One of the most common questions asked by patients with Parkinson's disease, essential, tremor, OCD, Tourette, Epilepsy and other indications is what is the mechanism underpinning the benefits of deep brain stimulation?
This question was addressed in a recent article and we will summarize the key points below:
- We don’t fully understand and appreciate the underpinnings of DBS
- In the early years many experts proposed that DBS simply blocked brain cells and inhibited activity
- We now believe that DBS drives a larger neural network
- Early thoughts were that the most likely mechanism of action was jamming (retrograde activation of axons) of the electrical circuit
- Later it was proposed that DBS was similar to making a lesion in the brain
- Modeling DBS in the lab has led to a better appreciation of the important role of axons (pipes) in the effects
- In DBS iactivity in the axon and in the cell body can be decoupled which is unique
- The glue of the nervous system called astrocytes triggers a propagating calcium wave, glial activation, neurotransmitter release and subsequent neuromodulation, based not only on electrical influences, but also chemical influences. It is now believed that DBS has effects beyond electrical.
- DBS changes the rate, and also the firing pattern of neurons (i.e. disrupts the disruption)
- DBS can be both excitatory and inhibitory
- DBS can affect local blood flow
- DBS can possibly stimulate neurogenesis or new blood cells
- In total DBS acts on a larger neural network
- DBS changes network-wide oscillations and that there may be coherence between subcortical and cortical brain signals
- We continue to uncover the mechanisms of DBS which are complex, but potentially powerful in controlling symptoms of Parkinson's and other diseases.
Okun MS, Oyama G. Mechanism of action for deep brain stimulation and electrical neuro-network modulation (ENM). Rinsho Shinkeigaku. 2013;53(9):691-694. PubMed PMID: 24097315.