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Edward R. Smith and R. Michael Scott

Object

Progression of vasculopathy associated with moyamoya syndrome is extremely variable. The authors review their experience in patients with unilateral moyamoya syndrome to identify factors predictive of contralateral clinical and imaging-documented disease progression.

Methods

The authors reviewed the clinical and imaging records of all patients with moyamoya syndrome and unilateral disease who underwent cerebral revascularization surgery between January 1985 and June 2006 by using a standardized surgical procedure, pial synangiosis.

Results

Of 235 surgically treated patients with moyamoya syndrome, 33 (14%) presented with unilateral disease (4 adults and 29 children). There were 16 female and 17 male patients, with an average age of 10.4 years (26.8 years for adults and 8.1 years for children; range 1.5–39 years). Twenty patients presented with left-sided disease and 13 with right-sided disease.

The average follow-up after surgery was 5.3 years (3.1 years for adults and 5.6 years for children; range 1–16 years). During this period, 10 (30%) of 33 patients progressed to bilateral disease. The mean time until disease progression was 2.2 years (range 0.5–8.5 years). Factors associated with progression in this series included contralateral abnormalities on initial angiography, previous history of congenital cardiac anomaly, cranial irradiation, Asian ancestry, and familial moyamoya syndrome. Young age at diagnosis was associated with a more rapid rate of progression (age < 7 years, 0.9 years to progression and age ≥ 7 years, 3.1 years to progression).

Conclusions

Of patients with unilateral moyamoya syndrome, 30% will have progression of arteriopathy during long-term follow-up. In this series, the average time of progression from unilateral to bilateral angiographic disease was 2.2 years. Several factors, including contralateral abnormalities on initial imaging, congenital cardiac anomaly, previous cranial irradiation, Asian ancestry, and familial moyamoya syndrome, were associated with an increased risk of progression. Patients with known unilateral angiographic disease should undergo continued monitoring by using MR imaging and MR angiography at regular intervals. Treatment with pial synangiosis is safe and confers durable protection against stroke in patients with both bilateral and unilateral moyamoya syndrome.

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Edward R. Smith and R. Michael Scott

Moyamoya is a progressive arteriopathy of unknown origin affecting the branches of the internal carotid artery (ICA). The arteriopathy can present as an isolated medical condition, affecting both sides of the brain (“moyamoya disease”) or can be unilateral or found in association with systemic disorders (“moyamoya syndrome”). The ischemia resulting from luminal narrowing predisposes children to transient ischemic attacks and stroke—the primary presentations of affected patients. Although it is rare—affecting 1 in 1 million children in the US—moyamoya is implicated in 6% of all childhood strokes. Diagnosis is defined by characteristic findings on arteriograms, including stenosis of the branches of the ICA and a pathognomonic spray of small collateral vessels in this region, descriptively likened to a “puff of smoke” (“moyamoya” in Japanese). Treatment is predicated on restoration of cerebral blood flow by surgical revascularization. The rarity of this disorder has limited research and the development of evidence-based clinical management. While acknowledging these limitations, in this article the authors aim to summarize current studies of pediatric moyamoya, with the objective of providing a framework for construction of evidence-based guidelines for treatment. The compilation of current data in these guidelines should serve as a resource to aid pediatric neurosurgeons in their role as advocates for providing appropriate care to affected children.

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R. Michael Scott and Edward R. Smith

This issue of Neurosurgical Focus is devoted to the topic of moyamoya disease/syndrome. When the senior editor (R.M.S.) was a neurosurgical resident in the late 1960s and early 1970s, the condition was virtually unknown in the Western hemisphere, and patients with “cerebrovascular insufficiency” and the typical arterial findings on angiography were believed to have a type of arteritis. The refinement of catheter angiography techniques and the development of the imaging modalities of CT and MR imaging clarified the significance of making the correct diagnosis of moyamoya disease in affected patients, and with the development of direct and then indirect revascularization procedures during this same period, neurosurgeons became involved in the disease's treatment.

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Jose F. Laguna and Michael S. Smith

✓ Aberrant regeneration of the oculomotor nerve usually follows injury to the nerve by posterior communicating artery aneurysms or trauma. A case of idiopathic third nerve palsy with pupillary involvement occurred in an otherwise healthy 38-year-old man. Follow-up examination 32 months later showed evidence of oculomotor function with aberrant regeneration.

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Zane Schnurman, Michael L. Smith and Douglas Kondziolka

OBJECTIVE

Off-label therapies are widely used in clinical practice by spinal surgeons. Some patients and practitioners have advocated for increased regulation of their use, and payers have increasingly questioned reimbursment for off-label therapies. In this study, the authors applied a model that quantifies publication data to analyze the developmental process from initial on-label use to off-label innovation, using as an example recombinant human bone morphogenetic protein 2 (rhBMP-2) because of its wide off-label use.

METHODS

As a case study of off-label innovation, the developmental patterns of rhBMP-2 from FDA-approved use for anterior lumbar interbody fusion to several of its off-label uses, including posterolateral lumbar fusion, anterior cervical discectomy and fusion, and posterior lumbar interbody fusion/transforaminal lumbar interbody fusion, were evaluated using the “progressive scholarly acceptance” (PSA) model. In this model, PSA is used as an end point indicating acceptance of a therapy or procedure by the relevant scientific community and is reached when the total number of peer-reviewed studies devoted to refinement or improvement of a therapy surpasses the total number assessing initial efficacy. Report characteristics, including the number of patients studied and study design, were assessed in addition to the time to and pattern of community acceptance, and results compared with previous developmental study findings. Disclosures and reported conflicts of interest for all articles were reviewed, and these data were also used in the analysis.

RESULTS

Publication data indicated that the acceptance of rhBMP-2 off-label therapies occurred more rapidly and with less evidence than previously studied on-label therapies. Additionally, the community appeared to respond more robustly (by rapidly changing publication patterns) to reports of adverse events than to new questions of efficacy.

CONCLUSIONS

The development of off-label therapies, including the influence of investigative methods, regulation, and changing perspectives, can be characterized on the basis of publication patterns. The approach and findings in this report could inform future off-label development of therapies and procedures as well as attempts to regulate off-label use.

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Bradley A. Gross, Edward R. Smith and R. Michael Scott

Object

Cavernous malformations (CMs) of the basal ganglia are relatively rare lesions that can lead to considerable neurological impairment because of their eloquent location. The authors reviewed the clinical course and surgical outcome of a series of children with basal ganglia CMs.

Methods

The authors retrospectively reviewed the operative experience of the senior author (R.M.S.) and the 1997–2011 database of Boston Children's Hospital for children with CM of the basal ganglia (which includes CM of the caudate and/or lentiform nucleus and excludes CM of the thalamus). They evaluated baseline demographics, presenting signs, operative outcomes, and condition at long-term follow-up visits and compared these characteristics among patients who underwent surgery and those who were observed.

Results

Of 180 children with a diagnosis of CM, 11 (6%) had CM of the basal ganglia. The mean age at diagnosis was 9.3 years, and the male/female ratio was 1.8:1. Presenting signs were as follows: hemorrhage (8 children), incidental lesions (2), and seizures (1); 2 children had choreiform movement disorders. Treatment was observation or surgery. Observation was chosen for 5 children either because the lesions were asymptomatic (2 children) or because the risk for neurological dysfunction after attempted excision was believed to be high (3 children). These 5 children were observed over a combined total of 30.4 patient-years; none experienced neurological deterioration or symptomatic hemorrhage from their lesions. The other 6 children underwent microsurgical resection of the lesion because they were symptomatic from hemorrhage or increasing mass effect. All 6 of these children had hemorrhagic lesions, of which the smallest dimension was at least 1.5 cm. Of these 6 lesions, 5 were excised completely, and over a combined total of 46 patient-years of follow-up, no rebleeding or late neurological deterioration after surgery was reported.

Conclusions

In this patient population, the natural history of small and asymptomatic CMs of the basal ganglia was benign. The children with large (> 1.5 cm) symptomatic lesions underwent excision; neurological impairment was apparently minimal, and no hemorrhage or neurological deterioration occurred later.

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Tony P. Smith, Michael J. Alexander and David S. Enterline

✓ Three patients with carotid artery (CA) pseudoaneurysms were treated using four polyethylene terephthalate endografts (Wallgraft endoprostheses). Two patients received a single graft and one patient with bilateral pseudoaneurysms received two grafts. Complete occlusion of the pseudoaneurysm with patency of the arterial lumen was achieved following endograft placement in all patients. The clinical follow-up interval ranged from 12 to 18 months and included angiography or ultrasonography studies or both. One patient experienced neurological symptoms, and in-graft stenosis ranging from 50 to 100% occurred in three of the four grafts. Although the Wallgraft endoprosthesis produced good initial results for the treatment of cervical CA pseudoaneurysms, as demonstrated on radiography, it was associated with a high rate of stenosis or occlusion in all three patients.

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Patrick J. Codd, R. Michael Scott and Edward R. Smith

Seckel syndrome is an autosomal recessive disorder characterized by intrauterine and postnatal growth delay, microcephaly with mental retardation, and facial dysmorphisms including micrognathia, a recessed forehead, and a large beaked nose. Occurring in 1 in 10,000 children without sex preference, it is the most common primordial microcephalic osteodysplastic dwarfism and has been associated with a variety of congenital brain malformations and intracranial aneurysms. Moyamoya syndrome is an idiopathic, chronic, progressive cerebrovascular disorder marked by stenosis of the intracranial internal carotid arteries and concurrent development of hypertrophied collateral vessels. These tortuous arterial collaterals appear radiographically as “puffs of smoke,” giving the syndrome its name. In this report, the authors describe the case of a 16-year-old girl with coincident Seckel and moyamoya syndromes. To their knowledge, this is the first reported case of such an association being treated with surgical revascularization.

The patient presented with persistent headaches and a 2-year history of progressive hand, arm, and face numbness. Imaging studies revealed multiple completed cerebral infarcts, global ischemic changes, and vascular anatomy consistent with moyamoya syndrome. Bilateral pial synangioses successfully revascularized each hemisphere with resolution of the patient's symptoms. The patient died 1 year later of complications related to treatment of a rapidly progressing intracranial aneurysm.

This report documents the first case associating moyamoya and Seckel syndromes. In addition, the report reveals the rapid development of an intracranial aneurysm in a patient with this syndrome. When coupled with previous reports of other types of cerebrovascular disease in patients with Seckel syndrome or other primordial dwarfisms, the authors' findings are important because they suggest that physicians treating patients with dwarfism should consider the diagnosis of moyamoya syndrome when symptoms suggestive of cerebral ischemia are present. Prompt diagnosis and treatment of moyamoya syndrome, including the use of proven surgical revascularization procedures such as pial synangiosis, may significantly improve the long-term outcomes of these patients.

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Alan I. Faden, Thomas P. Jacobs and Michael T. Smith

✓ The potent, centrally active, calcium channel antagonist, nimodipine, was utilized in a highly predictive “spinal stroke” model in order to investigate the potential pathophysiological effects of calcium flux in spinal injury, as well as to evaluate the potential therapeutic role of the newly developed dihydropyridine derivatives in ischemic central nervous system injury. Nimodipine, administered before or after ischemia, at doses shown to be effective in improving cerebral blood flow and in dilating central blood vessels, failed to improve either the histopathological changes or the functional deficit caused by temporary aortic occlusion in the unanesthetized rabbit.

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Don B. Smith, Michael Hitchcock and Peter J. Philpott

✓ Cerebral amyloid angiography can cause ischemic stroke and transient ischemic attacks (TIA's), as illustrated by this case report and literature review. It is possible that the use of anticoagulant or platelet-antiaggregant drugs in elderly patients with TIA's but no angiographic abnormalities may increase the risk of hemorrhage from unsuspected amyloid angiopathy.