Neuromodulation (medicine)

Neuromodulation

Neuromodulation is "the alteration of nerve activity through targeted delivery of a stimulus, such as electrical stimulation or chemical agents, to specific neurological sites in the body". It is carried out to normalize – or modulate – nervous tissue function. Neuromodulation is an evolving therapy that can involve a range of electromagnetic stimuli such as a magnetic field (rTMS), an electric current, or a drug instilled directly in the subdural space (intrathecal drug delivery). Emerging applications involve targeted introduction of genes or gene regulators and light (optogenetics), and by 2014, these had been at minimum demonstrated in mammalian models, or first-in-human data had been acquired.[1] The most clinical experience has been with electrical stimulation.

Neuromodulation, whether electrical or magnetic, employs the body's natural biological response by stimulating nerve cell activity that can influence populations of nerves by releasing transmitters, such as dopamine, or other chemical messengers such as the peptide Substance P, that can modulate the excitability and firing patterns of neural circuits. There may also be more direct electrophysiological effects on neural membranes as the mechanism of action of electrical interaction with neural elements. The end effect is a "normalization" of a neural network function from its perturbed state. Presumed mechanisms of action for neurostimulation include depolarizing blockade, stochastic normalization of neural firing, axonal blockade, reduction of neural firing keratosis, and suppression of neural network oscillations.[2] Although the exact mechanisms of neurostimulation are not known, the empirical effectiveness has led to considerable application clinically.

Existing and emerging neuromodulation treatments also include application in medication-resistant epilepsy,[3] chronic head pain conditions, and functional therapy ranging from bladder and bowel or respiratory control to improvement of sensory deficits, such as hearing (cochlear implants and auditory brainstem implants) and vision (retinal implants).[4] Technical improvements include a trend toward minimally invasive (or noninvasive) systems; as well as smaller, more sophisticated devices that may have automated feedback control,[5] and conditional compatibility with magnetic resonance imaging.[6][7]

Neuromodulation therapy has been investigated for other chronic conditions, such as Alzheimer's disease,[8][9] depression, chronic pain,[10][11] and as an adjunctive treatment in recovery from stroke.[12][13]

  1. ^ "International Neuromodulation Society home page". Retrieved 1 October 2013.
  2. ^ Karas PJ, Mikell CB, Christian E, Liker MA, Sheth SA (November 2013). "Deep brain stimulation: a mechanistic and clinical update". Neurosurgical Focus. 35 (5): E1. doi:10.3171/2013.9.focus13383. PMID 24175861. S2CID 26756883.
  3. ^ Al-Otaibi FA, Hamani C, Lozano AM (October 2011). "Neuromodulation in epilepsy". Neurosurgery. 69 (4): 957–79, discussion 979. doi:10.1227/NEU.0b013e31822b30cd. PMID 21716154. S2CID 23473956.
  4. ^ Krames, Elliot S.; Peckham, P. Hunter; Rezai, Ali R., eds. (2009). Neuromodulation, Vol. 1-2. Academic Press. p. 274. ISBN 9780123742483.
  5. ^ Wu C, Sharan AD (2013). "Neurostimulation for the treatment of epilepsy: a review of current surgical interventions". Neuromodulation. 16 (1): 10–24, discussion 24. doi:10.1111/j.1525-1403.2012.00501.x. PMID 22947069. S2CID 1711587.
  6. ^ "Precision™ Plus Spinal Cord Stimulator System Receives CE Mark Approval as MRI Conditional". Paris, France: Boston Scientific Corporation. August 28, 2012. Retrieved September 27, 2013.
  7. ^ "Medtronic Introduces the First and Only Neurostimulation Systems for Chronic Pain Designed for Full-Body MRI Safety". Minneapolis, MN: Medtronic, Inc. August 6, 2013. Archived from the original on 2019-04-17. Retrieved September 27, 2013.
  8. ^ Clinical trial number NCT01559220 for "Deep Brain Stimulation for the Treatment of Alzheimer's Disease." at ClinicalTrials.gov
  9. ^ Clinical trial number NCT01608061 for "Functional Neuromodulation Ltd. ADvance DBS-f in Patients With Mild Probable Alzheimer's Disease." at ClinicalTrials.gov
  10. ^ Kortekaas R, van Nierop LE, Baas VG, Konopka KH, Harbers M, van der Hoeven JH, et al. (2013). "A novel magnetic stimulator increases experimental pain tolerance in healthy volunteers - a double-blind sham-controlled crossover study". PLOS ONE. 8 (4): e61926. Bibcode:2013PLoSO...861926K. doi:10.1371/journal.pone.0061926. PMC 3631254. PMID 23620795.
  11. ^ Shupak NM, Prato FS, Thomas AW (June 2004). "Human exposure to a specific pulsed magnetic field: effects on thermal sensory and pain thresholds". Neuroscience Letters. 363 (2): 157–62. doi:10.1016/j.neulet.2004.03.069. PMID 15172106. S2CID 41394936.
  12. ^ Matsumura Y, Hirayama T, Yamamoto T (2013). "Comparison between pharmacologic evaluation and repetitive transcranial magnetic stimulation-induced analgesia in poststroke pain patients". Neuromodulation. 16 (4): 349–54, discussion 354. doi:10.1111/ner.12019. PMID 23311356. S2CID 206204986.
  13. ^ Feng WW, Bowden MG, Kautz S (2013). "Review of transcranial direct current stimulation in poststroke recovery". Topics in Stroke Rehabilitation. 20 (1): 68–77. doi:10.1310/tsr2001-68. PMID 23340073. S2CID 39688758.