Vessel wall MRI in moyamoya disease: arterial wall enhancement varies depending on age, arteries, and disease progression.

OBJECTIVE: To investigate the relationship of followings for patients with moyamoya disease (MMD): arterial wall enhancement on vessel wall MRI (VW-MRI), cross-sectional area (CSA), time-of-flight MR angiography (MRA), age, locations from intracranial internal carotid artery (ICA) to proximal middle cerebral artery (MCA), disease progression, and transient ischemic attack (TIA). METHODS: Patients who underwent VW-MRI between October 2018 and December 2020 were enrolled in this retrospective study. We measured arterial wall enhancement (enhancement ratio, ER) and CSA at five sections of ICA and MCA. Also, we scored MRA findings. Multiple linear regression (MLR) analysis was performed to explore the associations between ER, age, MRA score, CSA, history of TIA, and surgical revascularization. RESULTS: We investigated 102 sides of 51 patients with MMD (35 women, 16 men, mean age 31 years ± 18 [standard deviation]). ER for MRA score 2 (signal discontinuity) was higher than ER for other scores in sections D (end of ICA) and E (proximal MCA) on MLR analysis. ER in section E was significantly higher in patients for MRA score 2 with TIA history than without. ER significantly increased as CSA increased in section E, which suggests ER becomes less in decreased CSA due to negative remodeling. CONCLUSION: Arterial wall enhancement in MMD varies by age, location, and disease progression. Arterial wall enhancement may be stronger in the progressive stage of MMD. Arterial wall enhancement increases with history of TIA at proximal MCA, which may indicate the progression of the disease. CLINICAL RELEVANCE STATEMENT: Arterial wall enhancement in moyamoya disease varies by age, location of arteries, and disease progression, and arterial wall enhancement may be used as an imaging biomarker of moyamoya disease. KEY POINTS: It has not been clarified what arterial wall enhancement in moyamoya disease represents. Arterial wall enhancement in moyamoya disease varies by age, location of arteries, and disease progression. Arterial wall enhancement in moyamoya disease increases as the disease progresses.

Posterior cerebral artery involvement in unilateral moyamoya disease is exclusively ipsilateral and influenced by RNF213 mutation gene dose: The SUPRA Japan study: PCA involvement in unilateral moyamoya.

OBJECTIVES: The characteristics and clinical implications of posterior cerebral artery (PCA) involvement in unilateral moyamoya disease (U-MMD), such as laterality, frequency of the RNF213 p.R4810K mutation, and clinical outcomes, have not been well studied. POPULATION AND METHODS: We analyzed a cohort of 93 patients with U-MMD who participated in the SUPRA Japan study. Clinical characteristics and radiological examinations were collected from medical records. The presence of the p.R4810K mutation was determined using a TaqMan assay. The clinical outcome was assessed using the modified Rankin Scale (mRS). Univariate and multivariate logistic regression analyses were performed to assess the associations. RESULTS: Among the patients with U-MMD, PCA involvement was observed in 60.0 % (3/5) of patients with homozygous mutation, 11.3 % (7/62) of those with heterozygous mutation, and 3.8 % (1/26) of those with wild type, showing a significant linear trend (p < 0.001 for trend). PCA involvement was observed exclusively on the same side as the affected anterior circulation. Dyslipidemia and cerebral infarction at initial onset were independently associated with mRS ≥1. Hypertension was associated with mRS ≥1 and it was also linked to infarction at initial onset, suggesting a potential confounding effect. Although PCA involvement showed a trend for higher mRS, it was not statistically significant. CONCLUSIONS: Our findings indicate a gene dose effect of the p.R4810K mutation on PCA involvement, with the homozygous state showing the most significant effect. Both genetic and modifiable factors such as dyslipidemia may influence the progression of U-MMD.

Five-Year Stroke Risk and Its Predictors in Asymptomatic Moyamoya Disease: Asymptomatic Moyamoya Registry (AMORE).

BACKGROUND: Long-term outcomes are unknown in patients with asymptomatic moyamoya disease. In this report, we aimed to clarify their 5-year risk of stroke and its predictors. METHODS: We are conducting a multicenter, prospective cohort study (Asymptomatic Moyamoya Registry) in Japan. Participants were eligible if they were 20 to 70 years, had bilateral or unilateral moyamoya disease, experienced no episodes suggestive of TIA and stroke; and were functionally independent (modified Rankin Scale score 0-1). Demographic and radiological information was collected at enrollment. In this study, they are still followed up for 10 years. In this interim analysis, we defined the primary end point as a stroke occurring during a 5-year follow-up period. Independent predictors for stroke were also determined, using a stratification analysis method. RESULTS: Between 2012 and 2015, we enrolled 109 patients, of whom 103 patients with 182 involved hemispheres completed the 5-year follow-up. According to the findings on DSA and MRA, 143 hemispheres were judged as moyamoya disease and 39 hemispheres as questionable manifestations (isolated middle cerebral artery stenosis). The patients with questionable hemispheres were significantly older, more often male, and more frequently had hypertension than those with moyamoya hemisphere. Moyamoya hemispheres developed 7 strokes, including 6 hemorrhagic and 1 ischemic stroke, during the first 5 years. The annual risk of stroke was 1.4% per person, 0.8% per hemisphere, and 1.0% per moyamoya hemisphere. Independent predictor for stroke was Grade-2 choroidal anastomosis (hazard ratio, 5.05 [95% CI, 1.24-20.6]; P=0.023). Furthermore, microbleeds (hazard ratio, 4.89 [95% CI, 1.13-21.3]; P=0.0342) and Grade-2 choroidal anastomosis (hazard ratio, 7.05 [95% CI, 1.62-30.7]; P=0.0093) significantly predicted hemorrhagic stroke. No questionable hemispheres developed any stroke. CONCLUSIONS: The hemispheres with asymptomatic moyamoya disease may carry a 1.0% annual risk of stroke during the first 5 years, the majority of which are hemorrhagic stroke. Grade-2 choroidal anastomosis may predict stroke, and the microbleeds and Grade-2 choroidal anastomosis may carry the risk for hemorrhagic stroke. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: UMIN000006640.

"Transcallosal" periventricular anastomosis in moyamoya disease: the fourth periventricular anastomosis and a potential predictor of hemorrhage.

OBJECTIVES: Choroidal anastomosis is a risk factor for hemorrhage in moyamoya disease. One variant of choroidal anastomosis, "transcallosal anastomosis," originates from the medial posterior choroidal artery, and penetrates the corpus callosum to reconstruct the pericallosal artery. We aimed to investigate the prevalence and the bleeding rate of transcallosal anastomosis using sliding thin-slab maximum intensity projection reformatted from magnetic resonance angiography (MRA). MATERIALS AND METHODS: This study included 222 patients. We defined transcallosal anastomosis grades (0-2) and the stenosis of the anterior (ACA, 0-2), middle (MCA, 1-3), and posterior cerebral artery (PCA, 0-2) by MRA scores, independently by two coauthors. RESULTS: Grade-2 transcallosal anastomosis was detected in 21 patients (9.5 %). There were no correlations of the incidence of transcallosal anastomosis with previous bypass surgery (P = 0.23). Multivariate analysis revealed a significantly higher incidence in hemorrhagic onset and younger age (odds ratio [OR] 3.77, and 0.97). Transcallosal anastomosis had statistically significant correlation with ACA and PCA scores (P = 0.01 and 0.03), but not with MCA scores (P = 0.1). In multivariate analysis, ACA scores 1 and 2 were significantly higher (OR, 15.44 and 11.17), and PCA score 1 was also higher (OR, 3.07), but PCA score 2 was not. Interrater agreement for judgment of transcallosal anastomosis grade was strong (κ = 0.89). Two patients with Grade-2 transcallosal anastomosis had late hemorrhage in the corpus callosum (bleeding rate: 2.5 % per year). CONCLUSIONS: Transcallosal anastomosis may be associated with both advanced ACA and moderate PCA stenosis, and cause hemorrhage at the corpus callosum.

Detecting immunoglobulin G4-related intracranial arteriopathy with magnetic resonance vessel wall imaging: a preliminary experience in two cases.

BACKGROUND: Detecting immunoglobulin G4 (IgG4)-related intracranial arteriopathy, a rare neurovascular complication of IgG4-related disease, is challenging. While magnetic resonance (MR) vessel wall imaging (VWI) can visualize various neurovascular pathologies, its application to this arteriopathy has not been reported as of this writing. CASE PRESENTATION: A 74-year-old male and a 65-year-old female manifested multiple cranial nerve palsy and neck pain, respectively. Both cases exhibited multiorgan masses with markedly elevated serum IgG4 levels and were clinically diagnosed with IgG4-related disease. Three-dimensional T1-weighted black blood VWI with and without contrast agent identified intracranial vascular lesions characterized as nearly-circumferential mural thickening with homogeneous contrast enhancement in the internal carotid and vertebral arteries; some of the lesions had been unrecognized with screening MR angiography due to expansive remodeling. The former patient underwent corticosteroid therapy, and VWI after treatment revealed decreased mural thickening and enhancement. CONCLUSION: Further studies to elucidate characteristic findings of VWI might contribute to early detection of this treatable pathology.

Lack of Association between Seropositivity of Vasculopathy-Related Viruses and Moyamoya Disease.

OBJECTIVES: Although the association between genetic factors, such as RNF213 mutations, and moyamoya disease (MMD) has been well investigated, environmental factors are largely undetermined. Thus, we aimed to examine whether viral infection increases the risk of MMD. MATERIALS AND METHODS: To eliminate the effect of presence or absence of the RNF213 p.R4810K mutation, the entire study population was positive for this mutation. We collected whole blood from 111 patients with MMD (45 familial and 66 sporadic cases) and 67 healthy volunteers, and we measured the immunoglobulin G titer of 11 viruses (cytomegalovirus, varicella-zoster virus, measles virus, rubella virus, herpes simplex virus, mumps virus, Epstein-Barr virus, human parvovirus B19, human herpesvirus 6 [HHV6], human herpesvirus 8, and John Cunningham virus) that were presumed to be associated with vasculopathy using the enzyme-linked immunosorbent assay. Positivity for past viral infection was determined by cut-off values obtained from previous reports and the manufacturer's instructions, and the positive rate was compared between cases and age- and sex-matched controls. We performed familial case-specific and sporadic case-specific analyses, as well as a case-control analysis. RESULTS: There was no significant difference in the positive rate between the case group and the control group in any of the analyses. A significant difference was only observed in the combined case-control analysis for HHV6 (p = 0.046), but the viral antibody-positive rate in control individuals was higher than in MMD cases. CONCLUSIONS: Our cross-sectional study suggest that the investigated 11 viruses including HHV6 are unlikely to have an impact on MMD development.

Characterization of Moyamoya and Middle Cerebral Artery Diseases by Carotid Canal Diameter and RNF213 p.R4810K Genotype.

OBJECTIVES: It is sometimes difficult to differentiate middle cerebral artery disease from moyamoya disease because the two can present similarly yet have different treatment strategies. We investigated whether the presence of a narrow carotid canal and the RNF213 mutation can help differentiate between the two phenotypes. POPULATION AND METHODS: We analyzed 78 patients with moyamoya disease, 27 patients with middle cerebral artery disease, and 79 controls from 2 facilities. The carotid canal diameter was measured using computed tomography. The p.R4810K mutation was genotyped by TaqMan assay. A receiver operating characteristics analysis was performed to assess the significance of the carotid canal diameter for the accurate diagnosis of moyamoya disease. RESULTS: The carotid canal diameter was significantly narrower in patients with moyamoya disease than in controls. The optimal cutoff values were 5.0 mm for adult males and 4.5 mm for adult females and children (sensitivity: 0.82; specificity: 0.92). Among the patients with middle cerebral artery disease, 18.5% and 25.0% of the affected hemispheres had the p.R4810K mutation and narrow canal (i.e., below the cutoff), respectively, whereas only 3.1% of those had both. Contrastingly, 68.8% of the affected hemispheres in patients with moyamoya disease had both these characteristics. Among the patients with moyamoya disease, those with the p.R4810K mutation tended to have narrower carotid canals. CONCLUSIONS: Although the presence of a narrow carotid canal or the p.R4810K mutation alone could not be used to distinguish those with moyamoya disease from those with middle cerebral artery disease, the combination of these factors could better characterize the two phenotypes.

[Moyamoya Disease].

In this educational article for young neurosurgeons, the author highlights the characteristic CT and MRI findings for diagnosing moyamoya disease. The author also provides guidelines for the systematic interpretation of angiographic findings in patients with moyamoya disease.

Restoration of periventricular vasculature after direct bypass for moyamoya disease: intra-individual comparison.

BACKGROUND: While periventricular anastomosis, a unique abnormal vasculature in moyamoya disease, has been studied in relation to intracranial hemorrhage, no study has addressed its change after bypass surgery. The authors sought to test whether direct bypass surgery could restore normal periventricular vasculature. METHODS: Patients who had undergone direct bypass surgery for moyamoya disease at a single institution were eligible for the study. Baseline, postoperative, and follow-up magnetic resonance angiography (MRA) scans were scheduled before surgery, after the first surgery, and 3 to 6 months after contralateral second surgery, respectively. Sliding-thin-slab maximum-intensity-projection coronal MRA images of periventricular anastomoses were scored according to the three subtypes (lenticulostriate, thalamic, and choroidal anastomosis). Baseline and postoperative MRA images were compared to obtain a matched comparison of score changes in the surgical and nonsurgical hemispheres within individuals (intra-individual comparison). RESULTS: Of 110 patients, 42 were identified for intra-individual comparisons. The periventricular anastomosis score decreased significantly in the surgical hemispheres (median, 2 versus 1; p < 0.001), whereas the score remained unchanged in the nonsurgical hemispheres (median, 2 versus 2; p = 0.57); the score change varied significantly between the surgical and nonsurgical hemispheres (p < 0.001). Of the 104 periventricular-anastomosis-positive hemispheres undergoing surgery, 47 (45.2%) were assessed as negative in the follow-up MRA. Among the subtypes, choroidal anastomosis was most likely to be assessed as negative (79.7% of positive hemispheres). CONCLUSIONS: Periventricular vasculature can be restored after direct bypass. The likelihood of correction of choroidal anastomosis is a subject requiring further studies.

Development of Hemorrhage-prone Anastomoses in Asymptomatic Moyamoya Disease-A Comparative Study with Japan Adult Moyamoya Trial.

OBJECTIVE: Present study was aimed to precisely evaluate the angio-architectures in patients with asymptomatic moyamoya disease (MMD) by comparing with those with hemorrhagic stroke. METHODS: This study used the data set of cerebral angiography in Asymptomatic Moyamoya Registry (AMORE) Study and Japan Adult Moyamoya (JAM) Trial at enrollment. The development of 3 subtypes of collateral vessels, including lenticulostriate, thalamic, and choroidal anastomosis, was evaluated on cerebral angiography. Suzuki's angiographical stage and posterior cerebral artery (PCA) involvement were also assessed. These findings were compared between asymptomatic (AMORE) and hemorrhagic (JAM) groups. RESULTS: This study included 55 hemispheres of 35 patients in asymptomatic group and 75 hemispheres of 75 patients in hemorrhagic group. In asymptomatic group, thalamic anastomosis was less developed than in hemorrhagic group (P = .011), but there were no significant differences in the development of lenticulostriate and choroidal anastomosis between the 2 groups (P = .077 and P = .26, respectively). Suzuki's stage was more progressed and the prevalence of PCA involvement was significantly higher in hemorrhagic group than in asymptomatic group (P = .0033 and P = .016, respectively). CONCLUSIONS: This study reveals no significant differences in the development of choroidal anastomoses between asymptomatic and hemorrhagic-onset MMD. On the other hand, disease stage and PCA involvement were less advanced in asymptomatic MMD than in hemorrhagic-onset MMD. These findings strongly suggest a certain subgroup of asymptomatic patients with MMD is at potential risk for hemorrhagic stroke.

Sudden Intracranial Hemorrhage in a Patient With Atypical Chronic Myeloid Leukemia in Chronic Phase.

A 16-year-old boy was incidentally found to have hyperleukocytosis during a school physical examination. He was diagnosed with atypical chronic myeloid leukemia in chronic phase. Although treatment with hydoxyurea was started, his white blood cell count increased and he eventually developed lethal intracranial hemorrhage. Although very rare, intracranial hemorrhage should be considered as a possible complication in patients with atypical chronic myeloid leukemia, even in chronic phase, if they have hyperleukocytosis and thrombocytopenia.

Efficacy of Ifosfamide-Cisplatin-Etoposide (ICE) Chemotherapy for a CNS Germinoma in a Child With Down Syndrome.

Intracranial germ cell tumor is sometimes associated with Down syndrome; however, no optimal treatment has been developed due to the high risk of recurrence and treatment-related mortality. Here, we report on a patient with an intracranial germinoma in the bilateral basal ganglia. The patient received 3 courses of ifosfamide-cisplatin-etoposide in combination with whole-brain irradiation (24 Gy), with no serious complications. The patient is alive and disease free 16 months after the initial diagnosis. This regimen is a feasible treatment for intracranial germ cell tumor associated with Down syndrome, although careful attention must be paid to the increased risk for severe infection.

RNF213 p.R4810K Variant and Intracranial Arterial Stenosis or Occlusion in Relatives of Patients with Moyamoya Disease.

BACKGROUND: This study aimed to determine the effectiveness of genetic testing for the p.R4810K variant (rs112735431) of the Mysterin/RNF213 gene, which is associated with moyamoya disease and other intracranial vascular diseases, in the family members of patients with moyamoya disease. METHODS: We performed genotyping of the RNF213 p.R4810K polymorphism and magnetic resonance angiography on 59 relatives of 18 index patients with moyamoya disease. Nineteen individuals had follow-up magnetic resonance angiography with a mean follow-up period of 7.2 years. RESULTS: Six of the 34 individuals with the GA genotype (heterozygotes for p.R4810K) showed intracranial steno-occlusive lesions in the magnetic resonance angiography, whereas none of the 25 individuals with the GG genotype (wild type) showed any abnormalities. Follow-up magnetic resonance angiography revealed de novo lesions in 2 and disease progression in 1 of the 11 individuals with the GA genotype, despite none of the 8 individuals with the GG genotype showing any changes. Accordingly, 8 individuals had steno-occlusive lesions at the last follow-up, and all had the p.R4810K risk variant. The prevalence of steno-occlusive intracranial arterial diseases in family members with the p.R4810K variant was 23.5% (95% confidence interval: 9.27%-37.78%), which was significantly higher than in those without the variant (0%, P = .0160). CONCLUSIONS: Genotyping of the p.R4810K missense variant is useful for identifying individuals with an elevated risk for steno-occlusive intracranial arterial diseases in the family members of patients with moyamoya disease.

Significance of the Hemorrhagic Site for Recurrent Bleeding: Prespecified Analysis in the Japan Adult Moyamoya Trial.

BACKGROUND AND PURPOSE: The primary results of the Japan Adult Moyamoya Trial revealed the statistically marginal superiority of bypass surgery over medical treatment alone in preventing rebleeding in moyamoya disease. The purpose of this analysis is to test the prespecified subgroup hypothesis that the natural course and surgical effects vary depending on the hemorrhagic site at onset. METHODS: The hemorrhagic site, classified as either anterior or posterior, was the only stratifying variable for randomization. Statistical analyses were focused on the assessment of effect modification according to the hemorrhagic site and were based on tests of interaction. RESULTS: Of 42 surgically treated patients, 24 were classified as anterior hemorrhage and 18 as posterior hemorrhage; of 38 medically treated patients, 21 were classified as anterior and 17 as posterior. The hazard ratio of the primary end points (all adverse events) for the surgical group relative to the nonsurgical group was 0.07 (95% confidence interval, 0.01-0.55) for the posterior group, as compared with 1.62 (95% confidence interval, 0.39-6.79) for the anterior group (P=0.013 for interaction). Analysis within the nonsurgical group revealed that the incidence of the primary end point was significantly higher in the posterior group than in the anterior group (17.1% per year versus 3.0% per year; hazard ratio, 5.83; 95% confidence interval, 1.60-21.27). CONCLUSIONS: Careful interpretation of the results suggests that patients with posterior hemorrhage are at higher risk of rebleeding and accrue greater benefit from surgery, subject to verification in further studies. CLINICAL TRIAL REGISTRATION: URL: http://www.umin.ac.jp/ctr/index.htm. Unique identifier: C000000166.

Reversible striatal hypermetabolism in chorea associated with moyamoya disease: a report of two cases.

BACKGROUND: The pathophysiological mechanism of chorea as a presentation of pediatric moyamoya disease remains unknown, although ischemia is suspected as a likely cause. The authors describe two cases of pediatric moyamoya disease, both of which presented with hemichorea in the stable phase after successful bypass surgery. CLINICAL PRESENTATION: Cerebral blood flow was almost normal in one case and decreased in the basal ganglia and watershed area in the other case due to infarcts occurring before surgery. In both cases, 18F-fluorodeoxyglucose positron emission tomography revealed elevated glucose metabolism in the corresponding side of the striatum, which reverted to normal after recovery from chorea. Magnetic resonance angiography revealed a dilated and extended lenticulostriate artery at the exact site of the hypermetabolic lesion.

Significant Association of the RNF213 p.R4810K Polymorphism with Quasi-Moyamoya Disease.

BACKGROUND: Quasi-moyamoya disease is an angiographical moyamoya disease equivalent accompanied by known underlying diseases. Mysterin/RNF213 is a major susceptibility gene for moyamoya disease, of which the p.R4810K variant is a founder polymorphism. The genetics of quasi-moyamoya disease is poorly understood, therefore, this study investigated a potential association between the p.R4810K polymorphism and quasi-moyamoya disease. METHODS: Genotyping of the p.R4810K variant was performed on 18 quasi-moyamoya disease cases and 91 controls, who visited Kyoto University Hospital or Kobe City Medical Center, Japan, between 2006 and 2015. RESULTS: The p.R4810K variant was found in 12 of 18 quasi-moyamoya disease patients. The frequency of p.R4810K carriers was significantly higher in quasi-moyamoya disease cases than in controls (66.7% versus 2.2%, odds ratio 89.0, 95% confidence interval: 19.2-669.4). CONCLUSIONS: Our data showed that the RNF213 p.R4810K polymorphism was significantly associated with quasi-moyamoya disease.

Apparent Diffusion Coefficient and Transient Neurological Deficit after Revascularization Surgery in Moyamoya Disease.

BACKGROUND: Transient neurological deficits are relatively common after direct revascularization surgery for moyamoya disease (MMD). Although recent evidence has revealed the clinical features and pathophysiology, preoperative predictors have remained unclear. This study investigated whether the apparent diffusion coefficient (ADC) in normal-appearing white matter (NAWM) on magnetic resonance imaging could offer a predictor of postoperative transient neurological deficits. METHODS: This study included adult patients with MMD who underwent superficial temporal artery-middle cerebral artery bypass. Preoperative ADCs were measured in NAWM on ipsilateral hemisphere. Single photon emission computed tomography (SPECT) with (123)I-iodoamphetamine was performed on postoperative days 2-6. Relationships between mean ADC and postoperative transient neurological deficits were assessed. RESULTS: Twenty of the 26 subjects (76.9%) experienced transient neurological deficits. Focal hyperemia on postoperative SPECT appeared in 11 of the 20 subjects with postoperative transient neurological deficits and 1 of the 6 subjects without (P = .12). Mean ADCs in patients with and without postoperative transient neurological deficits were 748.3 ± 12 mm(2)/second × 10(-6) and 679.7 ± 21.9 mm(2)/second × 10(-6), respectively (P = .0091). CONCLUSIONS: Preoperative ADC elevation in NAWM may indicate postoperative transient neurological deficits not only in patients with postoperative hyperemia on SPECT, but also in patients with this pathology.

[Three Cases of Moyamoya Disease with a History of Kawasaki Disease].

Here, we report three cases of moyamoya disease with a history of Kawasaki disease. A 33-year-old man was found to have stenotic lesions of the internal carotid arteries(ICAs)on both sides at a nearby hospital where he visited complaining of headache and lisping. He had received immunoglobulin therapy for Kawasaki disease at the ages of 1, 2, and 6 years. MRI showed only a chronic ischemic lesion in the white matter. Angiography showed occlusion at the terminal portion of the ICAs on both sides. He was diagnosed with moyamoya disease, but as he had no symptoms and preserved cerebral blood flow (CBF), he was kept under observation. An 8-year-old boy was diagnosed with moyamoya disease and underwent right encephaloduroarteriosynangiosis at a nearby hospital. He had received immunoglobulin therapy for Kawasaki disease at the age of 1 year. His ischemic symptoms worsened. Although MRI detected no apparent ischemic lesion, angiography revealed severe stenosis at the terminal portions of the ICAs on both sides, and 123I-IMP SPECT showed CBF impairment. Bilateral direct bypass was performed. His father was subsequently also diagnosed with moyamoya disease. A 4-year-old girl with epilepsy was diagnosed with moyamoya disease at a nearby hospital. She had been treated with aspirin for Kawasaki disease at the age of 1 year. MRI detected no remarkable ischemic lesions, but angiography revealed mild stenosis at the terminal portions of the ICAs on both sides. Five months later, her ischemic symptoms were worsening with progressing stenotic lesions, and she underwent bilateral direct bypass.

Incidence of late cerebrovascular events after direct bypass among children with moyamoya disease: a descriptive longitudinal study at a single center.

BACKGROUND: The potential for late cerebrovascular events following surgical revascularization presents a challenge in the treatment of pediatric moyamoya disease. Limited information is available on the incidence of such events after direct bypass. The objective of this descriptive study was to examine the incidence of late cerebrovascular events after direct bypass for pediatric moyamoya disease. METHODS: The study cohort comprised consecutive patients with moyamoya disease who had undergone direct bypass at less than 18 years of age in the authors' institute between 1978 and 2003. They were prospectively followed until the end of the study period or, if applicable, the time of death. RESULTS: Fifty-six of 58 enrolled patients (96.6%) were followed for a mean period of 18.1 years. Four patients experienced late cerebrovascular events, comprising one stroke and three hemorrhages, an average of 13 years after surgery, one of whom experienced a fatal second hemorrhage. The only late ischemic stroke in the cohort occurred after a severe head injury and emergent craniotomy. The incidence of late cerebrovascular events was 0.41% per year (95% confidence interval, 0.15-1.08); 10-year, 20-year, and 30-year cumulative incidences were 1.8%, 7.3%, and 13.1%, respectively. CONCLUSIONS: Despite the efficacy of surgical revascularization, pediatric patients remain at risk of future cerebrovascular events, especially hemorrhage, after reaching adulthood and thus require careful long-term follow-up.

Microsurgical anatomy of the trigeminal nerve.

The objective of this study is to review surgical anatomy of the trigeminal nerve. We also demonstrate some pictures involving the trigeminal nerve and its surrounding connective and neurovascular structures. Ten adult cadaveric heads were studied, using a magnification ranging from 3× to 40×, after perfusion of the arteries and veins with colored latex. The trigeminal nerve is the largest and most complex of the cranial nerves. It serves as a major conduit of sensory input from the face and provides motor innervation to the muscles of mastication. Because of its size and complexity, it is essential to have thorough knowledge of the nerve before diagnoses and treatment of the pathologic processes in the orofacial, temporomandibular, infratemporal, and pterygopalatine areas. The trigeminal nerve is encountered with imaging or surgery of the skull base surgery. Thus, a comprehensive knowledge of the anatomy of the trigeminal nerve is crucial for performing the surgical procedures without significant complication.