Amiodarone-induced experimental acute neuropathy in rats.

Amiodarone was injected endoneurially at increasing doses into the exposed tibial nerve of rats to study its electrophysiologic and pathologic effects on peripheral nerve fibers. Forty-five male Wistar rats were used, and each of the following concentrations was injected into 15 nerves: 25 micrograms/mL, 50 micrograms/mL, and 100 micrograms/mL. Microinjection of a 25 micrograms/mL concentration of amiodarone resulted in a subacute, incomplete conduction block evident at day 3 postinjection. This conduction block remained stable until day 10 and recovery was complete at day 35. Microinjection of a 50 micrograms/mL concentration of amiodarone produced a faster evolving conduction block, and significant axon degeneration (approximately 40% of fibers). Injection of a 100 micrograms/mL concentration resulted in severe acute motor axon degeneration followed by complete but delayed regeneration. Results of morphological studies closely correlated with electrophysiological findings. Amiodarone thus seems to have a direct toxic effect on axons at high concentrations in the peripheral nerve, and we suggest that different pathological changes described in human amiodarone neuropathy could be related to different concentrations of the drug in the nerve, perhaps due to variability of blood-nerve barrier efficacy.     

A computer and video display based system for training eccentric viewing in macular degeneration with an absolute central scotoma

A new approach designed to establish the most suitable area for eccentric viewing and to teach and train patients with severe age-related macular degeneration (AMD) to use the eccentric viewing technique is described. Using a computer and video display based system, as well as software written specifically for this purpose, we investigated and trained ten consecutive patients with AMD. The patients were 80.1 ± 5.6 years old, on average. All of them had an absolute central scotoma. Mean visual acuity was 0.035 ± 0.016. After 30 min of testing, instruction and reading on the screen, followed by 2.6 ± 0.69 one-hour training sessions, on average, with the low vision therapist, reading newspaper and book texts with the aid of hyperoculars or aplanatic systems and a very short reading distance, the patients achieved a reading speed of 58.9 ± 19.7 words/min, significantly (p<0.001) higher than the initial speed when reading on the screen, 11.5 ± 4.5 words/min.     

Added value of OCT in evaluating the presence of leakage in patients with age-related macular degeneration treated with PDT

Background Evaluating the presence of leakage on fluorescein angiography (FA) in patients with age-related macular degeneration (AMD) retreated with photodynamic therapy (PDT) can be difficult. New diagnostic tools such as optical coherence tomography (OCT) might help to optimize PDT management.Methods Thirty AMD patients scheduled for regular follow-up FA in conjunction with PDT treatment were also scanned with OCT. Follow-up data at 9 months were retrieved from the patients’ medical records. Inter-observer agreement [kappa (κ) coefficient] for the presence of leakage on FA, for OCT parameters for leakage, and agreement between FA and OCT evaluations were calculated. The indication for retreatment was evaluated using the leakage analysis based on FA alone, OCT alone, and both examinations combined, and compared to the actual follow-up of the patients at 9 months.Results Agreement between the two observers for the presence of leakage on FA was moderate (κ=0.51). OCT agreement between the two observers for the presence of leakage was good (κ=0.85). Agreement between FA and OCT for the presence of leakage was poor (κ=0.16). Follow-up data at 9 months on all patients were analyzed. Seven out of 30 patients were not retreated at the time of examination, and four of these patients (57%) remained stable without further treatment. Twenty-three patients did receive a PDT treatment at the time of examination; and eight of these patients did not show leakage on OCT, and five of these patients (62%) remained stable without additional treatment. In contrast, only three out of 15 patients (20%) with leakage on both FA and OCT remained stable during this 9 month follow-up period.Conclusions Inter-observer agreement for the presence of leakage was moderate for FA and good for OCT. There was considerable disagreement between leakage as judged by OCT and by FA. OCT could be of help in the decision regarding PDT retreatment. Assuming that 57% of the patients without leakage either on FA or OCT would remain stable without retreatment, the rate of probable ineffective retreatment could be reduced from 35% to 20%.There was no financial support for this study. The authors have full access to the data and will allow Graefe’s Archive for Clinical and Experimental Ophthalmology to review the data if requeste.d     

Intravitreal injection of 0.3 ml of SF6 gas for persistent subfoveal fluid after scleral buckling for rhegmatogenous retinal detachment

Purpose  To determine the efficacy of intravitreal injection of sulphur hexafluoride (SF6) gas for reducing persistent subfoveal fluid after scleral buckling surgery for macula-off rhegmatogenous retinal detachments. Methods  We injected 0.3 ml of SF6 gas into the vitreous cavity of two eyes of two patients with persistent macular retinal detachment 3 and 5 months after successful scleral buckling. Optical coherence tomography was performed before and after surgery. Results  Subfoveal fluid was displaced peripheral to the fovea immediately after gas injection and the fluid was absorbed gradually in both eyes. Conclusions  Persistent subfoveal fluid after scleral buckling may be treated with intravitreal SF6 gas injection. The authors have no proprietary interest in any aspect of this report     

Holmes-like tremor of the lower extremity following brainstem hemorrhage.

Holmes tremor is an arrhythmic, 2- to 5-Hz resting, postural, and kinetic upper extremity movement disorder that occurs weeks to months after acute mesencephalic pathology. We present a patient who developed tremor in three body parts postbrainstem hemorrhage with subsequent hypertrophic olivary degeneration and discuss the relevant clinical evolution. Our case is unique because in addition to expected upper extremity and cervical dystonic head tremors, the patient also developed a severe lower extremity movement disorder, which we believe to be a form of Holmes tremor. Tremor involving the lower extremity in this setting has not been previously reported.     

微囊化猪视网膜色素上皮细胞移植治疗帕金森病的实验研究(英文)

目的研究微囊化后的猪视网膜色素上皮细胞(retinal pigment epithelial,RPE)对帕金森病大鼠模型的移植疗效。方法原代培养RPE 并传代,高效液相色谱法测定培养液上清中多巴胺(dopamine, DA)和高香草酸(homovanillic acid, HVA)的含量,ELISA法检测脑源性神经营养因子(brain-derived neurotrophic factor, BDNF)和胶质细胞源性神经营养因子(glial-derived neurotrophic factor, GDNF)的含量。用高压静电成囊装置制备海藻酸钠-多聚赖氨酸-海藻酸钠微囊化细胞。6-羟基多巴胺(6-hydroxydopamine, 6-OHDA)毁损内侧前脑束 (medial fore-brain bundle,MFB)建立 SD 大鼠帕金森病模型。立体定向移植 RPE+ 微囊,检验旋转实验、免疫组化和脑内生化的变化。结果 RPE 培养上清液中DA、HVA、BDNF、GDNF 的含量稳定,微囊化后细胞长期存活,活性没有明显变化。6-OHDA毁损MFB建立大鼠帕金森病模型的成模率为83%。移植微囊化的RPE后有效率为33%。结论猪 RPE 体外培养生长旺盛,持续分泌 DA、BDNF 和 GNDF,微囊化不影响其分泌功能。RPE 移植对帕金森病大鼠有一定的治疗作用。     

Sub‐retinal neovascular membrane in exudative macular degeneration

Age‐related macular degeneration is a major cause of serious vision loss. The earliest stages of age‐related maculopathy may be defined by the size of the drusen present in the macula and the effects on vision. Further manifestations may include soft drusen, choroidal neovascularisation, macular haemorrhage and cicatricial or disciform degeneration of the macula. This report describes a patient with a macular haemorrhage, a choroidal neovascular membrane and serious loss of vision. In addition, the pathogenesis, diagnosis and treat‐ment options of macular degeneration are reviewed.     

MR Findings of Intrathecal Chemotherapy-Related Myelopathy in Two Cases: Mimicker of Subacute Combined Degeneration

We report the findings of spinal magnetic resonance imaging (MRI) in 2 patients who had undergone intrathecal chemotherapy and presented with the subacute onset of ascending numbness and weakness. MRI revealed a symmetric hyperintensity at the posterior columns of the spinal cord from the lower cervical region down to the conus medullaris level on T2-weighted images, and no abnormal enhancement. The imaging findings are similar to those seen in subacute combined degeneration (SCD), but the serum vitamin B(12) levels were normal in these 2 cases.     

THE CLINICAL AND NEURO-ELECTROPHYSIOLOGIC STUDY ON CORTICOBASAL DEGENERATION

目的：探讨皮质基底节变性(CBD)患者的临床和神经电生理特征。方法：对29例临床诊断为CBD患者，系统分析其临床症状、体征、常规化验检查、脑CT／MRI、SPECT以及神经电生理改变，并与其它疾病相对比。结果：结果显示，29例患者均出现不对称性帕金森样表现，皮层功能受损占79．3％，其它功能障碍占37．9％。21例患者脑CT或MRI显示不对称性脑萎缩，SPECT显示额顶区低灌注表现，以受损肢体的功能区较明显。EEG显示19例患者出现不对称性慢波，伴有肌阵挛的15例病人，表面肌电图显示患肢随意运动时可诱发巨大电位，皮层反应增强，SEP无特殊变化，运动诱发电位检查，26例患者中枢运动传导时间正常。结论：CBD是一种累及皮层和基底节、病程以缓慢进展为特征的变性性疾病。大部分患者可出现帕金森综合征样表现，皮层及其他运动功能障碍。脑影象学显示额顶叶萎缩。神经电生理检查表现为皮层兴奋性增强，而锥体束传导功能正常。