That is a 3mm non-enhancing lesions in the right thalamus. The comments about mass effect, restriction, or no abnormal enhancement mean that whatever it is, it doesn't act like a tumor.
Thalamic lesions have been associated with a higher occurrence of cluster headaches and amnesia. In terms of the metabolic issues with a thalamic lesion, you need to consult with a neurologist. Lesions of the thalamus can have some pretty systemic effects like tremors and ataxia.
These type of lesions are also associated with decreased Thalamic O2 consumption and Thalamic hypometabolic states.
Understand, that "associated with" means sometimes seen. It would be best to let the neurologist examine your fiancee and make a diagnosis based on the symptoms, the clinical exam, and the diagnostic findings from the MRI and Lab studies.
* Multiple areas of T2/ FLAIR hyper intensity in B/L white matter (involving sub cortical & deep white matter of B/L frontal, parietal & occipital lobes) and left cerebral peduncle - s/o sequela to old ADEM. * Minimal diffuse cerebral atrophy.
Multiple areas of T2/ FLAIR hyper intensity in B/L (Bi-Lateral) white matter (involving sub cortical & deep white matter of B/L frontal, parietal & occipital lobes) and left cerebral peduncle (the area where the lower brain (brain stem, spinal cord and cerebrum connect to the rest of the brain)- s/o sequela to old ADEM (Acute disseminated encephalomyelitis - A post viral demyelinating disease). * Minimal diffuse cerebral atrophy (brain has slightly decreased in size.)
So they think you have lesions related to a previous outbreak of acute disseminated encephalomyelitis. This is an MS mimic.