Intraoperative 3-Tesla MRI in the management of paediatric cranial tumours--initial experience.

BACKGROUND: Intraoperative MRI (ioMRI) has been gaining recognition because of its value in the neurosurgical management of cranial tumours. There is limited documentation of its value in children. OBJECTIVES: To review the initial experience of a paediatric 3-Tesla ioMRI unit in the management of cranial tumours. MATERIALS AND METHODS: Thirty-eight children underwent ioMRI during 40 cranial tumour resections using a 3-Tesla MR scanner co-located with the neurosurgical operating theatre. IoMRI was performed to assess the extent of tumour resection and/or to update neuronavigation. The intraoperative and follow-up scans, and the clinical records were reviewed. RESULTS: In 27/40 operations, complete resection was intended. IoMRI confirmed complete resection in 15/27 (56%). As a consequence, surgical resection was extended in 5/27 (19%). In 6/27 (22%), ioMRI was equivocal for residual tumour. In 13/40 (33%) operations, the surgical aim was to partially resect the tumour. In 7 of the 13 (54%), surgical resection was extended following ioMRI. CONCLUSION: In our initial experience, ioMRI has increased the rate of complete resection, with intraoperative surgical strategy being modified in 30% of procedures. Collaborative analysis of ioMRI by the radiologist and neurosurgeon is vital to avoid errors in interpretation.

Tuberculous meningitis: protracted course and clinical response to interferon-gamma.

A 12-year-old girl with protracted tuberculous meningitis received standard chemotherapy and dexamethasone and had a progressive cerebrospinal fluid neutrophilia, raised protein and depressed glucose levels. Her temperature was raised for 5 months until a second course of dexamethasone was given. At week 15, multiple tuberculomas and hydrocephalus were detected followed by acute hydrocephalus (week 58), which required a ventricular-peritoneal shunt. Tuberculomas resolved after a second course of dexamethasone but recurred 15 months later. Immunological investigations were normal including integrity of the type 1 cytokine pathway. From month 24, interferon-gamma was given subcutaneously (initially 50 microg/m(2)) and continued for 19 months. Within 2 weeks she responded clinically followed by a reduction in inflammatory signs on magnetic resonance imaging scan (but not in the tuberculomas). At month 44, when chemotherapy was stopped, the cerebrospinal fluid/serum albumin quotient was 57x10(-3) (normal <6.0x10(-3)), which supports continuing major impairment of the blood-brain barrier. Gene expression in peripheral blood mononuclear cells before and during treatment with interferon-gamma, assessed by gene array analysis, showed reduction in a number of cytokine and chemokine genes. The response to interferon-gamma might have been secondary to downregulation of certain cytokine and chemokine genes.