In itself, the presence of prions causes reduced glucose use by the thalamus and a mild hypo-metabolism of the cingulate cortex. The extent of this symptom varies between two variations of the disease, these being those presenting methionine homozygotes at codon 129 and methionine/valine heterozygotes being the most severe in the latter one. Given the relationship between the involvement of the thalamus in regulating sleep and alertness, a causal relationship can be drawn, and is often mentioned as the cause.
Fatal insomnia
Transmissible spongiform encephalopathy
Excited delirium
Frontotemporal dementia
Masked depression
Alzheimer's disease
Suicide crisis
Transient epileptic amnesia