Quantification of 10 elements in human cerebrospinal fluid from chronic pain patients with and without spinal cord stimulation

Neuropathic pain affects 1–10% of the general population and is caused by a lesion or disease of the somatosensory nervous system. Spinal cord stimulation (SCS), a method where implanted electrodes stimulate the spinal cord, has been successfully used to treat drug-resistant neuropathic pain, but the mechanism of action is largely unknown. Studies show that SCS changes the protein levels in CSF (cerebrospinal fluid) of pain patients. Several neurological conditions have been shown to alter the elemental composition of CSF. Therefore changes in the levels of ions and trace elements in the CSF may correspond to SCS use. This study used ICP-MS (Inductively coupled plasma mass spectrometry) and ICP-AES (Inductively coupled plasma atomic emission spectroscopy) to quantify 10 elements in CSF from chronic neuropathic pain patients using SCS. The element concentrations in CSF from patients with SCS treatment on/off, were measured. No effect on the element concentrations in CSF from treatment with SCS could be detected. Also, the elemental concentrations in pooled CSF from patients without chronic neuropathic pain was determined and compared to the patients using SCS. The concentration of the elements Ca, Sr, Na, K, P, Mg and Ti were, significantly higher in patients compared to the CSF-control.