Chronic cerebrospinal venous insufficiency (CCSVI) proposes hindrances to the venous drainage of the brain and spine. Clinically diagnosed or definite multiple sclerosis (CDMS) is diagnosed by a "dissemination in space and time" of brain and spinal cord lesions in want of a specific characterization. This definition of CDMS and its attribution to auto-immune mediated demyelination (somehow also destructing axons) has never been proven and complicates the assessment of its role in CCSVI and other venous anomalies in the development of conditions categorized as CDMS. In this review, post mortem and serial MRI observations made in historically specific instances of multiple sclerosis are focused on. They demonstrate the existence of venodynamic lesions that can only be explained by the forceful impacts of fleeting venous flow inversions (FVFIs) which may be of very short duration. To understand the venodynamics of this typical, or "VDMS" it is necessary to determine the source of the venous impacts and how they are directed and limited to the lesion domains. Understanding these venous flow dynamics is critical for evaluating the significance of CCSVI in general; it further seems indispensable for ensuring the success of venoplasties; and it is crucial to the development of alternative rational treatment options in those instances of CDMS in which interventions for CCSVI do not achieve the intended results.