Clinical characteristics of patients with idiopathic pain syndromes. Depressive symptomatology and patient pain drawings.

The frequency of depressive symptomatology as estimated by means of self-rating on a visual analogue scale and the pain drawings by patients were compared between healthy volunteers, patients with neurogenic pain syndromes and patients with idiopathic pain syndromes. All patients with chronic pain syndromes had significantly more depressive symptomatology than the healthy volunteers. Patients with idiopathic pain syndromes had significantly more inhibition symptoms--memory disturbances and concentration difficulties--than patients with neurogenic pain syndromes. In the pain drawings, estimated by means of the technique suggested by Margolis et al. [10], the idiopathic pain patients had significantly higher scores on both raw scores and weighted body surface scores than the patients with neurogenic pain syndromes. Thus, both self-rating of depressive symptomatology and pain drawings can be of some help in the difficult clinical delineation between patients with idiopathic and neurogenic pain syndromes, respectively, but used as single measures, both methods have low discriminative power.

Pain perception and endorphin levels in cerebrospinal fluid.

In 45 consecutive patients with chronic pain syndromes endorphins, fraction I of the cerebrospinal fluid and pain measures by means of electric stimulation via saline electrodes were investigated. In patients with high levels of fraction I (above median) pain threshold, PT and tolerance level, TL, in condition C (continuous stimulation increase) were found to be significantly higher than in patients with low levels of fraction I (below median). The results indicate that the endorphins are one of the physiological factors that contribute to the pain threshold and the tolerance level.

Endorphins in chronic pain. I. Differences in CSF endorphin levels between organic and psychogenic pain syndromes.

A series of 37 patients with chronic pain was investigated with regard to neurologic and psychiatric variables. Twenty of the patients were classified as having mainly organic (= somatogenic) pain syndromes while 17 patients were rather suffering from psychogenic pain syndromes. Samples of lumbar cerebrospinal fluid (CSF) were obtained from the patients and analyzed for the presence of opiate receptor-active material, here called endorphins. Patients classified as having mainly organic pain syndromes were found to have significantly lower endorphin levels than patients with predominantly psychogenic pain syndromes. In the total group of patients as well as in the two subgroups, there was a significant correlation between CSF endorphin levels and the depth of depressive symptomatology as reported by the patients. On the other hand, there was no correlation between CSF endorphin levels and extent of anxiety or motor retardation. It is concluded that CSF endorphins reflect central processes involved in chronic pain syndromes.