A Likely Cause of Lithium-Associated Parkinsonian Tremor

Lithium increases iron in the substantia nigra, as does Parkinson disease, via pathways that lower amyloid and phosphorylated tau levels and impair cellular iron efflux.

Lithium has been found to be neuroprotective (e.g., it increases hippocampal size; NEJM JW Psychiatry Mar 2012 and Biol Psychiatry 2012, 71:855); yet, patients taking therapeutic levels of lithium can experience parkinsonian tremors. Because patients with Parkinson disease have elevated iron levels in the substantia nigra (SN; J Neuro Transm 1988; 74:199), investigators questioned whether lithium-associated tremors might also be caused by excess SN iron.

First, the investigators studied magnetic resonance imaging (MRI) in people at ultrahigh risk for psychosis enrolled in a lithium study. The MRI T2 relaxation time (i.e., time for the magnetic signal to dissipate) — which can be caused by increased iron or edema — was reduced in the hippocam…

Reviewing Author

Barbara Geller, MD

Disclosures

Nothing to disclose

Barbara Geller, MD

Disclosures

Nothing to disclose

A Likely Cause of Lithium-Associated Parkinsonian Tremor

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Reviewing Author