Revascularization surgery in patients with MMD carries a low risk, is effective at preventing future ischemic events, and improves quality of life. Patients in whom symptomatic MMD is diagnosed should be offered revascularization surgery.

Background and Purpose Determining the presence and adequacy of collateral blood flow is important in cerebrovascular disease. Therefore, we explored whether a noninvasive imaging modality, arterial spin labeling (ASL) MRI, could be used to detect the presence and intensity of collateral flow using digital subtraction angiography (DSA) and stable xenon CT cerebral blood flow as gold standards for collaterals and cerebral blood flow, respectively. Methods ASL and DSA were obtained within 4 days of each other in 18 patients with Moyamoya disease. Two neurointerventionalists scored DSA images using a collateral grading scale in regions of interest corresponding to ASPECTS methodology. Two neuroradiologists similarly scored ASL images based on the presence of arterial transit artifact. Agreement of ASL and DSA consensus scores was determined, including kappa statistics. In 15 patients, additional quantitative xenon CT cerebral blood flow measurements were performed and compared with collateral grades. Results The agreement between ASL and DSA consensus readings was moderate to strong, with a weighted kappa value of 0.58 (95% confidence interval, 0.52–0.64), but there was better agreement between readers for ASL compared with DSA. Sensitivity and specificity for identifying collaterals with ASL were 0.83 (95% confidence interval, 0.77–0.88) and 0.82 (95% confidence interval, 0.76–0.87), respectively. Xenon CT cerebral blood flow increased with increasing DSA and ASL collateral grade (P<0.05). Conclusions ASL can noninvasively predict the presence and intensity of collateral flow in patients with Moyamoya disease using DSA as a gold standard. Further study of other cerebrovascular diseases, including acute ischemic stroke, is warranted.

Surgical correction of unilateral coronal synostosis offers a unique opportunity to examine the molecular differences between an abnormal and a normal cranial suture. We isolated and identified a cDNA fragment whose expression was up-regulated in the premature fusing and fused coronal sutures, as compared with normal coronal sutures. The nucleotide sequence of the full-length cDNA of this gene, human NELL-1, has ∼61% homology with the chicken Nel gene. Both chicken Nel and human NELL-1 are comprised of six epidermal growth factor-like repeats. The human NELL-1 messages were localized primarily in the mesenchymal cells and osteoblasts at the osteogenic front, along the parasutural bone margins, and within the condensing mesenchymal cells of newly formed bone in sites of premature sutural fusion. Human multiorgan tissue mRNA blot showed that NELL-1 was specifically expressed in fetal brain but not in fetal kidney, liver, or lung. We also showed that Nell-1 was expressed in rat calvarial osteoprogenitor cells and was largely absent in rat tibiae and fibroblast cell cultures. In conclusion, our data suggest that the NELL-1 gene is preferentially expressed in cranial intramembranous bone and neural tissue (both of neural crest cell origin) and is up-regulated during unilateral premature closure of the coronal suture. The precise role of this gene is unknown. (J Bone Miner Res 1999;14:80-89)

Background and Purpose-Medical treatment of symptomatic intracranial stenosis carries a high risk of stroke. This study was done to evaluate the clinical and angiographic outcomes after intracranial angioplasty for this disease. Methods-A total of 120 patients with 124 intracranial stenoses were treated by primary angioplasty. All patients had neurologic symptoms (stroke or transient ischemic attack) attributable to intracranial stenoses Ն50%. Angiograms were evaluated before and after angioplasty for the degree of stenosis. Results-Pretreatment stenoses varied from 50% to 95% (mean 82.2Ϯ10.2). Post-treatment stenoses varied from 0% to 90% (mean 36.0Ϯ20.1). There were 3 strokes and 4 deaths (all neurological) within 30 days of the procedure, giving a combined periprocedural stroke and death rate of 5.8%. A total of 116 patients (96.7%) were available for a mean follow-up time of 42.3 months. There were 6 patients who had a stroke in the territory of treatment and 5 additional patients with stroke in other territories. Ten deaths occurred during the follow-up period, none of which were neurological. Including the periprocedural stroke and deaths, this yielded an annual stroke rate of 3.2% in the territory of treatment and a 4.4% annual rate for all strokes. Conclusion-Intracranial angioplasty can be performed with a high degree of technical success and a low risk of complications. Long-term clinical follow-up of intracranial angioplasty patients demonstrates a risk of future strokes that compares favorably to patients receiving medical therapy.

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Treatment of pediatric AVMs with multimodality therapy can substantially improve obliteration rates and may decrease AVM hemorrhage rates. The poor natural history and risks of intervention must be carefully considered when deciding to treat high-grade pediatric AVMs.

Background: The natural history of unilateral moyamoya disease (MMD) in adult patients is not clearly described in the literature. We present a series of 18 patients with unilateral MMD and analyze the risk factors for progression to bilateral disease. Methods: A retrospective review of 157 MMD patients treated at Stanford University Medical Center from 1991 to 2005 identified 28 patients with unilateral MMD (defined as none, equivocal or mild involvement on the contralateral side). Results: Eigh teen patients (5 males and 13 females) were identified with unilateral MMD and angiographic follow-up of ≧5 months. Mean radiologic follow-up (± standard error of the mean) was 19.3 ± 3.4 months and mean clinical follow-up was 24.5 ± 3.7 months. Five patients had childhood onset MMD and 13 patients had adult onset disease. Angiographic progression from unilateral to bilateral disease was seen in 7 patients (38.9%) at a mean follow-up of 12.7 ± 2.4 months. Four of the 7 patients had significant clinical and radiologic progression requiring surgical intervention. Five of 7 patients that progressed had adult onset MMD. The presence of equivocal or mild stenotic changes of the contralateral anterior cerebral artery (ACA), middle cerebral artery (MCA) or internal carotid artery (ICA) was an important predictor of progression (p < 0.01); 6 of 8 patients (75%) with equivocal or mild contralateral disease progressed, whereas only 1 of 10 patients (10.0%) with no initial contralateral disease progressed to bilateral MMD. One patient had mild or equivocal MCA, ICA and ACA stenosis at the time of initial diagnosis and this patient progressed. Conclusions: Contralateral progression in the adult form occurs more commonly than previously reported. The presence of minor changes in the contralateral ACA, intracranial ICA and MCA is an important predictor of increased risk of progression. Patients with a completely normal angiogram on the contralateral side have a very low risk of progression.

A high rate of recanalization and clinical improvement can be observed in patients with ischemic stroke using low-dose thrombolytic agents with adjunctive mechanical disruption of clot. Moreover, this strategy may reduce the risk of intracerebral hemorrhage observed with thrombolytics.