Endocisternal interfaces for minimally invasive neural stimulation and recording of the brain and spinal cord

Minimally invasive neural interfaces can be used to diagnose, manage, and treat many disorders with substantially reduced risks of surgical complications. Endovascular neural interfaces implanted in the veins or arteries is one approach, but it requires prescriptions of anti-thrombotic medication and are likely not explantable after endothelialization. More critically, the approach is limited by the small size and location of blood vessels, such that many important cortical, subcortical, spinal targets cannot be reached. Here, we demonstrate a chronic endocisternal neural interface that approaches brain and spinal cord targets through inner and outer cerebral spinal fluid (CSF) spaces. These spaces surround the nervous system and lack the tortuosity of the circulatory system, giving us access to the entire brain convexity, deep brain structures within the ventricles, and the spinal cord from the spinal subarachnoid space. Combined with miniature magnetoelectric-powered bioelectronics, the entire wireless system is deployable through a percutaneous procedure. The flexible catheter electrodes can be freely navigated throughout the body from the spinal to cranial subarachnoid space, and from the cranial subarachnoid space to the ventricles. We show in a large animal model that we can also reposition the recording and stimulation electrodes or explant the neural interface after chronic implantation. This enables applications in therapies that require transient or permanent brain/machine interface such as stroke rehabilitation and epilepsy monitoring and opens a new class of minimally invasive endocisternal bioelectronics. ### Competing Interest Statement JTR, SuAS, SaAS, and JW receive monetary and/or equity compesnation from Motif Neurotech, SaAS has consulting agreements with Boston Scientific, Zimmer Biomet, Koh Young, Neuropace, Sensoria Therapeutics, Varian Medical. SuAS has consulting agreements with Viz. AI, Penumbra, Medtronic, and Imperative Care as well as grant funding from McNair Foundation and NIH. The terms of these agreements have been reviewed and approved by Rice University, UTHealth, and Baylor College of Medicine in accordance with their policies on conflicts of interest in research. The other authors declare no competing interests.