Idiopathic Parkinson's disease(s) may follow subclinical episodes of perivenous demyelination.

Three case studies of postvaccinal parkinsonism (PVP) demonstrated signs and symptoms identical to conventional diagnostic standards of idiopathic Parkinson's disease (PD). PVP is a sub-type of acute disseminated encephalomyelitis (ADE) that also includes postinfectious parkinsonism (PIP) and postinfectious encephalomyelitis (PIE). All ADE has a unitary pathology consisting of monophasic perivenous inflammation followed by demyelination compared with PD in which Lewy bodies are present in only 75% of studies. We hypothesize that: (1) The seminal event in PD is latent viral invasion emanating from cranial and dorsal root ganglia. (2) Viruses intermittently invade and damage neuropigmented cells secondary to perivenous demyelination. This may explain the numerous clinical and pathological manifestations of PD. Evidence is presented that this pathoetiology probably accumulates subclinically over a long timespan prior to Levy body formation and presentation of clinical signs. This hypothesis has key features similar to one previously published that will be summarized concerning multiple sclerosis.