Peripheral Neuropathy in Parkinson's disease

Abstract

Parkinson's disease is a neurodegenerative entity with predominant extrapyramidal and dysautonomic features and, in the final stages, cognitive and neuropsychiatric manifestations. Since 1976, the involvement of the peripheric nervous system has been recognized, mainly through neurosensorial symptoms affecting almost half of the Parkinson patients, even before the onset of motor symptoms. Initially, these symptoms were attributed to dystonia or the use of levodopa in the absence od medications; however, recent studies suggest an intrinsic etiology in idiopathic Parkinson's disease. Chronic (the most frequently described), subacute and acute polyneuropathy are the main clinical forms. The sensory symptoms coexist with those of Parkinson's disease. The diagnosis is essentially based on a clinical examination supported by electromyography and tests of neuro-conduction velocity whose normality does not rule out this entity, however. Its management depends on the etiological assumptions, and includes the eventual use of vitamin B12, B1 and folates replacement therapy. The etiology, the prognosis and the physiopathology are still topics of debate whose clarification requires further research.