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.

Intrathecal steroid therapy for postherpetic neuralgia: a review.

Two recent publications advocated intrathecal injection of methylprednisolone acetate for postherpetic neuralgia. Conceptually, these therapeutic trials were based on the failed assumption that chronic inflammation persists in dorsal root ganglia even after the lesions of acute zoster have healed. Constructionally, these publications can be criticized on numerous grounds: cranial zoster was excluded, follow up periods were too short, dangers or reactivating the varicella virus were ignored, no methylprednisolone acetate-only group was included, pharmacological dangers of intrathecal lidocaine were overlooked. In addition to these basic conceptual deficiencies, multiple dangers of intrathecal methylprednisolone (therapeutically and by accidental injection) are manifest in a literature dating back over two decades in which several hundred serious complications are described. In summary, all rational evidence indicates that this treatment should not be prescribed.