Uveal effusion syndrome complicated by anterior ischemic optic neuropathy

We report on a case of idiopathic uveal effusion syndrome complicated by AION. To our knowledge such an association hasn't been previously described. We suggest that scleral thickening caused obstruction of vortex veins followed by uveal effusion and compression of posterior ciliary arteries within their intrascleral tract, leading to AION. Nevertheless it can't be excluded that AION was the result of mechanical compression on ciliary vessels of optic disc by choroidal detachment.     

The CT criteria for conservative treatment — but under close clinical observation — of posterior fossa epidural haematomas

Summary In order to assess whether the indications for conservative treatment of supratentorial epidural haematomas are applicable also to posterior fossa epidural haematomas (PFEDH), the author reviewed the records of 25 patients. With a PFEDH volume of no more than 10 ml, a thickness of no more than 15 mm, a midline shift of no more than 5 mm, and in the absence of a significant intracranial haematoma elsewhere on computed tomography (CT) scans, the patients undergoing conservative treatment achieved the same excellent outcome as those undergoing early surgery. These CT criteria for conservative treatment of PFEDHs are similar to those of supratentorial epidural haematomas except the volume factor, namely, 10 ml in the former against 30 ml in the latter. That means a PFEDH of 10 ml or larger in the small posterior fossa may produce the same degree of midline shift and compression, and be as dangerous as an epidural haematoma of 30 ml or larger in the more capacious supratentorial compartment. But also for epidural haematomas of the posterior fossa, which initially are smaller than 10 ml, the general rule remains valid that they should be under close clinical supervision     

Experimental study of spinal cord compression by epidural tumors using electron probe X-ray microanalysis and confocal laser scanning microscopy

Changes in the nerve fibers of the spinal cord were studied in rat experimental epidural tumor models. Light microscopy showed demyelinization in all with rats paraparesis and paraplegia. Cross-sectional views of nerve fibers stained with 3,3dipentyloxacarbo-cyanine iodide, obtained by confocal laser scanning microscopy, showed distorted, shrunken fibers with a low fluorescence intensity. Changes in the electrolyte contents of nerve fibers were studied by electron probe X-ray microanalysis. The K concentration in axons and the myelin sheath was increased in the paraparesis group, but was decreased in the paraplegia group. These findings suggest that, in the paraparesis group, compression of the spinal cord damaged cell membrane channels, which subsequently caused an increase in intracellular K, a decline in the action potential, and low-intensity fluorescence of nerve fibers. On the other hand, in the paraplegia group, destruction of cell membranes caused a decrease in intracellular K until it approached the extracellular level. This reduced both the action potential and the fluorescence intensity. As Ca and Mg concentrations in both axons and the myelin sheath increased in relation to the severity of neurologic damage, it appears that these electrolytes may also play an important role in damage to nerve fibers.     

Epidural abscess following epidural steroid and local anaesthetic injection

Epidural abscess is a well-recognised but rare complication of epidural catheter placement. We have found only five previous reports of epidural abscess from noncatheter-related administration of steroids and/or local anaesthetic. We describe a further case which led to critical illness and emphasise the association between diabetes mellitus and epidural infection.     

The anterior inferior cerebellar arterial network supplying the rat cochlea and its role in autoregulation of cochlear blood flow

Summary The sensitivity of the cochlea is dependent upon maintenance of a delicate homeostatic environment. One mechanism which participates in providing this environment is the autoregulation of cochlear blood flow. This autoregulation is ensured through the interaction of sympathetic, peptidergic and hemodynamic mechanisms. The current study demonstrates an adaptation that also participates in cochlear blood flow autoregulation. Specifically, an anterior inferior cerebellar arterial network is described and the relative contributions of each of its vessels to total cochlear blood flow is measured using laser Doppler flowmetry. The results show that each collateral vessel contributes to the blood supply of the cochlea and that reperfusion is accompanied by hyperemia. These findings suggest an adaptation that provides stable blood flow through redundancy and compensatory potential. Additionally, these observations have implications for experimental models of ischemia.     

颈椎病前方入路术后恢复不良的原因分析

１９８０年１２月至１９９３年１２月，我科经前方入路治疗颈椎病并获随访１８３例，其中３７例（２０．２％）术后恢复不满意，ＪＯＡ恢复率小于６０％。根据主诉与症状，我们把这些病人分成４组。（１）术后症状立即加重，１年内仍无改善者４例。（２）术后症状无明显改善，１年后仍无进步者１１例。（３）术后症状减轻，但经过一段时间后，原症状又复出现者８例。（４）双下肢症状好转，但又出现新的上肢症状或上肢原症状加重者１４例。结合术后Ｘ线、ＣＴ、ＭＲＩ和椎管造影等检查所见，我们将发现的主要问题归纳为手术操作、病情发展演变、原有胸腰椎病和脊髓受压变性等情况。本文对以上发生的问题进行了分析，提出在以后的手术中应特别注意的事项。     

胸腰椎骨折伴脊髓损伤前后路手术适应证的选择

目的 通过107例胸腰椎骨折伴脊髓损伤病例的治疗,探讨前、后路手术适应证的选择。方法 31例经前路减压植骨,采用Z-Plate等内固定。76例经后路采用短节段椎弓根钉内固定。结果 两组均获得了满意的疗效。结论 选择前或后路手术,应综合考虑脊髓损伤程度、手术时机与技巧、骨折的部位、骨折类型和影像结果等,才能确实做到减压、恢复脊柱序列和坚强固定的目的。     

Partial k-space reconstruction in single-shot diffusion-weighted echo-planar imaging.

Partial k-space sampling is frequently used in single-shot diffusion-weighted echo-planar imaging (DW-EPI) to reduce the TE and thereby improve the SNR. However, it increases the sensitivity of the technique to bulk rotational motion, which introduces a phase gradient across the tissue that shifts the echo in k-space. If the echo is displaced into the high spatial frequencies, conventional homodyne reconstruction fails, causing intensity oscillations across the image. Zero-padding, on the other hand, compromises the image resolution and may cause truncation artifacts. We present an adaptive version of the homodyne algorithm that detects the location of the echo in k-space and adjusts the center and width of the homodyne filters accordingly. The adaptive algorithm produces artifact-free images when the echo is shifted into the high positive k-space range, and reduces to the standard homodyne algorithm in the absence of bulk motion.