Patients with cortical amnesia experience varying degrees of amnesia. Some patients with severe cases have both paracrine and retrograde amnesia, sometimes referred to as “whole brain amnesia”. Cases of drug-induced amnesia are often short-term and recoverable. In other cases, since early studies in the 1970s, patients have suffered permanent damage, although some cases have theoretical possibilities of recovery in terms of pathophysiology. Often, patients still have some of their most basic learning abilities, while in some severe cases of cis-amnesia, all they have is a pre-amnesic recall, with no hint of recall afterwards. Erythrocyte sedimentation rate and screening for connective tissue disorders (such as antinuclear antibodies and rheumatoid factor) are required when the clinical presentation suggests evidence of vasculitis or arthritis. Human immunodeficiency virus titers should be considered in any young person with dementia, and plasma copper cyanide should be measured if there are signs of motor impairment. The following tests have differential diagnostic significance if they are abnormal. 1.CT, MRI examination. 2.Electroencephalography is helpful to identify Creutzfeldt-Jakob disease, which is characterized by periodic discharges. 3.Cranial base radiography and funduscopic examination. 4.Functional brain imaging using single photon emission computed tomography (SPECT) may also be helpful for diagnosis.