1.
1H-magnetic resonance spectroscopy in diffuse and focal cervical cord lesions in multiple sclerosis.
Bellenberg, B, Busch, M, Trampe, N, Gold, R, Chan, A, Lukas, C
European radiology. 2013;(12):3379-92
Abstract
OBJECTIVES To investigate differences between focal and diffuse cervical lesions in multiple sclerosis (MS) by proton magnetic resonance spectroscopy ((1)H-MRS) at 1.5 T in comparison to quantitative MR imaging of the upper cervical cord area and T2 relaxometry at baseline and follow-up. METHODS Including 22 MS patients with persistent spinal cord symptoms by either diffuse or focal lesions and 17 controls, we acquired MRS, the mean cord area and the water T2 relaxation time and disability at baseline and follow-up. Cross-sectional analyses included group-level comparisons and correlation studies. Follow-up studies covered assessment of reproducibility and progression of the baseline results. RESULTS Compared with focal lesions, diffuse lesions were attended by more cord atrophy, longer T2, elevated levels of creatine (Cre) and reduced N-acetyl aspartate (NAA)/Cre (focal/diffuse: 83 ± 9/73 ± 15 mm(2), 121 ± 21/104 ± 13 ms, 3.6 ± 1.1/5.1 ± 2.4 mM, 2.4 ± 1.1/2.0 ± 0.9). NAA/Cre at baseline was associated significantly with cord atrophy and with clinical progression during follow-up. Baseline MRS results were not significantly correlated to the clinical disability parameters. The reproducibility of MRS was 0.17-0.30. Longitudinal changes of the MRS results were not statistically significant. CONCLUSIONS MRS indicated differences in demyelination and gliosis between diffuse and focal cervical lesions in MS. Although longitudinal spectral and clinical changes were sparse, NAA/Cre turned out to be the most sensitive spectral parameter.
2.
Spinal prostaglandin formation and pain perception following thoracotomy: a role for cyclooxygenase-2.
McCrory, C, Fitzgerald, D
Chest. 2004;(4):1321-7
Abstract
STUDY OBJECTIVE Prostaglandins (PGs) generated in the spinal cord may play a major role in pain perception. Consequently, the suppression of spinal cyclooxygenase (COX) and PG formation may contribute to the analgesic effect of nonsteroidal anti-inflammatory drugs (NSAIDs) in pain following surgery. Which isoform of COX is responsible for postsurgical pain and, consequently, should be targeted, is unclear. DESIGN Prospective randomized blinded study. SETTING University teaching hospital. PATIENTS Thirty patients undergoing thoracotomy for lobectomy were recruited. INTERVENTIONS Patients were randomized to receive the COX-2 selective inhibitor nimesulide, 100 mg orally twice daily, or ibuprofen (nonselective), 400 mg orally three times daily, in an open-label study. In addition, there was a randomized control group that received no NSAIDs. Cerebrospinal fluid (CSF) was analyzed for 6-keto-PGF(1)alpha, the principle metabolite of prostacyclin. COX-1 and COX-2 activity was determined by measuring serum thromboxane (TX) B(2) and endotoxin-induced PGE(2) generation in whole blood. MEASUREMENTS Pain perception was measured by visual analog scores, and blinded assessment of opioid analgesic requirements and expiratory peak flow measurements were performed. RESULTS At the doses used, nimesulide was selective for COX-2, while ibuprofen was nonselective based on serum TXB(2) levels. The mean (+/- SEM) levels of 6-keto-PGF(1)alpha in CSF increased following surgery from 32 +/- 4.9 to 127 +/- 29 pg/mL (p < 0.001), and this was suppressed by nimesulide (49 +/- 9.3 pg/mL; p = 0.0025) but not by ibuprofen (122 +/- 35 pg/mL). Pain scores (p < 0.001), morphine requirement (p = 0.0175), and the fall in peak expiratory flow rate (p < 0.001) were significantly lower in the nimesulide group. CONCLUSIONS Increases in spinal PG synthesis after thoracotomy are repressed by a selective COX-2 inhibitor. This suggests that the inducible COX-2 mediates central PG synthesis, which may be important in the generation of pain, as the use of nimesulide also resulted in significant decreases in postoperative pain perception.