A reduced cortical Direct Current (DC) potential correlates with brain metabolic depression and is a common sign in various forms of traumatic brain injury (TBI), stroke, neurodegenerative diseases, tumors and dementia. Reduced DC is associated with decreased blood brain flow, low glucose oxidation, mitochondrial impairment and increased brain oxidative stress. Neuroimaging methods, such as PET, SPECT and MRI that are used for brain metabolism evaluation have a common disadvantage of being costly and time-consuming, which limits their usefulness in ambulatory diagnostics and monitoring of brain metabolism in AD patients. A complementary method called The Neuro-Metabolic Activity Mapping (NMAM) employs the principle of DC electroencephalography. The method is based on measurement of the brain DC potentials followed by computer analysis of acquired data and visual presentation of cortical metabolic map. The method employs correlation of a certain spectrum of DC potentials and metabolic activity of the brain. The method is similar to PET, though based on visualization of metabolic electrophysiology of the brain. The method provides a dynamic mapping and visualization of changes of brain metabolism under various stimuli and helps evaluate response in the course of therapy. A comparison of a standard EEG and NMAM during challenges, such as hypercapnia and hypoxia shows that the NMAM analysis and visualization of cortical field potentials provides a more accurate picture of the actual metabolic functional state of brain cortex. The NMAM utilizes qualitative visual neuroimaging towards prevention of cognitive decline in populations at high risk for dementia and neurodegeneration and is conveniently applicable in ambulation settings. The NMAM can help identify and differentiate early signs of metabolic perturbations in ambulation patients, as well as in TBI, brain tumors and stroke. The findings obtained by the NMAM method can facilitate beneficial lifestyle changes in patients to reduce risks for neurodegenerative diseases and stroke