[Intra-optic nerve and chiasmal abscess caused by methicillin-resistant Staphylococcus aureus (a case report and literature review)]. / Abstsess intrakranial'noi chasti zritel'nogo nerva i khiazmy, vyzvannyi metitsillinorezistentnym zolotistym stafilokokkom (klinicheskoe nabliudenie i obzor literatury).

A 27-year-old immunocompetent male with headache, transient polydipsia, and polyuria suddenly developed visual impairment (predominantly in the left eye) and, 2 days later, left-sided amaurosis. MRI in T1, T2, DWI, and FLAIR modes revealed a space-occupying lesion of the left intracranial optic nerve and chiasm. According to the clinical X-ray picture, malignant chiasmal glioma was suspected; another and less likely variant was lymphoma. An open biopsy of the space-occupying lesion of the chiasmal-sellar region revealed purulent-necrotic masses. Material from the operative wound was positive for a Staphylococcus aureus strain. The polymerase chain reaction of a cerebrospinal fluid sample revealed methicillin-resistant Staphylococcus aureus. The patient underwent systemic and intrathecal antibiotic therapy with linezolid and vancomycin, respectively, with a good clinical effect: there was an improvement in the vision in a right single sighted eye and normalization of the cerebrospinal fluid composition.

Intensity-modulated fractionated stereotactic radiotherapy with reduced margin for high grade gliomas: dosimetric analysis of sparing optic nerve & chiasm.

The aim of this study was to evaluate the potential advantage of intensity modulation fractionated stereotactic radiotherapy (IM-FSRT) for sparing the optic nerve and chiasm in the management of anaplastic astrocytoma (AA) or glioblastoma (GBM). Clinical data of 16 patients with high grade gliomas were retrospectively reviewed. All patients had tumors close to the optic chiam that prohibited the full dose radiation therapy. The patients were treated with either IM-FSRT in conjunction with external beam radiation or IM-FSRT only to a total dose of 60 Gy. The final dosimetric analysis was performed. The estimated average maximum optic nerve and chiasm dose 48.6±5.0 Gy (range, 34.2-55.9). Conformity index reached as high as 0.98, and inhomogeneity coefficient was low enough to deliver the prescribed radiation dose. IM-FSRT showed excellent dose conformality to the target volume with superior normal tissue sparing effect. High precision therapy such as IM-FSRT could be a reliable treatment technique for the patients with AA or GBM for a maximal sparing of optic apparatus.