Blog March 22, 2021

Medical Device Technology and CNS Diseases

Central nervous system (CNS) and psychiatric disorders can be highly debilitating for patients and costly for society. For many years, drug developers deprioritized neuroscience research in favor of oncology and other areas, such as rare diseases, due in part to long development timelines, limited understanding of the driving factors behind CNS disorders, and few validated targets for many conditions. That situation is now changing, with a number of major pharmaceutical companies expanding their CNS portfolios, and important new drugs for some conditions like migraine and major depression having reached the market. But the field of CNS drug development has also seen a number of disappointments, especially in the area of Alzheimer’s disease R&D.

The story is very different in the field of medical devices for CNS disorders, however, with several recent approvals and new interventions advancing towards the market.

One such area is deep brain stimulation (DBS), a well-established treatment that can help improve motor symptoms like slowed movement, tremor, and stiffness in conditions such as Parkinson’s disease and reduce seizures in epilepsy. DBS is most commonly used as an adjunctive therapy for patients with moderate-to-severe Parkinson’s disease whose symptoms are not controlled with medication alone. It involves implanting electrodes in certain areas of the brain which then produce electrical impulses that help regulate abnormal brain activity. The degree of stimulation is controlled by a pacemaker-like device that is implanted under the skin in the upper chest, with wires connecting the device to the electrodes in the brain. Until now, the electrical stimulation was delivered continuously and fine-tuned manually by the physician over a period of months, but DBS technology has recently seen some important advances.

In June 2020, Medtronic launched its Percept PC DBS system with Brain Sense technology, a DBS implant with the ability to read, capture, and transmit a patient’s brain activity during therapy, allowing for more personalized treatment of such conditions as Parkinson’s disease, tremors, epilepsy, dystonia or obsessive-compulsive disorders. The device correlates brain readings with patient-recorded actions and symptoms, as well as medication intake, and gives clinicians feedback directly from the DBS patient’s brain, allowing neurostimulatory signals from the device to be tailored accordingly. Medtronic additionally began clinical trials in January 2021 of its ADAPT-PD system, the first DBS device that automatically adjusts the degree of brain stimulation based on brain signals from the implanted patient, allowing the device to directly manage a patient’s symptoms based on clinical state.

In January of this year, the U.S. FDA also approved Boston Scientific’s newest DBS device, the fourth generation of the Vercise Genus DBS system (pictured). The Genus system, which includes a Bluetooth-enabled pulse generator and offers both rechargeable and non-rechargeable models, enables more precise delivery of stimulatory signals for better control of the patient’s symptoms than earlier versions. Boston Scientific launched the Vercise Genus in Europe in September 2020, and plans a limited U.S. launch this spring.

DBS is being studied for its utility in treating a variety of other CNS-related conditions including major depression, addiction, chronic pain, cluster headache, dementia, Huntington disease, multiple sclerosis, stroke recovery, traumatic brain injury, and Tourette syndrome. Direct electrical stimulation to the spinal cord, using either implantable or external devices, is also showing clinical promise in restoring function to spinal cord injury patients, with GTX Medical receiving FDA Breakthrough Designation for both versions of its Go-2 Targeted Epidural Spinal Stimulation system in June 2020. The company hopes to initiate clinical trials later this year.

CNS device technologies are advancing in other areas as well. Swedish medical device company Flow Neuroscience has developed a wearable treatment for adults with depression. Paired with a behavioral therapy software app, Flow’s headset device delivers low levels of constant electrical stimulation to the user’s left frontal lobe. People with depression often have lower activity in this region of the brain, which helps govern cognition and emotional expression. The stimulation provided by Flow’s device rebalances that brain activity, providing outcomes similar to those typically achieved with anti-depressant drugs, but with fewer side-effects. While undergoing stimulation, the app provides videos and advice for dealing with depression, as well as techniques for reducing symptoms through sleep, nutrition, fitness, and meditation. The initial therapy requires three 30-minute sessions per week for six weeks, after which the patient continues with one to two stimulation sessions per week. The Flow device received CE Mark in 2019 and has been launched in the United Kingdom and Sweden, while the company remains in talks with FDA in the United States. In February 2021, Flow purchased fellow brain stimulation company, Halo Neuroscience, which also has headset brain stimulation technology aimed at treating mental health conditions that are often co-morbid with depression.

Brain stimulation via transcranial pulsed stimulation (TPS) with ultrasound, the only technique that can reach deep regions of the brain in a targeted, noninvasive way, is also showing promise for treating a range of brain diseases. The goal of such treatments, developed by researchers at the University of Toronto and Med Uni Vienna, is to improve brain function by externally activating still functional neurons in patients with various neuropsychiatric brain diseases, including Alzheimer’s, Parkinson’s, stroke, multiple sclerosis and neuralgia. A clinical study in Alzheimer’s disease patients showed that treatment led to sustained clinical improvements over three months, without any side-effects. The method has received CE certification for that use.  Other research has shown that such stimulation via ultrasound can be used to quiet overactive neurons for the treatment of motor disorders. These methods are limited, however, by the requirement that clinicians have specific neurologic expertise and training in the use of targeted ultrasound methods, as well as an understanding of brain function.

The field of wearable devices is also seeing advances in the CNS area. In September 2020, Cala Health presented real-world data that its wrist-worn electrical stimulation device could help patients with essential hand tremor significantly improve symptoms.  A study that tracked 44 device-wearing patients at home for three months found that 93% of them achieved at least a 50% reduction in tremor strength, and many reported improvements in their ability to eat, drink, write, as well as overall gains in their quality of life. The device non-invasively delivers electrical stimulation to the wrist to counteract uneven signals sent from the patient’s brain.