Chiari 1 malformation and holocord syringomyelia presenting as abrupt onset foot drop.

We present two patients with a Chiari 1 malformation and holocord syringomyelia who presented with abrupt onset unilateral foot drop. Neurophysiologic testing was consistent with a proximal nerve root lesion. This assisted with localization and directed magnetic resonance (MR) imaging to lumbosacral spine and nerve roots. Each child underwent a suboccipital craniectomy and laminectomy with duroplasty to decompress the foramen magnum. Each child also showed rapid and complete clinical recovery despite the significant electromyographic and MRI abnormalities on initial study.

Classification of symptomatic Chiari I malformation to guide surgical strategy.

BACKGROUND: Treatment options for Chiari I malformations include posterior fossa decompression (PFD) with additional techniques including laminectomy, intradural exploration, and duraplasty. Neuroimaging findings of cisterna magna volume, syringomyelia, and intraoperative ultrasonography may tailor surgical intervention. METHODS: We developed an algorithm classifying symptomatic Chiari I patients into three groups to define minimum operation. Without syringomyelia, the presence of cisterna magna defined Group A and the absence defined Group B. Patients with syrinx formed Group C. Mild structural pathology (Group A) or adequate space following PFD (Group B, normal intraoperative ultrasound (IOUS)) should be treated by PFD alone. Conversely, presence of syringomyelia (Group C) or inadequate space following PFD (Group B, abnormal IOUS) should additionally have duraplasty. We applied this algorithm to patients treated at a single institution over 16 years. RESULTS: Twenty-four symptomatic Chiari I malformation patients were divided into three groups that did not differ by age, gender, or extent of tonsillar ectopia. All patients treated by this algorithm experienced clinical and radiographic improvement. This included eight Group B patients who underwent PFD only (n=6) or additional duraplasty (n=2) decided by IOUS. CONCLUSION: Treatment of symptomatic Chiari I malformation may have inadequate outcome with conservative strategy or complications with aggressive strategy. This algorithm utilizes preoperative neuroimaging and intraoperative ultrasound to tailor intervention, with excellent clinical outcome and radiographic syrinx resolution on application to 24 patients. Further validation requires prospective multicenter evaluation with larger patient population.

Intracranial tumors in first year of life: the CHEO experience.

INTRODUCTION: One seventh of pediatric brain tumors are diagnosed in the first year of life. With more widespread and accessible neuroimaging, these lesions are being diagnosed earlier, but there remains scant literature about their natural history. METHODS: A retrospective review was performed of brain tumor patients presenting to the Children's Hospital of Eastern Ontario (CHEO) through the last 34 years. Patients presenting in the first year of life, including symptoms, management features, and functional outcome, were analyzed using ANOVA and chi (2) statistics. RESULTS: Eighteen cases of brain tumors in the first year of life were identified: 12 suptratentorial, eight with benign histology, and six infratentorial all with malignant histology. Median age of presentation differed by lesion location (p = 0.05) and glial tumors were most common. Raised intracranial pressure was more than twice as prevalent with posterior fossa lesions (p < 0.01) with equivalent likelihood of increasing head circumference (p = 0.74), whereas seizures were more frequent with supratentorial tumors (p = 0.04). Gross total resection was achieved in 47% of patients, cerebrospinal fluid diversion was more frequently necessary among infratentorial lesions (p = 0.02), and adjuvant therapy was more utilized for infratentorial lesions (p < 0.01). Among eight surviving infants, seven had supratentorial tumors, five survived to adulthood, and six are functionally independent. CONCLUSIONS: Brain tumors in the first year of life represent 4.8% of patients treated at CHEO. Mode of presentation, utilization of adjuvant therapy, and survival depend on tumor location and histology, with worse prognosis for infratentorial lesions. One third of patients had acceptable functional outcome requiring no special assistance.

Functional outcomes among premature infants with intraventricular hemorrhage.

OBJECTIVE: This work evaluated the mortality and functional outcomes of premature infants sustaining intraventricular hemorrhage (IVH). These outcomes were analyzed for their association with IVH severity, development of hydrocephalus and need for ventriculoperitoneal (VP) shunt insertion. METHODS: A retrospective review was performed of neonates at the Children's Hospital of Eastern Ontario who sustained IVH (1989-2005). Logistic regression tested demographic predictors of IVH severity, development of hydrocephalus and mortality. Chi(2) analysis differentiated functional outcomes and mortality by IVH grade, development of hydrocephalus and intervention for cerebrospinal fluid diversion. All analyses used the 0.05 significance level. RESULTS: Data were available for 284 patients with an average follow-up of 5.1 years. These were distributed as grade I (n = 135), grade II (n = 52), grade III (n = 43) and grade IV (n = 54), with lower gestational age and birth weight predicting disease severity. Hydrocephalus developed in 21% of patients, of whom 39% required VP shunt insertion. Overall mortality of 20% depended on IVH grade and was highest for grade IV patients (59%). Functional independence diminished with IVH severity, and patients with hydrocephalus fared worse than those without this sequel. Outcomes of patients developing hydrocephalus were similar whether or not they eventually required VP shunt insertion. CONCLUSIONS: This study describes a large cohort of neonatal IVH, describing how disease severity affects mortality and functional outcome. The overall mortality of nearly 1 in 5 patients is primarily of grade IV patients, with no difference between grade II and grade III. Further, patients surviving their hydrocephalus exhibited no worse functional deterioration if they required surgical intervention.

Cortical spreading depression releases ATP into the extracellular space and purinergic receptor activation contributes to the induction of ischemic tolerance.

Cortical Spreading Depression (CSD) is a well-studied model of preconditioning that provides a high degree of tolerance to a subsequent ischemic event in the brain. The present study was undertaken in order to determine whether the release of ATP during CSD could contribute to the induction of ischemic tolerance. Direct measurement of ATP levels during CSD indicates that with each CSD wave ATP is released into the extracellular space at levels exceeding 100 microM. Cultures of rat primary cortical neurons exposed to low levels of extracellular ATP developed tolerance to subsequent oxygen-glucose deprivation (OGD) or metabolic hypoxia. The preconditioning effect requires new protein synthesis and develops with time, suggesting that a complex genomic response is required for the induction of tolerance. Multiple purinergic receptors are involved in mediating tolerance, with P2Y receptor activation having the greatest effect. Although extracellular adenosine or glutamate may make a small contribution, most of the tolerance was found to be induced independently of adenosine or glutamate receptor activation. Multiple signal transduction pathways mediate the response to extracellular ATP with the protein kinase A pathway and activation of phospholipase C contributing the most. The results are consistent with the proposal that CSD releases ATP into the extracellular space and the subsequent activation of P2Y receptors makes a major contribution to the induction of ischemic tolerance in the brain.

Cognitive sequelae in children with posterior fossa tumors.

Late effects of radiotherapy on intellectual functioning have been well documented in children treated for posterior fossa tumors. Other aspects of cognitive functioning, such as memory, have not been adequately assessed in this population. This retrospective review reports on 15 children diagnosed with medulloblastoma or cerebellar astrocytoma who were administered a norm-referenced standardized test of memory functioning (i.e., Wide Range Assessment of Memory and Learning) an average of 3.5 years after treatment. Analyses revealed that sample means of IQ and memory were significantly lower than those of the normative population. No significant differences were found between the verbal and nonverbal IQ, or verbal and visual memory. Age at diagnosis accounted for a significant proportion of variability in the intelligence ratings but not in the memory indexes. The IQ scores of children less than 6 years of age at diagnosis were significantly lower than those of children diagnosed when over 6 years of age. Given the substantial variability within the older age group, there was insufficient power to detect true differences between memory index means for children by age at diagnosis. Follow-up assessments over 5 years may better identify the long-term effects of radiotherapy on memory functioning.

Fast-brain MRI in children is quick, without sedation, and radiation-free, but beware of limitations.

Fast-brain MRI is a promising technique for young children who require anesthesia for conventional MRI; however, poor contrast resolution and the use of one type of pulse sequence only has limitations. We aimed to review and document pitfalls of fast-brain MRI in non-sedated children. Fifty fast-brain MRI studies (Fast Imaging Employing sTeady State Acquistion [FIESTA] protocol; 1.5-Tesla Signa Excite HD, GE HealthCare, Milwaukee, WI, USA) performed between January 2008 and August 2010 in 30 non-sedated patients aged 1 day to 5 years of age (mean: 18 months) were reviewed retrospectively and compared to the most recent MRI or CT scan. The indications were: ventriculoperitoneal (VP) shunt insertion or revision or follow-up (20/50, 40%), postoperative follow-up (9/50, 18%), macrocephaly, ventriculomegaly or congenital malformation (15/50, 30%), complications of prematurity (6/50, 12%). The VP shunt position and size of fluid-filled structures were satisfactorily assessed in all patients. Undetected findings in 7/50 studies (14%) were: venous sinus thrombosis (one patient), subdural hematoma (three), failure to differentiate blood products (two), and limited evaluation of extra-axial collections (one). FIESTA fast-brain MRI provides satisfactory assessment of shunt position and the size of fluid-filled structures, but radiologists should be aware of limitations for depiction of venous sinus thrombosis, and bleeding. Modification of fast-brain protocols appears to be indicated.

Treatment of posterior fossa tumors in children.

The most common posterior fossa tumors in children are medulloblastoma, astrocytoma and ependymoma. Atypical rhabdoid teratoid tumors and brain stem gliomas are relatively rare. As the posterior fossa is a limited space, the tumors presenting in this region cause symptoms early on and require prompt treatment to avoid potential morbidity and mortality. Early detection and diagnosis of these tumors and prompt neurosurgical consultation is crucial in the optimum management of pediatric infratentorial brain tumors. Surgery is the mainstay of treatment, as it provides biopsy and decompression of the tumor. Adjuvant therapy is required in the majority of cases. Recent advances in the field of radiation biology and pharmacology have improved dose and delivery techniques of chemoradiation therapy. In the current era, advances in translational research and molecular genetics have assumed a major role in the pursuit of achieving a 'cure' for these potentially malignant tumors.

The necessity of shunt series.

OBJECT: This work assessed the value of shunt series in the evaluation of children with CSF shunts, a test that is frequently ordered as part of the assessment of shunt integrity. METHODS: The medical records of all children who underwent shunt series at Children's Hospital of Eastern Ontario between 1975 and 2007 were reviewed. Ancillary studies that were performed within 2 days of the shunt series (brain CT, MR imaging, ultrasonography, and radionuclide shuntography) were noted, as well as the subsequent requirement for a shunt revision. Shunt series and ancillary studies were categorized as either positive (revealing an observable sign that a shunt-related problem was present, such as shunt discontinuity on the shunt series or enlargement of the ventricles on the brain CT scan) or negative (no clear sign of a shunt-related problem). Shunt series were further grouped into shunt series performed for diagnostic reasons, shunt series performed on a routine basis during follow-up in clinic, and shunt series performed postoperatively. The length of time between shunt insertion and shunt fracture was noted. Statistical analyses were performed, including the derivation of sensitivities and specificities. RESULTS: There were 3416 shunt series in 394 patients, of which 3004 were performed with ancillary studies. On average, patients underwent 9 shunt series, with a minimum of 1 and a maximum of 43, during the follow-up period (range 3 weeks to 19 years). A total of 2493 shunt series and ancillary studies (83%) yielded negative results and no surgery was performed. One hundred thirty shunts series were negative with a positive ancillary study (4.3%) and no surgery was required. In 8.7% (261 shunt series negative, ancillary studies positive) shunt revision surgery was necessary. The opposite trend was far less prevalent (17 shunt series positive, ancillary test negative; 0.6%) in which surgery was required. There were 87 patients with 96 shunt fractures (2.8% of shunt series). The average time between shunt insertion and shunt fracture was 7.9 years (range 3 months to 18 years). Shunt series had a sensitivity of 18% and a specificity of 97%. The ancillary studies had a sensitivity of 84% and a specificity of 85%. CONCLUSIONS: The routine utilization of shunt series in the evaluation of a child with a CSF shunt is not necessary. This study showed that a very small number (0.6%) of shunt series helped in surgical decision making. Shunt series can be performed in selected cases, especially preoperatively in the absence of a baseline study to obtain information necessary for surgical planning.

Inadvertent intracranial insertion of a soft rubber tube in a patient with Treacher-Collins syndrome: case report and review of literature.

CASE REPORT: An inadvertent insertion of a soft rubber tube into the intracranial compartment in a patient with Treacher-Collins syndrome is reported. The neonate was delivered vaginally at 34 weeks gestation, had bilateral choanal atresia and presented with apnea at birth. An emergency orotracheal intubation was performed, and ventilatory support was instituted. Computed tomography scan of the facial bones showed a bilateral bony choanal atresia, with a thick posterior nasal septum, and complete absence of maxillary sinuses, external auditory canal, middle ear and ossicles, and roof of ethmoid bone. There was a central cleft in the frontoethmoidal area. The inner ear and the semicircular canals were present. The patient underwent successful transpalatal repair with nasal stenting. During surgery, two unsuccessful attempts to negotiate a soft rubber tube through the occluded choana were made. Postoperative magnetic resonance imaging revealed a linear hemorrhagic tract created by the soft rubber tube coursing through the anteroinferior basal frontal lobe, thalamus, basal ganglia and terminating in the occipital lobe. The patient developed bacterial meningitis, communicating hydrocephalus followed by cerebrospinal fluid rhinorrhea. A transcranial repair of the anterior cranial fossa was performed followed by ventriculoperitoneal shunt insertion. Subsequently, he underwent shunt revision for suspected shunt malfunction and developed peritoneal abscess for which the shunt was exteriorized and later removed. An endoscopic third ventriculostomy was performed, and the patient is recovering well. DISCUSSION: The potential implications of an inadvertent foreign body penetration into the intracranial compartment in such a rare event are discussed and the relevant literature is briefly reviewed.

Transient ventriculoperitoneal shunt malfunction after chronic constipation: case report and review of literature.

BACKGROUND: Significant constipation in patients with shunt-dependent hydrocephalus may often be enough to bring a subclinical shunt malfunction to clinical attention or even to be the cause of temporary distal peritoneal shunt malfunction. The treatment of the constipation may address the symptomatic shunt dysfunction so as to avoid operative intervention. The pathogenesis of distal shunt malfunction and its management in such a situation are discussed, and the relevant literature is briefly reviewed. CASE REPORT: A 16-year-old young boy had shunt-dependent hydrocephalus secondary to prematurity and intraventricular hemorrhage at birth. He was chronic flaccid paraplegic and had a neurogenic bladder and bowel involvement. He presented with acute dull aching intermittent headaches, nausea, and constipation of short duration. There was no underlying shunt infection. CT brain showed dilated lateral ventricles. Shunt survey revealed a convoluted course and kink in the distal peritoneal catheter. After administration of a bowel enema, the headaches and nausea resolved over the next few hours, and the posttreatment CT showed significant decrease in ventricular size. CONCLUSION: Chronic constipation is an important predisposing factor for distal malfunction in shunt-dependent hydrocephalus and should be ascertained in evaluation of a ventriculoperitoneal shunt malfunction. Appropriate treatment of significant constipation can relieve shunt malfunction and reestablish cerebrospinal fluid circulation. A shunt exploration can be avoided in such a situation. A close neurological monitoring of the patient is essential during the course of treatment. An interdisciplinary approach between concerned medical specialties and enhanced awareness is mandatory to ensure appropriate bowel management.

Tonsillar herniation and cervical syringomyelia in association with posterior fossa tumors in children: a case-based update.

BACKGROUND: Posterior fossa tumors most commonly occur in children. They frequently present with raised intracranial pressure and may have tonsillar herniation. The symptomatology is predominantly directed towards the tumor. The occurrence of syringomyelia in such cases is most unusual. Symptomatic syringomyelia is rare. CASE REPORT: We describe a case of a pilocytic astrocytoma of the cerebellum in a 13-year-old girl who presented with clinical features of progressively worsening raised intracranial pressure and secondary tonsillar herniation and cervical syringomyelia. Magnetic resonance (MR) imaging showed a large midline inhomogenously enhancing vermian tumor causing moderate obstructive hydrocephalus. In addition, the cerebellar tonsils herniated down to the C2 level, and there was a centrally located syrinx from C2-T1. The tumor was resected through a suboccipital craniectomy. At follow-up after 3 months, MR imaging demonstrated total resolution of tonsillar herniation and cervical syringomyelia. CONCLUSIONS: The occurrence of tonsillar herniation and syringomyelia in association with a slow growing benign tumor like pilocytic astrocytoma of the cerebellum is uncommon. The blockade of normal cerebrospinal fluid circulation pathway at the foramen magnum is the crucial factor. Surgical extirpation of the tumor restores the normal cerebrospinal fluid circulation at the foramen magnum and produces an excellent outcome. The need for an additional surgical procedure for treatment of associated tonsillar herniation and syringomyelia can be avoided. Volumetric assessment of the posterior fossa may provide a better understanding of the pathophysiology of syringomyelia in such patients.

Primary giant congential infantile fibrosarcoma of the scalp: case report and review of literature.

CASE REPORT: A primary giant infantile fibrosarcoma of the scalp in a 6-month-old boy is reported. He presented with a rapidly enlarging right paramedian parietal scalp swelling since birth. There were no signs of raised intracranial tension. Magnetic resonance (MR) imaging of the brain revealed a large vascular scalp tumor extending over the posterior frontal and parietal region bilaterally crossing the midline. There was no intracranial extension. Carotid angiography revealed an extremely vascular tumor supplied by the external carotid artery branches. The tumor was completely resected through a curvilinear scalp incision. Histology was consistent with diagnosis of an infantile fibrosarcoma. The patient had an uneventful course and received no postoperative adjuvant therapy. MR imaging of the brain at follow-up after 5 years showed no evidence of recurrence of tumor. At follow-up after 10 years, he is asymptomatic and leading an active life. DISCUSSION: The pathology and management of primary scalp fibrosarcoma is discussed, and the relevant literature is briefly reviewed.

Intrauterine penetrating direct fetal head trauma following gunshot injury: a case report and review of the literature.

CASE REPORT: An unusual case of an intrauterine penetrating head injury due to a pellet from an airgun is described. A 28-year-old pregnant woman, at term, shot herself intravaginally with a toy BB gun. Following a spontaneous precipitous vaginal delivery, the neonate presented with persistent seizure disorder, meningitis, cerebritis, and a right parietal region scalp swelling. Imaging studies revealed intracranial hemorrhage, and the metallic pellet was adjacent to the right lateral ventricle, which was removed through a parietal craniotomy. Computed tomography of the brain after 1 week demonstrated early abscess formation in the left frontal operculum and a subdural empyema in the posterior fossa. The abscesses were evacuated, and the meningitis was treated vigorously with broad-spectrum antibiotics. Although well for the past 6 years, the child demonstrates significant mental handicap and developmental delay. DISCUSSION: The pathogenesis, management, and medicolegal issues pertaining to the above case are discussed, and the relevant literature is briefly reviewed.

Anterior cranial base glioneuronal heterotopia.

BACKGROUND: Cranial base glioneuronal heterotopia is a nest or linear array of glioneuronal tissue within the basal meninges. It is thought to arise from aberrant migration of embryonic neuroepithelial tissues into the subarachnoid space. It frequently mimics tumors and may extend through basal skull bones into extracranial soft tissues. CASE REPORT: We describe a case of intracranial anterior skull base leptomeningeal glioneuronal heterotopia in a newborn female who was diagnosed in the prenatal period by ultrasound examination to have an intracranial space-occupying lesion at 35 weeks of gestation. There was no evidence of increased intracranial pressure at birth. Magnetic resonance imaging showed a large, predominantly solid, minimally enhancing tumor in the anterior cranial fossa extending into the suprasellar region as well as into the right and left middle fossae. The gross tumor was totally resected through bifrontal craniotomy. CONCLUSIONS: Although uncommon, diagnosis of intracranial extracerebral glioneuronal heterotopia should be strongly ascertained while evaluating intracranial space-occupying lesions during the prenatal period and infancy. It needs to be distinguished histologically from teratoma and primary central nervous system tumors. Prenatal screening for early diagnosis of the lesion is vital. The location of the lesion and its relationship to the surrounding structures should lead to an accurate diagnosis in the majority of cases. Complete resection is curative and should be the goal. Long-term prognosis is excellent in view of the benign nature and extraaxial origin of the lesion.

Neuroendoscopic intracranial pressure monitoring.

OBJECT: We wished to find a way of monitoring patients' intracranial pressure (ICP) during endoscopic surgery. METHODS: The Codman Microsensor ICP monitor can be inserted through the working channel of an endoscope with an interposed assembly (Check Flo II with male fitting, 9 F, manufactured by Cook, model #CFM-100TM) to provide a water-tight seal and allow simultaneous irrigation. During endoscopic third ventriculostomy surgery with this setup in our hospital, the ICP was continuously monitored. The effects of irrigation on ICP were also followed. The sensor was assumed to be absolutely accurate and not referenced to a column of water. CONCLUSION: The small size of the Microsensor ICP monitor enabled easy placement through the working channel of the endoscope and interposed assembly. The ICP reading was continuously available, even during irrigation. The effect of irrigation on ICP was carefully monitored, and limited when pressure changes were noted.