Minimally invasive neural interface allows brain access without skull opening

A team of researchers led by Rice University’s Jacob Robinson and the University of Texas Medical Branch’s Peter Kan has developed a technique for diagnosing, managing and treating neurological disorders with minimal surgical risks. The team’s findings were published in Nature Biomedical Engineering.

While traditional approaches for interfacing with the nervous system often require creating a hole in the skull to interface with the brain, the researchers have developed an innovative method known as endocisternal interfaces (ECI), allowing for electrical recording and stimulation of neural structures, including the brain and spinal cord, through cerebral spinal fluid (CSF).

“Using ECI, we can access multiple brain and spinal cord structures simultaneously without ever opening up the skull, reducing the risk of complications associated with traditional surgical techniques,” said Robinson, professor of electrical and computer engineering and bioengineering.

ECI uses CSF, which surrounds the nervous system, as a pathway to deliver targeted devices. By performing a simple lumbar puncture in the lower back, researchers can navigate a flexible catheter to access the brain and spinal cord.

Using miniature magnetoelectric-powered bioelectronics, the entire wireless system can be deployed through a small percutaneous procedure. The flexible catheter electrodes can be navigated freely from the spinal subarachnoid space to the brain ventricles.

“This is the first reported technique that enables a neural interface to simultaneously access the brain and spinal cord through a simple and minimally invasive lumbar puncture,” said Kan, professor and the Robert L. Moody Sr. Chair of Neurosurgery at UTMB. “It introduces new possibilities for therapies in stroke rehabilitation, epilepsy monitoring and other neurological applications.”

To test the hypothesis, the research team characterized the endocisternal space and measured the width of the subarachnoid, or fluid-filled space, in human patients using magnetic resonance imaging. The researchers then conducted experiments in large animal models, specifically sheep, to validate the feasibility of the new neural interface.

Their experiments showed that the catheter electrodes could be successfully delivered and guided into the ventricular spaces and brain surface for electrical stimulation. By using the magnetoelectric implant, the researchers were able to record electrophysiologic signals such as muscle activation and spinal cord potentials.

Preliminary safety results showed that the ECI remained functional with minimal damage up to 30 days after the electronic device was implanted chronically into the brain.

Moreover, the study revealed that unlike endovascular neural interfaces that require antithrombotic medication and are limited by the small size and location of blood vessels, ECI offers broader access to neural targets without the medication.

“This technology creates a new paradigm for minimally invasive neural interfaces and could lower the risk of implantable neurotechnologies, enabling access to wider patient populations,” said Josh Chen, Rice alumnus and lead author of the study.