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NEUROLOGICAL PICTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
doi: 10.1136/jnnp.2003.031393

Unusual differential diagnosis of leptomeningeal enhancement: moyamoya disease

W

e report on a 13 year old boy
who presented with a focal left
sided motoric seizure and a
history of progressive headaches since 6
years of age. On neurological examination, motor function of the limbs, deep
tendon reflexes, and sensory examination
were normal, but there was slight left
sided bradydisdiadochokinesis. Routine
blood tests and anti-immune antibody
screening as well as cerebrospinal fluid
(CSF) analysis were normal.
Magnetic resonance imaging (MRI)
showed multiple curvilinear areas of
high signal intensity in leptomeninges
(fig 1A) and diffuse enhancement along
leptomeningeal surfaces (fig 1B). Digital
subtraction angiography demonstrated
severe stenoses of both distal internal
carotid artery (ICA) segments (fig 1C)
as well as extensive leptomeningeal
collaterals (fig 1D).
Leptomenigeal enhancement on postcontrast T1 weighted MR images has
been reported in association with
meningitis, meningeal carcinomatosis,
and angiitis. Common among these
diseases is pathologic inflammation or
carcinomatous infiltration of the leptomeninges, with or without involvement
of the small leptomeningeal vessels.
In 1995 Ohta et al1 reported diffuse
leptomeningeal enhancement on postcontrast T1 weighted MRI in children
with moyamoya disease and named
these finding the ‘‘ivy-sign’’, because it
resembles ivy creeping on stones. The
ivy-sign can be found on fluid attenuation inversion recovery (FLAIR) images,
as well as on contrast enhanced MRI.2 3
The characteristic enhancement is
caused by an engorged pial network
via leptomeningeal anastomosis. The
source of leptomeningeal high signal
intensity on FLAIR images is not clear
but it seems largely due to slow flowing
vessels of the engorged pial network.2
Thus, the mechanism of the leptomeningeal ivy-sign can be explained by an
engorged pial network and possibly the
congested meninges.
J Gaa, S Weidauer
Institute of Neuroradiology, Klinikum der
Johann Wolfgang Goethe-Universität Frankfurt,
Germany

www.jnnp.com

Figure 1 (A) Axial FLAIR MRI reveals multiple areas of high signal intensity (arrows) in
leptomeninges. (B) Axial contrast enhanced T1 weighted image shows diffuse enhancement along
leptomeningeal surfaces (arrows). (C) Lateral view of right carotid angiogram and (D) right
vertebral angiogram demonstrate severe stenoses at the distal ICA (arrow) and wide terminal
segments of the posterior and middle cerebral arteries due to extensive leptomeningeal collateral
flow (arrowheads).

Correspondence to: Dr J Gaa, Department of
Neuroradiology, University of Frankfurt,
Schleusenweg 2-16, 60528 Frankfurt,
Germany; jochen.gaa@kgu.de

References
1 Ohta T, Tanaka H, Kuroiwa T. Diffuse
leptomeningeal enhancement, ‘‘ivy sign’’, in
magnetic resonance images of moaymoya

disease in childhood: case report. Neurosurg
1995;37:1009–12.
2 Maeda M, Tsuchida C. ‘‘Ivy-sign’’ on fluidattenuated inversion recovery images in
childhood moyamoya disease. American Journal
of Neuroradiology 1999;20:1836–38.
3 Yoon HK, Shin HJ, Chang YW. ‘‘Ivy sign’’
in childhood moyamoya disease: depiction
on FLAIR and contrast-enhanced T1weighted MR images. Radiology
2002;223:384–89.