Clinical feature and outcome of pediatric cerebrovascular disease: a neurosurgical series

Evidence of pial synagiosis through ventriculoperitoneal shunt entry site in a patient who manifested Moyamoya syndrome later in childhood: A case report and historical perspective

The term Moyamoya , or "puff of smoke" in Japanese , was first used in 1969 by Suzuki and Takaku to describe the classical appearance of collateral blood vessels in response to progressive vascular stenosis of distal internal carotid artery (ICA). Such condition may result in various clinical presentations ranging from strokes to developmental delays. In order to cease the progression of such stenotic vasculopathy, several means of revascularization have been developed over the years. In this paper we present a case of a two-year-old girl with history of myelomeningocele repair and ventriculoperitoneal shunt insertion followed by manifestation of Moyamoya syndrome later in childhood as an evidence of revascularization through a burr hole. To our knowledge, this paper is the first of its kind to report such findings in one patient. Moreover, this paper provides a historical perspective on the development of different types of revascularization techniques.

Clinical Usefulness of Genetic Testing For Patients with Moyamoya Disease: A Systematic Review

BACKGROUND

The effect of genetic factors on presentation and outcomes of moyamoya disease (MMD) is unclear. We aimed to examine differences in presentation of MMD by genetic variant, delineate the influence of genetic factors on outcomes, and characterize the applicability of genetic testing to management.

METHODS

A systematic review was conducted using the PubMed, Embase, and Scopus databases. Title/abstract screening, full-text screening, and data extraction were conducted.

RESULTS

Of 1329 articles, 12 were included. Genes included RNF213 (ring finger protein 213), VEGF (vascular endothelial growth factor), and soluble VEGR receptor (sVEGFR) 1 and 2. Patients heterozygous and homozygous for the p.R1480K variant of RNF213 had younger age of onset; were more frequently familial, had posterior cerebral artery involvement, had bilateral lesions; and were more likely to present with cerebral infarction or transient ischemic attack. The heterozygous p.4810K variant is associated with improved postoperative collateral formation. Stroke recurrence, stroke-free survival, neurologic status, and functional condition after surgery are not associated with the p.4180K genotype. Patients homozygous for p.4180K more frequently experience long-term cognitive impairment. Patients with the C/C genotype of VEGF 2634 or decreased sVEGFR-1 and sVEGFR levels postoperatively had greater postoperative collateral formation.

CONCLUSIONS

Genetic factors correlate with MMD presentation including age of onset, severity, and symptoms, and angiographic and clinical outcomes after surgery. Incorporation of genetic testing panels into practice may allow for risk stratification, management, and follow-up of children and adults with MMD. However, future studies are necessary to validate the usefulness of genetic testing for MMD before this situation occurs.

Failures in Revascularization for Pediatric Moyamoya Disease and Syndrome: A Scoping Review

BACKGROUND

Moyamoya disease (MMD) and moyamoya syndrome (MMS) are a rare cause of stroke commonly managed surgically. We conducted a scoping review to identify the current scope of the literature regarding factors associated with failure of revascularization surgery for MMD and MMS in pediatric patients and to catalyze future research.

METHODS

A scoping review was conducted to explore failures of revascularization surgery for MMD and MMS in pediatric patients using the PubMed, Embase, and Scopus databases. Titles and abstracts returned from searches were screened for full-text review. Studies meeting inclusion criteria were reviewed in full, and relevant data were extracted.

RESULTS

Of 2450 resultant articles, 15 were included. Angiographic outcomes were reported for 900 hemispheres, of which 442 (49.1%) were denoted as Matsushima grade A, 299 (33.2%) as Matsushima grade B, and 159 (17.7%) as Matsushima grade C. Patients with MMS had poorer angiographic outcomes than did patients with MMD. Patients with poor neovascularization had a greater degree of moyamoya vessels on follow-up angiogram. Suzuki stage was not associated with angiographic outcome in individual patients. Angiographic outcomes differed by surgical approach and were not associated with clinical outcomes. Literature identifying factors was sparse.

CONCLUSIONS

The existing literature indicates that factors such as cause, degree of moyamoya vessels, and surgical approach may affect the likelihood of Matsushima grade C revascularization in pediatric patients with MMD and MMS. Future studies are necessary to definitively elucidate factors associated with failure of revascularization surgery for pediatric MMD.

Paediatric Moyamoya Disease and Tourette's Syndrome: An Unusual Association Responding Favourably to Direct and Indirect Cerebral Revascularisation Surgery

BACKGROUND

Moyamoya disease, an uncommon chronic intra-cerebral arteriopathy asymmetrically affecting the proximal vasculature, is rarely associated with clinical features pertaining to movement disorders.

CASE DESCRIPTION

A 5-year-and-9-month-old boy developed repetitive episodic involuntary winking of the right eye along with ipsilateral shoulder shrugging movements in an absolutely conscious state, associated with paroxysmal shouts and loud laughs and punctuated with abusive verbal expressions (coprolalia). These episodic features, over the course of the next 1.5 years, got progressively accentuated by situations which evoked stress. In addition, there was progressive regression of verbal and cognitive milestones, emotional lability and aspects of attention deficit hyperkinetic disorder. The child was evaluated by a neurologist with magnetic resonance imaging of the brain, which showed characteristic ischaemic areas involving the basal ganglia and fronto-parietal cortical areas along the middle cerebral artery territory, predominantly on the left side. Subsequent cerebral angiography revealed extensive stenosis of bilateral (predominantly left-sided) internal cerebral arteries and middle cerebral arteries with evidence of diffuse leptomeningeal collaterals. The electroencephalography was reported to be normal. He was eventually diagnosed to be suffering from Moyamoya disease with associated Tourette's syndrome. Subsequently, the child underwent left-sided superficial temporal artery to middle cerebral artery anastomosis along with encephalo-duro-arterio-myo-synangiosis. Significant clinico-radiological improvement was noted after 3 months. The clinical deficiencies had dramatically resolved. There was evidence of excellent development of both direct and indirect surgical collaterals along the left middle cerebral artery territory. He could go back to school.

CONCLUSION

Ours is probably the first case reporting an association of paediatric Moyamoya disease with Tourette's syndrome, which significantly resolved after cerebral revascularisation surgery.

Operative volume and outcomes of cerebrovascular neurosurgery in children

OBJECTIVE The impact of procedural volume on the outcomes of cerebrovascular surgery in children has not been determined. In this study, the authors investigated the association of operative volume on the outcomes of cerebrovascular neurosurgery in pediatric patients. METHODS The authors performed a cohort study of all pediatric patients who underwent a cerebrovascular procedure between 2003 and 2012 and were registered in the Kids' Inpatient Database (KID). To control for confounding, the authors used multivariable regression models, propensity-score conditioning, and mixed-effects analysis to account for clustering at the hospital level. RESULTS During the study period, 1875 pediatric patients in the KID underwent cerebrovascular neurosurgery and met the inclusion criteria for the study; 204 patients (10.9%) underwent aneurysm clipping, 446 (23.8%) underwent coil insertion for an aneurysm, 827 (44.1%) underwent craniotomy for arteriovenous malformation resection, and 398 (21.2%) underwent bypass surgery for moyamoya disease. Mixed-effects multivariable regression analysis revealed that higher procedural volume was associated with fewer inpatient deaths (OR 0.58; 95% CI 0.40-0.85), a lower rate of discharges to a facility (OR 0.87; 95% CI 0.82-0.92), and shorter length of stay (adjusted difference -0.22; 95% CI -0.32 to -0.12). The results in propensity-adjusted multivariable models were robust. CONCLUSIONS In a national all-payer cohort of pediatric patients who underwent a cerebrovascular procedure, the authors found that higher procedural volume was associated with fewer deaths, a lower rate of discharges to a facility, and decreased lengths of stay. Regionalization initiatives should include directing children with such rare pathologies to a center of excellence.

Scope of practice and outcomes of cerebrovascular procedures in children

PURPOSE

The impact of scope of practice of providers (predominantly adult versus predominantly pediatric) on the outcomes of cerebrovascular procedures in children remains an issue of debate. We investigated the association of scope of practice with the outcomes of cerebrovascular interventions.

METHODS

We performed a cohort study of all pediatric patients (younger than 18 years old) who underwent cerebrovascular procedures from 2009 to 2013 and were registered in the Statewide Planning and Research Cooperative System (SPARCS) database. In order to control for confounding, we used propensity score conditioning and mixed effects analysis to account for clustering at the hospital level.

RESULTS

During the study period, there were 1243 pediatric patients who underwent cerebrovascular procedures and met the inclusion criteria. Of these, 631 (50.7 %) underwent treatment by providers with predominantly adult practices and 612 (49.3 %) by physicians who operated predominantly on children. The mixed-effects multivariable regression analysis demonstrated lack of association of predominantly adult practice with inpatient mortality (OR, 1.20; 95 % CI, 0.61-2.38), discharge to a facility (OR, 1.50; 95 % CI, 0.73-3.09), and length of stay (LOS) (adjusted difference, 0.003; 95 % CI, -0.09 to 0.10). These associations persisted in propensity-adjusted models.

CONCLUSIONS

In a cohort of pediatric patients undergoing cerebrovascular procedures from a comprehensive all-payer database, we did not demonstrate a difference in mortality, discharge to a facility, and LOS between providers with predominantly adult and predominantly pediatric practices.

Direct versus indirect revascularization procedures for moyamoya disease: a comparative effectiveness study

OBJECTIVE Moyamoya disease (MMD) is a chronic cerebrovascular disease that can lead to devastating neurological outcomes. Surgical intervention is the definitive treatment, with direct, indirect, and combined revascularization procedures currently employed by surgeons. The optimal surgical approach, however, remains unclear. In this decision analysis, the authors compared the effectiveness of revascularization procedures in both adult and pediatric patients with MMD. METHODS A comprehensive literature search was performed for studies of MMD. Using complication and success rates from the literature, the authors constructed a decision analysis model for treatment using a direct and indirect revascularization technique. Utility values for the various outcomes and complications were extracted from the literature examining preferences in similar clinical conditions. Sensitivity analysis was performed. RESULTS A structured literature search yielded 33 studies involving 4197 cases. Cases were divided into adult and pediatric populations. These were further subdivided into 3 different treatment groups: indirect, direct, and combined revascularization procedures. In the pediatric population at 5- and 10-year follow-up, there was no significant difference between indirect and combination procedures, but both were superior to direct revascularization. In adults at 4-year follow-up, indirect was superior to direct revascularization. CONCLUSIONS In the absence of factors that dictate a specific approach, the present decision analysis suggests that direct revascularization procedures are inferior in terms of quality-adjusted life years in both adults at 4 years and children at 5 and 10 years postoperatively, respectively. These findings were statistically significant (p < 0.001 in all cases), suggesting that indirect and combination procedures may offer optimal results at long-term follow-up.

Clinical Application of Radiolabeled RGD Peptides for PET Imaging of Integrin αvβ3

Molecular imaging for non-invasive assessment of angiogenesisis is of great interest for clinicians because of the wide-spread application of anti-angiogenic cancer therapeutics. Besides, many other interventions that involve the change of blood vessel/tumor microenvironment would also benefit from such imaging strategies. Of the imaging techniques that target angiogenesis, radiolabeled Arg-Gly-Asp (RGD) peptides have been a major focus because of their high affinity and selectivity for integrin α_vβ₃--one of the most extensively examined target of angiogenesis. Since the level of integrin α_vβ₃ expression has been established as a surrogate marker of angiogenic activity, imaging α_vβ₃ expression can potentially be used as an early indicator of effectiveness of antiangiogenic therapy at the molecular level. In this review, we summarize RGD-based PET tracers that have already been used in clinical trials and intercompared them in terms of radiosynthesis, dosimetry, pharmacokinetics and clinical applications. A perspective of their future use in the clinic is also provided.

Importance of RNF213 polymorphism on clinical features and long-term outcome in moyamoya disease

OBJECT Moyamoya disease (MMD) is an idiopathic cerebrovascular occlusive disorder prevalent in East Asia. In the pathogenesis of MMD, the important role of genetic factors is being elucidated, and RNF213 has recently been identified as a susceptibility gene for MMD. The aim of this retrospective study was to investigate the RNF213 genotype in patients with MMD and to determine their genotype-phenotype associations. METHODS The study involved 165 Korean MMD patients from 155 unrelated families who were diagnosed with MMD at a single center from 1995 to 2013. Their demographic, radiological, and clinical findings were evaluated. Direct sequencing of the major RNF213 single nucleotide polymorphisms was performed. The association of the common RNF213 variant with MMD risk was evaluated using historical controls for comparison. Correlations between RNF213 genotype and phenotype were statistically analyzed. RESULTS The c.14429G>A (p.R4810K) variant was identified in 125 (75.8%) of 165 MMD patients. Most patients (112) were heterozygous, and 13 patients had 2 copies of the c.14429G>A variant. A novel heterozygous variant, c.12086A>G (p.Q4029R), was found in 1 additional patient. The minor allele frequency of the c.14429G>A variant was significantly higher in the MMD group (138 [41.8%] of 330 patients) than in the control group (8 [1.36%] of 588 subjects; p < 0.001). The c.14429G>A (p.R4810K) variant significantly increased the risk of MMD in Korean patients, with an OR of 52.11 (p < 0.001) compared with controls. Moreover, c.14429G>A (p.R4810K) genotypes occurred more frequently in patients with a family history of MMD. The homozygous variant was highly associated with early-onset MMD (age at onset < 5 years), cerebral infarction at diagnosis, and cognitive impairment in long-term outcome. CONCLUSIONS The findings indicate that the c.14429G>A (p.R4810K) allele of RNF213 is strongly associated with Korean patients with MMD. The homozygous c.14429G>A (p.R4810K) variant is particularly related to early-onset MMD, severe symptomatic manifestations at diagnosis, and poor prognosis. This genotypic variant may be a useful biomarker for early-onset MMD or unstable MMD with cerebral infarction, which requires early diagnosis and revascularization treatment.

Surgical outcomes and predictors of stroke in a North American white and African American moyamoya population

BACKGROUND

The majority of moyamoya surgical series have been confined to Asian and pediatric populations. Few have studied demographics, risk factors, and outcomes in adult North American populations.

OBJECTIVE

To examine outcomes after revascularization for moyamoya in white and African American adults and to assess for predictors of recurrent stroke.

METHODS

A retrospective review of 75 non-Asian patients undergoing 110 procedures at the Mayo Clinic was performed. Demographics, known moyamoya associations, cerebrovascular risk factors, and autoimmune diseases were recorded. Primary outcomes for vascular events were assessed with Kaplan-Meier analysis. Fisher exact methods were used to evaluate for associations with recurrent events.

RESULTS

Mean age was 42 years, and mean follow-up was 47 months. Seventy-one of the 75 patients were white. The majority had bilateral disease (n = 49). Perioperative ischemic events occurred in 5 patients (4.5%). The 5- and 10-year event rates were 5.8% and 9.9%. Significant associations were found with a history of thyroid disease (P = .05) and recurrent stroke. A trend was also found between hypertension and autoimmune disease with recurrent stroke.

CONCLUSION

Outcomes were favorable with revascularization in this subset with moyamoya. A significant association between a history of thyroid disease and recurrent stroke was found. Additionally, high prevalences of autoimmune disease, hypertension, and thyroid disease were found in our cohort, suggesting that they may play a role in the pathophysiology and progression of moyamoya disease in this population. A new classification for moyamoya is proposed based on these data.

In vivo evaluation of angiogenic activity and its correlation with efficacy of indirect revascularization surgery in pediatric moyamoya disease

Indirect revascularization is the most widely used treatment to induce angiogenesis in pediatric moyamoya disease (MMD). Molecular imaging methods targeted for angiogenesis have recently been developed. We performed angiogenesis imaging in indirect revascularization surgery for MMD to evaluate angiogenic activity and its correlation with treatment efficacy.

METHODS

Twelve patients with pediatric MMD were prospectively enrolled. Encephaloduroarteriosynangiosis surgery was conducted, and (68)Ga-Arg-Gly-Asp (RGD) PET was performed 3.7 ± 1.0 mo after surgery. Basal perfusion and stress perfusion (PStr) in the middle cerebral artery territory were evaluated by acetazolamide-stress brain perfusion SPECT using statistical probabilistic anatomic mapping, at preoperative, early postoperative, and long-term follow-up states. Angiogenic activity was assessed on the images in terms of maximal uptake ratio, volume of increased uptake, and uptake-volume product.

RESULTS

Basal perfusion and PStr were significantly improved after surgery. Increased angiogenic activity was observed in the revascularized area, mainly around the bony flap. Angiogenic activity gradually decreased with time and significantly correlated with the postoperative time interval (P = 0.0015 for maximal uptake ratio and 0.0069 for volume of increased uptake). It was estimated to normalize at 6.3 mo after surgery. Uptake-volume product was inversely correlated with PStr improvement at the early postoperative state (r = -0.5960, P = 0.0409) and also weakly correlated with PStr improvement at long-term follow-up (r = -0.5010, P = 0.1165).

CONCLUSION

Angiogenesis PET imaging with (68)Ga-RGD was successfully used for the assessment of angiogenic activity in indirect revascularization surgery for MMD, and angiogenic activation measured at approximately 3.7 mo after surgery was inversely correlated with perfusion improvement. The assessment of angiogenic activity using (68)Ga-RGD PET is expected to be effective for evaluating the mechanism or efficacy of revascularization treatment.

Electroencephalography in pediatric moyamoya disease: reappraisal of clinical value

PURPOSE

The clinical value of electroencephalography (EEG) in pediatric moyamoya disease has been underestimated, though the characteristic patterns are well known. We undertook this study to evaluate the clinical value of EEG as a diagnostic and postoperative follow-up modality in pediatric moyamoya disease.

METHODS

We retrospectively reviewed the pre and postoperative EEG with effective hyperventilation in 127 pediatric moyamoya patients and compared their patterns with hemodynamic images.

RESULTS

One hundred and two patients (80.3 %) among 127 showed abnormal EEG findings before revascularization surgery. The typical rebuild-up phenomenon was observed in 82 (64.6 %) and localized build-up in 32 (25.2 %) without any significant clinical ischemic events during and after hyperventilation. The rebuild-up was observed more frequently in younger age groups (less than 13 years) and Suzuki stages III. The location of the rebuild-up distribution and asymmetric build-up was consistent with the area showing hemodynamic abnormalities on single photon emission computed tomography and/or perfusion magnetic resonance imaging. Postoperative follow-up EEGs were performed in 41 patients. Six patients with remaining rebuild-up in postoperative follow-up EEG showed poorer postoperative clinical outcomes.

CONCLUSIONS

This study may reappraise EEG as an easy, safe, and adjunctive diagnostic and postoperative follow-up modality for evaluation of hemodynamic status and clinical outcome, especially in children with moyamoya disease.

Pediatric Moyamoya disease

Background:

Moyamoya disease (MMD) is a progressive cerebrovascular occlusive disease of the bilateral internal carotid arteries that leads to a compensatory abnormal vascular network at the base of the brain. Its average annual incidence 0.54 per 100,000 population but it is the most common pediatric cerebrovascular disease in East Asia. The reported incidence in USA is approximately 0.086 per 100,000 patients.

Case Report:

We present a case of Moyamoya disease that was to detected in a 7-year-old female who presented with transient altered mental status.

Conclusions:

Moyamoya disease can be diagnosed if history, physical exam and brain imaging is highly suspicious. Conventional angiography remains the gold standard for diagnosis and aids in surgical planning for patients with suspected Moyamoya disease.

Bifrontal encephalogaleosynangiosis for children with moyamoya disease

OBJECT

Several operative techniques have been reported to increase the cerebral blood flow (CBF) of the anterior cerebral artery (ACA) territory in patients with moyamoya disease. However, the optimal procedure has not yet been determined. This study compared the efficacy of performing bifrontal encephalogaleosynangiosis (EGS) using a craniotomy with performing EGS using bur holes.

METHODS

The authors retrospectively analyzed surgical results of pediatric patients with moyamoya disease treated using encephaloduroarteriosynangiosis (EDAS) and bifrontal EGS with a craniotomy, or EGS with bur holes, for the purpose of improving the ischemia of the ACA territory. Patients' demographic data, clinical presentations, surgical therapies, and clinical outcomes were reviewed.

RESULTS

Nine patients underwent EDAS with bifrontal EGS using a craniotomy. Three patients underwent EDAS with EGS using bur holes for 5 cerebral hemispheres (1 bur hole in 2 hemispheres, 2 bur holes in 2 hemispheres, and 3 bur holes in 1 hemisphere). The mean follow-up period was 46.8 months (range 7-96 months). Preoperative symptoms improved in all patients in each group. The collateral circulation in the ACA territory made by EGS was divided into 3 groups according to postoperative angiography results: Group A (revascularization of more than two-thirds of the ACA territory), Group B (revascularization between one-third and two-thirds), and Group C (revascularization less than one-third). Of 5 hemispheres treated with EGS using bur holes, 1 was evaluated as Group B and 4 as Group C. Of 18 hemispheres treated with bifrontal EGS using a craniotomy, 8 were evaluated as Group A, 7 as Group B, and 3 as Group C. The patients who underwent bifrontal EGS using a craniotomy showed significantly better revascularization than those who underwent EGS using bur holes (p = 0.0065). Cerebral blood flow in the ACA territory improved in 13 (92.9%) of 14 hemispheres in patients treated with bifrontal EGS. In contrast, only 3 (60%) of 5 hemispheres demonstrated an increase of CBF in patients treated with EGS using bur holes. A trend was demonstrated for better improvement with bifrontal EGS (p = 0.08).

CONCLUSIONS

Encephaloduroarteriosynangiosis with bifrontal EGS using a craniotomy demonstrated better revascularization and improvement of CBF in the ACA territory than with EGS using bur holes. Bifrontal EGS using a craniotomy is considered to be a simple, safe, and effective surgical procedure for improvement of the ischemia of the ACA territory in pediatric patients with moyamoya disease.

Pediatric moyamoya disease: An analysis of 410 consecutive cases

OBJECTIVE

Moyamoya disease (MMD) is a cerebrovascular occlusive disease of the bilateral internal carotid arteries that causes a compensatory abnormal vascular network at the base of brain. The rare incidence and various surgical techniques applied have limited the clinical research on MMD.

METHODS

We conducted a retrospective analysis of the surgical outcome of 410 pediatric MMD patients. All patients were treated in a relatively uniform scheme at a single institution. The surgical procedures consisted of bilateral encephaloduroarteriosynangiosis augmented by bifrontal encephalogaleo-/periosteal synangiosis. Logistic regression analyses were applied to reveal the prognostic factors for surgical outcome.

RESULTS

The overall clinical outcome was excellent in 66%, good in 15%, fair in 15%, and poor in 4% of the patients. Therefore, 81% of the patients had a favorable clinical outcome (excellent and good). Multivariate analyses revealed that infarction on presentation was associated with unfavorable clinical outcome (odds ratio [OR], 2.85; 95% confidence interval [CI], 1.49-5.46; p < 0.01) and decreased vascular reserve only on single-photon emission computerized tomography (OR, 0.07; 95% CI, 0.01-0.52; p < 0.01), with favorable clinical outcome.

INTERPRETATION

Our results indicate that an early diagnosis and active intervention before establishment of irreversible hemodynamic change are essential to achieve a favorable clinical outcome in children with MMD.

Clinical outcome after 450 revascularization procedures for moyamoya disease

Object

Moyamoya disease (MMD) is a rare cerebrovascular disease mainly described in the Asian literature. To address a lack of data on clinical characteristics and long-term outcomes in the treatment of MMD in North America, the authors analyzed their experience at Stanford University Medical Center. They report on a consecutive series of patients treated for MMD and detail their demographics, clinical characteristics, and long-term surgical outcomes.

Methods

Data obtained in consecutive series of 329 patients with MMD treated microsurgically by the senior author (G.K.S.) between 1991 and 2008 were analyzed. Demographic, clinical, and surgical data were prospectively gathered and neurological outcomes assessed in postoperative follow-up using the modified Rankin Scale. Association of demographic, clinical, and surgical data with postoperative outcome was assessed by chi-square, uni- and multivariate logistic regression, and Kaplan-Meier survival analyses.

Results

The authors treated a total of 233 adult patients undergoing 389 procedures (mean age 39.5 years) and 96 pediatric patients undergoing 168 procedures (mean age 10.1 years). Direct revascularization technique was used in 95.1% of adults and 76.2% of pediatric patients. In 264 patients undergoing 450 procedures (mean follow-up 4.9 years), the surgical morbidity rate was 3.5% and the mortality rate was 0.7% per treated hemisphere. The cumulative 5-year risk of perioperative or subsequent stroke or death was 5.5%. Of the 171 patients presenting with a transient ischemic attack, 91.8% were free of transient ischemic attacks at 1 year or later. Overall, there was a significant improvement in quality of life in the cohort as measured using the modified Rankin Scale (p < 0.0001).

Conclusions

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.

Single Nucleotide Polymorphisms of Tissue Inhibitor of Metalloproteinase Genes in Familial Moyamoya Disease

OBJECTIVE

The genes encoding tissue inhibitor of metalloproteinase (TIMP) 4 and TIMP2 span chromosomes 3p24.2-p26 and 17q25, respectively, which are the locations of familial moyamoya disease (FMMD) genes. We investigated single nucleotide polymorphisms of the TIMP2 and TIMP4 genes in FMMD patients to determine genetic predispositions.

METHODS

Eleven blood samples from FMMD patients were recruited. Controls included 50 blood samples from patients with nonfamilial moyamoya disease (MMD) and another 50 blood samples from non-MMD persons. We evaluated the promoter regions, exon-intron junctions, and the exons of the TIMP2 and TIMP4 genes by direct sequencing, and compared single nucleotide polymorphisms frequencies among the study groups.

RESULTS

A significantly higher frequency of a heterozygous genotype was found in the TIMP2 promoter region at position -418 in FMMD; that is, the G/C heterozygous genotype at position -418 was observed in nine of 11 patients with FMMD, in 16 out of 50 nonfamilial MMD control participants, and in 14 out of 50 non-MMD control participants (FMMD versus nonfamilial MMD: odds ratio, 9.56; 95% confidence interval, 1.85-49.48; P = 0.005; and FMMD versus non-MMD: odds ratio, 10.50; 95% confidence interval, 2.02-54.55; P = 0.001). This base at position -418 corresponds to the third base of the GAGGCTGGG sequence, an Sp1 binding site. Thus, changes in this position may influence Sp1 binding and subsequent transcription of the gene.

CONCLUSION

Our findings suggest that the presence of a G/C heterozygous genotype at position -418 in TIMP2 promoter could be a genetic predisposing factor for FMMD.

Surgical approaches to vascular anomalies of the child's brain

The population of pediatric patients with cerebrovascular disease presents a unique set of challenges to the neurosurgeon. The wide scope of pathology, including arteriovenous malformations, cavernous malformations and moyamoya disease, coupled with marked advances in diagnosis and treatment of these conditions over the past several years has resulted in a proliferation of the literature related to this subject. The present review provides an overview of current methods of surgical treatment for pediatric cerebrovascular diseases, focusing on indications and use of recent refinements of pre-existing surgical approaches, and newly evolved operative techniques developed to treat these entities.