Neurologists have by tradition separated disorders of the
central nervous system from those affecting the peripheral
nervous system. Arguments for this distinction have noted the
role of the blood-brain-barrier as protective to the CNS by
preventing ingress of toxins, poisons, and impacts of metabolic
disorders such as diabetes and uremia – whose effects are felt
primarily in the PNS. Demyelinative disorders such as multiple
sclerosis affect the CNS and those of acute polyradiculitis-
Guillain-Barre syndrome - primarily involve the PNS. Many
genetic disorders of neurological function are defined by
molecular pathologies that impact one site or the other-
leukodystrophies and Pelizaeus-Merzbacher disease affecting the
CNS and Charcot-Marie-Tooth the PNS. This concept has been
breaking down in recent years. In the case of the
neurodegenerative disorders such as Parkinson’s disease (PD)
recent clinical and pathological studies point to defects in
function of the peripheral nervous system and autonomic nervous
sy