Editing Human brain (section)

===Disease===
[[Neurodegenerative disease]]s result in progressive damage to, or loss of neurons affecting  different functions of the brain, that [[Aging brain|worsen with age]]. Common types are [[dementia]]s including [[Alzheimer's disease]], [[alcoholic dementia]], [[vascular dementia]], and  [[Parkinson's disease dementia]]. Other rarer infectious, genetic, or metabolic types include [[Huntington's disease]], [[motor neuron disease]]s, [[HIV dementia]], [[Neurosyphilis|syphilis-related dementia]] and [[Wilson's disease]]. Neurodegenerative diseases can affect different parts of the brain, and can affect movement, [[memory]], and cognition.{{sfn|Davidson's|2010|pp=1196-7}} Rare [[prion disease]]s including [[Creutzfeldt–Jakob disease]] and its [[Variant Creutzfeldt–Jakob disease|variant]], and [[Kuru (disease)|kuru]] are fatal neurodegenerative diseases.{{sfn|Davidson's|2010|pp=1205-15}}

[[Cerebral atherosclerosis]] is [[atherosclerosis]] that affects the brain. It results from the build-up of [[atheroma|plaques]] formed of [[cholesterol]], in the large arteries of the brain, and can be mild to significant. When significant, arteries can become narrowed enough to reduce blood flow. It contributes to the development of dementia, and has protein similarities to those found in Alzheimer's disease.<ref name="NN2020">{{cite journal |vauthors=Wingo AP, Fan W, Duong DM, Gerasimov ES, Dammer EB, Liu Y, Harerimana NV, White B, Thambisetty M, Troncoso JC, Kim N, Schneider JA, Hajjar IM, Lah JJ, Bennett DA, Seyfried NT, Levey AI, Wingo TS |title=Shared proteomic effects of cerebral atherosclerosis and Alzheimer's disease on the human brain |journal=Nat Neurosci |volume=23 |issue=6 |pages=696–700 |date=June 2020 |pmid=32424284 |pmc=7269838 |doi=10.1038/s41593-020-0635-5 |url=}}</ref>

The brain, although protected by the blood–brain barrier, can be affected by infections including [[virus]]es, [[bacteria]] and [[fungi]]. Infection may be of the [[meninges]] ([[meningitis]]), the brain matter ([[encephalitis]]), or within the brain matter (such as a [[cerebral abscess]]).{{sfn|Davidson's|2010|pp=1205-15}}