Before the advent of MRI, diagnosis was generally not established until autopsy. Even with MRI, however, diagnosis is difficult. Typically,<unk>  appears as a diffuse, poorly circumscribed, infiltrating non-enhancing lesion that is hyperintense on T2-weighted images and expands the<unk> l white matter. It is difficult to distinguish from highly infiltrative anaplastic astrocytoma or GBM.
Gliomatosis cerebri
Polioencephalitis
Meningism
Hypertensive leukoencephalopathy
Posterior reversible encephalopathy syndrome
Lymphocytic meningoradiculitis
Brain abscess
Autoimmune encephalitis