Different aspects of cognitive function in adult patients with moyamoya disease and its clinical subtypes.

OBJECTIVE: Although a few reports suggested that cognitive function impairment could be found in adult patients with moyamoya disease (MMD), there were still many aspects that are unclear. The aim of our study was to assess the cognitive function of adult patients with MMD and its clinical subtypes. METHODS: 49 patients with MMD and 23 healthy controls were asked to take cognitive function tests. Cognitive function tests included IQ, prospective memory (PM), immediate memory (IM), verbal fluency (VF), visual breadth, attention, retrospective memory (RM), Stroop test, Wisconsin Card Sorting Test, Trail-Making Test Part A (TMT-A) and Continuous Performance Test (CPT). Independent t-analysis, one-way analysis of variance and Pearson correlation were used to seek for differences between subgroups and the correlation between cognitive variables. RESULTS: Compared with healthy controls, adult patients with MMD had a comprehensive cognitive impairment, including IQ, PM, VF, attention, RM, Stroop, CPT and TMT-A, with more serious impairment in PM and attention. PM and RM were separated, indicating that they were independent of each other. Pattern of attention was significantly different from healthy controls. Female patients were better than male patients, where significant differences in PM, IM, Stroop and WCST could be found. The haemorrhagic patients exhibited poorer in the dimension of PM and RM than the ischaemic. The headache subtype exhibited poorer than healthy controls. PM, RM, attention and executive function were moderately correlated with each other. CONCLUSIONS: Adult patients with MMD had a wide range of cognitive impairment with more serious impairment in memory and attention. Differences in cognitive function existed between the different subtypes of adult MMD.

Hemodynamic stress distribution identified by SPECT reflects ischemic symptoms of Moyamoya disease patients.

This study aimed to validate the hypothesis that the ratio of cerebral blood flow (CBF) at rest in the lenticular nucleus (LN) territory to that in the middle cerebral artery (MCA) territory is higher in symptomatic Moyamoya disease (MMD) patients than in asymptomatic MMD patients. This was a retrospective observational study of adult patients with documented MMD who underwent single-photon emission computed tomography (SPECT) and had been examined at the Department of Neurosurgery of Keio University Hospital during a 10-year period (2006-2016). The diagnosis was made on the basis of typical imaging findings. We classified unoperated MMD patients into three groups: class I, no evidence of stenosis or occlusion hemispheres and without symptoms in unilateral MMD patients; class II, hemispheres with stenosis or occlusion but without ischemic symptoms; and class III, hemispheres with evidence of stenosis or occlusion associated with ischemic symptoms. Hemodynamic stress distribution (hdSD) was defined as the ratio of CBF in one LN to the CBF in the peripheral MCA; this was obtained by SPECT at rest. We compared the values of CBF and hdSD among the groups. A total of 173 adult patients were diagnosed with MMD from January 1, 2006, to January 1, 2016. Among them, 85 MMD patients underwent SPECT studies. After excluding inappropriate cases, 144 hemispheres were included in our analysis. hdSD was significantly higher (p < 0.001) in hemispheres with ischemic symptoms (class III, mean hdSD = 1.1; 36 sides) than in those without symptoms (class II, mean hdSD = 1.03; 82 sides). However, CBF at rest in the MCA or LN was not significantly associated with ischemic symptoms. The optimal threshold for hdSD to have ischemic symptoms was 1.040 (area under the curve; 74% sensitivity 91.7% and specificity 54.9%). We used SPECT to investigate cerebral blood from MMD patients and found that high hdSD values were predictive of ischemic symptom development in these patients.

Posterior Circulation Moyamoya Disease versus Primitive Vertebral-Basilar Artery System Moyamoya Disease: New Classification of Moyamoya Disease from the Perspective of Embryology.

BACKGROUND AND PURPOSE: Moyamoya disease (MMD) is a chronic cerebrovascular disorder with little known etiology. We aim to propose a new classification system for MMD from the perspective of embryology. METHODS: MMD patients' digital subtraction angiograms were retrospectively analyzed. Every angiogram was analyzed to find the abnormal vessels and from which part of the posterior cerebral artery (PCA) the lesions begin. RESULTS: In 262 MMD cases, 32 pediatric patients had PCA involvement, of which 17 were male and 15 were female; 68 adults had PCA involvement, of which 33 were male and 35 were female. The initially affected part of the PCA was compared between sexes and between pediatric and adult patients, and the findings are not statistically significant (P = 0.233, P = 0.855, P = 0.343, respectively). However, of the 100 cases with PCA involvement, only 4 had the lesions begin from the first part of the PCA, and all of the 4 cases had the basilar artery lesions. All the other 96 cases had the lesions begin from the second part of the PCA or from the posterior communication artery, which is derived from the caudal ramus of the primitive intracarotid artery, leaving the first part of the PCA and basilar artery excluded from affection. CONCLUSION: MMD should be classified into primitive intracarotid artery system-involved type and primitive vertebral basilar artery system-involved type. The reason that the vertebral basilar artery is so rarely involved in MMD might be because of its late development in the brain.

More Precise Imaging Analysis and Diagnosis of Moyamoya Disease and Moyamoya Syndrome Using High-Resolution Magnetic Resonance Imaging.

BACKGROUND: The diagnosis of moyamoya disease (MMD) is often uncertain. Moyamoya syndrome (MMS) is often misdiagnosed as MMD. High-resolution magnetic resonance imaging (HR-MRI) enables vessel wall assessment to obtain more precise diagnoses. The aim of this study was to determine the true etiologies of arterial steno-occlusion in patients with an angiographic diagnosis of MMD or MMS using HR-MRI. METHODS: HR-MRI was performed in 21 adult patients with angiographically proven MMD or MMS. A definite diagnosis was based on the HR-MRI findings. The diagnoses made via the 2 different imaging technologies were compared, and significant findings were analyzed. RESULTS: A total of 21 patients were enrolled, including 7 patients with angiographically proven MMD and 14 patients with angiographically proven MMS. Among the 7 patients with MMD, HR-MRI confirmed the diagnosis of MMD in 6; the remaining patient was considered to have atherosclerosis in the bilateral distal internal carotid arteries (ICAs) and the left middle cerebral artery. Among the 14 patients with MMS, HR-MRI confirmed MMD in 6 patients (including 2 patients with unilateral MMD), atherosclerosis in 5 patients (including 3 patients with bilateral atherosclerosis and 2 with unilateral atherosclerosis), arterial dissection of the left ICA in 1 patient, and MMD in the left cerebral hemisphere with atherosclerosis in the right hemisphere in 2 patients. CONCLUSIONS: Differentiating MMD from MMS is difficult in certain situations, and HR-MRI may help provide a more in-depth understanding of MMD and MMS, thereby achieving a more reliable diagnosis.

Is Quasi-moyamoya Disease a Uniform Disease Entity? A Three-Dimensional Constructive Interference in Steady State Imaging Study.

BACKGROUND: Quasi-moyamoya disease (MMD) or moyamoya syndrome is based on various underlying diseases and radiologically simulates MMD, but its disease entity is still unclear. Recent studies have proven specific shrinkage of the involved arteries in MMD. Using 3-dimensional constructive interference in steady state (3D-CISS), therefore, this study aimed to analyze the outer diameter of the involved arteries in quasi-MMD. METHODS: This study included 9 patients with quasi-MMD (unilateral type, n = 2; bilateral type, n = 7). Using 3D-CISS, the outer diameter was quantified in the internal carotid artery distal to the posterior communicating artery (C1), the horizontal portion of the middle and anterior cerebral arteries (M1 and A1, respectively), and the basilar artery. Control values were obtained from 17 healthy subjects. RESULTS: In 7 of 9 patients, the outer diameters of C1, M1, and A1 were significantly smaller than those of the controls. On the other hand, the values were normal in other 2 patients. There was no significant difference in the underlying disorders between the 2 groups. All 3 pediatric patients are categorized into the arterial shrinkage group, but 2 of 6 adult patients were not. CONCLUSIONS: These findings strongly suggest that quasi-MMD is not a uniform disease entity and includes at least 2 pathophysiologically different groups: the arterial shrinkage group and the nonarterial shrinkage group. A certain subgroup of MMD patients may be misdiagnosed as quasi-MMD because of the patients' comorbid disorders and mixed up with the patients who present angiographic findings similar to MMD in spite of the lack of arterial shrinkage.

Different aspects of dysexecutive syndrome in patients with moyamoya disease and its clinical subtypes.

OBJECTIVE Dysexecutive syndrome is common in patients with moyamoya disease (MMD), a chronic cerebrovascular disease that is characterized by stenosis of the bilateral internal carotid arteries and progressive collateral revascularization, and MMD can be classified as ischemic or hemorrhagic according to the disease presentation and history. In this study, the authors aimed to determine which aspects of executive function are impaired in patients with MMD, in addition to the specific dysexecutive functions present among its clinical subtypes and the mechanisms underlying dysexecutive function in these patients. METHODS The authors administered 5 typical executive function tests (the Stroop test, the Hayling Sentence Completion Test [HSCT], the verbal fluency [VF] test, the N-back test, and the Sustained Attention to Response Task [SART]) to 49 patients with MMD and 47 IQ-, age-, education-, and social status-matched healthy controls. The dysexecutive questionnaire (DEX) was also used to assess participants' subjective feelings about their executive function. A total of 39 of the patients were evaluated by CT perfusion (CTP) before the assessments were performed, and the correlations among the performances of the patients on the above tests with the parameters of cerebral blood volume, cerebral blood flow (CBF), mean transit time (MTT), and time-to-peak (TTP) in the frontal lobes of these patients were also analyzed. RESULTS Many aspects of executive function in the patients with MMD were significantly poorer than those in the healthy controls, and the patients performed particularly poorer on the VF test, HSCT, N-back test, and SART. The patients with hemorrhagic MMD exhibited worse executive inhibition, executive processing, and semantic inhibition compared with those with ischemic MMD, but the latter group presented a worse working memory and poorer sustained attention. There were no significant differences in the DEX scores between the patients with MMD and healthy controls. The other findings were as follows: CBF was significantly positively correlated with the number correct on part B of the HSCT (r = 0.481, p = 0.01) and accuracy on the 0-back task of the N-back (r = 0.346, p = 0.031); MTT was significantly positively correlated with accuracy on the 2-back task of the N-back (r = 0.349, p = 0.034) and factor 5 of the DEX (r = 0.359, p = 0.032); and TTP was significantly positively correlated with the number correct on part B of the HSCT (r = 0.402, p = 0.034) and the 1-back reaction time of the N-back (r = 0.356, p = 0.026). CONCLUSIONS The patients with MMD exhibited impairments in semantic inhibition, executive processing, working memory, and sustained attention, but they were not aware of these deficits. Moreover, differences in dysexecutive function existed between the different subtypes of MMD. Hypoperfusion of the frontal lobe may be related to working memory and semantic inhibition impairments in patients with MMD.

Selective and superselective angiography of pediatric moyamoya disease angioarchitecture: the anterior circulation.

The angioarchitecture of the so-called moyamoya vessels in children has not been explicitly analyzed. We aimed to investigate the precise anatomy of the vascular anastomotic networks in patients with childhood moyamoya disease. Six children diagnosed with moyamoya disease for the first time underwent an angiographic investigation with selective and superselective injections. We recorded the arterial branches feeding the moyamoya anastomotic networks, their connections and the recipient vessels. Depending on the level of the steno-occlusive lesion, the feeding vessels included the medial striate arteries, the perforators of the choroidal segment of the carotid, the uncal artery, the medial and lateral branches of the intraventricular segment of the anterior choroidal artery, perforators of the communicating segment, the superior hypophyseal arteries, the prechiasmal branches of the ophthalmic artery, the ethmoidal arteries and the dural branches of the cavernous carotid. Through connections, which are described, the recipient vessels were the lateral striate arteries and the middle cerebral, the medial striate arteries and the anterior cerebral, medullary arteries around the ventricular system, anterior temporal branches of the middle cerebral, orbitofrontal and frontopolar branches of the anterior cerebral, as well as other cortical branches of the anterior and middle cerebral territories. The use of high quality selective and superselective angiography enabled us to clearly demonstrate for the first time aspects of the microangiographic anatomy of the moyamoya anastomotic network previously only vaguely or incompletely described.

Selective and superselective angiography of pediatric moyamoya disease angioarchitecture in the posterior circulation.

The anastomotic network of the posterior circulation in children with moyamoya disease has not been analyzed. We aimed to investigate the angiographic anatomy of this unique vascular network in patients with childhood moyamoya disease. Selective and superselective injections of the posterior circulation were performed in six children with newly diagnosed moyamoya disease. The arterial branches feeding the moyamoya anastomotic network, their connections and the recipient vessels were demonstrated. Depending on the level of the steno-occlusive lesion, the feeding vessels were the thalamoperforators, the posterior choroidals, the splenic artery, parietoccipital artery, other cortical posterior cerebral artery (PCA) branches, the dural branch of the PCA, the premamillary artery and other posterior communicating artery perforators. Through connections, which are described, the recipient vessels were the striate and medullary arteries, other thalamic arteries with or without medullary extensions, the pericallosal artery, medial parietoccipital cortical branches of the PCA and the anterior choroidal artery. High quality selective and superselective angiography helped in demonstrating the angiographic anatomy of the moyamoya posterior anastomotic network previously either vaguely or incompletely described, as well as connections within the posterior circulation but also its relevance as a collateral to the anterior circulation.

New grading of moyamoya disease using color-coded parametric quantitative digital subtraction angiography.

BACKGROUND: Moyamoya disease (MMD) is an uncommon cerebrovascular disorder characterized by idiopathic progressive stenosis or the occlusion of the intracranial arteries. Digital subtraction angiography (DSA) is the reference diagnostic imaging modality for MMD. Use of the conventional Suzuki grading remains the gold standard for evaluating the severity of MMD. In this study, we propose a quantitative method using color-coded parametric quantitative DSA (QDSA) to improve prediction of the severity of MMD. METHODS: Eighteen DSA examinations from 18 patients with MMD and 14 control participants were included. All patients with MMD underwent DSA and dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI). QDSA was used to determine the delay time of maximal opacification (Td) between the internal carotid artery and the M2 segment of the middle cerebral artery. The time-to-peak (TTP) was measured in the medial frontal, lateral frontal, parietal, and occipital lobes from the DSC-PWI. The relative TTP (rTTP) values were then obtained by subtracting the TTP of the cerebellum. RESULTS: The Td was significantly longer in the patients with MMD presenting with infarction than in the control group. The Td significantly correlated with the angiographic Suzuki grading system and showed closer correlation with prolonged rTTP in the medial frontal, lateral frontal, and parietal regions compared with Suzuki grading. CONCLUSION: The Td significantly correlated with conventional angiographic grading and with the status of hemodynamic impairment in patients with MMD. QDSA and Td measurements can provide a simple and quantitative angiographic grading system for patients with MMD.

Proposal for a new grading of Moyamoya disease in adult patients.

BACKGROUND: Moyamoya disease (MMD) is graded based on digital subtraction angiography (DSA) with limited clinical applications. The aim was to identify clinically relevant parameters that may be used to develop a novel MMD grading system. METHODS: In 40 MMD patients bilateral revascularization surgery was performed. Clinical data including DSA, MRI and regional cerebral blood flow studies were assessed. χ(2) test corrected for dependency of measurements at the same subject and analysis of receiver operating characteristics were used to identify key parameters. Grading system included: DSA (stenosis/occlusion = 1 point; stenosis/occlusion + intracranial compensation = 2 points; stenosis/occlusion + intracranial compensation + extra-intracranial compensation = 3 points), MRI (no sign of ischemia = 0 points; signs of ischemia = 1 point) and cerebrovascular reserve capacity (CVRC > -5% = 0 points; CVRC < -5% = 2 points). MMD grade I referred to 1-2 points, grade II to 3-4 and grade III to 5-6 points. RESULTS: DSA, MRI and CVRC were dependent factors associated with the occurrence of clinical symptoms. Receiver operating characteristics analysis indentified the grading system as superior to each single parameter in predicting clinical symptoms. Fourteen hemispheres were graded as mild (grade I), 35 as moderate (grade II) and 31 as severe (grade III); 21% of grade I, 63% of grade II and 93% of grade III hemispheres were clinically symptomatic. CONCLUSIONS: The proposed grading system allows to stratify for clinical symptomatology in MMD patients. Future studies will have to investigate its value for assessing clinical symptoms and treatment risks.

Clinical features of unilateral moyamoya disease.

Moyamoya disease is characterized by progressive occlusion of the internal carotid artery or its terminal branches, associated with formation of extensive collateral vessels (moyamoya vessels) at the base of the brain. Whether unilateral moyamoya disease, confirmed by typical angiographic evidence of moyamoya disease unilaterally and normal or equivocal findings contralaterally, is an early form of definite (bilateral) moyamoya disease remains controversial. The present study investigated the incidence and clinical features of unilateral moyamoya disease in a series of patients treated for moyamoya disease. Fifty-two patients were diagnosed with definite moyamoya disease and nine patients with unilateral moyamoya disease. Sex, age, signs at onset, neuroimaging findings, treatment, course of the disease, and family history of unilateral moyamoya disease were reviewed. Among the nine patients with unilateral moyamoya disease, there were twice as many females as males, and mean age at onset was 39.0 years. The clinical presentation was ischemic in three patients, bleeding in one, and asymptomatic in five. Two had familial moyamoya disease. Progression to bilateral lesions is known to occur in pediatric patients and patients with stenotic changes of the contralateral internal carotid artery bifurcation. Some unilateral cases are caused by the same genetic defects as definite cases, and others seem to be an unusual form of stenoocclusive process of cerebral arteries. Surgical treatment on the symptomatic side followed by close observation for bilateral involvement is recommended.

Circulating endothelial progenitor cells as a pathogenetic marker of moyamoya disease.

Moyamoya disease (MMD) is an unusual form of chronic cerebrovascular occlusive disease that involves the formation of characteristically abnormal vessels. Recent studies have reported that colony-forming unit (CFU) and outgrowth cells represent a subpopulation of endothelial progenitor cells (EPCs). Here, we attempted to determine the significance of CFU number and outgrowth cell yield in MMD. Endothelial progenitor cells were isolated from the blood of 24 adult MMD patients and from 48 age- and risk factor-matched control subjects. After 7 days of culture, CFUs were determined, and yields of outgrowth cells were measured during 2 months of culture. The EPC function was also evaluated using matrigel plate assays. It was found that CFU numbers were significantly lower in MMD patients than in controls. Moreover, during long-term culture, outgrowth cells were isolated from only 10% of control subjects but from 33% of MMD patients, and CFU numbers and tube formation were found to be lower in advanced MMD cases than in those with early stage disease, whereas outgrowth cells were more frequently detected in those with early MMD and moyamoya vessels than in those with advanced disease. These characteristics of circulating EPCs reflect mixed conditions of vascular occlusion and abnormal vasculogenesis during the pathogenesis of MMD.

Morning glory disc anomaly, midline cranial defects and abnormal carotid circulation: an association worth looking for.

We report on a 4-year-old boy who presented to the ophthalmology department for assessment of convergent strabismus. Ophthalmic examination showed a left morning glory optic disc anomaly and retinal detachment. Plain films obtained for investigation of short stature prior to ophthalmic examination revealed delayed bone age. Ophthalmological findings prompted CT and MRI imaging and angiographic investigations. Midline cranial defects and abnormal carotid circulation were identified. These findings may be associated with morning glory optic disc anomaly, and their association is often under-recognized. It is important that clinicians and radiologists be aware of this spectrum of disorders, as the vascular abnormalities may predispose the patient to transient ischemic attacks and strokes. Growth delay may result from hypopituitarism.

Assessment of cerebral hemodynamics in childhood moyamoya disease using a quantitative and a semiquantitative IMP-SPECT study.

BACKGROUND: We evaluated the cerebral hemodynamics in childhood moyamoya disease patients before and after surgery to assess both surgical indication and the effect of revascularization using single photon emission computed tomography (SPECT) study with N-isopropyl-p-123I-iodoamphetamine (IMP). We compared results of quantitative and semi-quantitative SPECT studies to determine parameters by the semi-quantitative method to define severe hemodynamic ischemia. METHODS: There were 14 pediatric patients with moyamoya disease who suffered transient ischemic attacks (TIAs) in the anterior circulation. Before and after surgical revascularization by STA-MCA bypass and encephalomyosynangiosis (EMS), quantitative IMP-SPECT studies using the autoradiographic method (IMP-ARG method) were performed. Resting regional cerebral blood flow (rCBF) and regional vascular reserve (rVR) were measured in bilateral cortical territories (ROI) and cerebellum. Semi-quantitative parameters were calculated from the ratio of ROI counts to the dominant cerebellar counts (ROI/Ce ratio) at resting and acetazolamide-activated conditions. RESULTS: Before surgery, the mean resting rCBF and rVR in bilateral ACA and MCA territories were less than 40 ml/100 g/min and less than 10%, respectively, indicating severe hemodynamic ischemia. Except for the ACA territories, both the mean resting rCBF and mean rVR values in the entire cortex increased significantly after surgery (p < 0.05). By semi-quantitative studies, before surgery, the mean resting and acetazolamide-activated ROI/Ce ratios in bilateral ACA and MCA territories were less than 0.90 and 0.80, respectively. The mean resting and acetazolamide-activated ROI/Ce ratios increased significantly in the MCA territory after surgery. Severe hemodynamic ischemia, which categorized by the quantitative thresholds (resting rCBF < 40 ml/100 g/min and rVR < 10%) was diagnosed by the semi-quantitative thresholds (resting ROI/ Ce ratio < 0.90 and acetazolamide-activated ROI/Ce ratio < 0.85), the sensitivity and specificity of which were 87.5% and 90.9%, respectively. CONCLUSIONS: The cerebral hemodynamics in childhood moyamoya disease was improved entirely after surgery. Severe hemodynamic cerebral ischemia was diagnosed by not only quantitative but also semi-quantitative IMP-SPECT studies.

Predominant involvement of ipsilateral anterior and posterior circulations in moyamoya disease.

BACKGROUND AND PURPOSE: We encountered several patients with childhood onset of moyamoya disease in whom the ipsilateral anterior and posterior circulations were predominantly involved. This study investigated whether this is an angiographic characteristic of this disease. METHODS: We evaluated steno-occlusive lesions on angiograms of 85 patients with pediatric onset of moyamoya disease, using two 4-stage angiographic classification scales for the internal carotid artery and posterior cerebral artery systems (ICA and PCA staging, respectively) and determined whether lesions with more advanced ICA and PCA stages were on ipsilateral sides. RESULTS: When positive laterality was defined as the presence of a difference by > or =1 stage between the stages on both sides, lateralities in the ICA stages and in the PCA stages were present in 40 (47%) and 27 patients (32%), respectively. Lesions with more advanced ICA and PCA stages were on the same side, with significant probability (P=0.024, Fisher's exact test). Lateralities in both ICA and PCA lesions were found in 17 patients. In 14 (82%) of the 17 patients, the more advanced side of ICA lesions was the same as that of PCA lesions, while it was contralateral in 3 patients (18%). CONCLUSIONS: In pediatric-onset moyamoya disease, asymmetrical involvement of bilateral ICAs and PCAs was common, and the ipsilateral ICA and PCA tended to be predominantly involved.

'Angiographic moyamoya' its definition, classification, and therapy.

Are there any differences between probable Moyamoya disease and unilateral Moyamoya disease? What kinds of differences exist between definite and probable Moyamoya disease? Furthermore, according to the diagnostic criteria of Moyamoya disease, patients with systemic disorders and angiographic features similar to those of Moyamoya disease can not be diagnosed as Moyamoya disease. How should we call these? Such patients have been reported as 'Moyamoya syndrome,' 'quasi-Moyamoya disease', 'akin-Moyamoya disease'. etc. These variations of terminology including unilateral or probable Moyamoya disease have thus led to as state of confusion. In this study the previously reported cases in the literature were surveyed to clarify how these terms have been used and how we should use them correctly in the future. Since the diagnostic criteria of this disease are mainly based on angiographic findings, the term Moyamoya 'syndrome' should not be used. A unilateral involvement without any known cause should be called 'probable.' Because some systemic diseases commonly associated with Moyamoya disease might be genetically linked, it is better to avoid using such vague expressions as 'quasi', 'akin', or 'pseudo.' There might be a coexistence of two diseases. It is therefore better to simply state that the angiographic findings are similar to Moyamoya disease, or a systemic disease with 'angiographic Moyamoya' until the etiology of the Moyamoya disease is clarified.

Long-term follow-up study of "epileptic type" moyamoya disease in children.

Twenty-three patients with epileptic type moyamoya disease are reviewed among 200 moyamoya disease patients. Ten boys and 13 girls aged 5 months to 12 years were followed over 6 months to 17.3 years. Six had generalized seizure and 17 had focal seizure. Operations were performed within 1 year in eight patients, within 1-3 years in five, and more than 3 years after onset in 10. Nineteen patients improved and suffered no seizure without receiving antiepileptic drugs, but four patients developed true epilepsy and three of these suffered cerebral infarction. Multivariate analyses showed that toddlers aged less than 1 year and mild or severe abnormal computed tomographic (CT) findings correlated with a bad outcome. This study showed that epileptic type moyamoya disease has the same clinical features as transient ischemic attack or infarction type. Age under 1 year and CT abnormalities indicate a poor prognosis and necessity for early reconstructive surgery.

Perioperative complications of encephalo-duro-arterio-synangiosis: prevention and treatment.

We performed encephalo-duro-arterio-synangiosis on 169 sides of 81 Moyamoya and 8 non-Moyamoya patients in the past 10 years. The advantage of this operation is its minimal operative invasion, giving rise to few operative complications. During 10 years of practice, however, we encountered some perioperative problems. Perioperative cerebral infarction of varying severity was seen in six Moyamoya patients. Severe hyperventilation with crying was the main trigger of infarction. Two patients developed wound infection with Gram-negative rods. Removal of an infected bone flap was necessary. One Moyamoya patient developed malignant hyperthermia during the operation. One acute epidural hematoma necessitated an emergency hematoma removal. Five patients showed a temporary aggravation of involuntary movements. Prolonged mild fever and temporary and limited hair loss around the wound were often observed. Cases and their treatment are presented with discussion of preventive measures.