Genome-wide expression profiling of complex regional pain syndrome.

Complex regional pain syndrome (CRPS) is a chronic, progressive, and devastating pain syndrome characterized by spontaneous pain, hyperalgesia, allodynia, altered skin temperature, and motor dysfunction. Although previous gene expression profiling studies have been conducted in animal pain models, there genome-wide expression profiling in the whole blood of CRPS patients has not been reported yet. Here, we successfully identified certain pain-related genes through genome-wide expression profiling in the blood from CRPS patients. We found that 80 genes were differentially expressed between 4 CRPS patients (2 CRPS I and 2 CRPS II) and 5 controls (cut-off value: 1.5-fold change and p<0.05). Most of those genes were associated with signal transduction, developmental processes, cell structure and motility, and immunity and defense. The expression levels of major histocompatibility complex class I A subtype (HLA-A29.1), matrix metalloproteinase 9 (MMP9), alanine aminopeptidase N (ANPEP), l-histidine decarboxylase (HDC), granulocyte colony-stimulating factor 3 receptor (G-CSF3R), and signal transducer and activator of transcription 3 (STAT3) genes selected from the microarray were confirmed in 24 CRPS patients and 18 controls by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). We focused on the MMP9 gene that, by qRT-PCR, showed a statistically significant difference in expression in CRPS patients compared to controls with the highest relative fold change (4.0±1.23 times and p = 1.4×10(-4)). The up-regulation of MMP9 gene in the blood may be related to the pain progression in CRPS patients. Our findings, which offer a valuable contribution to the understanding of the differential gene expression in CRPS may help in the understanding of the pathophysiology of CRPS pain progression.

Disseminated herpes zoster in an immunocompetent elderly patient.

Herpes zoster is a cutaneous infection that is characterized by an acute vesicobullous rash with ipsilateral one or two dermatomal distribution and painful allodynia, while predominantly being found in the elderly. Extensive cutaneous dissemination has been reported in immune-compromised patients, such as those who suffer from HIV infections, cancer, chemotherapy, and corticosteroid therapy patients. However, we report a case of disseminated herpes zoster infection in an immuno-competent elderly individual.

Occurrence of trochlear nerve palsy after epiduroscopic laser discectomy and neural decompression.

Epiduroscopic laser discectomy and neural decompression (ELND) is known as an effective treatment for intractable lumbar pain and radiating pain which develop after lumbar surgery, as well as for herniation of the intervertebral disk and spinal stenosis. However, various complications occur due to the invasiveness of this procedure and epidural adhesion, and rarely, cranial nerve damage can occur due to increased intracranial pressure. Here, the authors report case in which double vision occurred after epiduroscopic laser discectomy and neural decompression in a patient with failed back surgery syndrome (FBSS).

Antinociceptive effect of phenyl N-tert-butylnitrone, a free radical scavenger, on the rat formalin test.

BACKGROUND: Reactive oxygen species (ROS) such as superoxide radicals, hydrogen peroxide, nitric oxide, and nitroperoxide, cause oxidative stress which interferes with normal cell functioning, resulting in cell damage. It is reported to be associated with chronic pain, especially neuropathic pain, and inflammatory pain. ROS is also closely related to central sensitization. Therefore, this study was designed to explore the effects of Phenyl N-tert-butylnitrone (PBN), an ROS scavenger, in acute, continuous, and increasing pain caused by central sensitization. METHODS: Male Sprague-Dawley rats were divided into 2 groups, an intraperitoneal group (IP) and an intrathecal group (IT), and once again divided into an experimental group and a control group. The experimental group was injected with Phenyl N-tert-butylnitrone (PBN), a free radical scavenger, either intraperitoneally or intrathecally. After inducing pain by injecting formalin into the hind paw, pain behaviors were measured. Lumbar enlargement immmunohistochemistry was performed to assess nitrotyrosine, an oxidative stress marker, to identify the degree of protein nitration. RESULTS: Both experimental groups of IP and IT showed statistically significant decreases in the number of flinches compared to the control group in phase 1 and 2. Immunohistochemical evaluation in the control group revealed an increase in nitrated proteins in the gray matter of the lumbar spinal cord, but a significant decrease in nitrated proteins in the gray matter of lumbar spinal cord of the experimental group. CONCLUSIONS: Intraperitoneal and intrathecal administration of PBN decreases analgesic behaviors, allowing us to believe that ROS is mainly responsible for acute pain and central sensitization.

Cauda equina syndrome after spinal anesthesia in a patient with severe spinal stenosis: A case report.

Cauda equina syndrome is a well-known but rare complication of spinal anesthesia. An 80-year-old man was scheduled for both herniorrhaphy. Spinal anesthesia was performed at the L3-4 interspinous space with 0.5% hyperbaric bupivacaine 12 mg. Eight hours after anesthesia, the patient complained bilateral sensorimotor deficits of the lower extremities and peroneal region. Urinary and fecal incontinence were also observed. MRI and myelography showed severe central spinal stenosis at L3-4 and L4-5. EMG showed cauda equina syndrome. Seven weeks after the procedure, left decompressive subtotal laminectomy L2-L5 was done. The patient still complains the neuropathic pain in the both lower extremities and ambulates using a walker. The local anesthetic was injected into thecal sac between maximum stenoses, and it is likely that there was poor upward spread leading to maldistribution of local anesthetic and resultant local anesthetic toxicity.

Arthroscopic posterior cruciate ligament augmentation using an autogenous hamstring tendon graft and the posterior-posterior triangulation technique.

We describe a modification of the currently practiced arthroscopic posterior cruciate ligament (PCL) reconstruction techniques. We augmented the injured PCL with quadrupled autogenous hamstring tendon grafts using the arthroscopic posterior-posterior triangulation method and a single-incision transtibial approach. The tibial drill guide was introduced through the anteromedial portal and positioned onto the fossa for the PCL on the tibia under arthroscopic guidance from the posterolateral portal. The femoral tunnel was made 10 mm posterior to the articular cartilage of the medial femoral condyle by use of the anterior cruciate ligament Beath pin (Arthrex, Naples, FL) introduced through the far-inferior anterolateral portal. The tendon graft was positioned in the knee joint by use of the tibial and femoral double-folded silk loops that traversed the bony tunnels. The graft was fixed by use of bioabsorbable Intrafix screw systems (DePuy Mitek, Raynham, MA) at both the ends. The arthroscopic posterior-posterior triangulation method provides adequate exposure of the posterior knee compartment; this allows for convenient instrumentation and safe and accurate placement of the bony tunnels with preservation of the PCL remnants. We believe that retention of the remnant PCL fibers is biologic and contributes to earlier healing and strengthening of the tendon graft.