What does 123I-DaTscan imaging typically reveal about essential tremors?

123I-DaTscan imaging assesses the density of dopamine transporters (DAT) in the brain and is specifically used for evaluating neurodegenerative conditions such as Parkinson's disease and essential tremors. In the case of essential tremors, 123I-DaTscan typically reveals normal dopamine transporter binding, meaning there is no significant reduction in DAT density in the basal ganglia compared to what would be observed in Parkinson's disease. This is a key aspect that differentiates essential tremors from other conditions associated with tremors, particularly Parkinsonian disorders, where there is marked reduction in DAT binding.

Normal DAT binding suggests that the underlying pathophysiology of essential tremors is different from that of conditions characterized by dopamine depletion, reinforcing that essential tremors are not primarily caused by the loss of dopaminergic neurons in the substantia nigra. Therefore, the observation of normal DAT binding on 123I-DaTscan imaging is consistent with the clinical understanding that essential tremors are not typically associated with the same patterns of basal ganglia dysfunction seen in more severe movement disorders.