ARACHNOID - PowerPoint Presentation

Slide1

ARACHNOID GRANULATIONS, VENOUS SINUSES AND HEADACHE, ARE THEY RELATED?

Quiñones Tapia D, Andreu

Arasa

C, and

Viaño

J.

Neuroradiology

Hospital Nuestra Señora del Rosario, Madrid SPAINSlide2

The authors have no disclosures to makeSlide3

PURPOSEArachnoid granulations (AG) are involved in CSF resorbption and increase with ageCystic arachnoid granulations are often detected inside dural venous sinusesNowadays, submilimeter resolution in CT and MRI permit in vivo visualization of arachnoid granulations and intracranial venous sinuses

AG may partially obstruct venous outflow, and thus could be related to some types of headaches or predispose to venous thrombosisSlide4

Approach/Method: A retrospective review of MRI and CT reports with the diagnosis of “prominent arachnoid granulation” was made from the last 3 years in an Imaging Center. 128 cases were reviewed27 cases had venous MRA40% of cases were obtained to study headaches related to valsalva or exertion.We tend to report AG when they are larger than 1cm or they obstruct aprox. 70% of the V sinus.Slide5

Dural sinus and arachnoid granulations

AG are normal

Cystic

and vascular

structures

that

may

be

located

inside dural sinuses. They colect CSF returning fluid to the venous system. With age AG increase in size and number

AG are also know as

Pacchioni

granulations.

When they erode bone they are called “

arachnoid pits

”Slide6

Arachnoid Granulations on MRI

Are always located adjacent to dural sinuses

may erode bone and be

intradiploic

(arachnoid pits)

May be completely inside the dural sinus, with a cystic non enhancing component and some small enhancing veins, and in these cases they may partially obstruct venous outflow

saggital

axial

coronalSlide7

Findings (N=120)In 4 cases AG were found associated with venous thrombosis28 patients studied for headaches (HA) had AG obstructing mayor dural sinuses (20 SSS or dominant transverse) or in the Straight Sinus 8 Venous variants with small dural sinuses were detected in 15 patients studied with VMRA for HA associated with exertion or Valsalva

2 patients had small

cephaloceles

into the AG and HA with

ValsalvaSlide8

A. AG associated with venous thrombosis (4 cases)In 4 cases of cerebral venous thrombosis we noticed prominent AG obstructing over 70% of a mayor venous sinus

(

related

to

the

site

of

venous

outflow)The A.G. may contribute for thrombosis to occur by decreasing venous flow. Predisposing factors such as dehydration and abnormal coagulation concur.Slide9

CASE 1: R

transverse

sinus

thrombosis

and

A

GSlide10

A CASE1: VENOUS INFARCT/THROMBOSED TORCULA

36

year

old

man

with

right

side

sensory

deficit

.

Imaging

findings

:

CT:

Brain

is

normal,

except

for

a

large

arachnoid

granulation in the torcula (low

attenuation on CT) and R hiperdense

transverse

S.

MRI:

on the following dayBright cortical-subcortical left medial occipital lobe lesion with slightly restricted diffusion (venous infarct)Large arachnoid granulation inside the torcula Abnormal content in the posterior sagital sinus (thrombus)Left transverse sinus is hypoplasic

James L.

Leach

, Robert B. Fortuna, Blaise V. Jones,

and

Mary F.

Gaskill

-

Shipley

. Imaging

of

Cerebral

Venous

Thrombosis

:

Current

Techniques

,

Spectrum

of

Findings

,

and

Diagnostic

Pitfalls

.

Radiographics

October

2006 26:

suppl

1 S19-S41;

doi

:10.1148/

rg

.26si055174Slide11

Cefaleas49 patients with ICHD-II criteria for HA, 41 complete imaging

with

Venous

Gd

angioRM

(

Headache

related

to

20 sexual intercourse, 10 cough, and 11 on exertion). Transverse Sinus stenosis in 43%, 37% y 20% and 0 in Control group.Slide12

B. AG inside mayor Venous Sinus:Headache and Giant AG in S.Saggital Sinus

Bone

remodeling

is

present

and

the

SSS

is

split by the AGThis patient’s HA did not worsen with valsalva

or

excerciseSlide13

Pacchioni granulations in the Straight Sinus (3/8 different cases studied for headache)

This location has been

reffered

by some anatomists as “Galen’s Ampulla” and hypothetically attributed a valve mechanism for regulation of deep venous cerebral flow

This anatomic disposition was found in 5 cases with HA on exertionSlide14

CASE

2

: 53 yo

female

. L

side

tinnitus

and HA.

L

transverse

Sinus hiperintensity in FLAIR due to slow venous

flow

in

the

non-

dominant

sinus

which

has a

partially

obstructing

AGSlide15

C CASE 3: 43 yo female with HA increasing with valsalva.L transverse Sinus AG/+ encephalocele



The dura and brain herniate inside the left transverse sinus (red arrow), possibly at a dural defect related to an arachnoid granulation.

T

he venous outflow reduction may be related to her headachesSlide16

CASE

4

: 73 yo

male

chronic

headache

Venous

sinus

thrombosis

suspected

.

Imaging

findings

:

Rounded

cystic

structure

in

the

proximal

right

transverse

sinus

Isointense

to

CSF in all sequences and

No

enhancement

(

arachnoid G.) Filling defect on post contrast images, the lateral R tranv sinus enhancesR transverse sinus decreased flow hiperintense T2w (not detected 3D PC MRA) James L. Leach, Robert B. Fortuna, Blaise V. Jones, and Mary F. Gaskill-Shipley. Imaging of Cerebral Venous Thrombosis: Current Techniques, Spectrum of Findings

,

and

Diagnostic

Pitfalls

.

Radiographics

October

2006 26:

suppl

1 S19-S41;

doi

:10.1148/

rg

.26si055174Slide17

D: Venous Variants on VMRAAbnormal development of dural sinuses in 15/27 cases with chronic HA and Venous MRAHypoplasic/agenetic transverse sinuses and infratentorial suboccipital sinuses may be unusually small

Intracranial

Hipertension

is related to small/ compressed venous sinuses

Agenesis

of

the

proximal

portion

of

the

non-

dominant L Tranverse SinusSlide18

CASE 5: 30 yo male with HA and dizziness

Double

posterior S.

Sinus

, and R

hypoplastic

Transverse

sinusSlide19

CASE 6: 53 yo slim female. Headache and elevated CSF pressure, several LP (>21 cmH20)

MRI:

normal ventricles and sulci.

The

torcula

is small.

Partially empty

sella

.

Small collapsed cavernous sinuses.

3D PC non

enhanced

MRA:Abnormal bilateral hypoplastic transverse sinuses.Enlarged

Saggital

sinus

.Slide20

Case 6 DSA: Abnormal torcula and proximal transverse sinuses

are

hypoplastic

.

Variant

of

suboccipital

sinus

comunicating

the straight sinus with the Right internal yugular bulb.No trombus. Restricted venous outflow?Slide21

CASE 7:

male

with

exertional

headache

, V.

variants

MRI

and 3D PC MRA (no

Gd)

Vertical

tentorium

.

Infratentorial

occipital sagital

sinus

and

left

transv

.

hypoplasic

sinus

originating

from

the

straight

sinus

.

All

the sinuses, have normal flow but are quite smallSlide22

Summary / ConclusionsIn our series of HA with Valsalva/exertion 40% had reported AG obstructing (>70%) of mayor venous sinuses, but medical implications and treatment are unclearArachnoid granulations, considered normal intracranial structures, may sometimes by size or location produce restricted cerebral venous outflowLooking at the veins and sinuses is mandatory in the evaluation of headache

to exclude thrombosis, intracranial hypertension or

hypotension

,

or to detect venous sinus hypoplasia in

exertional

headache.

55% of chronic HA with exertion had

venous

variants

on VMRA

Interventional treatment with venous stents should only be considered after clear relation with HA or increased intracranial pressure and demonstration of a venous pressure gradient in the affected venous sinus.

Contact: dquinones@rmrosario.comSlide23

References“Cranial Arachnoid Protusions and Contiguous Diploic Veins in CSF Drainage” Tsutsumi

S,

Ogino

i,

Miyajima

M,

nakamura

Y,

Arai

H and

Ito

M

. AJNR sept 2014, 35:1735-39.“Primary cough headache, primary exertional headache, and primary headache associated with sexual activity: a clinical and radiological study” Donnet A,

Valade

D, et al.

Neuroradiology

2013;55:297-305.

“

Imaging

of cerebral

venous

thrombosis

:

current

techniques

,

spectrum

of

findings

, and

diagnostic

pitfalls” Leach JL, Fortuna RB, Jones BV and Gaskill-Shipley MF. Radiographics 2006;26:S19_S43.“Cerebral Venous

Thrombosis: diagnostic accuracy of combined, dynamic and static, contrast-enhanced

MR Venography” Meckel S, Reisinger, Bremrich et al. AJNR Am J Neuroradiol Mar 2010;31:527-35.“The

jugular foramen: a review of anatomy, masses and imaging characteristics” Caldemeyer

KS,

Mathews

VP,

Azzarelli B, and Smith RR. Radiographics 1997;17:1123-1139.“Idiopathic Intracranial Hypertension: the prevalence and morphology of sinuvenous stenosis.” Farb RI, Vaneck I, Scott JN et al. 2003 Neurology 60(9):1418-142“Two cases of brain haemorrhage secondary to Developmental Venous Anomaly thrombosis. Bibliographic review” Abarca-Olivas J, Botella-Asunción C, et al. Neurocirugia 2009 jun20(3):265-71.