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Friederike Knerlich-Lukoschus, Paul Steinbok, Christopher Dunham and David Douglas Cochrane

OBJECT

Cerebellar cavernous malformations (CCMs) have not been specifically described in the pediatric age group. Authors of this study, after considering the published literature, describe the characteristic clinical, radiological, and surgical features of CCM in children.

METHOSDS

Patients younger than 18 years of age who were known to have CCM and had undergone surgery between 1992 and 2014 at the authors’ institution were reviewed. Pediatric CCM cases reported in the literature (case reports and cases included in series on CMs in the pediatric age group) were also analyzed for specific features of this entity.

RESULTS

Four male patients and 1 female patient (2.5–14 years of age) with CCM presented acutely with severe headache followed by cerebellar dysfunction. In all patients, neuroimaging (cranial CT and MRI) demonstrated hemorrhagic cerebellar lesions with heterogeneous T1 and T2 signal intensities and hyperintense blooming on susceptibility-weighted imaging. The lesions reached large sizes exhibiting spherical, cystic, and often “pseudotumoral” morphology. In 3 patients, developmental venous anomalies (DVAs) were found. In 4 of the 5 patients, the CCMs and hematomas were totally removed. All patients had a clinically excellent functional outcome without surgical complication and with complete resolution of their presenting symptoms.

CONCLUSIONS

Cerebellar CMs occur in all pediatric age groups and display characteristic clinical and imaging features. In children, CCMs reach large sizes and can result in massive hemorrhage, often leading to a possible diagnosis of hemorrhage into a tumor. An associated DVA is quite common. Surgery is a safe and efficient treatment option with excellent outcomes in patients.

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Ahmad Bader, Manraj Heran, Christopher Dunham and Paul Steinbok

OBJECT

Two of the more common infantile brain tumors, glioblastoma multiforme (GBM) and desmoplastic infantile tumors (DITs), can be difficult to distinguish on MRI. Both tumors occur in the supratentorial compartment and both have solid and cystic components. Differentiating between the 2 on MRI studies could assist the surgeon in discussions with family and child management. The authors report on their institutional experience with both tumors, focusing on radio-graphic features, especially the diffusion studies, which might be useful in distinguishing between infantile GBM and DIT.

METHODS

A retrospective review was undertaken of all infantile brain tumors treated at British Columbia’s Children’s Hospital between 1982 and 2012, and cases of GBM and DIT were recorded. Only cases that had imaging were included in the study. A literature review was completed to identify reported cases of infantile GBM and DIT. Only reports that described or included radiological studies (particularly MRI) of the tumors were included. Certain radiographic features of the tumors were reviewed, including location, size, consistency, pattern of enhancement, and features on MR diffusion studies.

RESULTS

Of 70 cases of infantile brain tumors, 2 GBM cases and 3 DIT cases (all 3 of which were desmoplastic infantile gangliogliomas [DIGs]) met the inclusion criteria. The radiological studies obtained in all 5 cases were reviewed by a neuroradiologist. All 5 patients had supratentorial tumors with cystic-solid consistency. Diffusion MRI studies showed restricted diffusion in the 2 GBM cases, but no evidence of restricted diffusion in the DIG tumors. The GBM tumors were heterogeneously enhancing, and the DIG tumors showed avid and homogeneous enhancement. The literature review revealed 29 cases of infantile GBM and 32 cases of DIG/DIT that met the inclusion criteria. The tumors were large in both groups. The tumors were cystic-solid in consistency in 10 of 30 (33%) of GBM cases and 28 of 32 (87.5%) of DIT cases. The contrast enhancement was heterogeneous in 9 of 30 (30%) GBM cases, and it was homogeneous and avid in 27 of 32 (84%) of DIT cases. Diffusion studies were recorded in 2 published infantile GBM cases, and in both of them diffusion was restricted. The authors only found 1 report that discussed DIG tumor features on MR diffusion studies, but the interpretation was difficult and unclear.

CONCLUSIONS

Magnetic resonance imaging, especially diffusion-weighted imaging, may be a useful aid in distinguishing between infantile GBM and DIT tumors, with infantile GBM demonstrating restricted diffusion.

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Michael M. H. Yang, Ash Singhal, Shahrad Rod Rassekh, Stephen Yip, Patrice Eydoux and Christopher Dunham

The authors describe an infant girl who, at 10 months of age, presented with a large right parietooccipital tumor causing increased intracranial pressure, mass effect, and midline shift. The tumor was completely resected, and the entirety of the histology was consistent with glioblastoma. She was subsequently placed on adjuvant high-dose chemotherapy consisting of carboplatin, vincristine, and temozolomide, according to Head Start III, Regimen C. Three months after the complete resection, tumor recurrence was noted on MR imaging, during the third cycle of chemotherapy, and biopsy revealed malignant astrocytoma. Given the recurrence and the patient's intolerance to chemotherapy, a palliative course was pursued. Unexpectedly, the patient was alive and had made significant developmental improvements 18 months into palliation. Subsequently, however, signs of increased intracranial pressure developed and imaging demonstrated a very large new tumor growth at the site of prior resection. The recurrence was again fully resected, but microscopy surprisingly revealed pleomorphic xanthoastrocytoma throughout. The clinicopathological and genetic features of this girl's unusual neoplasm are detailed and potential pathogenic hypotheses are explored in this report.

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Liat Apel-Sarid, Doug D. Cochrane, Paul Steinbok, Angela T. Byrne and Christopher Dunham

Object

Microfibrillar collagen hemostat (MCH; trade name Avitene) is a partially water-insoluble acid salt of purified bovine corium collagen. This agent has been widely used to control hemorrhage at surgery, and especially during pediatric neurosurgeries at the authors' institution. Despite its effectiveness, rare case reports detailing adverse inflammatory reactions to MCH have been documented. Based primarily on MR imaging, postoperative reactions have most commonly elicited clinical differential diagnoses of tumor recurrence or abscess. According to the literature, MCH induces a very characteristic mixed inflammatory response that is rich in eosinophils; in light of these observations, many authors have suggested an allergy-based pathogenesis.

Methods

The authors retrospectively reviewed 3 pediatric neurosurgical cases treated at their institution, wherein a common histomorphological inflammatory reaction to MCH was elicited at the site of prior craniotomy.

Results

Case 1 is that of a 10-year-old girl whose diagnosis was a right temporal lobe ganglioglioma, classified as WHO Grade I. Case 2 is that of a 9-year-old boy whose diagnosis was a left parietal lobe anaplastic ependymoma, classified as WHO Grade III. Finally, Case 3 is that of a 15-year-old girl whose diagnosis was focal cortical dysplasia Type IIA affecting the left occipital lobe. Each patient presented with new or recurrent seizures 5–6 weeks after the initial resection. The postsurgical reactions incited by MCH mimicked the radiological appearance of either an abscess (Cases 2 and 3) or recurrent tumor (Case 1). Histologically, the mixed inflammatory infiltrate was typified by the presence of MCH-centric necrotizing granulomas that were surrounded by a palisade of macrophages and often several eosinophils.

Conclusions

The findings are in keeping with previous case reports describing the clinicopathological features of adverse reactions occurring due to MCH. Based on the authors' observations, the possibility of an idiopathic inflammatory reaction to MCH should be considered when either seizures, a typical radiological appearance (that is, consistent with tumor recurrence or abscess formation), or both arise shortly after initial surgery. A conservative treatment approach to this type of inflammatory lesion appears to be the most appropriate management strategy.

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Amelie I. Stritzke, Christopher P. Dunham, John A. Smyth and Paul Steinbok

The authors describe the case of a late preterm infant girl who presented prenatally with a low lumbar neural tube defect and features of Chiari malformation type II (CM-II). At birth, she exhibited stridor and underwent surgical repair of a lumbosacral myelomeningocele on Day 2 of life. The prognosis was deemed to be poor, and hence a “Chiari decompression” procedure was not undertaken. The patient was subsequently extubated and died on Day 10. Postmortem findings included a rarely described but characteristic granulomatous meningitic reaction to vernix caseosa, which presumably entered the subarachnoid space and spinal cord syrinx antenatally via the open neural tube defect. The significance of congenital stridor in the context of CM-II and in particular the role of vernix caseosa granulomatous meningitis are examined. The antenatal repair of myelomeningoceles, as championed by some, may prevent this ominous meningitic complication.

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Friederike Knerlich-Lukoschus, Mary B. Connolly, Glenda Hendson, Paul Steinbok and Christopher Dunham

OBJECTIVE

Focal cortical dysplasia (FCD) Type II is divided into 2 subgroups based on the absence (IIA) or presence (IIB) of balloon cells. In particular, extratemporal FCD Type IIA and IIB is not completely understood in terms of clinical, imaging, biological, and neuropathological differences. The aim of the authors was to analyze distinctions between these 2 formal entities and address clinical, MRI, and immunohistochemical features of extratemporal epilepsies in children.

METHODS

Cases formerly classified as Palmini FCD Type II nontemporal epilepsies were identified through the prospectively maintained epilepsy database at the British Columbia Children's Hospital in Vancouver, Canada. Clinical data, including age of seizure onset, age at surgery, seizure type(s) and frequency, affected brain region(s), intraoperative electrocorticographic findings, and outcome defined by Engel's classification were obtained for each patient. Preoperative and postoperative MRI results were reevaluated. H & E–stained tissue sections were reevaluated by using the 2011 International League Against Epilepsy classification system and additional immunostaining for standard cellular markers (neuronal nuclei, neurofilament, glial fibrillary acidic protein, CD68). Two additional established markers of pathology in epilepsy resection, namely, CD34 and α-B crystallin, were applied.

RESULTS

Seven nontemporal FCD Type IIA and 7 Type B cases were included. Patients with FCD Type IIA presented with an earlier age of epilepsy onset and slightly better Engel outcome. Radiology distinguished FCD Types IIA and IIB, in that Type IIB presented more frequently with characteristic cortical alterations. Nonphosphorylated neurofilament protein staining confirmed dysplastic cells in dyslaminated areas. The white-gray matter junction was focally blurred in patients with FCD Type IIB. α-B crystallin highlighted glial cells in the white matter and subpial layer with either of the 2 FCD Type II subtypes and balloon cells in patients with FCD Type IIB. α-B crystallin positivity proved to be a valuable tool for confirming the histological diagnosis of FCD Type IIB in specimens with rare balloon cells or difficult section orientation. Distinct nonendothelial cellular CD34 staining was found exclusively in tissue from patients with MRI-positive FCD Type IIB.

CONCLUSIONS

Extratemporal FCD Types IIA and IIB in the pediatric age group exhibited imaging and immunohistochemical characteristics; cellular immunoreactivity to CD34 emerged as an especially potential surrogate marker for lesional FCD Type IIB, providing additional evidence that FCD Types IIA and IIB might differ in their etiology and biology. Although the sample number in this study was small, the results further support the theory that postoperative outcome—defined by Engel's classification—is multifactorial and determined by not only histology but also the extent of the initial lesion, its location in eloquent areas, intraoperative electrocorticographic findings, and achieved resection grade.