Brachioradial pruritus and cervical spine manipulation

Brachioradial pruritus (BRP) causes significant morbidity in the majority of patients for whom no effective treatment is found. Chronic ultraviolet radiation exposure has usually been cited as the cause, but nerve damage from cervical spine disease has also been implicated. We report on a small retrospective exploratory study, conducted by questionnaire, of a group of patients who were treated with a specific cervical spine manipulation. Ten of 14 patients reported resolution of symptoms following manipulative treatment. All six patients who had had previous cervical spine disease responded to manipulation, as did half the remaining eight patients who had no previous history of neck symptoms. Although patients with BRP, by definition, share similar symptoms, the aetiology is almost certainly multifactorial. Prospective studies looking for cervical spine disease, as well as assessment of this particular method of cervical spine manipulation as a treatment modality for BRP, should be considered.     

Repeated stress alters dendritic spine morphology in the rat medial prefrontal cortex

Anatomical alterations in the medial prefrontal cortex (mPFC) are associated with hypothalamopituitary adrenal (HPA) axis dysregulation, altered stress hormone levels, and psychiatric symptoms of stress-related mental illnesses. Functional imaging studies reveal impairment and shrinkage of the mPFC in such conditions, and these findings are paralleled by experimental studies showing dendritic retraction and spine loss following repeated stress in rodents. Here we extend this characterization to how repeated stress affects dendritic spine morphology in mPFC through the utilization of an automated approach that rapidly digitizes, reconstructs three dimensionally, and calculates geometric features of neurons. Rats were perfused after being subjected to 3 weeks of daily restraint stress (6 hours/day), and intracellular injections of Lucifer Yellow were made in layer II/III pyramidal neurons in the dorsal mPFC. To reveal spines in all angles of orientation, deconvolved high-resolution confocal laser scanning microscopy image stacks of dendritic segments were reconstructed and analyzed for spine volume, surface area, and length using a Rayburst-based automated approach (8,091 and 8,987 spines for control and stress, respectively). We found that repeated stress results in an overall decrease in mean dendritic spine volume and surface area, which was most pronounced in the distal portion of apical dendritic fields. Moreover, we observed an overall shift in the population of spines, manifested by a reduction in large spines and an increase in small spines. These results suggest a failure of spines to mature and stabilize following repeated stress and are likely to have major repercussions on function, receptor expression, and synaptic efficacy.     

Fibular allograft and anterior plating for dislocations/fractures of the cervical spine

Background:

Subaxial cervical spine dislocations are common and often present with neurological deficit. Posterior spinal fusion has been the gold standard in the past. Pain and neck stiffness are often the presenting features and may be due to failure of fixation and extension of fusion mass. Anterior spinal fusion which is relatively atraumatic is thus favored using autogenous grafts and cages with anterior plate fixation. We evaluated fresh frozen fibular allografts and anterior plate fixation for anterior fusion in cervical trauma.

Materials and Methods:

Sixty consecutive patients with single-level dislocations or fracture dislocations of the subaxial cervical spine were recruited in this prospective study following a motor vehicle accident. There were 38 males and 22 females. The mean age at presentation was 34 years (range 19-67 years). The levels involved were C5/6 (n = 36), C4/5 (n = 15), C6/7 (n = 7) and C3/4 (n = 2). There were 38 unifacet dislocations with nine posterior element fractures and 22 were bifacet dislocations. Twenty-two patients had neurological deficit. Co-morbidities included hypertension (n = 6), non-insulin-dependent diabetes mellitus (n = 2) and asthma (n = 1). All patients were initially managed on skull traction. Following reduction further imaging included Computerized Tomography and Magnetic Resonance Imaging. Patients underwent anterior surgery (discectomy, fibular allograft and plating). All patients were immobilized in a Philadelphia collar for eight weeks (range 7-12 weeks). Eight patients were lost to follow-up within a year. Follow-up clinical and radiological examinations were performed six-weekly for three months and subsequently at three-monthly intervals for 12 months. Pain was analyzed using the visual analogue scale (VAS). The mean follow-up was 19 months (range 14-39 months).

Results:

Eight lost to followup, hence 52 patients were considered for final evaluation. The neurological recovery was 1.1 Frankel grades (range 0-3) and two patients with root involvement recovered. At six months bony trabeculae at the graft-vertebrae interface were noted. There were 12 (20 %) cases of graft collapse and one case of angulation which showed no progression. At six months the VAS was 3 (range 0-6). There was no limitation of neck motion at six months in 47 patients.

Conclusion:

Fresh frozen fibular allografts are suitable and cost-effective for anterior fusion in cervical trauma.     

Penetrating cactus spine injury to the mediastinum of a child

Injuries from contact with cactus plants are not uncommon in the southwestern United States and other arid landscapes. Most often, accidental encounters with sharp spines and barbs result in little more than mechanical damage to the skin and soft tissues with minor pain and irritation. Although cactus spine penetration into the skin has been reported to be a stimulus for cutaneous granuloma formation, our review of the published literature did not reveal any potentially life-threatening injuries from such insults. We present a unique case of a penetrating cactus spine to the anterior mediastinum in a child which required surgical extraction.     

Partial volume tolerance of the spinal cord and complications of single-dose radiosurgery

BACKGROUND: Spine radiosurgery causes a rapid dose fall-off within the spinal cord. The tolerance of partial volume of the spinal cord may determine the extent of clinical application. The study analyzed the partial volume tolerance of the human spinal cord to single fraction radiosurgery. METHODS: A total of 230 lesions with spine metastases in 177 patients were treated with radiosurgery with single fraction of 8 to 18 Gy, prescribed to the 90% isodose line that encompassed the target volume. Spinal cord volume was defined as 6 mm above and below the radiosurgery target volume. Spinal cord dose was calculated from the radiation dose/spinal cord volume histogram and correlated with clinical/neurological status and radiographic studies. Median follow-up was 6.4 months (range, 0.5-49 months). The 1-year survival rate was 49%. RESULTS: The average spinal cord volume defined at the treated spinal segment was 5.9 +/- 2.2 mL. The average dose to the 10% spinal cord volume was 9.8 +/- 1.5 Gy, calculated from the dose-volume histogram in the group of 18 Gy prescribed dose. The spinal cord volume that received higher than 80% of the prescribed dose was 0.07 +/- 0.10 mL, which represented 1.3 +/- 1.8% of the cord volume. Among the 86 patients who survived longer than 1 year there was 1 case of radiation-induced cord injury after 13 months of radiosurgery. There were no other cases of spinal cord sequelae. CONCLUSIONS: Whereas the maximum spinal cord tolerance to single-dose radiation is not known, partial volume tolerance of the human spinal cord is at least 10 Gy to 10% of the spinal cord volume defined as 6 mm above and below the radiosurgery target.     

Zoonotic transmission of reassortant porcine G4P[6] rotaviruses in Hungarian pediatric patients identified sporadically over a 15 year period

Genotype G4P[6] Rotavirus A (RVA) strains collected from children admitted to hospital with gastroenteritis over a 15 year period in the pre rotavirus vaccine era in Hungary were characterized in this study. Whole genome sequencing and phylogenetic analysis was performed on eight G4P[6] RVA strains. All these RVA strains shared a fairly conservative genomic configuration (G4-P[6]-I1/I5-R1-C1-M1-A1/A8-N1-T1/T7-E1-H1) and showed striking similarities to porcine and porcine-derived human RVA strains collected worldwide, although genetic relatedness to some common human RVA strains was also seen. The resolution of phylogenetic relationship between porcine and human RVA genes was occasionally low, making the evaluation of host species origin of individual genes sometimes difficult. Yet the whole genome constellations and overall phylogenetic analyses indicated that these eight Hungarian G4P[6] RVA strains may have originated by independent zoonotic transmission, probably from pigs. Future surveillance studies of human and animal RVA should go parallel to enable the distinction between direct interspecies transmission events and those that are coupled with reassortment of cognate genes.     

镁离子对大鼠海马神经元γ-氨基丁酸A型受体介导电流的影响

目的：采用全细胞膜片钳技术，研究了镁离子（Mg^2 )对培养的大鼠海马神经元γ－氨基丁酸A型（GABAA）受体所介导电流的作用。方法：采用EPC－9型膜片钳放大器对培养的大鼠海马神经元进行全细胞记录，记录浓度为3，30，300μmol/L的γ－氨基丁酸A型（GABA）所引发的电流及合用80μmol/L的Mg^2 时对其的影响。结果：在钳制电压为－40mV时，GABA可通过GABAA受体介导产生内向电流，且随GABA的浓度增高，电流峰值增高，EC50和Hill coefficient分别是20μmol/L t 0.7(n=7);在Mg^2 存在的情况下，GABA的浓度－效应曲线向左，向上移动，EC50和Hill coefficient分别是10μmol/L和0．7。结论：推测Mg^2 能通过正性变构调节机制影响GABAA受体的功能。