Summary
Deep brain stimulation (DBS) is an invasive neurosurgical procedure involving the placement of a neurostimulator which sends electrical impulses through implanted electrodes to specific targets in the brain. The DBS system generally consists of three components: the neurostimulator called an implantable pulse generator (IPG), the lead, and an extension. The IPG is battery-powered and placed subcutaneously below the clavicle, or the abdomen. The lead consists of four electrodes placed in the brain nuclei, and connects to the IPG through an extension. DBS is predominately used in the treatment of movement disorders, including Parkinson's disease, essential tremor, dystonia, obsessive-compulsive disorder (OCD) and epilepsy. DBS is a sub-segment of the broader Neuroprosthetics market.
Viability (5)
First available in 1995 with over 160,000 patients implanted at over 700 centers worldwide as of 2019. DBS is a standard of care for variety of indications including Parkinson’s (PD), dystonia, essential tremor, OCD and severe epilepsy. There are also ongoing clinical trials for chronic pain, tourettes, huntington's disease and chorea, and cluster headaches. The exact mechanisms are still unknown and the direct effects on physiology of brain cells and neurotransmitters are hotly debated. Research is focused on understanding the mechanisms of DBS as well as discovering novel brain targets. There is some connection to connectome-specific harmonic wave (CSHW) framework for understanding why DBS might work but this is very early. DBS was a small <$1 billion market in 2021, growing at roughly 10% a year as a segment within the larger $5 billion Neuroprosthetics market. There are few catalysts on the horizon that suggest faster growth beyond benefits for stroke patients, for which clinical trails are in early stages. And in the long-term 10 year+, we would expect non-invasive solutions to win the market. It’s hard to make the case for investing in DBS without a credible plan to turn DBS into a Brain-Computer Interfaces.
Drivers (2)
On the demand side, the incidence of neurological disorders such as Parkinson's disease, epilepsy, and depression is increasing globally. Neurological disorders ranked as the leading cause of disability-adjusted life-years (DALYs, 276 million) and the second leading cause of death (9.0 million, comprising of 16.5% of global deaths) in 2016. Population ageing is recognised as the most important demographic factor for most neurological disorders and as such we can expect an increasing prevalence as the global population ages. DBS wouldn’t be possible on the supply-side without the miniaturisation of IPGs, and newer solutions are so small that they can be implanted directly in the skull removing the need for a lead or extension.
Novelty (4)
DBS competes with other treatments, drugs and lifestyle adaptations to prevent, reduce and cure neurological disorders. DBS is used to manage symptoms that drugs cannot, as such it competes mainly with non-consumption. As a surgical procedure DBS is used as a treatment for severe disease where anything other than resistant disease is treated with drugs. In the long-term, DBS is invasive and doesn’t cure the disorders. We can expect progress with Genomics and Cell and Gene Therapy to potentially prevent cases and Optogenetics to offer a non-invasive solution.
Diffusion (2)
The fundamentally barrier to adoption is a limited understanding of the mechanisms of action of DBS. Even within established indications such as PD, there is still a lack of biomarkers that predict clinical response and aid in patient selection and stimulation parameter settings are still largely lacking. DBS is also relatively expensive requiring expert long-term care as well as carrying the risks of all surgical procedures, and the higher risks of brain surgery. Additional risks can include neuropsychiatric side effects related to electrode placement or neuro-stimulator calibration. With smaller systems, surgical risk will be reduced but diffusion will be slow simply because surgery is needed. Faster adoption requires a non-invasive solution such as Optogenetics.
Impact (2)
There are no catalysts or drivers that suggest the DBS market will have a high impact. It is projected to be a small $1.6 billion market by 2026 helping patients motor-neuron diseases for whom drugs are ineffective. DBS for post-stroke rehabilitation shows encouraging results which could open up DBS to the over 110 million people who have experienced stroke globally. Still as an invasive solution, DBS will continue to be used for drug-resistant patients because of risk and cost. For those patients it is extraordinarily helpful and reduces disability-adjusted life-years, but in terms of wider societal impact it will be small. Any case for a large impact relies on a non-invasive DBS method enabling DBS to serve non-resistant patients rather than drugs. Or more speculatively, that DBS vendors are the first to develop viable non-invasive Brain-Computer Interfaces because they are able to build the most accurate models of brain activity. These devices will be medical devices but treat a much wider range of diseases at lower cost.
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