Memory disorder

Memory disorders are the result of damage to neuroanatomical structures that hinders the storage, retention and recollection of memories. Memory disorders can be progressive, including Alzheimer's disease, or they can be immediate including disorders resulting from head injury. Agnosia is the inability to recognize certain objects, persons or sounds. Agnosia is typically caused by damage to the brain (most commonly in the occipital or parietal lobes) or from a neurological disorder. Treatments vary depending on the location and cause of the damage. Recovery is possible depending on the severity of the disorder and the severity of the damage to the brain. Many more specific types of agnosia diagnoses exist, including: associative visual agnosia, astereognosis, auditory agnosia, auditory verbal agnosia, prosopagnosia, simultanagnosia, topographical disorientation, visual agnosia etc. Alzheimer's disease (AD) is a progressive, degenerative and fatal brain disease, in which cell to cell connections in the brain are lost. Alzheimer's disease is the most common form of dementia. Globally approximately 1–5% of the population is affected by Alzheimer's disease. Women are disproportionately affected by Alzheimer's disease. The evidence suggests that women with AD display more severe cognitive impairment relative to age-matched males with AD, as well as a more rapid rate of cognitive decline. File:PET_Normal_brain.jpg|PET scan of a healthy brain - Image courtesy of US [[National Institute on Aging]] Alzheimer's Disease Education and Referral Center File:PET_Alzheimer.jpg|PET scan of brain with AD - Image courtesy of US [[National Institute on Aging]] Alzheimer's Disease Education and Referral Center Amnesia is an abnormal mental state in which memory and learning are affected out of all proportion to other cognitive functions in an otherwise alert and responsive patient. There are two forms of amnesia: Anterograde amnesia and retrograde amnesia, that show hippocampal or medial temporal lobe damage.