BackgroundHeadache is the most common symptom of Chiari 1 malformation, a condition characterized by the herniation of cerebellar tonsils through the foramen magnum. However, the headache pattern of cases with Chiari 1 malformations is not well defined in the literature, especially in children.ObjectiveThe aim of this retrospective chart review was to evaluate the frequency and the characteristics of headache in children with Chiari 1 malformation at initial evaluation and during follow up.MethodsForty‐five cases with tonsillar ectopia were selected among 9947 cases under 18 years of age who underwent neuroimaging between 2002 and 2010. A semistructured clinical interview (mean follow‐up: 5.2 years) was conducted. Headache was classified according to the second edition of the International Classification of Headache Disorders.ResultsPossible associations between clinical picture, in particular headache pattern, but also other signs and symptoms attributable to Chiari 1 malformation, and the extent of tonsillar ectopia were found for 3 different groups: those with borderline (<5 mm, N = 12), mild (5‐9 mm, N = 27), and severe tonsillar ectopia (≥10 mm, N = 6), respectively. Twenty‐four out of 33 (73%) cases with Chiari 1 malformation complained of headache, and 9/33 (27%) of those patients (5 with mild and 4 with severe tonsillar ectopia) reported headache attributed to Chiari 1 malformation.ConclusionsIn our studied pediatric population, the most common symptom for cases diagnosed with Chiari 1 malformation was headache, and headache attributed to Chiari 1 malformation was the most common headache pattern in patients with Chiari 1 malformation. The presence of headache attributed to Chiari 1 malformation along with 3 other signs or symptoms of Chiari 1 malformation were highly predictive of severe tonsillar ectopia.

Chiari malformation type 2 is characterized by hindbrain protrusion and a constellation of supratentorial malformations. Chiari malformation type 2 is thought to be causally related to myelomeningocele due to intrauterine cerebrospinal fluid overdrainage. This relationship is so strong that it has become a rule. A 14-year-old girl affected by mental retardation, spastic triparesis, and epilepsy is presented. Brain magnetic resonance imaging disclosed a severe Chiari malformation type 2, whereas spine magnetic resonance imaging was unremarkable. The authors discuss previous literature describing rare cases of Chiari malformation type 2 without open spinal dysraphism and the relevance of concomitant, sometimes overlooked, neuroimaging findings, underlying how exceptions might be hurdles but might also eventually strengthen the rules.

Pleomorphic xanthoastrocytoma (PXA) is a rare astrocytic tumor that usually occurs in the superficial cerebral hemispheres of children and young adult and has a favorable prognosis. We report a case of a 14-year-old girl with a recent history of sciatica and ataxic gait. Pre- and post-contrast brain and spinal MRI revealed the presence of multiple solid lesions with a cystic component in the cerebellum and the spinal cord with a concomitant massive leptomeningeal involvement Histological and immunohistochemical findings were concordant with a final diagnosis of WHO grade II PXA. Even the biological indolent PXAs' behavior, this is the third report in the literature of such an unusual multicentric PXA with leptomeningeal dissemination.

We describe an 8-year-old boy admitted because of prolonged seizures during norovirus gastroenteritis without any signs of encephalopathy. Blood tests were normal and cerebrospinal fluid examination resulted negative for both bacteria and viruses. A reverse transcriptase polymerase chain reaction revealed norovirus RNA in a stool sample. A cerebral computed tomography turned out to be normal whereas subsequent cerebral magnetic resonance imaging showed transitory signal abnormalities consistent with vasogenic edema. The post-ictal electroencephalogram revealed normal background activity with sporadic left posterior delta waves. The child was discharged after 10 days with an unremarkable physical examination. A cerebral magnetic resonance imaging and an electroencephalogram after 1 month were both negative. We report a new case of benign infantile convulsions due to norovirus gastroenteritis with neuroradiological abnormalities to the pertinent literature in order to improve knowledge about this disorder and increase the possibility of clarifying its pathogenesis.

Object. Although a rarely reported occurrence, late failure of endoscopic third ventriculostomy (ETV) may occur in children as a result of a variety of factors. Delay in recognition of symptoms can lead to harmful deterioration in the patient's condition. The authors undertook this study to assess the capacity of cine phase-contrast MR imaging to identify late failure in asymptomatic pediatric patients treated with ETV for hydrocephalus.Methods. This study was a retrospective evaluation of cases involving patients who underwent ETV between January 1, 1999, and December 31, 2008, at the pediatric neurological surgery service of the University of Padua. Before 2004, patients were routinely followed up with cine MR imaging at 3, 6, and 12 months after ETV. In 2004, a protocol of annual cine MR follow-up was instituted as a result of a case of fatal late failure. The authors evaluated all cases of late failure identified through cine MR imaging and performed a statistical analysis to investigate the relationship between ETV failure and several variables, including the cause of hydrocephalus for which ETV was originally indicated.Results. In a series of 84 patients (age range 6 days-16 years), 17 patients had early ETV failure. Of the remaining 67 patients, 5 (7%) were found to have no CSF flow through the fenestration and recurrent ventriculomegaly when assessed with cine MR imaging at 1, 2, 3, 4, and 7 years after ETV. The patient in whom ETV failure was identified 1 year postoperatively had Dandy-Walker malformation. The patients in whom ETV failure was identified 2, 3, and 4 years postoperatively all had undergone ETV for treatment of postinfective hydrocephalus. The patient in whom ETV failure was identified 7 years postoperatively had a cystic arachnopathy in the fourth ventricle after cerebellar astrocytoma removal.Conclusions. Patients who undergo ETV for infective hydrocephalus and Dandy-Walker malformation should receive long-term follow-up, because late closure of the stoma may occur progressively and slowly. Intraoperative observation of thickened arachnoid membranes at the level of the interpeduncular cisterns at the first ETV and a progressive decreasing of CSF flow through the stoma on routine cine MR imaging should be considered unfavorable elements entailing a significant risk of deterioration. (DOI: 10.3171/2011.1.FOCUS10303)

INTRODUCTION:Thrombolytic therapy for acute ischemic stroke is based on clinical assessment, blood tests, and computed tomography (CT) findings. The presence of early CT ischemic changes may help support therapeutic decision. Our aim is to call attention to a likely overlooked "stroke mimic," Gliomatosis Cerebri (GC).CASE SERIES:Clinical and neuroimaging analysis of 3 patients with documented GC, whose acute clinical onset and CT data (lenticular and ribbon sign and a ipsilateral dot sign) were suggestive of ischemic stroke.CONCLUSION:Noncerebrovascular conditions may present with both acute onset and false CT signs of early ischemic stroke. Although rare, GC needs to be considered among the possible "stroke mimics" to avoid inappropriate thrombolytic therapy.

Polymicrogyria (involving or not the sylvian scissure) with cerebellar cortical dysplasia or vermis hypoplasia has been reported in few cases. In addition, the association between ectopic neurohypophysis and other cortical malformations, including bilateral perisylvian polymicrogyria, has been documented. We describe a girl affected by focal epilepsy since the age of 2 years. Magnetic resonance imaging (MRI) at 11 and 22 years of age showed bilateral perisylvian polymicrogyria, dysplasia of the left cerebellar hemisphere, and ectopic neurohypophysis. Genetic tests, including fluorescent in situ hybridization 22q11.2 and array-comparative genomic hybridization, and pituitary hormones (at the age of 20 years) were normal. The patient is now 22 years old, and she is seizure free under therapy with lamotrigine and levetiracetam. To the best of our knowledge, this is the first description of this complex cerebral malformation. This finding confirms that bilateral perisylvian polymicrogyria can be associated with other cerebral malformations; cerebellum and neurohypophysis must be carefully evaluated in patients with polymicrogyria.

Ischemic stroke is a recognized complication of varicella-zoster virus infections. We report on an immunocompetent 5-year-old girl who presented with acute neurologic deficits attributed to cerebral infarction, 3 months after varicella-zoster virus infection. Magnetic resonance imaging of the brain showed subacute ischemic lesions in the territory of the right middle cerebral artery. A literature review of 70 similar cases is reported.

Joubert syndrome is a disorder characterized by ataxia, developmental delay, oculomotor anomalies, and breathing irregularities, with cerebellar vermian and midbrain dysgenesis. The molar tooth sign, reflecting the midbrain dysgenesis of Joubert syndrome, is the neuroradiological hallmark and is an essential sign in the identification of this condition. Variable vermian agenesis, an expanded fourth ventricle, and a large posterior cranial fossa with a normal brainstem are typical of Dandy-Walker malformation. The authors report a case in which a Dandy-Walker malformation coexisted with Joubert syndrome, but initially prevented the ‘‘molar tooth sign’’ from being recognized because of an important cystic dilatation of the fourth ventricle. In this article, they discuss the importance of the re-examination of brain magnetic resonance features after decompression of the posterior cranial fossa in a patient with Dandy-Walker malformation and additional clinical neurological or systemic abnormalities typical of Joubert syndrome, to not miss the correct diagnosis.

Background: Hemiplegic migraine (HM) is a rare variety of migraine with aura, characterized by motor deficits during the aura, often beginning in childhood. The hemiplegic attacks can be severe and prolonged but the prognosis is usually good. Data on neuroimaging, including diffusion-weighted imaging (DWI) and spectroscopy, during prolonged attacks of HM are quite limited, particularly in children. Case: An eight-year-old female had a prolonged attack of sporadic HM characterized by right-sided hemiplegia, global aphasia, fever and impairment of consciousness. MRI nine hours after hemiplegia onset was negative, while the following MRI scans (days 4 and 11) documented a progressive increase in cortical swelling in the left hemisphere with mild hyperintensity on DWI and mild reduction of apparent diffusion coefficient values. Proton MRI spectroscopy (MRS) (day 15) showed a decrease in the N-acetylaspartate/creatine ratio in the left hemisphere. 99mTc-ECD single-photon emission tomography (SPET) (day 27) showed marked left hemispheric hypoperfusion. The patient recovered completely after 40 days and neuroimaging follow-up (MRI and SPET) after six months was normal. The patient carried a missense mutation of the ATP1A2 gene. Conclusion: Multimodal neuroimaging (MRI, DWI, MRS, SPET) in a prolonged HM attack supports evidence for a primary neuronal dysfunction.

Fibrocartilaginous embolization is a rare cause of ischemic myelopathy caused by embolization of intersomatic disk nucleus pulposus into spinal vasculature during Valsalva-like maneuvers. Diagnostic criteria are based on patient’s clinical history, magnetic resonance evidence of T2-hyperintense spinal cord lesion, and exclusion of other causes of ischemic myelopathy. These criteria do not take into account the development of magnetic resonance techniques able to enhance signal abnormalities within the neighboring intersomatic disc or vertebral body and to early characterize central nervous system lesions according to the presence of cytotoxic edema. We present 2 pediatric cases of progressive paraplegia attributed to fibrocartilaginous embolization in which short-tau inversion recovery and diffusion-weighted imaging sequences played a pivotal role showing the ischemic nature of spinal cord lesions. Due to its specificity, diffusion-weighted imaging should be included in the magnetic resonance criteria of fibrocartilaginous embolization and in standard magnetic resonance analysis when dealing with acute transverse myelopathy.

Background. Little is known about the visual outcome of children affected by an optic pathway glioma (OPG). Procedures. We evaluated the long-term visual outcome of 32 consecutive children affected by OPG without neurofibromatosis type-1 referred to the Pediatric Department of Padua University and managed according to standardized strategies. Results. Eight children received chemotherapy, 10 radiotherapy, 7 both chemotherapy and radiotherapy, whereas 7 were untreated. At presentation, visual acuity (VA) was normal in 22 children (13 unilaterally and 9 bilaterally), and reduced in 10. At follow-up, VA had improved in 6 patients; it was stable in 8 and worse in 18. Visual field, assessed in 29 children, was normal in 9 and reduced in 20. The number of children with some grade of visual impairment increased from 7 to 10 during follow-up. Of the 17 children in whom the tumor became significantly smaller, VA improved in 6, was stable in 3, and worse in 8. Of the 6 children with improved VA, 5 received radiotherapy, and their papilla was normal or mildly pale. After a median follow-up of 6 years, 26 patients are alive with stable disease. Conclusions. The visual prognosis of children with OPG is unsatisfactory. Older children treated with radiotherapy seem to have a better visual outcome than younger children. Severe optic pallor at diagnosis or during follow-up may be indicative of a negative prognosis. Pediatr Blood Cancer. 2010;55:1083-1088. (C) 2010 Wiley-Liss, Inc.

Ischemic stroke is a recognized complication of varicella-zoster virus infections. We report on an immunocompetent 5-year-old girl who presented with acute neurologic deficits attributed to cerebral infarction, 3 months after varicella-zoster virus infection. Magnetic resonance imaging of the brain showed subacute ischemic lesions in the territory of the right middle cerebral artery. A literature review of 70 similar cases is reported.

BACKGROUND:The growing teratoma syndrome (GTS) consists of a mature teratoma paradoxically enlarging during or after chemotherapy for malignant nongerminomatous germ cell tumors.METHODS AND RESULTS:We report two cases of GTS occurring in association with NSGCT of the pineal gland. Although an unusual event, clinicians and radiologists should be aware of its natural history.CONCLUSIONS:When normalized tumor markers after chemotherapy are associated with imaging features of a growing mass, the hypothesis of GTS must be taken in consideration. When early diagnosed, GTS can be managed surgically with good results.

Varicella zoster virus (VZV) is the only human virus known to replicate in arteries. After the acute infection, the virus persists in a noninfectious latent form in ganglia along the neuraxis, with intermittent periods of reactivation. Both primary and secondary reactivation are associated with stroke in children. These patients, regardless of the chosen treatment, have a high risk of recurrence, particularly those with worsening arterial stenosis. There are no specific therapy protocols for varicella-associated stroke in children, and the use of steroids or antiviral drugs is still controversial. We present a series of 4 children with stroke following varicella infection, with no recurrence and stable vascular stenosis at a mean follow-up of 18 months without steroid treatment. We also analyze possible correlations between anti-protein C, protein S and protein Z autoantibodies, and post-varicella arteriopathy.