Bruce M. Cameron

Preliminary study of an increase of a plasma apolipoprotein E variant associated with peripheral nerve damage. A finding in patients with chronic spinal pain.

Study Design This two-dimensional gel electrophoretic study analyzed the plasma of six groups of patients to determine the association of an elevated apolipoprotein E variant with peripheral nerve damage (PND). Objectives To find a statistically significant plasma protein alteration in patients with PND including chronic spinal pain. Summary of Background Data A twofold to fivefold increase in human plasma apolipoprotein E may be a physiologic response to PND as a 250-fold local increase in apolipoprotein E was reported in experimental PND studies in mammals. Methods A total of 36 patients with chronic lumbar pain, 28 normal control subjects, and 33 patients with other conditions were studied. Venipuncture was performed and plasma was studied using the technique of two-dimensional gel electrophoresis. Chi-square analysis was used to evaluate results. Results A statistically significant (P < 0.005) elevation of the plasma apolipoprotein E variant was found in patients with chronic lumbar pain. It also was elevated in patients with chronic cervical pain, extraspinal pain with PND, and chronic inflammatory diseases; but not in extraspinal pain without PND, or asymptomatic biomechanically deficient lumbar spines. Conclusions This quantitative protein alteration, although not specific for PND, may prove useful in the treatment of conditions with this disorder, including chronic spinal pain

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 to study serum esterase enzymatic activity in three groups of patients and one group of normal volunteers. Objectives. To determine whether there is a statistically significant correlation 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 extracellular space of the brain and in the cerebral spinal fluid have been found to be associated in animal pain experimentation. Methods. Ninety-three surgical patients with chronic spinal pain, six surgical control subjects operated for conditions not associated with pain, 21 normal control volunteers, and nine disabled patients receiving monetary benefits were studied. The patients were analyzed for a period of time by rating the perception of their pain with a visual assessment score at the time venous blood was drawn. Serum samples were prepared, serum pseudocholinesterase was monitored, separated, and quantified according to Allen et al. 5 Paired sample t tests were used to statistically evaluate the data. Results. A trend of correlation was noted between preoperative serum pseudocholinesterase levels and visual assessment score: serum pseudocholinesterase levels increased as visual assessment score increased. The mean preoperative serum pseudocholinesterase level of chronic spinal pain patients (1313; SE = 26), which was significantly higher than the mean levels of the normal control volunteers (941; SE = 24;P < 0.001) and that of surgical control subjects (1018; SE = 63;P < 0.01), decreased significantly with anesthesia (P < 0.005). The mean preoperative serum pseudocholinesterase level of the surgical controls, however, remained unchanged with anesthesia. A correlation demonstrated between visual assessment score and serum pseudocholinesterase in chronic spinal pain patients was not observed in six of nine patients receiving disability payments for more than a year. Conclusions. Measurements of quantitative alterations of serum pseudocholinesterase levels may be useful in the treatment of patients with chronic spinal pain.