Very extensive predominantly cortical based abnormality is seen throughout the superior and middle frontal gyrus extending back to involve the precentral gyrus-the parietal lobe is spared. A second area of signal abnormality and mass effect involves the insular cortex on the right, and posterior limb of the external capsule extending into the adjacent Corona radiata. Significant mass effect persists in the frontal lobe, with complete effacement of the sulci, as shown on the prior imaging, with no resolution. No abnormal contrast enhancement shown, no diffusion restriction, with heterogeneous MRS showing metabolite depletion with low NAA, and some minor elevation of Cho. No elevation of cerebral blood volume.Other areas of white matter and cortical signal change demonstrated, in the
left cerebral hemisphere, at the parieto-occipital Junction, and in the tail of the hippocampus. While the hippocampal change was present in retrospect on the prior examination, the parieto-occipital lesions were not identified. No hydrocephalus.
Conclusion: Multifocal cortical and subcortical lesions with persistent mass effect, abnormal spectroscopy, persistent for four months excludes post seizure effect alone, cerebritis would be expected to change, and the most likely single diagnosis would be of gliomatosis cerebri.