Neuromodulation & Neurorehabilitation
Modulation of Brain Activity in Healthy Subjects and Patients – Providing the Basis for Novel Concepts in Stroke Rehabilitation
How does stroke influence sensorimotor networks in the human brain? – This is the major question driving our research activities. Stroke is the leading cause of disability in the western world. In Germany, approximately 200.000 people per year suffer from a stroke, and over 50% of stroke survivors remain disabled by a permanent neurological deficit, despite pharmacological treatment and extensive physiotherapy (http://www.dgn.org). We, therefore, also focus on developing neurophysiologically based novel treatment strategies to promote recovery of function in patients.
Methods and Projects
Functional MRI (fMRI)
We use a Siemens Trio 3 Tesla machine for the acquision of structural (T1, T2, FLAIR, DWI, DTI) and functional (EPI: gradient echo, spin echo, arterial spin labeling) imaging sequences. For visual stimulus presentation, we either use high resolution video goggles or an MR compatible LCD screen. For auditory stimulation, we use high qualitiy MR headphones and MR compatible microphones.
See also: Magnetic Resonance Imaging (MRT / MRI)
One focus of interest of the „Neuromodulation & Neurorehabilitation“ group is to conduct pharmacological studies probing the effects of adrenergic, serotonergic or dopaminergic stimulation on motor behavior in patients with an ischemic lesion. Based on the literature, candidate drugs for an effective modulation of motor performance are reboxetine (adrenergic), fluoxetine (serotonergic) and levodopa (or dopamine agonists). Patients are recruited in close cooperation with the Department of Neurology, University of Cologne, which is situated directly next to the MPI for Neurological Research.
Transcranial magnetic stimulation
Another approach to modulate cortical excitability is to combine pharmacological stimulation with electrophysiological interventions such as transcranial magnetic stimulation (TMS). The MPI for Neurological Research uses a neuronavigated Eximia TMS device which enables fMRI guided interactions with cortical excitability. Most repetitive TMS stimulation protocols have been found to change cortical excitation for between 15 up to 60 minutes (depending on the stimulation protocol). Modulating cortical activity by means of neuropharmacological drugs might mobilise inherent electrophysiological properties of the cortex and ultimately lead to increased or more robust intervention effects.
Such effects might well be beneficial in a rehabilitative setting.
We use a Zebris CMS20S device for 3D real-time motion analysis. The system (Figure 1a) mainly consists of a measuring sensor (max. distance: 2.0 m) which captures the three-dimensional positions of ultrasonic pulses emitting markers (diameter: 5 mm, weight: 1 g) fixed on the body part to be examined with high spatial (0.1 mm) and temporal (100 Hz) resolution. The offline-analysis of the data allows assessing movement ranges, velocity, accelerations and other kinematic parameters (see Figure).
Research topics in detail:
PD Dr. Christian Grefkes
Jan 23, 2013 | ANIM - Mannheim
Netzwerkstörungen nach Schlaganfall - Neue Erkenntnisse durch Konnektivitätsanalysen
Mar 22, 2013 | DGKN - Leipzig
Mar 23, 2013 | DGKN - Leipzig
Selected Landmark in the competition "365 Orte im Land der Ideen"
Habilitationspreis der Medizinischen Fakultät der Universität zu Köln - C. Grefkes
Förderpreis der Deutschen Gesellschaft für Neurotraumatologie und Klinische Neurorehabilitation - A. Rehme
Niels-A.-Lassen-Preis der Deutschen Gesellschaft für Klinische Neurophysiologie (DGKN) - C. Grefkes
Young-Scientist-Award des Kompetenznetz Schlaganfall - C. Grefkes
Department of Neurology, University of Cologne (Prof. Fink)
Department of Neuro-Surgery, University of Cologne (Dr. Weiss, Prof. Dr. Goldbrunner)
Department of Psychiatry, University of Cologne (PREVENT- study group)
Institute of Medicine and Neurosciences, Jülich Research Center (Prof. Weiß-Blankenhorn, Prof. Eickhoff)
Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London (Prof. Rothwell, Dr. Hamada, Dr. Ward, Dr. Boudrias)