Neurodegenerative diseases, such as multiple sclerosis, may be caused or aggravated by insufficient venous draining from the central nervous system. Functional MRI measures the surge of blood flow into localized regions of cerebral cortex in response to activation of those regions by performing visual, auditory or executive tasks. These fMRI measurements are based on blood-oxygen-level dependence. The resulting fMRI/BOLD data is converted to hemodynamic response data and analyzed to determine any abnormality in the hemodynamic response data. Vascular drainage insufficiency is identified in the presence of abnormal hemodynamic response data. Abnormal hemodynamic response data can be determined by a negative trough in a graph of the HDR data or by the duration, depth, or area of the negative trough.
