Jeffrey Anderson
Functional neurosurgery is a rapidly emerging tool to treat dozens of neuropsychiatric and neurologic conditions. Yet, one of the biggest limitations of deep brain stimulator placement, high-frequency ultrasound ablations, and cortical stimulator treatments is identifying the correct target for therapy. I see image guidance for such therapies as a critical venue for functional neuroradiology. As surgical approaches mature, radiologists need to establish methods for targeting. With this in mind, we approached the problem of deep brain stimulator placement for essential tremor, where the surgeon must identify a thalamic subnucleus that has no anatomic landmarks beyond rough population-based coordinates, which vary among individuals and often lead to therapeutic failure.
Our first study was a proof of principle, showing that functional connectivity can be used with high accuracy given sufficient imaging time. We are now conducting similar studies in patients undergoing deep brain stimulation for essential tremor, hoping to show that the predicted target for a patient is well aligned with the actual electrode position in successful treatments. We are optimistic that functional connectivity MRI may be particularly well-suited for pinpointing precise coordinates for neurosurgical image guidance. We strongly believe that for single-voxel targeting to be successful, radiologists will need to use much longer imaging times, on the order of an hour or more, and not minutes, when acquiring functional connectivity datasets.
The feedback we have received since publication has been encouraging, and we are also enthusiastic about the attempts of other groups to use diffusion-tensor tractography to similarly identify image guidance targets for