Do animal models of brain tumors replicate human peritumoral edema? a systematic literature search.

INTRODUCTION: Brain tumors cause morbidity and mortality in part through peritumoral brain edema. The current main treatment for peritumoral brain edema are corticosteroids. Due to the increased recognition of their side-effect profile, there is growing interest in finding alternatives to steroids but there is little formal study of animal models of peritumoral brain edema. This study aims to summarize the available literature. METHODS: A systematic search was undertaken of 5 literature databases (Medline, Embase, CINAHL, PubMed and the Cochrane Library). The generic strategy was to search for various terms associated with "brain tumors", "brain edema" and "animal models". RESULTS: We identified 603 reports, of which 112 were identified as relevant for full text analysis that studied 114 peritumoral brain edema animal models. We found significant heterogeneity in the species and strain of tumor-bearing animals, tumor implantation method and edema assessment. Most models did not produce appreciable brain edema and did not test for observable manifestations thereof. CONCLUSION: No animal model currently exists that enable the investigation of novel candidates for the treatment of peritumoral brain edema. With current interest in alternative treatments for peritumoral brain edema, there is an unmet need for clinically relevant animal models.

Hereditary haemorrhagic telangiectasia manifesting as subdural empyema.

Hereditary haemorrhagic telangiectasia (HHT) also known as Osler-Weber-Rendu disease is a rare autosomal dominant condition causing vascular dysplasia. Cerebral abscess formation, secondary to paradoxical septic emboli via HHT-derived pulmonary arteriovenous malformations (pAVMs) in this context is well documented. Herein, we present the first case of subdural empyema with this aetiology.

Endoscopic transnasal external fistulation in recurrent cystic subdiaphragmatic craniopharyngioma: a novel technique.

The authors present a technique for the persistent external drainage of intractable subdiaphragmatic cystic recurrences with the creation of a fistula between the cyst wall epithelium and epithelium on the nasal cavity, using a pedicled nasoseptal flap as a conduit. The long-term efficacy of endoscopic transnasal external fistulation (ETEF) in controlling cystic recurrences in this patient group is addressed through a retrospective observational review of 3 male patients aged 8, 22, and 45 years with the diagnosis of recurrent cystic subdiaphragmatic craniopharyngioma who underwent the ETEF procedure between 2006 and 2009. Clinical presentation, neuroimaging, surgical interventions, and follow-up were recorded. The main outcome measure was cyst reaccumulation on MRI. Patients had a mean follow-up of 76 months (range 5-8 years) with no incidence of cystic recurrence. Follow-up imaging revealed sustained cyst involution contrary to the usual recurrent enlargement commonly seen in this patient group. Symptoms of headache and visual field defects improved post-ETEF. Long-term theoretical complications of a persistent fistula such as intracranial abscess, meningitis, or CSF leak were not observed. ETEF promotes nasalization of cystic recurrences in subdiaphragmatic craniopharyngioma. It is safe and effective, causing long-term involution of cysts and can be considered a definitive procedure.