[Nicotine and neurologic diseases--even a noxious substance may possess beneficial properties].

According to investigations, nicotine and its agonists may prevent the development of Parkinson's disease and reduce motor symptoms and dyskinesias in Parkinson's disease. It was shown recently that a transdermal nicotine patch reliefs the symptoms in patients suffering from mild cognitive impairment. In Alzheimer's disease an alpha7-selective agonist has been found to have positive effects on cognitive symptoms. Mutations of nicotinic receptors are underlying certain nocturnal frontal lobe epilepsies. The partial nicotine agonist varenicline may alleviate ataxia symptoms.