Neurotrophins in the cerebrospinal fluid of patient cohorts with neuropathic pain, nociceptive pain, or normal pressure hydrocephalus.
OBJECTIVE
The pathophysiology of neuropathic pain is still poorly understood. Studies in experimental animals showed that neurotrophic factors such as glial cell line-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), and nerve growth factor (NGF) might be involved in the pathophysiology of neuropathic pain. On the basis of these findings it is conceivable that neurotrophic factors also play a role in pain processing in man. Thus far, it remains unknown whether neurotrophic factors are altered in the cerebrospinal fluid (CSF) of patients with different pain syndromes. Here, we analyzed the concentrations of neurotrophic factors in the CSF of patients with chronic neuropathic pain in comparison to controls with nociceptive pain or hydrocephalus.


METHODS
The concentrations of GDNF, BDNF, CNTF, and NGF were analyzed in the lumbar CSF of 10 patients with chronic neuropathic pain, in 20 patients with lumbar back pain undergoing myelography, and in 10 patients with normal pressure hydrocephalus, by using enzymes-linked immunosorbent assay techniques.


RESULTS
The CSF concentrations of CNTF, BDNF, and NGF did not differ between the 3 patient cohorts. For GDNF a trend toward lower concentrations in neuropathic pain versus nociceptive back pain (P=0.17) was found.


CONCLUSIONS
We did not detect any difference between patients with neuropathic versus nociceptive pain and nonpainful controls for spinal CNTF, BDNF, and NGF levels. Lower GDNF concentrations found in neuropathic pain patients might be associated with increased receptor expression. Possible alterations of neurotrophic factors at spinal relays, however, might not be reflected adequately in changes of CSF concentrations.
Capelle
Hans-Holger
HH
Department of Neurosurgery, Medical University Hannover, MHH, Hannover, Germany. hhhc@gmx.net
Weigel
Ralf
R
Schmelz
Martin
M
Krauss
Joachim K
JK
D000368:Aged; D002908:Chronic Disease; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000134:cerebrospinal fluid*; D017116:Low Back Pain / Q000134:cerebrospinal fluid; D008297:Male; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000134:cerebrospinal fluid*; D010146:Pain / Q000134:cerebrospinal fluid*; D010523:Peripheral Nervous System Diseases / Q000134:cerebrospinal fluid*
D009414:Nerve Growth Factors