A Novel Visualization Method for Sleep Spindles Based on Source Localization of High Density EEG

Equivalent dipole source localization is a well-established approach to localizing the electrical activity in electroencephalogram (EEG). So far, source localization has been used primarily in localizing the epileptic source in human epileptic patients. Currently, source localization techniques have been applied to account for localizing epileptic source among the epileptic patients. Here, we present the first application of source localization in the field of sleep spindle in mouse brain. The spatial distribution of cortical potential was obtained by high density EEG and then the anterior and posterior sleep spindles were classified based on the K-mean clustering algorithm. To solve the forward problem, a realistic geometry brain model was produced based on boundary element method (BEM) using mouse MRI. Then, we applied four different source estimation algorithms (minimum norm, eLORETA, sLORETA, and LORETA) to estimate the spatial location of equivalent dipole source of sleep spindles. The estimated sources of anterior and posterior spindles were plotted in a cine-mode that revealed different topographic patterns of spindle propagation. The characterization of sleep spindles may be better be distinguished by our novel visualization method.

Surgical Treatment of Metacarpal and Phalangeal Fracture with Rotational Malalignment

PURPOSE: Hand fractures can be treated conservatively in many cases, but rotation malalignment is one of the important indications for surgical treatment because of dysfunction. We performed open reduction and internal fixation in these malalignment fractures and report clinical and radiological results. METHODS: This study included 28 patients (18 male, 10 female) who had metacarpal and phalangeal fractures with rotational malalignment of finger on initial examination. Patients with combined injuries including open soft tissue damage or multiple fractures were excluded. Mean age was 36.1 years and average follow-up period was 14.6 months. Perioperative extent of rotation and correction during the follow-up, union on the radiographs, Range of motion, disability of the arm, shoulder and hand (DASH) score, and pinch power at the last follow-up were evaluated. RESULTS: Average corrected angulation of rotation was 11.9° and no patient showed scissoring appearance of fingers at the last follow-up. All patients showed solid bony union on the radiographs during the follow-up. The average of total active motion of the injured fingers were average 254°, average DASH score was 3.2 and average pinch power was 3.0 kg at the last follow-up. CONCLUSION: Clinical and radiologically satisfactory results were obtained in all patients. Care should be taken not to overlook the rotational misalignment after fracture of the hand, and surgical treatment should be considered to ensure correct reduction and fixation.

Pulse-train Stimulation of Primary Somatosensory Cortex Blocks Pain Perception in Tail Clip Test

Human studies of brain stimulation have demonstrated modulatory effects on the perception of pain. However, whether the primary somatosensory cortical activity is associated with antinociceptive responses remains unknown. Therefore, we examined the antinociceptive effects of neuronal activity evoked by optogenetic stimulation of primary somatosensory cortex. Optogenetic transgenic mice were subjected to continuous or pulse-train optogenetic stimulation of the primary somatosensory cortex at frequencies of 15, 30, and 40 Hz, during a tail clip test. Reaction time was measured using a digital high-speed video camera. Pulse-train optogenetic stimulation of primary somatosensory cortex showed a delayed pain response with respect to a tail clip, whereas no significant change in reaction time was observed with continuous stimulation. In response to the pulse-train stimulation, video monitoring and local field potential recording revealed associated paw movement and sensorimotor rhythms, respectively. Our results show that optogenetic stimulation of primary somatosensory cortex at beta and gamma frequencies blocks transmission of pain signals in tail clip test.

A Case of Herpes Zoster Duplex Bilateralis, a Diagnostic Clue of Human Immunodeficiency Virus Infection / 대한피부과학회지

The skin lesion of herpes zoster is typically limited to a single dermatome. The clinical appearance of herpes zoster in immunocompromised patients is usually identical to typical zoster, but lesions may be more severe and there can be multidermatomal involvement. The appearance of herpes zoster occurring in two non-contiguous dermatomes has been referred to as zoster duplex unilateralis or bilateralis. Herpes zoster duplex bilateralis is a rare manifestation of herpes zoster and almost all reported cases have in immunocompromised patients with hematologic cancer, patients taking immunosuppressant drugs for chronic illnesses and patients receiving chemotherapy for solid cancers. We report a case of herpes zoster duplex bilateralis, which was a diagnostic clue of human immunodeficiency virus infection.

Small Dose of Midazolam Added to Fentanyl-Ropivacaine for Patient Controlled Epidural Analgesia after Subtotal Gastrectomy

BACKGROUND: Midazolam has been reported to have a spinally mediated antinociceptive effect. In this randomized, double-blind study, we evaluated whether a small dose of midazolam added to fentanyl-ropivacaine mixture for PCEA (patient controlled epidural analgesia) improves epidural analgesia in patients underwent elective subtotal gastrectomy. METHODS: Forty five patients, ASA physical status I and II, undergoing subtotal gastrectomy were randomly allocated to receive 0.2% ropivacaine mixed with fentanyl 4microg/ml or 0.2% ropivacaine mixed with fentanyl 4microg/ml and midazolam 0.2 mg/ml. The infusion rate was set to deliver 4 ml/hr of the study solution, with a bolus of 2 ml per demand and a 20 minutes lockout time. RESULTS: Infused volume (P < 0.05) and VAS scores (P < 0.05) was significantly lower in the patients receiving midazolam. However, there were no differences in requiring rescue analgesics, PONV (postoperative nausea and vomiting), sedation scores, urinary retention, and pruritus between groups. CONCLUSIONS: Small dose of midazolam could augment analgesia without adverse effects when added to thoracic epidural infusion of fentanyl and ropivacaine.