Moya Moya disease is an entity, whichrepresents chronic idiopathic non-inflammatory progressive occlusion of circleof Willis, which in course of time leads to development of collateral vessels. Itis more common in Japanese individuals. This should be considered as a differentialin young stroke.
Here we present a case of 8-year-old young female with righthemiparesis and headache with a known history of seizure disorder. Keywords: Moya Moya , puff ofsmoke, IVY signIntroductionMoya Moya is a idiopathic, chronic progressive non-atheroscleroticVasoocclusive disease involving circle of Willis arteries predominantly supraclinoid Internal carotid artery with multiple collateral vessels maintaining flow.Moya Moya is a japanese word representing puffy, hazy appearance , hence the “PUFFOF SMOKE” appearance1. It is first reported in Japanese population in 19572.It has bimodal age distribution: early childhood (two third cases), middle age(one-third cases).
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Incidence among females is greater than that among males(1.8:1) with japan having more prevalence than other Asian countries (0.35-2.0 casesper 100000, prevalence 3.16) 3.
10% of cases showed family history 4. Moya Moyasyndrome has similar appearance to Moya Moya disease but is associated withother conditions like meningitis, Head trauma, Neurofibromatosis I, Downsyndrome.CaseReport Fig 1 and Fig 2 showing area of acute infarct in left frontal region showing diffusion restriction (red arrow) and ADC suppression (yellow arrow) A8 year old female child presented with h/o sudden onset of right upper limbweakness with headache and photophobia.
No h/o fever, vomitings, trauma. She isa known case of seizure disorder. Laboratory investigations like CBP, CUE, homocysteinelevels, sickle cell test, antinuclear antibody test shows no abnormality.
Anon-contrast MRI brain was done onPhilips achieva 1.5T scanner.T1,T2,FLAIR,DWI/ADC maps were acquired. Thefindings included an area of acute infarct in left frontal region ( fig 1 andfig 2 ) with adjacent gliotic change. Fig 1.
Axial DWIimage Fig 2. Axial ADC imageThen a CT Cerebral angiogram with 128slice Philips CT scanner was done with administration of 40ml contrast at flowrate of 4ml/sec . Findings includeddiffusely reduced caliber of bilateral internal carotid arteries with abruptcut off of distal internal carotid arteries (post supraclinoid segment) withmultiple enhancing lenticulostriate and thalamoperforator vascular channels onright side , giving appearance of puff of smoke fig 3 and fig 4, maintaining flow in circle of Willis with one vesseljoining left posterior cerebral artery suggesting chronic vasocclusive changesa feature of Moya Moya disease stage II. Fig 3. CT angiogram MIP coronalimage Fig 4 .
CT angiogram 3D volume renderedimageFig 3and 4 showing multiple vascular channels (red arrow) in right basal gangliaregion representing lenticulostriate and Thalamoperforator vessels givingcharacteristic PUFF OF SMOKE appearance.An MRangiogram was performed showing similar findings further confirming thediagnosis by clearly depicting the abrupt cut off of internal carotid arteries fig5 and fig 6. Fig 5.MR angiogram sagital MIP image Fig 6. MR angiogram coronal MIP imageFig 5and 6 showing abrupt cut off of bilateralinternal carotid arteries(red arrows) and collateral vessels in right basal ganglia (yellow arrow) DiscussionMoya Moya is a non inflammatory chronicprogressive occlusion of arteries of circle of Willis leading to thedevelopment of collateral vessels seen on cerebral angiography 5. It has abimodal age distribution with early childhood and middle age adults representingtwo third and one third cases with peaks at 4yrs and 4th decaderespectively .
Clinical presentation may be ischemic (morein children),epileptic or hemorrhagic (more in adults). Behavioral disturbancesand cognitive dysfunction are uncommon symptoms and may occur based on the areaof insult 6. Radiological imaging has an importantrole in diagnosing Moya Moya disease. CT angiography and MR angiography aregood techniques for confirming the diagnosis. It can detect the stenosis orocclusion of internal carotid artery with multiple collateral vessels (pialcollaterals, lenticulostraite , Thalamoperforators, leptomeningeal vessels)with associated changes in brain like infarction and atrophy. Serpentine sulcalhigh signal intensity on MRI FLAIR representing IVY sign may be identified.
Conventional angiography is the goldstandard to demonstrate Puff Of Smoke appearance . Staging by SUZUKU and KODAMA is usefulin categorizing the disease into 6 phasesStageI -“Narrowing of the carotid fork” , narrowedICA bifurcationStage II-“Initiationof the MoyaMoya” – Dilated ACA, MCA and narrowed ICA bifurcation with MoyaMoyachangeStageIII-“Intensificationof the MoyaMoya “- further increase in MoyaMoya change of the ICA bifurcationand narrowed ACA and MCAStageIV-“Minimizationof the MoyaMoya” – MoyaMoya change reducing with occlusive changes in ICA and Tenuous ACA and MCAStageV -“Reductionof the MoyaMoya” – further decrease in MoyaMoya change with occlusion ofICA, ACA and MCAStageVI-“Disappearanceof the MoyaMoya” – ICA essentially disappeared with supply of brain fromECA Early diagnosis and treatment duringchildhood is essential to preventdisability . Acute medical management include symptomatic treatment directed towards controlling seizures,increasing cerebral blood flow 7 . Revascularization by bypass grafts fromexternal carotid artery to MCA or superficial temporal artery to MCA isbeneficial in ischemic cases8.
(ACA: anterior cerebral artery , MCA:middle cerebral artery , ICA: internal carotid artery, MRI: magnetic resonanceimaging, CT: computed tomography, MIP: maximum intensity projection, CBP:complete blood picture ,CUE: complete urine examination)