• loretta.png
  • stimulationHead.png
  • stimulations.png

Neurophysiology

Focus Areas of Research

  • Spinal and cortical evoked potentials
  • Brain source localization of evoked potentials
  • Nociceptive withdrawal reflexes
  • Resting state EEG frequency analysis and source localization
  • Conditioning pain modulation and offset analgesia
  • Parasympathetic tone

The human pain system consists of different levels and it can be modulated either physiologically, pathophysiologically or pharmacologically. In Mech-Sense, we investigate the neural processes underlying rest, sensation and pain perception. We furthermore investigate how these neural processes are modified due to different diseases (i.e. chronic pancreatitis, diabetes, esophagitis, irritable bowel syndrome, hepatic encephalopathy) and during pharmacological intervention which involves different mechanisms. We use a multidisciplinary neurophysiological setup in order to characterize the individual’s:

  1. Upstream activation via spinal and cortical evoked potentials
  2. Brain activation in response to perception via brain source localization of evoked potentials
  3. Spinal pain transmission via the nociceptive withdrawal reflexes
  4. Resting state brain activity via the resting state EEG time-frequency analysis and brain source localization
  5. Endogenous inhibitory pain pathways via conditioning pain modulation and offset analgesia
  6. Neuronal brainstem-vagal circuit by assessing the parasympathetic tone and the sympatico-vagal balance.

Responsible Researcher

Professor Asbjørn Mohr Drewes, MD, PhD, DMSc, EDPM

Selected Publications

  1. Lelic D, Valeriani M, Fischer IW, Dahan A, Drewes AM. Venlafaxine and oxycodone have different effects on spinal and supraspinal activity in man: a somatosensory evoked potential study. Br J Clin Pharmacol. 2016
  2. Botha C, Farmer AD, Nilsson M, Brock C, Gavrila AD, Drewes AM, Knowles CH, Aziz Q. Preliminary report –Modulation of Parasympathetic Nervous System Tone influences Oesophageal Pain Hypersensitivity. 1Gut.2016
  3. Brock C, Brock B, Aziz Q, Møller HJ, Pfeiffer Jensen M, Drewes AM, Farmer AD. Transcutaneous cervical vagal nerve stimulation modulates cardiac vagal tone and tumor necrosis factor-alpha. Neurogastroenterol Motil. 2016
  4. Frøkjaer JB, Bergmann S, Brock C, Madzak A, Farmer AD, Ellrich J, Drewes AM.Modulation of vagal tone enhances gastroduodenal motility and reduces somatic pain sensitivity. Neurogastroenterol Motil. 2016
  5. Lelic D, Fischer IW, Olesen AE, Mørch CD, Arguissain FG, Manresa JA, Dahan A, Drewes AM. Venlafaxine and oxycodone effects on human spinal and supraspinal pain processing: a randomized cross-over trial. Eur J Neurosci. 2016
  6. Lelic D, Olesen SS, Hansen TM, Valeriani M, Drewes AM. Functional reorganization of brain networks in patients with painful chronic pancreatitis. Eur J Pain. 2014
  7. Frøkjær JB, Graversen C, Brock C, Khodayari-Rostamabad A, Olesen SS, Hansen TM, Søfteland E, Simrén M, Drewes AM. Integrity of central nervous function in diabetes mellitus assessed by resting state EEG frequency analysis and source localization. J Diabetes Complications. 2016
  8. Gram M, Erlenwein J, Petzke F, Falla D, Przemeck M, Emons MI, Reuster M, Olesen SS, Drewes AM. Prediction of postoperative opioid analgesia using clinical-experimental parameters and electroencephalography. Eur J Pain. 2017
  9. Olesen SS, Gram M, Jackson CD, Halliday E, Sandberg TH, Drewes AM, Morgan MY. Electroencephalogram variability in patients with cirrhosis associates with the presence and severity of hepatic encephalopathy. J Hepatol. 2016
  10. Khodayari-Rostamabad A, Graversen C, Olesen SS, Malver LP, Kurita GP, Sjøgren P, Christrup LL, Drewes AM. Altered cortical causality after remifentanil administration in healthy volunteers: a novel approach for pharmaco-EEG. Conf Proc IEEE Eng Med Biol Soc. 2014