CHUNG, J.I., Department of Radiology, Suncheon Pyunghwa Hospital, Suncheon City, Republic of Korea

WEON, Y.C., Department of Radiology, Samsung Medical Center, Seoul, Republic of Korea

Unilateral Moyamoya Disease vs. Asymmetric Manifestations of Definite Moyamoya disease: Angiographic Pattern Analysis with Its Pathognomonic Find-

ings

Bilateral progressive steno-occlusive changes of supraclinoid ICA segments involving carotid fork region; Unilateral involvements (overall 20%) are also seen

“Puff of Smoke”; (1) Classical basal collater-als recruiting leptomeningeal vessels and deep parenchymal vessels of striatum (2) Collateral vessels are formed during prena-tal period

Pathophysiology; Fibrocellular intimal thick-enings with wavy internal elastic lamina and thinning of media

Moyamoya disease (MMD)

INTRODUCTION

Etiology; UnknownSome Genetic Predispositions; 10% of familial

incidence, hereditary and multifactorial, au-tosomal dominant familial MMD with re-duced penetrance

Genetically Susceptible Loci; 3p, 6p, 17q, and band 8q23

Angiographic Classification of MMD; Suzuki & Takaku since 1969, but often fail to repre-sent the disease progression

Controversies about its etiologies as congeni-tal vs. acquired

Moyamoya disease (MMD)

INTRODUCTION

Moyamoya disease (MMD)

Presumptive prenatal occlusive changes of carotid arteries during certain embryonic pe-riod: Stage IV & Stage V, Padget DH. The development of the cranial arteries in the human embryo. Contrib Em-bryol 1948;32:207-261

INTRODUCTION

Visualization of primitive embry-onic arteries with remnant anas-tomosis and annexations : cru-cial to understand the patho-physiologic mechanisms

Pathophysiologic target arterial segment could be located in proximal MCA just distal to AChA bifurcation during 14-20mm embryo stage: Stage IV & V, Pad-get DH

Persisted and annexed embryonic vessels which depicted as col-laterals in MMD patients: reveal the time specific occlusive changes of carotid arteries and show adjusted hemodynamic balances during the early em-bryonic period.

Moyamoya disease (MMD)

INTRODUCTION

Moyamoya disease (MMD)

Ophthalmic Rete Mirabile (ORM) annexations with PVOA (primi-tive ventral ophthalmic artery) and POlfA (primitive olfactory

artery): Visualization of Embryonic Remnant Vascular Configurations

Interventional Neuroradiology 14: 293-296, 2008

INTRODUCTION

Moyamoya disease (MMD)

Ophthalmic Ethmoidal Collaterals

20mm Stage: dwindling SOD of Stapedial Artery anasto-mosis with Ophthalmic Artery “arterial ring” which passes around the dorsal side of the optic nerve.

Stem of Ophthalmic artery -”arterial ring” of 2ndary anasto-mosis between SOD of SA and stem of OA – Anterior ethmoidal artery along the course of Nasociliary nerve. INTRODUCTION

Progression of Unilateral MMD: A Clinical Series. Kelly ME et al. Cerebrovasc Dis 2006;22:109-15

7/18 (38.9 %) OF ANGIO-GRAPHIC PROGRESSION

6/7 (85.7 %) OF INITIAL CAROTID FORK ABNORMAL-ITIES

Presence of contralateral carotid fork abnormalities are impor-tant prognostic factors of pro-gression

“True definition of Unilateral MMD is Unclear”

UNILATERAL MMD VS. ASYMMET-RIC DEFINITE MMD

PURPOSE

Anatomic configuration of the cerebral vessels of Uni-lateral MMD :

Presence of Contralateral carotid fork abnormali-ties & Remnant embryonic annexations and anas-tomosis represented as COLLATERALS

“UNDOUBTEDLY PLAYS A ROLE IN OUTCOME”Immediate Surgery for Moyamoya Syndrome? Not Nec-

essarily Roach ES. Arch Neurol 2001;58:130-31 Try to discern the Pathognomonic Angiographic

Manifestations Verifications and Predictable Natural History about

MMD “ TRUE DEFINITION OF UNILATERAL MMD ?”

UNILATERAL MMD VS. ASYMMET-RIC DEFINITE MMD

PURPOSE

March 2002 to April 2004Angiographic Analysis: Independently Reviewed by Two

Experienced Neuroradiologists (C.J.I & W.Y.C.) Based upon the Significant Contributions by Dorcas

Hager Padget (1906-1973) “The development of the cranial arteries in the

human embryo. Contrib Embryol 32:205-261, 1948”

Analysis of the Pathognomonic Angiographic Manifesta-tions

Carotid Fork Appearances Identification and Classification of Remnant Em-

bryonic Anastomosis and Annexations

RETROSPECTIVE REVIEW 204 ANGIOGRAMS (102 MMD PA-

TIENTS)

METHODS

All 20 patient showed Asymmetric Contralateral Carotid Fork Abnormalities with Typical MMD Collaterals

Disproportional Vessel Caliber Changes (2/19, 10.5%) and

Mild degree Stenosis of Carotid Fork Region (17/19, 89.5%)

TYPICAL MMD COLLATERALS POlfA with or without ORM (ophthalmic rete

mirabile): 8/19, 42.1% Ophthalmic Ethmoidal Collaterals: 2/19, 10.5% Callosal Artery Collaterals: 3/19, 15.8%

20 (19.6%) OF UNILATERAL MMD VS. ASYMMETRIC DEFINITE MMD

RESULTS

Dispropor-tional Vessel

Caliber Changes

RESULTS

Mild Degree Stenosis of Carotid Fork Regions: A1

segment nar-rowings

POlfA Collat-erals

RESULTS

Typical MMD Collaterals of POlfA with or without ORM (Ophthalmic

Rete Mirabile)

POlfA Collater-als

Basal Collater-als

RESULTS

Ophthalmic Ethmoidal Col-

laterals

Basal Collat-erals

RESULTS

Callosal Artery Collaterals

POlfA Collaterals with ORM (Oph-

thalmic Rete Mirabile)

RESULTS

The definition of Unilateral MMD is IncorrectMMD is Bilateral Disease without Exception, but

Sometimes do Manifests as Asymmetric In-volvements

Must Understand the Characteristic Angiographic Findings of Typical MMD Collaterals: Remnant Embryonic Anastomosis and Annexations

Pathognomonic Angiographic Findings of Asymmet-ric MMD Carotid Fork Abnormalities

Identification and Understand the patterns of Remnant Embryonic Anastomosis and Annexa-tions

UNILATERAL MMD VS. ASYMMETRIC DEFINITE MMD

CONCLUSION