TY  - JOUR
A1  - Üçeyler, Nurcan
A1  - Kewenig, Susanne
A1  - Kittel-Schneider, Sarah
A1  - Fallgatter, Andreas J.
A1  - Sommer, Claudia
T1  - Increased cortical activation upon painful stimulation in fibromyalgia syndrome
JF  - BMC Neurology
N2  - Background
Fibromyalgia syndrome (FMS) is a chronic condition characterized by widespread pain and associated symptoms. We investigated cerebral activation in FMS patients by functional near-infrared spectroscopy (fNIRS).

Methods
Two stimulation paradigms were applied: a) painful pressure stimulation at the dorsal forearm; b) verbal fluency test (VFT). We prospectively recruited 25 FMS patients, ten patients with unipolar major depression (MD) without pain, and 35 healthy controls. All patients underwent neurological examination and all subjects were investigated with questionnaires (pain, depression, FMS, empathy).

Results
FMS patients had lower pressure pain thresholds than patients with MD and controls (p < 0.001) and reported higher pain intensity (p < 0.001). Upon unilateral pressure pain stimulation fNIRS recordings revealed increased bilateral cortical activation in FMS patients compared to controls (p < 0.05). FMS patients also displayed a stronger contralateral activity over the dorsolateral prefrontal cortex in direct comparison to patients with MD (p < 0.05). While all three groups performed equally well in the VFT, a frontal deficit in cortical activation was only found in patients with depression (p < 0.05). Performance and cortical activation correlated negatively in FMS patients (p < 0.05) and positively in patients with MD (p < 0.05).

Conclusion
Our data give further evidence for altered central nervous processing in patients with FMS and the distinction between FMS and MD.
KW  - fibromyalgia syndrome
KW  - depression
KW  - cortical activation
KW  - pain
KW  - near-infrared spectroscopy
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125230
VL  - 15
IS  - 210
ER  - 
TY  - JOUR
A1  - Üçeyler, Nurcan
A1  - Kewenig, Susanne
A1  - Kafke, Waldemar
A1  - Kittel-Schneider, Sarah
A1  - Sommer, Claudia
T1  - Skin cytokine expression in patients with fibromyalgia syndrome is not different from controls
N2  - Background

Fibromyalgia syndrome (FMS) is a chronic pain syndrome of unknown etiology. There is increasing evidence for small nerve fiber impairment in a subgroup of patients with FMS. We investigated whether skin cytokine and delta opioid receptor (DOR) gene expression in FMS patients differs from controls as one potential contributor to small nerve fiber sensitization.

Methods

We investigated skin punch biopsies of 25 FMS patients, ten patients with monopolar depression but no pain, and 35 healthy controls. Biopsies were obtained from the lateral upper thigh and lower calf. Gene expression of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF), interleukin (IL)-6, and IL-8 and of the anti-inflammatory cytokine IL-10 was analyzed using quantitative real-time PCR and normalizing data to 18sRNA as housekeeping gene. Additionally, we assessed DOR gene expression.

Results

All cytokines and DOR were detectable in skin samples of FMS patients, patients with depression, and healthy controls without intergroup difference. Also, gene expression was not different in skin of the upper and lower leg within and between the groups and in FMS patient subgroups.

Conclusions

Skin cytokine and DOR gene expression does not differ between patients with FMS and controls. Our results do not support a role of the investigated cytokines in sensitization of peripheral nerve fibers as a potential mechanism of small fiber pathology in FMS.
KW  - Fibromyalgia syndrome
KW  - Skin biopsy
KW  - Monopolar depression
KW  - Cytokines
KW  - Opioid receptor
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-110624
ER  -