Vagus nerve stimulation is effective in reducing pain in humans. In humans, the antinociceptive effect might rely on central inhibition rather than alterations of peripheral nociceptive mechanisms. These results indicate a promising, potential future role of vagus nerve stimulation in pain treatment.

Left vagus nerve stimulation reduces pain perception in humans. In animal studies it has been shown that beyond the inhibitory effect, which the vagus nerve exerts via its widespread central connections, there might be also a peripheral effect on nociceptors. In humans, the exact mechanisms of VNS-mediated analgesia are still unclear. To test whether VNS also affects activation of primary nociceptive afferents in humans, we investigated 11 patients before and after implantation of a vagus nerve stimulator by using tonic pressure as pain stimulus. Vasodilator axon reflexes ("neurogenic" inflammation) were quantified by laser-Doppler-imaging and served as surrogates for primary afferent activation. Pain was measured on a visual analogue scale (VAS). The squeezing experiment was performed three times at 15 min intervals in each session. As controls 9 healthy age- and gender-matched subjects were studied. As shown in our previous study, VNS significantly reduces pain to tonic pressure. Likewise, there was a moderate reduction of the blood flow within the area of the axon reflex, which indicates a possible but limited inhibitory effect of VNS on peripheral nociceptors. Our data suggests that VNS might affect peripheral nociceptor function in humans. Since VNS has been shown to be more effective in experimental procedures in which pain magnitude is amplified by central processing, further studies are warranted to elucidate whether the central or peripheral effect is most important for VNS-mediated analgesia.

Binding of ligands to the receptor for advanced glycation endproducts (RAGE) results in activation of the proinflammatory transcription factor nuclear factor-kappaB (NF-kappaB) and subsequent expression of NF-kappaB-regulated cytokines. In order to determine whether engagement of RAGE contributes to the pathogenesis of vasculitic neuropathy, we studied the presence of the RAGE ligand N(epsilon)-(carboxymethyl)lysine (CML), the receptor itself, NF-kappaB, and interleukin-6 (IL-6) in sural nerve biopsies of 12 patients with vasculitic neuropathies and 12 controls. In the patients, CML, RAGE, NF-kappaB, and IL-6 were localized in mononuclear cells, epineurial and endoneurial vessels and the perineurium. CML, RAGE, NF-kappaB, and IL-6 were expressed by CD4(+), CD8(+), and CD68(+) cells invading the nerves. Controls showed only weak staining. These data suggest that the RAGE pathway plays a critical proinflammatory role in vasculitic neuropathy.

Botulinum toxin (BTX) has become a safe and effective therapeutic tool in the treatment of a variety of neurological disorders, especially dystonias. One major disadvantage, however, is the high cost of a single injection of BTX. In this study of 835 patients, we calculated the cost of treatment with BTX serotype A (BTX-A) for different dystonias and hemifacial spasm. The annual expenditure per patient for BTX-A injections in this cohort totalled (mean +/- standard deviation) 1030 Deutschmarks (DM) [1996 values] +/- DM610 [$US570 +/- $US340; 230 +/- 130 pounds sterling (Pound)] for blepharospasm (n = 158), DM1450 +/- DM1520 ($US800 +/- $US830; 310 Pounds +/- 280 Pounds) for craniocervical dystonia (n = 148), and DM1480 +/- DM780 ($US810 +/- $US430; 330 Pounds +/- 180 Pounds) for oromandibular dystonia (n = 16), while the treatment of cervical dystonia consumed DM4590 +/- DM2060 ($US2520 +/- $US1130; 960 Pounds +/- 420 Pounds) [n = 362] per patient. In order to alleviate symptoms in patients with hemifacial spasm (n = 151), DM510 +/- DM270 ($US280 +/- $US150; 110 Pounds +/- 60 Pounds) had to be spent annually. The expenses for surgical therapy for cervical dystonia were DM10,120 +/- DM1900 (n = 54). No major differences concerning expenditure could be found in this study between the 2 available preparations of BTX. However, there appeared to be a lower rate of adverse effects with the Botox formulation, compared with the Dysport formulation, of BTX-A (this difference was statistically significant, i.e. p < 0.001). Although the cost of an individual injection is high, other cost factors also substantially contribute to the societal costs of adult-onset dystonias. Some of these costs may be attenuated with the use of BTX. The subjective and objective relief of these socially devastating and sometimes painful conditions rewards the expenditure associated with the use of BTX-A.

Withdrawal of CBZ is followed more quickly by an increase of seizure frequency and severity than is the case for VPA withdrawal. Both CBZ and VPA withdrawal influences seizure propagation rather than the seizure-onset characteristics, which speaks in favor of its use in presurgical evaluation.