Prof. Dr. Peter Schwenkreis, Neurologische Universitätsklinik, BG-Kliniken Bergmannsheil, Faculty of Medicine

Peter Schwenkreis

Research Programme:

My scientific work focuses on the examination of plastic changes in the somatosensory and motor cortex in patients with lesions of the peripheral or central nervous system, and especially in patients with chronic pain syndromes (e.g., phantom pain, complex regional pain syndrome CRPS, neuropathic pain after nerve lesions).

Using paired transcranial magnetic stimulation (TMS), it is possible to study the excitability of intracortical inhibitory (presumably GABAergic) and excitatory (presumably glutamatergic) interneuronal circuits in the motor cortex, which might provide insight into the underlying mechanisms of cortical reorganisation. Additionally, I use the techniques of TMS and SSEP mapping to assess non-invasively reorganisation in the primary motor and somatosensory cortex. In patients with upper limb amputation, we found an enlargement as well as a lateral shift of the cortical output map of proximal stump muscles, suggesting plastic changes in the cortical representation of these muscles. These representational changes are paralleled by changes in motor cortex excitability. However, we could not establish a relationship between chronic phantom pain and these cortical changes in limb amputees, suggesting a more important role of the peripheral deafferentation for its occurrence. On the other hand, we found a bilaterally altered excitability in the motor cortex of patients with CRPS, which was related to the pain intensity. Pain intensity did also influence the somatosensory hand representation in these patients, suggesting an important influence of chronic pain on the somatosensory and motor system.