[Diurnal rhythm of pain in sciatica. Preliminary report]

Similarly as nearly all processes taking place continuously in the organism pain shows also frequently a circadian rhythm. In 30 patients with ischalgia pain intensity was studied over 24-hour periods during 7 successive days. The patients noted graphically the intensity of pain on a specially prepared scale. In the light of the data obtained from the patients three types of circadian pain rhythm curves were isolated. In 83,3% of cases the co urse of pain had an evident circadian rhythm returning during successive days. In 19 cases (63.3%) pain was particularly increased in the evening and night hours. In 6 cases (20%) the peak intensity of pain was in the morning hours (5-10 a.m.). In the remaining 5 cases (16%) its intensity was unchanged, without any circadian fluctuations. No relationship was demonstrated between pain rhythm and the age, sex, disease duration, spinal radiological changes, sensory or motor deficit. Pain rhythm is individual feature connected, probably, with other rhythmic processes in the organism, particularly with the rhythm of corticosteroid or endorphin release. Increased intensity of pain may be connected with falling level of these substances in the organism. In 35 patients with a significant nocturnal rhythm of ischalgic pain a trial was undertaken of treating the pain with dexomethasone administered in the evening hours in the painless period. The doses were 1-2 mg. In nearly 70% of cases (24 patients) a good effect of this treatment was obtained. This work based exclusively on clinical observations requires further studies and it is regarded by the authors as a preliminary communication.