Right lower limb apraxia in a patient with left supplementary motor area infarction: intactness of the corticospinal tract confirmed by transcranial magnetic stimulation

We reported a 50-year-old female patient with left supplementary motor area infarction who presented right lower limb apraxia and investigated the possible causes using transcranial magnetic stimulation. The patient was able to walk and climb stairs spontaneously without any assistance at 3 weeks after onset. However, she was unable to intentionally move her right lower limb although she understood what she supposed to do. The motor evoked potential evoked by transcranial magnetic stimulation from the right lower limb was within the normal range, indicating that the corticospinal tract innervating the right lower limb was uninjured. Thus, we thought that her motor dysfunction was not induced by motor weakness, and confirmed her symptoms as apraxia. In addition, these results also suggest that transcranial magnetic stimulation is helpful for diagnosing apraxia.     

Chemoattractive capacity of different lengths of nerve fragments bridging regeneration chambers for the repair of sciatic nerve defects

A preliminary study by our research group showed that 6-mm-long regeneration chamber bridging is equivalent to autologous nerve transplantation for the repair of 12-mm nerve defects. In this study, we compared the efficacy of different lengths (6, 8, 10 mm) of nerve fragments bridging 6-mm regeneration chambers for the repair of 12-mm-long nerve defects. At 16 weeks after the regeneration chamber was implanted, the number, diameter and myelin sheath thickness of the regenerated nerve fibers, as well as the conduction velocity of the sciatic nerve and gastrocnemius muscle wet weight ratio, were similar to that observed with autologous nerve transplantation. Our results demonstrate that 6-, 8-and 10-mm-long nerve fragments bridging 6-mm regeneration chambers effec-tively repair 12-mm-long nerve defects. Because the chemoattractive capacity is not affected by the length of the nerve fragment, we suggest adopting 6-mm-long nerve fragments for the repair of peripheral nerve defects.     

Use of FK506 and bone marrow mesenchymal stem cells for rat hind limb allografts

Dark Agouti rat donor hind limbs were orthotopically transplanted into Lewis rat recipients to verify the effects of bone marrow mesenchymal stem cells on neural regeneration and functional recovery of allotransplanted limbs in the microenvironment of immunotolerance. bone marrow mesenchymal stem cells were intramuscularly (gluteus maximus) injected with FK506 (tacrolimus) daily, and were transplanted to the injured nerves. Results indicated that the allograft group not receiving therapy showed severe rejection, with transplanted limbs detaching at 10 days after transplantation with complete necrosis. The number of myelinated axons and Schwann cells in the FK506 and FK506 + bone marrow mesenchymal stem cells groups were significantly increased. We observed a lesser degree of gastrocnemius muscle degeneration, and increased polymorphic fibers along with other pathological changes in the FK506 + bone marrow mesenchymal stem cells group. The FK506 + bone marrow mesenchymal stem cells group showed significantly better recovery than the autograft and FK506 groups. The results demonstrated that FK506 improved the immune microenvironment. FK506 combined with bone marrow mesenchymal stem cells significantly promoted sciatic nerve regeneration, and improved sensory recovery and motor function in hind limb allotransplant.     

Cutaneous postural vasoconstriction is modified by exogenous but not endogenous female hormones in young women

Previously reported attenuation of skin postural vasoconstriction in women during the luteal menstrual cycle phase may be due to a progesterone-mediated decrease in myogenic or veno-arteriolar (VAR) mechanisms. Skin perfusion was measured in the shin and foot dorsum by Laser Doppler Fluxometry during leg dependency that increased vascular transmural pressure below (myogenic constriction only) and above (myogenic and VAR) the 25 mmHg threshold for activation of the VAR, and during venous distension to activate the VAR alone (cuff inflation to 50 mmHg). In six young women with normal menstrual cycles, vasoconstrictor responses to all interventions did not differ between days 7–13 (follicular) and 18–23 (luteal) of the normal menstrual cycle when progesterone levels were low and at their peak respectively. In eight women taking combined oral contraceptives (OC) and tested during pill consumption days, reductions in foot skin perfusion were smaller (P = 0.05) than in the luteal phase of the normal cycle for leg dependency below (−36.9 ± 5.2% OC vs. −52.5 ± 7.8% luteal, mean ± S.E.M.) and above (−43.7 ± 3.4% OC vs. −55.1 ± 4.8% luteal) the VAR threshold, and for venous distension (−53.1 ± 2.6% OC vs. 66.4 ± 5.5% luteal). In women with normal menstrual cycles, impaired postural vasoconstriction may be confined to those who experience pre-menstrual symptoms rather than a direct effect of endogenous hormones. Reduced vasoconstriction in the dependent foot during OC use is consistent with the known vasodilator action of exogenous hormones and its long-term effects     

肢体缺血后处理改善脑梗死预后和认知障碍

目的 观察肢体缺血后处理（RIPostC）对急性脑梗死神经功能的治疗作用及其对认知障碍的影响,且探讨适宜的疗程。方法 收录发病72 h以内、未溶栓的急性前循环梗死患者,随机分为4组,即RIPostC 10 d组、RIPostC 14 d组和对照10 d组、对照14 d组,并分别进行4个循环的充气和放气。比较美国国立卫生研究院卒中量表（NIHSS）评分、脑梗死体积（入院时、10 d时、14 d时和90 d时）,改良Rankin量表（mRS）评分（入院时、90 d时良好转归率）,简易智能精神状态检查量表（MMSE）和蒙特利尔认知评估量表（MoCA）（14 d时、90 d时认知障碍率）。结果 纳入89例符合标准的急性脑梗死患者（44例RIPostC组,45例对照组）,在RIPostC 10 d组中仅有1例不能耐受而放弃治疗,对照组完全耐受。在对照组中,3名患者复发脑梗死（分别为30 d时、65 d时和78 d时）,而在RIPostC各亚组中均没有发生任何相关的心脑血管事件。在90 d时,与对照10 d组和对照14 d组相比,RIPostC 10 d组和RIPostC 14 d组的NIHSS评分均显著性降低（P<0.05）;梗死体积分别减少33.7%和37.2%,差异有统计学意义（P<0.05）;mRS的良好转归率明显增高（P<0.05）;MoCA、MMSE认知障碍率显著性降低（P<0.05）。与RIPostC 10 d组相比,RIPostC 14 d组中NIHSS评分、mRS的良好转归率无明显变化,差异无统计学意义（P>0.05）。结论 急性脑梗死后进行RIPostC具有很好的耐受性、安全性及可行性,能减少脑梗死体积,减少残疾,改善预后。同时,也能够改善脑梗死后认知功能障碍。但RIPostC 10 d和14 d对脑梗死神经功能的治疗作用及其对认知障碍的影响无显著差别,所以,RIPostC治疗10 d是较为合适的治疗疗程。     

血管紧张素转换酶基因多态性与白族脑血管病患者的相关性研究

目的研究血管紧张素转换酶(ACE)基因插入/缺失多态性与云南大理白族脑血管病患者的相关性。方法应用聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)技术,对73例白族脑血管病(ICVD)组患者(其中脑梗死40例,脑出血33例)和43例性别年龄相匹配的白族健康对照组进行ACE基因型检测和基因插入/缺失多态性分析;并进行ACE基因双向测序。结果(1)脑梗死组的DD基因型频率和D等位基因频率明显高于对照组(P<0.05);(2)脑出血组与对照组相比较,未发现DD基因型频率和D等位基因频率有明显差异(P>0.05);(3)脑血管组内伴高血压与不伴高血压,伴糖尿病与不伴糖尿病,伴血脂异常与血脂正常者相比较,未发现DD基因型频率和D等位基因频率有显著差异(P>0.05);(4)D等位基因和I等位基因其核苷酸序列和长度与国内外文献报道无明显差别。结论(1)ACE基因插入/缺失多态性与脑梗死的发生有关联性,DD基因型和D等位基因是脑梗死患者的高危因素;(2)ACE基因插入/缺失多态性与脑出血发生未发现有关联性;(3)脑血管病的其他相关危险因素如高血压,糖尿病,血脂与ACE基因多态性可能无关联;(4)ACE基因16内含子...     

Descending brain neurons in larval lamprey: Spinal projection patterns and initiation of locomotion

In larval lamprey, partial lesions were made in the rostral spinal cord to determine which spinal tracts are important for descending activation of locomotion and to identify descending brain neurons that project in these tracts. In whole animals and in vitro brain/spinal cord preparations, brain-initiated spinal locomotor activity was present when the lateral or intermediate spinal tracts were spared but usually was abolished when the medial tracts were spared. We previously showed that descending brain neurons are located in eleven cell groups, including reticulospinal (RS) neurons in the mesenecephalic reticular nucleus (MRN) as well as the anterior (ARRN), middle (MRRN), and posterior (PRRN) rhombencephalic reticular nuclei. Other descending brain neurons are located in the diencephalic (Di) as well as the anterolateral (ALV), dorsolateral (DLV), and posterolateral (PLV) vagal groups. In the present study, the Mauthner and auxillary Mauthner cells, most neurons in the Di, ALV, DLV, and PLV cell groups, and some neurons in the ARRN and PRRN had crossed descending axons. The majority of neurons projecting in medial spinal tracts included large identified Müller cells and neurons in the Di, MRN, ALV, and DLV. Axons of individual descending brain neurons usually did not switch spinal tracts, have branches in multiple tracts, or cross the midline within the rostral cord. Most neurons that projected in the lateral/intermediate spinal tracts were in the ARRN, MRRN, and PRRN. Thus, output neurons of the locomotor command system are distributed in several reticular nuclei, whose neurons project in relatively wide areas of the cord.     

Comparison of orally dissolving carbidopa/levodopa (Parcopa) to conventional oral carbidopa/levodopa: A single‐dose,double‐blind,double‐dummy,placebo‐controlled,crossover trial

Levodopa use in fluctuating Parkinson's disease (PD) is complicated by an inconsistent and prolonged onset to clinical improvement. An orally dissolved carbidopa/levodopa (OD C/L) preparation (Parcopa UCB Pharma) is available in the United States. This offers potential advantages to shorten the duration from ingestion to clinical improvement. Surprisingly, this has never been clinically assessed. We tested 20 patients with fluctuating PD and a Unified Parkinson's Disease Rating Scale (UPDRS) “off” motor score of ≥25 in a 2‐day, single‐dose, double‐blind, double‐dummy, crossover study. Patients arrived in the morning in the practically defined “off” state and were randomly assigned to receive identical doses of either oral C/L and OD placebo or OD C/L and oral C/L placebo on 1st day and the reverse combination on a 2nd day. After training, patients underwent bilateral hand tapping at baseline and every 5 minutes for 60 minutes after dose ingestion. Stride length (SL) was recorded at 5‐minute intervals with an ambulatory gait monitor. Patients identified their subjective latency to “on” and noted drug preferences and adverse events. They also underwent a UPDRS motor examination at baseline and 60 minutes after dose. Twenty subjects [15 male, age 68.7 (9.7), PD duration 13.4 (6.8)] completed. There were no significant group differences in tapping speed, subjective time to “on,” latency of increased SL, or overall preference. However, all trends did favor OD C/L. Adverse events were similar. This small pilot study did not show significant group differences favoring OD C/L; however, larger studies may be justified, and individual patients may benefit. © 2010 Movement Disorder Society     

The zebrafish cerebellar upper rhombic lip generates tegmental hindbrain nuclei by long‐distance migration in an evolutionary conserved manner

The upper rhombic lip (URL) of the developing mammalian cerebellum produces different neuronal cell types in a temporal sequence. The first neuronal populations arising from this proliferation zone include the progenitors of the parabrachial, parabigeminal, and laterodorsal‐pedunculopontine tegmental hindbrain nuclei. By means of expression analysis, histology, and retrograde neuronal tracing, we have identified the zebrafish homologues of these nuclei, namely, the secondary gustatory/viscerosensory nucleus, the nucleus isthmi, and the superior reticular nucleus, respectively, in the embryonic and larval brain of a stable transgenic wnt1:Gal4‐VP16‐14 × UAS:GFP zebrafish strain. Combining time‐lapse confocal imaging with individual cell tracing, we characterize the migratory behavior of these neuronal precursor populations in detail by revealing their migration path, velocity, and directionality. In addition, we identify neuronal progenitors of the secondary gustatory/viscerosensory nucleus and nucleus isthmi/superior reticular nucleus as belonging to the polysialic acid (PSA)‐expressing cell population in the cerebellar plate that migrates in a PSA‐dependent manner. Finally, we reveal that circuitries involved in the processing of sensory information (visual, gustatory, general viscerosensory) are already established in the zebrafish larva at day 4 of development. Also the wnt1‐expressing pretectal neuronal precursors (not originating from the URL) sending mossy fiber‐like projections into the cerebellar corpus are established at that time. In sum, our results show that the origin of neurons of some tegmental hindbrain nuclei, namely, nucleus isthmi/superior reticular nucleus and secondary gustatory/viscerosensory nucleus is in the URL, and that the temporal order of cell types produced by the URL and their developmental program are conserved among vertebrate species. J. Comp. Neurol. 518:2794–2817, 2010. © 2010 Wiley‐Liss, Inc.