电刺激多巴胺能神经纤维或末梢对纹状体多巴胺释放的影响

采用快速周期伏安法,以碳纤维微电极在体研究了电刺激黑质－纹状体多巴胺（ＤＡ）能神经通路前脑内侧束（ＭＦＢ）或刺激纹状体内的神经纤维末梢对纹状体ＤＡ释放量的影响。结果如下：电刺激ＭＦＢ与刺激纹状体诱发纹状体的ＤＡ释放量明显不同。二者的ＤＡ释放量取决于所用的刺激强度、脉冲和频率;当给予２．０ｍＡ,２００次脉冲,１２５Ｈｚ电刺激ＤＡ能神经纤维ＭＦＢ时,可诱发纹状体（２１．５６±５．７７）μｍｏｌ／Ｌ的最大ＤＡ释放量,而在ｎｏｍｉｆｅｎｓｉｎｅ存在的前提下,给予０．１０ｍＡ,３０次脉冲,２０Ｈｚ电刺激纹状体ＤＡ能神经末梢时,仅诱发（９．０２±２．７２）μｍｏｌ／Ｌ的最大ＤＡ释放量。以上结果表明,尽管刺激强度、脉冲、频率均构成影响ＤＡ释放的相关因素,但刺激ＤＡ能神经纤维和末梢诱发的ＤＡ释放量及所用刺激参数均不相同,提示在刺激不同部位的实验研究中,应重视适宜刺激参数的选择和应用,以便获得更好的实验结果。     

THE EFFECT OF REPETITIVE ELECTRICAL STIMULATION ON THE MOTOR EVOKED HEMODYNAMIC RESPONSES

The aim of this study was to investigate the influence of short-term repetitive electrical stimulation (rES training session) on the motor-evoked hemodynamic responses. The fMRI echo-planar images (EPI) were recorded before and after the rES training. The right median nerve (MN) was stimulated during rES. The rES training resulted in a significant increase in activity in a number of supraspinal regions, including sensorimotor and associative cortical areas. On the subcortical level, the effect was also found in the cerebellum, the midbrain, and the thalamus. Possible mechanisms of the neuronal plastic changes observed after rES, and memory processes involved in learning are discussed.     

EFFICACY AND ACCEPTABILITY OF HIGH FREQUENCY REPETITIVE TRANSCRANIAL MAGNETIC STIMULATION (rTMS) VERSUS ELECTROCONVULSIVE THERAPY (ECT) FOR MAJOR DEPRESSION: A SYSTEMATIC REVIEW AND META‐ANALYSIS OF RANDOMIZED TRIALS

Clinical trials comparing the efficacy and acceptability of high frequency repetitive transcranial magnetic stimulation (HF‐rTMS) and electroconvulsive therapy (ECT) for treating major depression (MD) have yielded conflicting results. As this may have been the result of limited statistical power, we have carried out this meta‐analysis to examine this issue. We searched the literature for randomized trials on head‐to‐head comparisons between HF‐rTMS and ECT from January 1995 through September 2012 using MEDLINE, EMBASE, PsycINFO, Cochrane Central Register of Controlled Trials, and SCOPUS. The main outcome measures were remission rates, pre‐post changes in depression ratings, as well as overall dropout rates at study end. We used a random‐effects model, Odds Ratios (OR), Number Needed to Treat (NNT), and Hedges’ g effect sizes. Data were obtained from 7 randomized trials, totalling 294 subjects with MD. After an average of 15.2 HF‐rTMS and 8.2 ECT sessions, 33.6% (38/113) and 52% (53/102) of subjects were classified as remitters (OR = 0.46; p = 0.04), respectively. The associated NNT for remission was 6 and favoured ECT. Also, reduction of depressive symptomatology was significantly more pronounced in the ECT group (Hedges’ g = ?0.93; p = 0.007). No differences on dropout rates for HF‐rTMS and ECT groups were found. In conclusion, ECT seems to be more effective than HF‐rTMS for treating MD, although they did not differ in terms of dropout rates. Nevertheless, future comparative trials with larger sample sizes and better matching at baseline, longer follow‐ups and more intense stimulation protocols are warranted.     

REPETITIVE BEHAVIORS IN CHRONIC SCHIZOPHRENIA: USING THE JAPANESE VERSION OF THE ELGIN BEHAVIOR RATING SCALE (JEBRS)

The main aim of this study was to test the reliability and value of the Japanese Elgin Behavior Rating Scale (JEBRS) with 92 schizophrenia patients. Cronbach's a for the JEBRS was 0.61. All inter-rater reliability coefficients were in the satisfactory range. The JEBRS had a high stability over time. Almost all of the correlations among the nine item scores and total score in the JEBRS were significant. The total score for nine repetitive behaviors in the JEBRS was positively correlated with positive and negative symptoms. This study showed that the JEBRS is a useful and reliable scale.     

ENLARGEMENT OF THE RECEPTIVE FIELD SIZE TO LOW INTENSITY MECHANICAL STIMULATION IN THE RAT SPINAL NERVE LIGATION MODEL OF NEUROPATHY

Twenty-three patients with advanced and heavily pretreated myeloma were treated with thalidomide. Starting dose was 200 mg/d, and 20 patients had dose escalations up to 400 (n = 5), 600 (n = 12) or 800 mg/d (n = 3), usually in divided doses. Nineteen patients were refractory to recent chemotherapy, and four had untreated relapse after prior intensive therapy. Ten out of 23 patients (43%) achieved partial response (PR; nine with refractory and one with relapsed disease), six patients had minor response or stabilization of the disease and four had disease progression. Another three patients died early from advanced myeloma at less than 3 weeks of thalidomide therapy. Of the 10 patients with PR, seven had a better response than after any prior therapy, despite vincristine-doxorubicin-dexamethasone (VAD)-based treatment in all but one and high-dose melphalan with autologous stem cell support in four. Time to achieve PR was rapid in patients receiving thalidomide in divided doses (median 31 d). Responses also included reduced bone marrow plasma cell infiltration and improved general status. Normalized polyclonal gammaglobulin levels were seen in four cases. Six out of 10 patients with PR remained in remission with a median time on treatment of 23 weeks (range 15–50 weeks). Sedation was common but usually tolerable, and some patients continued full- or part-time work. Four patients had skin problems, three patients had pneumonia, one hypothyrosis, one sinus bradycardia and one minor sensory neuropathy. Thalidomide may induce good partial remissions in advanced refractory myeloma with tolerable toxicity, and should be evaluated in other settings for myeloma patients. Divided thalidomide doses seem to reduce time to achieve remission and may improve response rate.     

AN ANALYSIS OF EVOKED ELECTROMYOGRAM FROM ORBICULARIS OCULI IN PATIENTS WITH MYASTHENIA GRAVIS

Evoked electromyograms of the orbicularis oculi muscle with repeated stimulation given at frequencies of 5, 10, 20, 50 and 100 c/s were examined in myasthenia gravis; and the following results were obtained. 1. In the normal subject, the amplitude of M-waves showed almost no change by stimulation at frequencies of 5 and 10 c/s, and a mild gradual increase by stimulation at a frequency of 20 c/s. On stimulation with 50 and 100 c/s, the amplitude of M-waves showed a marked gradual increase and maintained nearly the peak value after a maximum had been reached. 2. In a total of 23 patients with myasthenia gravis, the amplitude of M-waves showed several specific changes against the stimulation frequencies employed. The patterns of the amplitude of M-waves appearing with each frequency were classified into 3 types: Type I, which showed an initial gradual decrease in amplitude with all the stimulation frequencies employed, was observed in 13 patients (56.5%). Type II, which showed an initial gradual decrease at frequencies of 5 c/s and 10 c/s, but a gradual increase followed by gradual decrease at frequencies of 50 and 100 c/s, was observed in 8 patients (34.8%). Type III, which showed no obvious difference from the pattern of the normal curve with stimulation given at not more than 50 c/s but a gradual increase followed by gradual decrease at a frequency of 100c/s, was observed in 2 patients (8.7%). 3. No distinct differences were noted in other neuromuscular diseases taken as control, as compared with the normal.     

OSMOTIC OPENING OF PERINEURIAL DIFFUSION BARRIER IN PERIPHERAL NERVE

The effects of hyperosmolar solutions (sodium chloride and urea) on the perineurial diffusion barrier were tested in experiments using adult mouse sciatic nerves. The solutions were either injected around the nerves in living mice or applied to nerves from killed animals. Thereafter horseradish peroxidase (HRP) was injected around the nerves in order to detect any changes in permeability. HRP was visualized in frozen sections by an enzyme histochemical technique. Hypertonic solutions both in vivo and in vitro caused a pronounced increased permeability of the perineurial diffusion barrier, which persisted for at least one month after injection of 20% NaCl in living mice. In other experiments a hypertonic solution (20% NaCl) was injected one day prior to intradermal inoculation of herpes simplex virus into one hind limb. This treatment dramatically increased the susceptibility of the mice to the infection. This virus has the capacity to spread along nerves to the central nervous system from the site of injection, and is probably taken up at the periphery and then transported centrally inside axons to the cell bodies. The hypothesis is put forward that an important factor for this increased susceptibility is that virions may have an easier access to available surfaces of the nerve fibres due to osmotic opening of the perineurium.