Po-Chou Liliang

Sacroiliac Joint Pain after Lumbar and Lumbosacral Fusion: Findings Using Dual Sacroiliac Joint Blocks

OBJECTIVE The present study was performed to ascertain whether sacroiliac joint (SIJ) pain represents a potential source of pain in patients who have undergone lumbar or lumbosacral fusions. DESIGN Prospective cohort study. PATIENTS AND METHODS Between June 2007 and June 2009, 130 patients who underwent lumbar or lumbosacral fusions were evaluated for SIJ pain. Fifty-two patients for whom positive findings were obtained on at least three of the provocating tests for SIJ pain were selected to receive dual diagnostic blocks. OUTCOME MEASURES A positive response was defined as characteristic pain reduction of 75% for 1-4 hours following the SIJ blocks. Predictive factors for a positive response to the SIJ blocks were also investigated. RESULTS Among the 52 patients, 21 were considered to have SIJ pain on the basis of two positive responses to diagnostic blocks. Univariate analysis revealed that the predictive factors related to positive responses were unilateral pain (P = 0.002), more than three positive responses to provocating maneuvers (P = 0.02), and postoperative pain with characteristics different from those of preoperative pain (P = 0.04). CONCLUSIONS SIJ pain is a potential source of pain after lumbar and lumbosacral fusion surgeries. Provocating SIJ maneuvers represent reliable tests for SIJ pain. The characteristics of postoperative SIJ pain frequently differ from those of preoperative pain.

Post-neurosurgical nosocomial bacterial meningitis in adults: microbiology, clinical features, and outcomes

The clinical data of 62 adult patients who suffered post-neurosurgical nosocomial bacterial meningitis, retrospectively collected over a 16-year period, were studied. Cases were divided into two groups based on the date of presentation, the first period being 1986-1993 and the second 1994-2001. Fever and progressive consciousness disturbance were the most consistent clinical features - signs that may also be attributed to other postoperative neurosurgical problems. The common pathogens included Staphylococcus aureus, coagulase negative Staphylococcus, Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter baumannii. An increase in polymicrobial infections and multi-antibiotic resistance during the second period was identified. In the first half of the study, mortality was 22%, and in the second half 36%. Adult post-neurosurgical nosocomial bacterial meningitis has become an important clinical problem. The choice of appropriate empirical antibiotics is challenging and must be guided by an awareness of the relative frequency of various pathogens and the increasing incidence of resistant strains. Although high mortality rates may, in part, be related to the primary brain pathology, early diagnosis and the timely use of antibiotics based on antimicrobial susceptibility testing are essential for survival.

Pulsed Radiofrequency Lesioning of the Suprascapular Nerve for Chronic Shoulder Pain : A Preliminary Report

OBJECTIVE Chronic shoulder pain is difficult to treat, and the efficacy of most interventions is limited. This study was conducted to evaluate pulsed mode radiofrequency (PRF) lesioning of the suprascapular nerve for treating chronic shoulder pain. Interventions. Thirteen procedures using PRF lesioning of suprascapular nerve were performed under fluoroscopic guide in 11 patients (13 shoulder joints) with chronic shoulder pain for at least 3 months. OUTCOME MEASURES The patients were evaluated for pain, shoulder disability function, and medication requirements prior to and after treatment. RESULTS At 1-month follow-up assessment, 10 (76.9%) shoulder joints had significant pain relief (visual analog scale >or= 50% reduction), and at 6-month follow-up assessment, nine (69.2%) still had significant pain relief. The mean VAS score of 11 patients before PRF was 7.5 +/- 1.0, and the scores at 1-month and 6-month follow-up were 2.8 +/- 2.6 and 2.5 +/- 2.8, respectively. A significant pain reduction (P < 0.001) was observed. The mean Shoulder Pain and Disability Index scores at 6-month follow-up also showed a significant decrease compared with pre-PRF (P < 0.001). Medication requirements were evaluated 1 month and 6 months after the PRF. Nine (81.8%) patients had their medication requirement decreased. CONCLUSIONS Pulsed mode radiofrequency lesioning to suprascapular nerve is a potential treatment option for patients suffering chronic shoulder pain. It provides long-lasting pain relief and decreases pain medication requirements.

Profiling muscle-specific microRNA expression after peripheral denervation and reinnervation in a rat model.

MicroRNAs (miRNAs) are a class of highly conserved, non-coding RNAs involved in post-transcriptional gene regulation. The muscle-specific miRNAs, miR-1, miR-133a, and miR-206, are expressed in skeletal muscles and have been shown to contribute to muscle development. To profile their expression after sciatic nerve denervation and reinnervation, the soleus muscles of the rats were analyzed with quantitative real-time PCR at 1 week, 1 month, 2 months, and 4 months after the experiments. In addition, a combined approach using computational prediction by the miRanda website and the Agilent Whole Rat Genome 4 x 44 k oligo microarray experiment was performed to investigate the potential target genes of these three miRNAs in the denervated and reinnervated muscles. The results revealed that with the first downregulation of miR-1 and miR-133a within 1 month in the denervated muscle, the expression of miR-1 and miR-133 increased by approximately 2-fold at 4 months after denervation and reinnervation; on the other hand, the expression of miR-206 was significantly increased to approximately 3-fold 1 month later only following reinnervation but not following denervation, and lasted at least for 4 months. The expression pattern of miR-206 was different from that of miR-1 and miR-133a. Notably, two genes (Hnrpu and Npy) and one gene (Ptprd) were potentially regulated both in the denervated and reinnervated muscle by miR-1 and miR-133a, respectively. There were six potential target genes (Hnrpu, Lsamp, MGC108776, Mef2, Npy, and Ppfibp2) of the upregulated miR-206 in the reinnervated muscle. Among these, three (Hnrpu, Npy, and MGC108776) were potentially regulated by both miR-1 and miR-206. Because the Mef2 transcription factor was reported to promote the transformation of type II fast glycolytic fibers into type I slow oxidative fibers, the upregulation of miR-206 with decreased expression of the Mef2 transcript in the 4 month reinnervated muscle, which presented type II fiber predominance 4 months after nerve microanastomosis, might indicate the role of miR-206 in determining the fiber type after peripheral nerve regeneration.

Percutaneous Vertebroplasty Improves Pain and Physical Functioning in Elderly Osteoporotic Vertebral Compression Fracture Patients

Background: Osteoporotic vertebral compression fractures are being recognized increasingly often in the elderly. They frequently cause severe and prolonged back pain and physical decline. Bed rest, narcotic analgesia, and external bracing were the only therapeutic modalities available in the past and had limited success. Objective: The purpose of our study was to determine the efficacy of percutaneous vertebroplasty in treating osteoporotic vertebral compression fractures in the elderly. Methods: Twenty-two vertebroplasties were performed in 16 elderly patients. Pain relief, medication requirements, and physical functioning were evaluated before and 24 h and 6 months after vertebroplasty. Results: There was 81% improvement in pain intensity 24 h after operation, and 94% improvement was noted at the 6-month follow-up checkup. Physical functioning improved 69% 24 h after vertebroplasty and 63% 6 months later. Medication requirements also decreased in 75% of the patients. Conclusion: Percutaneous vertebroplasty for osteoporotic vertebral compression fractures is safe and effective and should not be withheld from the elderly.

Entrapment neuropathy results in different microRNA expression patterns from denervation injury in rats

BackgroundTo compare the microRNA (miRNA) expression profiles in neurons and innervated muscles after sciatic nerve entrapment using a non-constrictive silastic tube, subsequent surgical decompression, and denervation injury.MethodsThe experimental L4-L6 spinal segments, dorsal root ganglia (DRGs), and soleus muscles from each experimental group (sham control, denervation, entrapment, and decompression) were analyzed using an Agilent rat miRNA array to detect dysregulated miRNAs. In addition, muscle-specific miRNAs (miR-1, -133a, and -206) and selectively upregulated miRNAs were subsequently quantified using real-time reverse transcription-polymerase chain reaction (real-time RT-PCR).ResultsIn the soleus muscles, 37 of the 47 miRNAs (13.4% of the 350 unique miRNAs tested) that were significantly downregulated after 6 months of entrapment neuropathy were also among the 40 miRNAs (11.4% of the 350 unique miRNAs tested) that were downregulated after 3 months of decompression. No miRNA was upregulated in both groups. In contrast, only 3 miRNAs were upregulated and 3 miRNAs were downregulated in the denervated muscle after 6 months. In the DRGs, 6 miRNAs in the entrapment group (miR-9, miR-320, miR-324-3p, miR-672, miR-466b, and miR-144) and 3 miRNAs in the decompression group (miR-9, miR-320, and miR-324-3p) were significantly downregulated. No miRNA was upregulated in both groups. We detected 1 downregulated miRNA (miR-144) and 1 upregulated miRNA (miR-21) after sciatic nerve denervation. We were able to separate the muscle or DRG samples into denervation or entrapment neuropathy by performing unsupervised hierarchal clustering analysis. Regarding the muscle-specific miRNAs, real-time RT-PCR analysis revealed an ~50% decrease in miR-1 and miR-133a expression levels at 3 and 6 months after entrapment, whereas miR-1 and miR-133a levels were unchanged and were decreased after decompression at 1 and 3 months. In contrast, there were no statistical differences in the expression of miR-206 during nerve entrapment and after decompression. The expression of muscle-specific miRNAs in entrapment neuropathy is different from our previous observations in sciatic nerve denervation injury.ConclusionsThis study revealed the different involvement of miRNAs in neurons and innervated muscles after entrapment neuropathy and denervation injury, and implied that epigenetic regulation is different in these two conditions.

The impact of tracheostomy timing in patients with severe head injury: An observational cohort study

STUDY DESIGN A retrospective analysis of 66 adults with severe head injury admitted to the neurosurgical intensive care unit (ICU) who required tracheostomy. OBJECTIVE The purpose of this cohort study was to examine the impact of the tracheostomy timing in patients with severe head injury. METHODS Patients were included in this study if they were admitted to the neurosurgical ICU because of severe head injury and if tracheostomy was performed. The patients were classified into 2 groups: early tracheostomy (ET) and late tracheostomy (LT). The timing of tracheostomy was considered early if it was performed by day 10 of mechanical ventilation and late if it was performed after day 10. We compared the duration of mechanical ventilation, length of stay (LOS) at ICU, hospital LOS, incidence of pneumonia, duration of antibiotics use, and mortality between the ET and LT groups. RESULTS Of the 2481 patients with severe head injury admitted to the neurosurgical ICU, 66 (2.7%) required tracheostomy; 16 of whom were in the ET group and 50 were in the LT group. The ICU LOS was significantly shorter in the ET group (p<0.001). The incidence of nosocomial pneumonia was lower in the ET group (p=0.04) and the duration of antibiotic use was significantly shorter in the ET group (p<0.001). The patients in the ET group had a lower incidence of pneumonia caused by gram-negative microorganisms (p=0.001). CONCLUSIONS ET in patients with severe head injury might contribute to a shorter duration of ICU LOS, lower incidence of gram-negative microorganism-related nosocomial pneumonia, and shorter duration of antibiotic use.

Pulsed radiofrequency of cervical medial branches for treatment of whiplash-related cervical zygapophysial joint pain

BACKGROUND The aim of this study is to assess the efficacy of pulsed RF lesioning of cervical medial branches in patients with whiplash-related chronic cervical zygapophysial joint pain in whom other conservative treatments failed. METHODS Cervical zygapophysial joint pain was confirmed in 14 patients undergoing double diagnostic blocks. These patients underwent pulsed RF lesioning of the cervical medial branches. Pulsed RF procedures were performed in 2 cycles of 180 seconds after localization under fluoroscopy guide. RESULTS Twelve (85.7%) patients had substantial pain relief at 1 month. Eleven (78.3%) patients still had more than 60% pain relief at 6 months. Only 5 (35.7%) patients recurred within 12 months. At 12-month follow-up, 9 (64.3%) patients had significant pain improvement. Medication requirements decreased in 13 (92.8%) patients at 1 month, 12 (85.7%) patients at 6 months, and 10 (71.4%) patients at 12 months. CONCLUSIONS Pulsed RF of cervical medial branches is a potential treatment for patients with chronic whiplash-related cervical zygapophysial joint pain that failed other conservative treatments. This treatment provides long-lasting pain relief and reduces pain medication requirements.

MicroRNA profiling in ischemic injury of the gracilis muscle in rats

BackgroundTo profile the expression of microRNAs (miRNAs) and their potential target genes in the gracilis muscles following ischemic injury in rats by monitoring miRNA and mRNA expression on a genome-wide basis.MethodsFollowing 4 h of ischemia and subsequent reperfusion for 4 h of the gracilis muscles, the specimens were analyzed with an Agilent rat miRNA array to detect the expressed miRNAs in the experimental muscles compared to those from the sham-operated controls. Their expressions were subsequently quantified by real-time reverse transcription polymerase chain reaction (real-time RT-PCR) to determine their expression pattern after different durations of ischemia and reperfusion. In addition, the expression of the mRNA in the muscle specimens after 4 h of ischemia and reperfusion for 1, 3, 7, and 14 d were detected with the Agilent Whole Rat Genome 4 × 44 k oligo microarray. A combined approach using a computational prediction algorithm that included miRanda, PicTar, TargetScanS, MirTarget2, RNAhybrid, and the whole genome microarray experiment was performed by monitoring the mRNA:miRNA association to identify potential target genes.ResultsThree miRNAs (miR-21, miR-200c, and miR-205) of 350 tested rat miRNAs were found to have an increased expression in the miRNA array. Real-time RT-PCR demonstrated that, with 2-fold increase after 4 h of ischemia, a maximum 24-fold increase at 7 d, and a 7.5-fold increase at 14 d after reperfusion, only the miR-21, but not the miR-200c or miR-205 was upregulated throughout the experimental time. In monitoring the target genes of miR-21 in the expression array at 1, 3, 7, 14 d after reperfusion, with persistent expression throughout the experiment, we detected the same 4 persistently downregulated target genes (Nqo1, Pdpn, CXCL3, and Rad23b) with the prediction algorithms miRanda and RNAhybrid, but no target gene was revealed with PicTar, TargetScanS, and MirTarget2.ConclusionsThis study revealed 3 upregulated miRNAs in the gracilis muscle following ischemic injury and identified 4 potential target genes of miR-21 by examining miRNAs and mRNAs expression patterns in a time-course fashion using a combined approach with prediction algorithms and a whole genome expression array experiment.

Risk Factors of Subsequent Vertebral Compression Fractures After Vertebroplasty

OBJECTIVE To elucidate the risk factors for a subsequent vertebral compression fracture following percutaneous vertebroplasty, we analyzed the potential predictors of vertebral compression fractures adjacent to or remote from fractures previously treated with percutaneous vertebroplasty. DESIGN This is a retrospective cohort study. BACKGROUND A major concern after percutaneous vertebroplasty in patients with osteoporosis is the occurrence of subsequent vertebral compression fractures in the untreated vertebral bodies. The risk factors for the development of subsequent vertebral compression fractures after percutaneous vertebroplasty are unclear. METHODS Two hundred four consecutive patients underwent percutaneous vertebroplasty for acute vertebral compression fractures between January 2007 and December 2008. Forty-nine patients were excluded. Subsequent vertebral compression fractures were diagnosed by bone edema changes on magnetic resonance imaging. Patients demographic data were used for univariate and multivariable binary logistic regression analyses. RESULTS Forty-three (27.7%) of the 155 patients had subsequent vertebral compression fractures within 2 years of percutaneous vertebroplasty, with 21 (48.8%) of these patients having fractures detected within 3 months. Adjacent vertebral compression fractures tended to occur sooner, although not significantly (log-rank test, P = 0.112). On multivariate analyses, only the T-score of bone mineral density was significantly associated with subsequent vertebral compression fractures (P < 0.0001; odds ratio = 0.27; 95% confidence interval, 0.15-0.49). CONCLUSIONS The only risk factor significantly associated with subsequent vertebral compression fractures following percutaneous vertebroplasty was a low bone mineral density T-score. Patients with lower bone mineral density have a higher incidence of vertebral compression fractures and thus need more intensive clinical and radiological follow-up.