neurons Leukodystrophies, such as Krabbe disease, which destroy the myelin sheath that protects axons Multiple sclerosis, which causes inflammation, myelin damage, and lesions in cerebral tissue Epilepsy, in which lesions cause abnormal electrochemical discharges that result in seizures Anorexia nervosa, bulimia nervosa, and other eating disorders Malnutrition, caused by lack or excess of nutrition from foods Type II diabetes, where the body does not use insulin properly resulting in high blood sugar Bipolar disorder, significant loss of brain tissue during manic episodes; however it's not verified whether the episodes cause brain tissue loss or vice versa Schizophrenia Mitochondrial encephalomyopathies, such as Kearns–Sayre syndrome, which interfere with the basic functions of neurons Posterior cortical atrophy: In the most posterior area of the brain lies the visual cortex, the area of the brain where visual information is received and processed. When cortical atrophy occurs in this brain area due to neurodegeneration, the first symptom is impairment in vision. A common vision impairment seen in patients with posterior cortical atrophy is simultanagnosia, where a person is unable to see multiple locations at once or to quickly shift attention between these locations. When looking at images of a brain with posterior cortical atrophy, one can see a loss in volume of the dorsal and ventral visual pathways, where visual stimuli is brought to the visual cortex and integrated information is sent back out to other areas of the brain. Because this disorder results in visual impairments, there is often a missed or delayed diagnosis, as the assumption is that there is a problem is in the eyes when the reality is that the problem is all the way in the back of the brain. Prion diseases, a group of invariably fatal encephalopathies that cause the progressive death of neurons. Infections Where an infectious agent or the inflammatory reaction to it destroys neurons and their axons, these include... Encephalitis, acute inflammation in the brain Neurosyphilis, an infection in the brain or spinal chord AIDS, disease of the immune system Drug-induced Alcohol (partially reversible): Standardized MRI evidence suggest chronic alcoholism (alcohol use disorder) is associated with widespread cortical atrophy and major brain changes. In contrast to healthy controls, macrostructural findings indicate alcoholic brains are smaller in mass and volume. Neuroimaging studies also show that cortical shrinkage in "uncomplicated alcoholism" is most severe in the frontal lobe in comparison to the other divisions of the cerebral cortex.