Prominent fatigue in spinal muscular atrophy and spinal and bulbar muscular atrophy: Evidence of activity-dependent conduction block

ObjectivesTo clarify whether patients with spinal muscular atrophy (SMA) or spinal and bulbar muscular atrophy (SBMA) suffer disabling muscle fatigue, and whether activity-dependent conduction block (ADCB) contributes to their fatigue. ADCB is usually caused by reduced safety factor for impulse transmission in demyelinating diseases, whereas markedly increased axonal branching associated with collateral sprouting may reduce the safety factor in chronic lower motor neuron disorders.MethodsWe assessed the fatigue severity scale (FSS) in 22 patients with SMA/SBMA, and in 100 disease controls (multiple sclerosis, myasthenia gravis, chronic inflammatory demyelinating polyneuropathy (CIDP), and axonal neuropathy). We then performed stimulated-single fibre electromyography (s-SFEMG) in the extensor digitorum communis (EDC) muscle of 21 SMA/SBMA patients, 6 CIDP patients, and 10 normal subjects.ResultsThe FSS score was the highest in SMA/SBMA patients [4.9 ± 1.1 (mean ± SD)], with 81% of them complaining of disabling fatigue, compared with normal controls (3.5 ± 1.0), whereas patients with multiple sclerosis (4.3 ± 1.6), myasthenia gravis (4.0 ± 1.6) or CIDP (4.3 ± 1.4) also showed higher FSS score. When 2000 stimuli were delivered at 20 Hz in s-SFEMG, conduction block of single motor axons developed in 46% of patients with SMA/SBMA, and 40% of CIDP patients, but in none of the normal controls.ConclusionSMA/SBMA patients frequently suffer from disabling fatigue presumably caused by ADCB induced by voluntary activity.SignificanceADCB could be the mechanism for muscle fatigue in chronic lower motor neuron diseases.     

周围神经减压术治疗枕大神经痛疗效观察

目的探讨周围神经减压术治疗枕大神经痛的临床疗效。方法共选择临床诊断明确的枕大神经痛患者62例,于局部麻醉下施行枕大神经减压术,术后随访6~12个月。结果治愈54例、有效5例、无效2例、失访1例。结论周围神经减压术是治疗枕大神经痛安全、有效的方法。     

血清尿酸水平与脑动脉狭窄的相关性研究

【摘要】
目的 探讨血清尿酸与脑动脉狭窄之间的关系。
方法 连续入组2011年10月至2012年5月因缺血性脑血管病住院并行脑血管造影的患者509例,依据血管造影脑动脉狭窄部位及狭窄程度（≥50%）分为四组：颅内动脉狭窄组（198例）、颅外动脉狭窄组（107例）、脑动脉狭窄组（55例）及无脑动脉狭窄的对照组（149例）。分析患者临床资料及血尿酸水平与颅内动脉狭窄之间是否存在相关性。
结果 颅内动脉狭窄组血尿酸水平显著高于对照组（P＜0.001）,血尿酸异常患者的比例也显著高于对照组（χ2=7.388,P=0.007）;将所有患者按血尿酸水平4分位分组,随着血尿酸水平的升高,颅内动脉狭窄的发生率逐渐增加（χ2=9.230,P=0.026）。Logistic回归分析显示,血尿酸水平升高是颅内动脉狭窄的独立危险因素之一［比值比（odds ratio,OR）1.005,P=0.001］。同样方法分析颅外动脉狭窄组与尿酸的关系未得到显著性结果。
结论 血尿酸水平升高与颅内动脉狭窄密切相关。     

The Effectiveness of Early Tracheostomy (within at least 10 Days) in Cervical Spinal Cord Injury Patients

Objective

This study aimed to determine the optimal time for tracheostomy by evaluating the benefits and safety of early versus late tracheostomy in spinal cord injury (SCI) patients.

Methods

We retrospectively reviewed a total of 254 patients with spinal cord injury. Of them, we selected 21 spinal cord injury patients who required tracheostomy due to long-term mechanical ventilation and analyzed their medical records. The patients were categorized into two groups. Early tracheostomy was performed day 1-10 from intubation in 10 patients and the late tracheostomy was performed after day 10 in 11 cases. We also evaluated the duration of mechanical ventilation, stay in the ICU and complications related to tracheostomy, the injury level of and clinical severity. All data was analyzed using SPSS 18.0/WIN.

Results

The early tracheostomy offered clear advantages for shortening the total ICU stay (20.8 day vs. 38.0 day, p=0.010). There was also statistically significant reduction in the total length of time on mechanical ventilation (5.2 day vs. 29.2 day, p=0.009). However, the reductions in the incidence of pneumonia (40% vs. 82%) and the length of ICU stay post to tracheostomy (6 day vs. 15 day) were found to be statistically not significant. There were also no statistically significant differences in the injury level and clinical severity between the groups.

Conclusion

We concluded that the early tracheostomy (at least 10 days) is beneficial for SCI patients who are likely to require prolonged mechanical ventilation.     

Epigenetic Regulation in the Brain after Spinal Cord Injury : A Comparative Study

Objective

After spinal cord injury (SCI), functional and structural reorganization occurs at multiple levels of brain including motor cortex. However, the underlying mechanism still remains unclear. The current study was performed to investigate the alterations in the expression of the main regulators of neuronal development, survival and death, in the brain following thoracic contusive SCI in a mouse model.

Methods

Eight-week-old female imprinting control region mice (n=60; 30-35 g) were used in this study. We analyzed the expression levels of regulators such as brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), nerve growth factor (NGF) and histone deacetylase (HDAC) 1 in the brain following thoracic contusive SCI.

Results

The expression of BDNF levels were elevated significantly compared with control group at 2 weeks after injury (p<0.05). The expression of NGF levels were elevated at 2, 4 weeks compared with control group, but these difference were not significant (p>0.05). The GDNF levels were elevated at 2 week compared with control group, but these differences were not significant (p>0.05). The difference of HDAC1 levels were not significant at 2, 4 and 8 weeks compared with control group (p>0.05).

Conclusion

These results demonstrate that the upregulation of BDNF may play on important role in brain reorganization after SCI.     

Factors Associated with the Success of Trial Spinal Cord Stimulation in Patients with Chronic Pain from Failed Back Surgery Syndrome

Objective

Spinal cord stimulation (SCS) is an effective means of treatment of chronic neuropathic pain from failed back surgery syndrome (FBSS). Because the success of trial stimulation is an essential part of SCS, we investigated factors associated with success of trial stimulation.

Methods

Successful trial stimulation was possible in 26 of 44 patients (63.6%) who underwent insertion of electrodes for the treatment of chronic pain from FBSS. To investigate factors associated with successful trial stimulation, patients were classified into two groups (success and failure in trial). We investigated the following factors : age, sex, predominant pain areas (axial, limb, axial combined with limbs), number of operations, duration of preoperative pain, type of electrode (cylindrical/paddle), predominant type of pain (nociceptive, neuropathic, mixed), degree of sensory loss in painful areas, presence of motor weakness, and preoperative Visual Analogue Scale.

Results

There were no significant differences between the two groups in terms of age, degree of pain, number of operations, and duration of pain (p>0.05). Univariate analysis revealed that the type of electrode and presence of severe sensory deficits were significantly associated with the success of trial stimulation (p<0.05). However, the remaining variable, sex, type of pain, main location of pain, degree of pain duration, degree of sensory loss, and presence of motor weakness, were not associated with the trial success of SCS for FBSS.

Conclusion

Trial stimulation with paddle leads was more successful. If severe sensory deficits occur in the painful dermatomes in FBSS, trial stimulation were less effective.     

Effect of Pulsed Radiofrequency Neuromodulation on Clinical Improvements in the Patients of Chronic Intractable Shoulder Pain

Objective

The aim of this study was to evaluate effect of pulsed radiofrequency (PRF) neuromodulation of suprascpaular nerve (SSN) in patients with chronic shoulder pain due to adhesive capsulitis and/or rotator cuff tear.

Methods

The study included 11 patients suffering from chronic shoulder pain for at least 6 months who were diagnosed with adhesive capsulitis (n=4), rotator cuff tear (n=5), or adhesive capsulitis+rotator cuff tear (n=2) using shoulder magnetic resonance imaging or extremity ultrasonography. After a favorable response to a diagnostic suprascapular nerve block twice a week (pain improvement >50%), PRF neuromodulation was performed. Shoulder pain and quality of life were assessed using a Visual Analogue Scale (VAS) and the Oxford Shoulder Score (OSS) before the diagnostic block and every month after PRF neuromodulation over a 9-month period.

Results

The mean VAS score of 11 patients before PRF was 6.4±1.49, and the scores at 6-month and 9 month follow-up were 1.0±0.73 and 1.5±1.23, respectively. A significant pain reduction (p<0.001) was observed. The mean OSS score of 11 patients before PRF was 22.7±8.1, and the scores at 6-month and 9 month follow-up were 41.5±6.65 and 41.0±6.67, respectively. A significant OSS improvement (p<0.001) was observed.

Conclusion

PRF neuromodulation of the suprascapular nerve is an effective treatment for chronic shoulder pain, and the effect was sustained over a relatively long period in patients with medically intractable shoulder pain.