Science Daily reports a new study which claims that low-dose lithium reduced involuntary motor movements or dyskinesia — the troubling side effect of the medication most commonly used to treat Parkinson’s disease (PD) — in a mouse model of the condition. The third in a series of studies from the Andersen lab involving PD and low-dose lithium, the results add to mounting evidence that low-doses of the psychotropic drug could benefit patients suffering from the incurable, degenerative condition.
This study, published online in Brain Research, involved Parkinsonian mice that were given Carbidopa/Levodopa (sold as Sinemet®), a drug used to boost levels of the neurotransmitter dopamine, which is lost in PD. While the medication remains the single most effective agent in the management of PD symptoms, long-term use causes its own side effects, among them abnormal involuntary movements or AIMS (dyskinesia).
In this study, Andersen and her team dosed the mice with an amount of lithium equivalent to about a quarter of what humans receive for the treatment of psychiatric diseases. Researchers found that lithium boosted the expression of tyrosine hydroxylase which increases dopamine synthesis via the inhibition of calpain-1, an enzyme that normally reduces dopamine synthesis.
Plans for a clinical trial of low-dose lithium for PD patients are in early stages. Previous studies suggest that at low doses lithium has a protective effect in other neurodegenerative diseases including Alzheimer’s and Huntington’s.
Carol A. Lazzara, Rebeccah R. Riley, Anand Rane, Julie K. Andersen, Yong-Hwan Kim. The combination of lithium and l-Dopa/Carbidopa reduces MPTP-induced abnormal involuntary movements (AIMs) via calpain-1 inhibition in a mouse model: Relevance for Parkinson׳s disease therapy. Brain Research, 2015; 1622: 127 DOI: 10.1016/j.brainres.2015.06.018