Lithium-induced parkinsonism associated with vocal cord paralysis: an atypical presentation

Drug-induced parkinsonism has been commonly studied and discussed regarding antipsychotic agents, but lithium-induced parkinsonism should also be considered when patients present with parkinsonian symptoms and chronic lithium use. There are several reports of parkinsonism arising during lithium administration and regressing following its reduction or discontinuation. Our case is, to date, the first case in the literature in which vocal cord paralysis occurred as the first symptom of lithium-induced parkinsonism, contributing to confuse doctors and patients and to delay diagnosis and treatment. In our clinical case prompt withdrawal of lithium and its reintroduction at lower doses led to complete resolution of this disabling clinical presentation. This report emphasizes the importance of careful monitoring of lithium levels, especially in elderly subjects, and the need to consider lithium-induced parkinsonism even when unusual motor symptoms appear in chronic lithium users.