A prospective study of serum pseudocholinesterase levels in patients with chronic spinal pain - A preliminary study

Study Design, One-dimensional polyacrylamide gel electrophoresis was used t o study serum esterase enzymatic activity in three groups of patients and o ne group of normal volunteers. Objectives. To determine whether there is a statistically significant corre lation between variations of serum pseudocholinesterase and the perception of pain in patients with chronic spinal pain. Summary of Background Data, Changes in levels of cholinesterase in the extr acellular space of the brain and in the cerebral spinal fluid have been fou nd to be associated in animal pain experimentation. Methods. Ninety-three surgical patients with chronic spinal pain, six surgi cal control subjects operated for conditions not associated with pain, 21 n ormal control volunteers, and nine disabled patients receiving monetary ben efits were studied. The patients were analyzed for a period of time by rati ng the perception of their pain with a visual assessment score at the time venous blood was drawn. Serum samples were prepared, serum pseudocholineste rase was monitored, separated, and quantified according to Alien et al.(5) Paired sample t tests were used to statistically evaluate the data. Results. A trend of correlation was noted between preoperative serum pseudo cholinesterase levels and visual assessment score: serum pseudocholinestera se levels increased as visual assessment score increased. The mean preopera tive serum pseudocholinesterase level of chronic spinal pain patients (1313 ; SE = 26), which was I significantly higher than the mean levels of the no rmal control volunteers (941; SE = 24; P < 0.001) and that of surgical cont rol subjects (1018; SE = 63; P < 0.01), decreased significantly with anesth esia (P < 0.005), The mean preoperative serum pseudocholinesterase level of the surgical controls, however, remained unchanged with anesthesia. A corr elation demonstrated between visual assessment score and serum pseudocholin esterase in chronic spinal pain patients was not observed in six of nine pa tients receiving disability payments for more than a year. Conclusions. Measurements of quantitative alterations of serum pseudocholin esterase levels may be useful in the treatment of patients with chronic spi nal pain.