Dorsal and ventral dopaminergic innervation of the spinal cord: Functional implications

Several studies have demonstrated that a descending dopaminergic pathway innervates the dorsal and the intermediate gray matter of the spinal cord and have suggested that this pathway is involved in pain modulation and in the control of autonomie functions. Other studies have also demonstrated the presence of dopamine (DA) and DA metabolites as well as of DA receptors in the ventral cord. There is also evidence for the implication of DA in the control of motor functions at the spinal level. The occurrence of a dopaminergic innervation in the ventral horn has been, however, disputed until recently. But recent work has demonstrated that the motoneural cell groups in the ventral horn (lamina IX) are a target for descending dopaminergic fibers. In addition, the possibility that DA is a mediator of primary afferent fibers has also been postulated. Finally, the occurrence of dopaminergic cell bodies has been suggested in the spinal cord. This indicates that DA is probably implicated in a complex manner in spinal functions. In the present paper the possible involvement of DA in sensory and in motor functions at spinal level will be discussed in view of neurochemical observations made in polyarthritic rats, in which pain-related behavior and reduction of locomotor activity associated with a marked decrease in mobility, are observed.     

Cervical intramedullary cavernous angioma with MRI-proven haemorrhages

Summary Two contrasting cases of cervical intramedullary cavernous angioma in young female patients are reported. One patient had a 3-year course of step-wise progressive tetraparesis; at each of the five events intramedullary bleeding from a cryptic vascular malformation at C6–7 level was diagnosed by MRI. The other patient presented with one episode which led to MRI diagnosis of a vascular malformation at the C2 level. Both patients eventually underwent complete surgical excision of the angioma with subsequent steady improvement of the neurological deficit.     

转移性肝癌B超声像图特点

目的探讨转移性小肝癌的B超声像图特点及在鉴别诊断中的意义。方法对原发癌明确的直径小于3cm肝转移瘤超声检查资料进行回顾性分析，对比小于2cm和大于2cm病灶及不同脏器来源转移灶的超声像图特点。结果多数肝转移瘤呈圆形、有晕环(Halo)、内部可呈高、等、低回声；小于2cm病灶内部回声均匀，大于2cm病灶内部回声多不均匀；来源于结肠者多呈高回声、胰腺者多呈低回声。结论B超对转移性小肝癌的分辨能力较强，可以间接提示转移瘤来源。     

Percent spinal canal compromise on MRI utilized for predicting the need for surgical treatment in single-level lumbar intervertebral disc herniation

BACKGROUND CONTEXT: There is limited information describing the correlation between the initial quantitative measurements on magnetic resonance imaging (MRI) scans of disc herniation area, canal cross-section areas, percent canal compromise, and disc herniation location to the need for surgery. PURPOSE: Our aim is to determine if the size of disc herniation area, canal cross-section area, percent canal compromise, and disc herniation location taken from MRI images of patients with symptomatic single-level lumbar herniated intervertebral discs upon initial presentation to a spine surgeon, were predictive of the need for surgical treatment. STUDY DESIGN/SETTING: This is a retrospective case matched study of patient MRI images in the senior author's private practice. PATIENT SAMPLE: From a pool of 332 patients with sciatica caused by lumbar intervertebral disc herniations at our institution, 65 patients had surgery, of which MRI images were available and analyzed on 44 patients. Forty-four additional patients were randomly selected from the remaining 267 original group as nonoperative controls. METHODS: The axial MRI image showing the largest canal compromise by the herniated disc was selected for measurements. Using T1- and T2-weighted images, the areas of interest were digitally scanned at high resolution. The canal area and disc herniation area measurement were calculated from the total number of pixels per cross-sectional area, multiplied by a scan correction factor, mm(2) /pixel. Disc herniation locations were classified into either central or paracentral. The percent canal compromise was obtained by disc herniation area divided by canal cross-section area and multiplied by 100. RESULTS: The surgical group's overall mean herniated disc area was 219.6 square millimeter (mm(2)), 179.8 at L4-5, and 267.4 at L5-S1. The nonoperative group's overall mean herniated disc area was 178.4 mm(2), 135.1 at L2-3, 160.3 at L4-5, and 207.4 at L5-S1. The surgical group's overall mean canal cross-sectional area was 471.8 mm(2), 418.6 at L4-5, and 535.6 at L5-S1. The nonoperative group's overall mean canal cross-sectional area was 541.3 mm(2), 518.1 at L2-3, 446.8 at L4-5, and 669.9 at L5-S1. The overall percent canal compromise ratio in the surgery group was 46.7%, 44.1% at L4-5, and 49.8% at L5-S1. The overall percent canal compromise in the nonoperative group was 34.2%, 34.1% at L2-3, 36.1% at L4-5, and 31.8% at L5-S1. The percent canal compromise in central herniations at L4-5 level was 53.0% in the surgical group, and 32.8% in the nonoperative group; at the L5-S1 level surgical group percent canal compromise was 64.1% and in the nonoperative group canal compromise was 27%. L4-L5 level paracentral herniations canal compromise was 36.7% in the surgical group compared with 42.5% canal compromise in the nonoperative group. At the L5-S1 level the canal compromise was 45% in the surgical group and 34.8% in the nonoperative group. CONCLUSIONS: Our findings show a trend for patients treated with surgery to have larger disc herniation areas and smaller canal cross-section areas, corresponding to larger percent canal compromise than the nonoperative group. Centrally located herniations followed this trend closely at all levels studied. However, the paracentral herniation at the L4-5 level does not follow this trend, possibly because paracentral disc herniation clinical course is determined more by herniation location rather than the overall herniation size.     

Three-dimensional spinal curvature in idiopathic scoliosis

Scoliosis is usually considered as a deformity of the spine in the frontal plane, without reference to curvatures in other planes. In this study, the three-dimensional shape of the spine of 104 patients with untreated idiopathic scoliosis (5-55 degrees Cobb) was studied by means of stereo radiographs to determine relationships between curvature of the spine in the frontal plane view, in the lateral view, and in the intermediate views. There was a weak but statistically significant correlation (r = 0.2) relating greater scoliosis with lesser kyphosis or greater lordosis. In the thoracic region, the sagittal plane spinal curvature was less than that measured in a population without scoliosis (mean difference, 7.72 +/- 9.9 degrees). Seventy-four of 76 scolioses in the upper region of the spine with lateral curvature greater than 5 degrees Cobb were kyphotic. Sixty-four of 84 curves greater than 5 degrees Cobb in the lower region were lordotic. Measuring curvatures in the plane of symmetry of the rotated apical vertebra altered these ratios to 69 of 76 kyphotic in the upper region and 68 of 84 lordotic in the lower region. The plane of maximum curvature of sections of the spine with scoliosis was not related to the plane of symmetry of the rotated apical vertebra, for in kyphotic regions of the spine the rotations of these two planes were in opposite directions. In all cases, the magnitudes of the rotations were quite different, i.e., by a factor of -0.22 for curves in thoracic region and by a factor of 0.24 for curves in the lumbar region. This implies that mechanical measures to correct this spinal deformity or to prevent progression should apply different rotations to the apex from those applied to the curve as a whole and, in opposite senses, in curves in kyphotic regions. There was no evidence of an abnormality of sagittal curvature of a magnitude to implicate it in the etiology or in the treatment.     

转TrkC基因神经干细胞移植对脊髓损伤的治疗作用

目的 研究转酪氨酸激酶C（tyrosine kinase C，TrkC）基因神经干细胞（neural stem cells，NSCs）移植治疗脊髓损伤的作用。方法 60只SD大鼠随机分成正常对照组（A组）、脊髓半切组（B组）、NSCs移植组（C组）、NSCs移植＋神经营养素（NT）-3局部使用（D）组、转TrkC基WNSCs移植组（E组）和转TrkC基因NSCs移植＋NT-3局部使用组（F组），每组10只。脊髓损伤后第9天进行细胞移植。各组大鼠在细胞移植后2个月，行体感诱发电位（SEP）和运动诱发电位（MEP）检查以及脊髓运动功能（BBB）评分。结果 细胞移植后2个月SEP和MEP发生潜伏期和峰峰波幅以及右后肢BBB评分的恢复均以下组最佳，与其他各组比较，差异有统计学意义（P＜ 0．05，0．01）。结论在局部给予的NT-3作用下，转TrkC基因NSCs能较好地促进损伤脊髓功能的恢复。     

Soma size and oxidative enzyme activity in normal and chronically stimulated motoneurones of the Cat''s spinal cord

In normal adult cats we measured the density of staining for the activity of succinate dehydrogenase (SDH staining) in ventral horn cells of different sizes. The measurements were restricted to that part of the lumbar ventral horn (L6-L7) which is known to contain motoneurones of the peroneal nerve. A statistically significant tendency was found for the SDH staining to be denser in smaller than in larger neurones within the size range of a motoneurones (soma diameter greater than 40 microns). These results are consistent with recently published evidence for ventral horn cells of rats and qualitatively similar relationships between size and SDH staining have also been observed among skeletal muscle fibres (confirmed for mixed muscle of cat in present study). In hindlimb muscles, size as well as SDH staining are known to be markedly activity-dependent. We tested whether this is the case for peroneal motoneurones as well by analyzing the effects of chronic nerve stimulation on the properties of neurones within the appropriate region of the ventral horn. Prior to the final acute experiment, these cats had been subjected to a left-side dorsal rhizotomy and hemispinalization. By aid of a portable mini-stimulator, the left-side common peroneal nerve was activated by repetitive pulses during 50% of total time per day (intra-activity rate: 10, 20 or 40 Hz). After 8 weeks of such treatment, cell sizes as well as the densities of SDH staining showed hardly any differences between peroneal ventral horn cells of the experimental and control sides of the spinal cord.(ABSTRACT TRUNCATED AT 250 WORDS)