Preclinical evaluation of a miniaturized Deep Brain Stimulation electrode lead

The effect of miniaturizing the electrode lead for Deep Brain Stimulation (DBS) therapy was investigated in this work. A direct comparison was made between a miniature lead (0.65 mm diameter) and a lead of standard size (1.3 mm). Acute in vivo implantation in two cat brains was performed to evaluate surgical trauma and confirm capacity to target thalamic nuclei. Insertion into a homogeneous gel model of neural tissue was used to compare insertion forces while visualizing the process. The standard size cannula, used first to guide lead insertion, required substantially higher insertion force compared with the miniature version and produced a significantly larger region of tissue disruption. The characteristic hemorrhage and edema extended 119-352 μm from the implanted track surface of the miniature lead and cannula, while these extended 311-571 μm for the standard size lead and cannula. A miniature DBS implant can reduce the extent of trauma and could potentially help improve neural function preservation after functional neurosurgery.