R. Michael Scott and Edward R. Smith
Katie Pricola Fehnel, Jennifer Klein, Benjamin C. Warf, Edward R. Smith, and Darren B. Orbach
Pediatric hydrocephalus is a well-studied and still incompletely understood entity. One of the physiological means by which hydrocephalus and intracranial hypertension evolve is through perturbations to normal vascular dynamics. Here the authors report a unique case of an extracranial vascular anomaly resulting in persistently elevated intracranial pressures (ICPs) independent of CSF diversion in a patient with a Joubert syndrome–related disorder. The patient developed worsening intracranial hypertension after successful CSF diversion of Dandy-Walker malformation–associated hydrocephalus via endoscopic third ventriculostomy–choroid plexus cauterization (ETV/CPC). Vascular workup and imaging revealed an extracranial arteriovenous fistula of the superficial temporal artery at the site of a prior scalp intravenous catheter. Following microsurgical obliteration of the lesion, ICP normalized from > 30 cm H2O preoperatively to 11 cm H2O postoperatively. A repeat lumbar puncture at 4 months postoperatively again demonstrated normal pressure, and the patient remained asymptomatic for 9 months. Recurrent symptoms at 9 months were attributed to inadequate CSF diversion, and the patient underwent ventriculoperitoneal shunt placement. This is the first report of an extracranial-to-extracranial vascular anastomosis resulting in intracranial hypertension. This case report demonstrates the need to consider extracranial vascular anomalies as potential sources of persistently elevated ICP in the syndromic pediatric population.
Coleman P. Riordan, Darren B. Orbach, Edward R. Smith, and R. Michael Scott
The most significant adverse outcome of intracranial hemorrhage from an arteriovenous malformation (AVM) is death. This study reviews a single-center experience with pediatric AVMs to quantify the incidence and characterize clinical and radiographic factors associated with sudden death from the hemorrhage of previously undiagnosed AVMs in children.
A single-center database review of the period from 2006 to 2017 identified all patients with a first-time intracranial hemorrhage from a previously undiagnosed AVM. Clinical and radiographic data were collected and compared between patients who survived to hospital discharge and those who died at presentation.
A total of 57 patients (average age 10.8 years, range 0.1–19 years) presented with first-time intracranial hemorrhage from a previously undiagnosed AVM during the study period. Of this group, 7/57 (12%) patients (average age 11.5 years, range 6–16 years) suffered hemorrhages that led directly to their deaths. Compared to the cohort of patients who survived their hemorrhage, patients who died were 4 times more likely to have an AVM in the posterior fossa. No clear pattern of antecedent triggering activity (sports, trauma, etc.) was identified, and 3/7 (43%) experienced cardiac arrest in the prehospital setting. Surviving patients were ultimately treated with resection of the AVM in 42/50 (84%) of cases.
Children who present with hemorrhage from a previously undiagnosed intracranial AVM had a 12% chance of sudden death in our single-institution series of pediatric cerebrovascular cases. Clinical triggers of hemorrhage are unpredictable, but subsequent radiographic evidence of a posterior fossa AVM was present in 57% of fatal cases, and all fatal cases were in locations with high risk of potential herniation. These data support a proactive, aggressive approach toward definitive treatment of AVMs in children.
Daniel Duran, Philipp Karschnia, Jonathan R. Gaillard, Jason K. Karimy, Mark W. Youngblood, Michael L. DiLuna, Charles C. Matouk, Beverly Aagaard-Kienitz, Edward R. Smith, Darren B. Orbach, Georges Rodesch, Alejandro Berenstein, Murat Gunel, and Kristopher T. Kahle
Vein of Galen malformations (VOGMs) are rare developmental cerebrovascular lesions characterized by fistulas between the choroidal circulation and the median prosencephalic vein. Although the treatment of VOGMs has greatly benefited from advances in endovascular therapy, including technical innovation in interventional neuroradiology, many patients are recalcitrant to procedural intervention or lack accessibility to specialized care centers, highlighting the need for improved screening, diagnostics, and therapeutics. A fundamental obstacle to identifying novel targets is the limited understanding of VOGM molecular pathophysiology, including its human genetics, and the lack of an adequate VOGM animal model. Herein, the known human mutations associated with VOGMs are reviewed to provide a framework for future gene discovery. Gene mutations have been identified in 2 Mendelian syndromes of which VOGM is an infrequent but associated phenotype: capillary malformation–arteriovenous malformation syndrome (RASA1) and hereditary hemorrhagic telangiectasia (ENG and ACVRL1). However, these mutations probably represent only a small fraction of all VOGM cases. Traditional genetic approaches have been limited in their ability to identify additional causative genes for VOGM because kindreds are rare, limited in patient number, and/or seem to have sporadic inheritance patterns, attributable in part to incomplete penetrance and phenotypic variability. The authors hypothesize that the apparent sporadic occurrence of VOGM may frequently be attributable to de novo mutation or incomplete penetrance of rare transmitted variants. Collaboration among treating physicians, patients’ families, and investigators using next-generation sequencing could lead to the discovery of novel genes for VOGM. This could improve the understanding of normal vascular biology, elucidate the pathogenesis of VOGM and possibly other more common arteriovenous malformation subtypes, and pave the way for advances in the diagnosis and treatment of patients with VOGM.
David L. Penn, Arianna B. Lanpher, Jennifer M. Klein, Harry P. W. Kozakewich, Kristopher T. Kahle, Edward R. Smith, and Darren B. Orbach
The most common primary cardiac tumor is myxoma, typically originating in the left atrium. Emboli to the central nervous system can cause cerebral infarction or, rarely, seed tumor growth within vessel walls, causing myxomatous aneurysms. Fewer than 60 myxomatous aneurysms have been reported, including 2 cases in children. Here, the authors describe 2 different growing myxomatous aneurysms in a child successfully managed using a combined multidisciplinary approach. A 12-year-old boy developed a sudden headache, diplopia, gait instability, and speech difficulty. Magnetic resonance imaging revealed a left parietal hemorrhage and multifocal cerebral infarction, suspicious for an embolic etiology. A cardiac myxoma was identified in the left atrium and resected. Follow-up cranial vasculature imaging demonstrated multiple intracranial myxomatous aneurysms. These lesions were followed up, and serial imaging identified marked growth of 2 of them (right occipital and left parietal), prompting invasive intervention. The deep occipital lesion was better suited to endovascular treatment, while the superficial parietal lesion was amenable to resection. The patient underwent embolization of an enlarging fusiform aneurysm of the distal right posterior cerebral artery, followed by a left parietal craniotomy for a lesion of the distal left middle cerebral artery. Both procedures were performed without complications and achieved successful obliteration of the lesions, as confirmed by catheter angiography at the 30-month follow-up. To the authors’ knowledge, this report illustrates the first combined endovascular and open surgical treatment of 2 myxomatous aneurysms in a single patient. While acknowledging the rarity of this condition, this report illustrates the clinical manifestations and treatment challenges posed by myxoma and details a successful strategy that could be employed in similar scenarios.
Katie Pricola Fehnel, Micah Duggins-Warf, David Zurakowski, Maxwell McKee-Proctor, Rajarshi Majumder, Michael Raber, Xuezhe Han, and Edward R. Smith
The authors report the use of urinary biomarkers as a novel, noninvasive technique to detect juvenile pilocytic astrocytomas (JPAs), capable of distinguishing JPAs from other CNS diseases, including other brain tumors. Preliminary screening of an array of tumors implicated proteases (including matrix metalloproteinases [MMPs]) and their inhibitors (tissue inhibitors of metalloproteinase [TIMPs]) as well as growth factors (including basic fibroblast growth factor [bFGF]) as candidate biomarkers. These data led the authors to hypothesize that tissue inhibitor of metalloproteinase 3 (TIMP3) and bFGF would represent high-probability candidates as JPA-specific biomarkers.
Urine was collected from 107 patients, which included children with JPA (n = 21), medulloblastoma (n = 17), glioblastoma (n = 9), arteriovenous malformations (n = 25), moyamoya (n = 14), and age- and sex-matched controls (n = 21). Biomarker levels were quantified with enzyme-linked immunosorbent assay, tumor tissue expression was confirmed with immunohistochemical analysis, and longitudinal biomarker expression was correlated with imaging. Results were subjected to univariate and multivariate statistical analyses.
Using optimal urinary cutoff values of bFGF > 1.0 pg/μg and TIMP3 > 3.5 pg/μg, multiplexing bFGF and TIMP3 predicts JPA presence with 98% accuracy. Multiplexing bFGF and MMP13 distinguishes JPA from other brain tumor subtypes with up to 98% accuracy. Urinary biomarker expression correlated with both tumor immunohistochemistry and in vitro tumor levels. Urinary bFGF and TIMP3 decrease following successful tumor treatment and correlate with changes in tumor size.
This study identifies 2 urinary biomarkers—bFGF and TIMP3—that successfully detect one of the most common pediatric brain tumors with high accuracy. These data highlight potential benefits of urinary biomarkers and support their utility as diagnostic tools in the treatment of children with JPA.
Bradley A. Gross, Rose Du, Darren B. Orbach, R. Michael Scott, and Edward R. Smith
Cerebral cavernous malformations (CMs) are a source of neurological morbidity from seizures and focal neurological deficits due to mass effect and hemorrhage. Although several natural history reports exist for adults with CMs, similar data for pediatric patients are limited.
The authors reviewed hospital databases to identify children with CMs who had not been treated surgically and who had clinical and radiological follow-up. Annual hemorrhage rates were calculated in lesion-years, and risk factors were assessed using the Cox proportional hazards model.
In a cohort of 167 patients with 222 CMs, the mean patient age at the time of diagnosis was 10.1 years old (SD 6.0). Ninety patients (54%) were male. One hundred four patients (62%) presented with hemorrhage from at least 1 CM, 58 (35%) with seizures with or without CM hemorrhage, and 43 (26%) with incidental lesions. Twenty-five patients (15%) had multiple CMs, 17 (10%) had a family history of CMs, and 33 (20%) had radiologically apparent developmental venous anomalies (DVAs). The overall annual hemorrhage rate was 3.3%. Permanent neurological morbidity was 29% per hemorrhage, increasing to 45% for brainstem, thalamic, or basal ganglia CM and decreasing to 15% for supratentorial lobar or cerebellar lesions. The annual hemorrhage rate for incidental CMs was 0.5%; for hemorrhagic CMs, it was 11.3%, increasing to 18.2% within the first 3 years. Hemorrhage clustering within 3 years was statistically significant (HR 6.1, 95% CI 1.72–21.7, p = 0.005). On multivariate analysis, hemorrhagic presentation (HR 4.63, 95% CI 1.53–14.1, p = 0.007), brainstem location (HR 4.42, 95% CI 1.57–12.4, p = 0.005), and an associated radiologically apparent DVA (HR 2.91, 95% CI 1.04–8.09, p = 0.04) emerged as significant risk factors for hemorrhage, whereas age, sex, CM multiplicity, and CM family history did not.
Prior hemorrhage, brainstem location, and associated DVAs are significant risk factors for symptomatic hemorrhage in children with CMs. Hemorrhage clustering within the first 3 years of a bleed can occur, a potentially important factor in patient management and counseling.
Ning Lin, Edward R. Smith, R. Michael Scott, and Darren B. Orbach
The safe treatment of children using catheter-based angiography and embolization poses unique challenges because of the technical factors regarding the size and fragility of access and target vessels, as well as unique pediatric cerebrovascular pathologies. The complication rates for neurointerventional procedures in children have not been established.
The records of a consecutive cohort of pediatric patients who underwent neuroangiography and/or embolization between 2007 and 2013 were reviewed retrospectively to identify both intraprocedural and postprocedural complications. Demographic and clinical risk factors were analyzed with a multivariate logistic regression model.
The 697 consecutive procedures consisted of 429 diagnostic angiograms and 268 embolizations (mean age of patients 11.1 years; range 4 days to 18 years; 217 females). There were 130 intracranial, 122 extracranial, and 16 spinal embolizations. Pathologies included 28 intracranial arteriovenous malformations (AVMs), 12 spinal AVMs, 19 aneurysms, 29 vein of Galen malformations, 29 dural arteriovenous fistulas, 96 extracranial AVMs, 39 tumors, 3 strokes, and 13 others. Overall, 2 intraprocedural and 1 postprocedural complication (0.7%) occurred in the diagnostic group, all of which were nonneurological events. In the embolization group, 7 intraprocedural and 11 postprocedural complications (6.7%) were observed. Of these complications, 15 were nonneurological events (5.6%), 1 was a short-term neurological event (0.4%), and 2 were long-term neurological events (0.7%).
Neither the technical challenges posed by children’s access and target vessels nor the unique neuro-vascular pathologies seen in children need result in an elevated morbidity rate related to neuroangiography and embolization. At a dedicated high-volume center, the complication rates may be lower than those for comparable procedures performed in adults.