[Uncommon or unusual encephalopathies]

Rare encephalopathies are here described in order to summarize practical tools that should be considered in the anamnesis, as well as in the physical examination. The way in which the clinical picture was established was the primary point for structuring the review; subsequently, the encephalopathies were subclassified etiologically. Focal symptoms, headaches, abdominal pain, fever or extrapyramidalism, added to the findings in the magnetic resonance imaging, especially if damage to the gray or white matter is observed, and if the lesions are bilateral or not, can be helpful when hypothesizing the etiology of the encephalopathy.