<unk>  can present with a variety of symptoms, but is divided generally into two types. Amnestic<unk>  (aMCI) is<unk>  with memory loss as the predominant symptom; aMCI is frequently seen as a prodromal stage of Alzheimer's disease. Studies suggest that these individuals tend to progress to probable Alzheimer's disease at a rate of approximately 10% to 15% per year. It is possible that being diagnosed with cognitive decline may serve as an indicator of<unk> . Nonamnestic<unk>  (naMCI) is<unk>  in which impairments in domains other than memory (for example, language, visuospatial, executive) are more prominent. It may be further divided as nonamnestic single- or multiple-domain<unk> , and these individuals are believed to be more likely to convert to other dementias (for example, dementia with Lewy bodies). The International Classification of Diseases classifies<unk>  as a "mental and behavioural disorder."
Mild cognitive impairment
Severe cognitive impairment
Dyssomnia
Extrapyramidal symptoms
Irregular sleep–wake rhythm
Orthosomnia
Parasomnia
Hypersomnia