identifiable cause. Diagnosis is made by clinical presentation, intracranial pressu
rior displacement of the cerebellar tonsils of
J.A. Hoots
the opisthion-basion line.13,14 Inmeasurement, cerebellar
the healthy adult, and supportive imaging findings. A subset of patients with IIH may have tonsil
A.M. Saindane
tonsils are rarely Ͼ3 mm below the foramen magnum. Paectopia, meeting the criteria for Chiari malformation type I but not responding to surgical decompre
P.A. Hudgins
tients with the radiographic appearancefor(the I malformasion of Chiari first sequenceof this study almost) Brain MRI)
Chiari I. The purpose for all (or was to determine the incidence and morphology
tion can be asymptomatic, but the most common clinical
cerebellar tonsillar ectopia in patients with IIH.
symptoms include headache, neck pain, vertigo, sensory
changes, and poor coordination. Therefore, clinical symptoms
MATERIALS AND METHODS: Forty-three patients with clinically confirmed IIH and 44 age-match
may overlap IIH.11 Chiari I malformation is also associated
controls were included. Two neuroradiologists with CAQs reviewed sagittal T1-weighted MRI in
with abnormal CSF flow, which can lead to syringomyelia.
blinded surgical and measured cerebellar tonsil and obex positions relative to the foramen magnum a
Treatment of Chiari I consists primarily offashion hindbrain
prepontine to restore nordecompression with suboccipital craniectomy cistern width at the level of the midpons.
mal flow at the foramen magnum.15
Tonsillar Ectopia in
RESULTS: Nine of subset
Previous studies in the surgical literature describe a 43 patients with IIH and 1/44 controls had cerebellar tonsillar ectopia of Ն5 mm. Fi
MRI
Sagittal T1w sequence
ter revision January 12, 2012.
-Empty (or partially empty) sella : longstanding effects
d Imaging Sciences, Emory University, Atlanta,
ual Meeting of the American Society of Neurorangton.
- downward displacement of chiasma and/or cerebellar tonsils (20%)
ey H. Aiken, MD, Radiology Department, Emory
Suite BG 26, Atlanta, GA 30322; e-mail:
Incidence of Cerebellar
Idiopathic Intracranial Hypertension: A Mimic of of 9 of patients with IIH with ectopia of Ն5 mm also had a “peglike” tonsil configuration. Patients w
Nov had significantly lower
the Chiari I Malformation AJNR Am J Neuroradiol 33:1901– 06 ͉ IIH 2012 ͉awww.ajnr.org 1901 tonsillar position (2.1 Ϯ 2.8 mm) than age-matched controls (0.7 Ϯ1.9 m
P Ͻ .05). The obex position was significantly lower in patients with IIH versus controls (Ϫ7.9 m
[above the FM] versus Ϫ9.4 mm [above the FM], P Ͻ .05). The prepontine width was not significan
different between the groups.
BACKGROUND AND PURPOSE: IIH is a syndrome of elevated intracranial pressure without hydrocephalus, mass, or identifiable cause. Diagnosis is made by clinical presentation, intracranial pressure
measurement, and supportive imaging findings. A subset of patients with IIH may have tonsillar
ectopia, meeting the criteria for Chiari malformation type I but not responding to surgical decompression for Chiari I. The purpose of this study was to determine the incidence and morphology of
cerebellar tonsillar ectopia in patients with IIH.
CONCLUSIONS: Cerebellar tonsil position in patients with IIH was significantly lower than that
MATERIALS AND METHODS: Forty-three patients with clinically confirmed IIH and 44 age-matched
age-matched controls, often times peglike, mimicking Chiari I. A significantly lower obex positi
suggests an inferiorly displaced brain stem and cerebellum. When tonsillar ectopia of Ͼ5 mm
RESULTS: Nine of 43 patients with IIH and 1/44 controls had cerebellar tonsillar ectopia of Ն5 mm. Five
identified, imaging and clinical consideration of IIH are warranted to avoid misdiagnosis as Chiari I
controls were included. Two neuroradiologists with CAQs reviewed sagittal T1-weighted MRI in a
blinded fashion and measured cerebellar tonsil and obex positions relative to the foramen magnum and
prepontine cistern width at the level of the midpons.
of 9 of patients with IIH with ectopia of Ն5 mm also had a “peglike” tonsil configuration. Patients with
IIH had a significantly lower tonsillar position (2.1 Ϯ 2.8 mm) than age-matched controls (0.7 Ϯ1.9 mm,
P Ͻ .05). The obex position was significantly lower in patients with IIH versus controls (Ϫ7.9 mm
[above the FM] versus Ϫ9.4 mm [above the FM], P Ͻ .05). The prepontine width was not significantly
different between the groups.
CONCLUSIONS: Cerebellar tonsil position in patients with IIH was significantly lower than that in
ABBREVIATIONS: CAQ ϭ Certificate of Added Qualification; CM ϭ Chiari malformation; FM ϭ
foramen magnum; ICP ϭ intracranial pressure; IIH ϭ idiopathic intracranial hypertension
(
age-matched controls, often times peglike, mimicking Chiari I. A significantly lower obex position
suggests an inferiorly displaced brain stem and cerebellum. When tonsillar ectopia of Ͼ5 mm is
identified, imaging and clinical consideration of IIH are warranted to avoid misdiagnosis as Chiari I.
I
ABBREVIATIONS: CAQ ϭ Certificate of Added Qualification; CM ϭ Chiari malformation; FM ϭ
foramen magnum; ICP ϭ intracranial pressure; IIH ϭ idiopathic intracranial hypertension
BRAIN
9,10
ORIGINAL RESEARCH
seudotumor cerebri, is a synated ICP with normal CSF comble cause.1 It has been proposed
elated to decreased CSF resorpoutflow and elevated venous
y still surrounds the significance
H as the cause or the result of
antly affects young overweight
en with a reported incidence of
2,3
Patients with IIH most comes, occurring in 68%–98%.2,4
IH, previously known as pseudotumor cerebri, is a syndrome characterized by elevated ICP with normal CSF com1
have been described. Theseno other identifiable cause. It has been proposed
position and include flattening of the posterior
sclera, tortuosity of the optic nerve sheath, empty sella synthat the elevated ICP venous be related to decreased CSF resorpdrome, and stenosis of the transverse may sinuses.
Therefore, imaging can aid in making or supporting the clintion due to impaired venous outflow and elevated venous
ical diagnosis in some cases, especially if clinicians are not as
familiar with the diagnosis. The incidence and morphology of
pressure; however, controversy still surrounds the significance
cerebellar tonsillar ectopia in IIH has not been previously described in the radiology literature, to our knowledge. IIH as the cause or the result of
of venous sinus stenosis in When
present, tonsillar ectopia in IIH may confuse the radiographic
elevated ICP.2 IIH commonly associated
picture and mimic other entities more predominantly affects young overweight
with tonsillar ectopia, such as Chiari I malformation and
have been described. These include flattening of the posteri
sclera, tortuosity of the optic nerve sheath, empty sella sy
drome, and stenosis of the transverse venous sinuses.9
Therefore, imaging can aid in making or supporting the cli
ical diagnosis in some cases, especially if clinicians are not
familiar with the diagnosis. The incidence and morphology
cerebellar tonsillar ectopia in IIH has not been previously d
scribed in the radiology literature, to our knowledge. Wh
55. Technical note
MR venography
=
Angio 3D with injection or Angio 4D (TRICKS, TWIST)
Old venous Thrombosis
Technical note
CT venography = excellent tool for vessels exploration
56. Stenosis :
Cause or effect of IIH ??
Neuroradiology (2008) 50:999–1004
DOI 10.1007/s00234-008-0431-5
DIAGNOSTIC NEURORADIOLOGY
The relationship of transverse sinus stenosis to bony groove
dimensions provides an insight into the aetiology
Neuroradiology (2008) 50:999–1004
of idiopathic intracranial hypertension
1003
Neuroradiology (2008) 50:999–1004
S. E. J. Connor & M. A. Siddiqui & V. R. Stewart &
E. A. M. O’Flynn
DOI 10.1007/s00234-008-0431-5
DIAGNOSTIC NEURORADIOLOGY
Received: 20 March 2008 / Accepted: 25 June 2008 / Published online: 12 July 2008
# Springer-Verlag 2008
3D Phase Contraste
subjects. There were a further 8/23 cases where the small or
Abstract
Introduction Transverse sinus tapered narrowings are freabsent sinus was associated with an absent bony groove.
Conclusion Transverse sinus tapered narrowings in subjects
quently identified in patients with idiopathic intracranial
without IIH and in the majority of patients with IIH were
hypertension (IIH); however, it remains unclear whether
associated with proportionately small or absent grooves,
they are primary stenoses or whether they occur secondary
and these are postulated to be primary or fixed. Some
to raised cerebrospinal fluid pressure. Computed tomopatients with IIH demonstrate tapered transverse sinus
graphic venography demonstrates both the morphology of
stenoses with disproportionately large bony grooves,
the venous system and the adjacent bony grooves so it may
occipital bone in an
Fig. 6 Reformatted image
suggesting secondary bone in an
provide an insight into the aetiologya of these transverse perpendicular toathe occipitalor acquired narrowing. This implies IIH subject at areamin demonstrates narrowing
IIH subject at areamin demonstrates narrowing withfor heightbone to sinus stenoses bone to heightsinus ratio of 1.6
a varied aetiology a the transverse with a heightof IIH.
sinus stenoses.
S. E. and methods Tapered A. Siddiquib,& cV.
heightsinus ratio of 2.2.
Reformatted images perpendicular to the
Materials J. Connor & M.transverse sinus narrow- R. Stewart &
ings (>50%) were studied in 19 patients without IIH and 14
Keywords Idiopathic intracranial hypertension . Computed
E. A. M. O’Flynn
further 8/23 cases where tomographic absent sinus was
actually stenosis
patients with IIH. Computed tomography vascular studies the small orvenography . Venous sinus . Vascularrepresents an expected increase in size of a primary
were reviewed and the dimensions of the with ansinuses bony groove. It is of note that
associated venous absent
narrowing as per the Monro–Kellie hypothesis. Studying
and bony grooves at the sites of maximum and stenoses have only previously been studied
venous sinuses minimum
the adjacent bony groove may provide further insight into
transverse sinus area dimensions weretime of clinical presentation or following intervention
Introduction
at the recorded.
the pre-morbid venous sinus appearances in such cases.
Results There was demonstrated to be a strong correlation
such as CSF drainage. It is possible that the observed July The
Received: 20 March 2008 / Accepted: 25 June 2008 / Publishedsinus stenoses are detectedstudy may be criticised since observers were not
online: 12
2008on neuroof bony groove height with venous sinus height at the
Bilateral transverse
“reversibility” of stenoses by lowering intracranial pressure
blinded with respect to the identification of IIH and non-IIH
# Springer-Verlag 2008
largest portions of the transverse sinus in both IIH patients
imaging studies in the majority of patients with idiopathic
data. these stenoses
and non-IIH subjects as well as at the transverse sinus
intracranial hypertension (IIH) [1–4]. Whether The non-IIH subjects could be recognised since CTA
studies were used
narrowing in non-IIH subjects. There was a discordant
are the cause or effect of raised cerebrospinal fluid (CSF) for the analysis. CTVs could not be used
relationship between bony groove height and venous sinus
pressure remains controversial. Some for the non-IIH data due to the potential high rate of
investigators have
subjects. There pathology. In addition, non-IIH where
Abstract site of transverse sinus stenoses in IIH proposed that primary fixed transverse sinus stenoses result were a further 8/23 casespatients the small or
height at the
associated venous
patients. In 5/23 IIH Transverse sinus tapered narrowings are fre- increased resistancean ideal “control” group with they absent bony groove.
Introduction transverse sinus stenoses, the bony in venous hypertension [4–6], absent not to CSF associated since an were being
were sinus was
groove height was proportionate to that seen in non-IIH
absorption
pressure [4,7]. This has
investigated Transverse sinus tapered narrowings
quently identified in patients with idiopathic and hence increased CSFConclusion forinneurological complaints; however, these in subjects
intracranial
led to the application of intravascular patients stenting
venous were considered to have a low likelihood of venous
patients with intractable IIH
a pressure IIH has
hypertension (IIH);: however, it remains unclear whether when withoutgradient and in the majority of patients with IIH were
S. E. J. Connor (*) : V. R. Stewart E. A. M. O’Flynn
been demonstrated across
stenoses
associated is Other
they are primary stenoses or whether they occur secondarysuchsinus Table[8–10]. with proportionately small or absent grooves,
1 Heightmore
Neuroradiology Department, Ruskin Wing,
bone /heightsinus for the areamin points in IIH patients.
authors suggest that transverse
narrowing
The relationship of transverse sinus stenosis to bony groove
dimensions provides an insight into the aetiology
of idiopathic intracranial hypertension
3D Phase Contraste
If suspicion of IIH, MR Venography is required +++
ehcuag te tiord esrevsnart sunis sed setru
seérres sesonéts ed noicipsuS
eiregamI
? eriatnemélpmo
King’s College Hospital,
Denmark Hill,
London SE5 9RS, UK
e-mail: Steve.Connor@kch.nhs.uk
to the these are for
to raised cerebrospinal fluid pressure. likely a secondary phenomenon due and raised intracranial postulated ofto be primary or fixed. Some
Computed tomoHeightbone /heightsinus
Number sinuses
pressure and resulting expansion
CSF and
the IIH with
patientsareamin points
graphic venography demonstrates both the morphologysupportedofby studies parenchymalIIH demonstrate tapered transverse sinus
of
compartments. This is
which have
gradient or the stenosis ratio 8
the venous system and the adjacent bonyrecorded a reversal it may
grooves so of the pressure stenoses with disproportionately large bony grooves,
0–indeterminate small
M. A. Siddiqui
following lumbar puncture or CSF diversion [6, 11–15]. It is
−3
Institute of Neurological Sciences, Southern General Hospital,
suggesting a that
or groove–small sinus
provide4TF, Scotland
an insight into the aetiology of these patients with transverse sinus stenoses secondaryabsentacquired narrowing. This implies
transverse
argued that
Glasgow G51
−5 absent groove–absent sinus
a varied aetiology for(aplastictransverse sinus stenoses of IIH.
the segment)
sinus stenoses.
Materials and methods Tapered transverse sinus narrowRatio 1.02–1.5 (range
5
ings (>50%) were studied in 19 patients without IIH and 14
Keywords subjects)
for non-IIH Idiopathic intracranial hypertension . Computed
patients with IIH. Computed tomography vascular studies
tomographic venography . Venous sinus . Vascular stenosis
Ratio >1.5
8
were reviewed and the dimensions of the venous sinuses
−4 cases demonstrated true
disproportionately large bony grooves
and bony grooves at the sites of maximum and minimum
−4 cases discordance could be explained
transverse sinus area dimensions were recorded.
Introduction
by the presence of associated draining
Angio 3D with injection
59. Treatment
— Medical
Angiographie veineuse cérébrale
— Weight loss
— Corticosteroids in acute phase : ?
Sténoses serrées des sinus transverses
— Acetazolamide
droit et tinnitus
— Improvement of headaches,gauche
Gradient de pression trans— Iterative Lumbar puncture : ?
sténotique de 35mmHg à droite
— If weakening of visual acuity persists:
— Drains of CSF
— Fenestration of the optic nerve sheath.
— Interventional Vascular Therapy
— Transverse sinuses angioplasty
Intravenous pressure measurements
with abrupt pressure gradient > 10 mmHg
Angioplastie de la
sténose droite au ballon
60. Conclusion (1)
IIC
IC Hypotension
— Orthostatic Headache
— Global and diffuse
enhancement of dura
mater
Venous congestion
— TTT : blood patch
— Headache, visual troubles,
tinnitus
— Empty sellae, enlargment
of CSF resorption ways
(peri optic)
— TTT to preserve visual
functions
