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ABSTRACT Transaxonal degenerations result from neuronal death or the interruption of synaptic connections among neuronal structures. These degenerations are not common but may be recognized by conventional magnetic resonance imaging. Objective: The learning objectives of this review include recognition of the imaging characteristics of transaxonal degenerations involving cerebellar connections, the identification of potential encephalic lesions that can lead to these degenerations and correlation of the clinical manifestations with imaging findings that reflect this involvement. Methods: In this report, we review the neuroanatomical knowledge that provides a basis for identifying potential lesions that can result in these degenerations involving cerebellar structures. Results: Hypertrophic olivary degeneration results from an injury that interrupts any of the components of the Guillain-Mollaret triangle. In this work, we describe cases of lesions in the dentate nucleus and central tegmental tract. The crossed cerebellar diaschisis presents specific imaging findings and clinical correlations associated with its acute and chronic phases. The Wallerian degeneration of the middle cerebellar peduncle is illustrated by fiber injury of the pontine cerebellar tracts. A T2-hyperintensity in the dentate nucleus due to a thalamic acute lesion (in ventral lateral nuclei) is also described. Each condition described here is documented by MRI images and is accompanied by teaching points and an anatomical review of the pathways involved. Conclusion: Neurologists and radiologists need to become familiar with the diagnosis of these conditions since their presentations are peculiar and often subtle, and can easily be misdiagnosed as ischemic events, degenerative disease, demyelinating disease or even tumors.
RESUMO Degenerações transaxonais resultam da morte neuronal ou da interrupção de conexões sinápticas entre estruturas neurais. Essas degenerações não são comuns, mas podem ser reconhecidas por imagens de ressonância magnética convencional. Objetivo: Os objetivos de aprendizado desta revisão incluem o reconhecimento das características de imagem de degenerações transaxonais envolvendo conexões cerebelares, a identificação de possíveis lesões encefálicas que podem levar a essas degenerações e a correlação das manifestações clínicas com os achados de imagem que refletem esse envolvimento. Métodos: Neste artigo, revisamos conhecimentos neuroanatômicos que fornecem a base para identificar possíveis lesões que podem resultar nessas degenerações envolvendo estruturas cerebelares. Resultados: A degeneração olivar hipertrófica resulta de uma lesão que interrompe algum dos componentes do triângulo de Guillain-Mollaret. Neste trabalho, descrevemos casos de lesões no núcleo denteado e no trato tegmentar central. A diásquise cerebelar cruzada apresenta achados de imagem específicos e correlações clínicas associadas às suas fases aguda e crônica. A degeneração walleriana dos pedúnculos cerebelares médios é ilustrada pela lesão dos tratos pontino-cerebelares. Uma hiperintensidade em T2 do núcleo denteado devido a uma lesão talâmica aguda (no núcleo ventrolateral) também é descrita. Cada condição aqui descrita é documentada por imagens de ressonância magnética e é acompanhada por pontos didáticos e uma revisão anatômica das vias envolvidas. Conclusão: Neurologistas e radiologistas precisam estar familiarizados com o diagnóstico dessas condições, uma vez que suas apresentações são peculiares e frequentemente sutis, e podem ser facilmente equivocadamente diagnosticadas como lesões isquêmicas, doenças degenerativas, desmielinizantes, ou mesmo tumorais.
Subject(s)
Olivary Nucleus , Cerebellum , Brain , Pons/physiology , Magnetic Resonance ImagingABSTRACT
Objective@#To discuss the neuroimaging characteristics of transcranial ultrasound in end-stage renal disease (ESRD) with restless legs syndrome.@*Methods@#Transcranial sonography (TCS) was performed in ESRD with restless legs syndrome (RLS+ group, n=41), ESRD without restless legs syndrome (RLS- group, n=57) and control group (n=47), who were enrolled in the Second Affiliated Hospital of Soochow University from January 2017 to December 2018. The differences of the neuroimaging characteristics of TCS in substantia nigra (SN), brainstem raphe (BR) and red nucleus(RN) among the three groups were analyzed.@*Results@#The rate of SN hypoechogenicity was significantly higher in RLS+ group (36.6%, 15/41) than that in RLS- group (19.3%, 11/57) and control group(8.5%, 4/47) (χ2=10.6, P<0.05). The rate of abnormal BR echogenicity was significantly higher in RLS+ group (34.1%, 14/41) and RLS- group (29.8%, 17/57) than that in control group(10.6%, 5/47) (χ2=7.7, P<0.05). The rate of RN hyperechogenicity was significantly higher in RLS+ group (51.2%, 21/41) than that in RLS- group (21.1%, 12/57) and control group (10.6%, 5/47) (χ2=19.8, P<0.05). Between RLS+ and RLS- groups, when SN, BR and RN were all of positive performance, the accuracy of diagnosing RLS+ reached 70% (7/10).@*Conclusions@#The echogenicity changes of SN, BR and RN on TCS could provide valuable neuroimaging information for the clinical diagnosis and treatment of ESRD with restless legs syndrome.
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Objective To discuss the neuroimaging characteristics of transcranial ultrasound in end‐stage renal disease ( ESRD ) with restless legs syndrome . Methods T ranscranial sonography ( TCS ) was performed in ESRD with restless legs syndrome ( RLS + group , n ＝ 41 ) ,ESRD without restless legs syndrome ( RLS － group , n ＝57) and control group ( n ＝47) ,w ho were enrolled in the Second Affiliated Hospital of Soochow University from January 2017 to December 2018 . T he differences of the neuroimaging characteristics of TCS in substantia nigra ( SN ) ,brainstem raphe ( BR) and red nucleus ( RN ) among the three groups were analyzed . Results T he rate of SN hypoechogenicity was significantly higher in RLS +group ( 36 .6% ,15/41) than that in RLS － group ( 19 .3% ,11/57) and control group( 8 .5% ,4/47) ( χ2 ＝10 .6 ,P＜0 .05) . T he rate of abnormal BR echogenicity was significantly higher in RLS + group ( 34 .1% , 14/41) and RLS － group ( 29 .8% ,17/57) than that in control group( 10 .6% ,5/47) ( χ2 ＝7 .7 , P ＜0 .05) . T he rate of RN hyperechogenicity was significantly higher in RLS + group ( 51 .2% ,21/41 ) than that in RLS － group ( 21 .1% ,12/57) and control group ( 10 .6% ,5/47) ( χ2 ＝19 .8 , P ＜0 .05 ) . Between RLS+and RLS － groups ,when SN ,BR and RN were all of positive performance ,the accuracy of diagnosing RLS+ reached 70% ( 7/10 ) . Conclusions The echogenicity changes of SN ,BR and RN on TCS could provide valuable neuroimaging information for the clinical diagnosis and treatment of ESRD with restless legs syndrome .
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BACKGROUND AND PURPOSE: Previous T2 relaxometry studies have provided evidence for regional brain iron deficiency in patients with restless legs syndrome (RLS). Measurement of the iron content in several brain regions, and in particular the substantia nigra (SN), in early- and late-onset RLS patients using T2 relaxometry have yielded inconsistent results. In this study the regional iron content was assessed in patients with early- and late-onset RLS using magnetic resonance imaging (MRI), and compared the results with those in controls. METHODS: Thirty-seven patients with idiopathic RLS (20 with early onset and 17 with late onset) and 40 control subjects were studied using a 3.0-tesla MRI with a gradient-echo sampling of free induction decay and echo pulse sequence. The regions of interest in the brain were measured independently by two trained analysts using software known as medical image processing, analysis, and visualization. The results were compared and a correlation analysis was conducted to investigate which brain areas were related to RLS clinical variables. RESULTS: The iron index in the SN was significantly lower in patients with late-onset RLS than in controls (p=0.034), while in patients with early-onset RLS there was no significant difference. There was no significant correlation between the SN iron index of the late-onset RLS group and clinical variables such as disease severity. CONCLUSIONS: Late-onset RLS is associated with decreased iron content in the SN. This finding supports the hypothesis that regional brain iron deficiency plays a role in the pathophysiology of late-onset RLS.
Subject(s)
Humans , Brain , Iron , Magnetic Resonance Imaging , Red Nucleus , Restless Legs Syndrome , Substantia NigraABSTRACT
Holmes' tremor is a condition characterized by a mixture of postural, rest, and action tremors due to midbrain lesions in the vicinity of the red nucleus. Hypertrophic olivary degeneration (HOD) is a rare type of neuronal degeneration involving the dento-rubro-olivary pathway and may present clinically as Holmes tremor. We report on a 59-year-old female patient who developed Holmes tremor in association with bilateral HOD, following brain stem hemorrhage.
Subject(s)
Female , Humans , Middle Aged , Brain Stem , Hemorrhage , Mesencephalon , Neurons , Olivary Nucleus , Red Nucleus , TremorABSTRACT
Objective To study the effects of embryonic neural stem cells transplantion on trauma of red nucleus neu-rons of the rats with spinal cord injury.Methods NSCs in logarithmic phage were labeled with BrdU,a Sprague Dawley rat mode of spinal cord injury (SCI) was developed with electrocircuit control spinal cord injuring device.Thirty SD rats were randomly divided into three groups: sham group,SCI group and NSC group.The NSCs were trans-planted into injured site three days after SCI.Then NSCs labeled with Brdu were detected by immunohistochemisty,rubrospinal tract (RST) neurons were labeled by retrograde transport of the horseradish peroxidase (HRP) from the lesion site,which were taken by damaged axons and remained in the neurons,then the labeled red nucleus (RN) neurons were counted.Hind limb function of experimental rats was evaluated by a blinder observer using BBB open field locomotion rating score.Results BrdU positive NSCs were detected in the spinal cord after transplantation,the number of RST neurons labeled by HRP in NSC group was more than that in SCI group (P <0.01),the BBB score of NSC group was higher than SCI group (P <0.01).Conclusion The transplanted NSCs can survive in the injured site of spinal cord and protect RN,then promote more remarkably functional recovery after SCI.
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Objective To study the morphological changes of soleus muscle spindle and electrical activity of neurons in Red Nucleus(RN) of the rat after 2 weeks' simulated weightlessness, and to reveal the interaction between proprioceptive inputs of muscle spindles and reciprocal alterations in RN under simulated weightlessness. Methods Twenty female rats were exposed to weightlessness simulated by tail-suspension for 14 days (SW-14d). Body weight(200-220g) matched female rats were control group(Con). The morphological changes in isolated muscle spindle of soleus muscle, the discharges of red nucleus neurons were observed after 14d tail-suspensions by silver staining and extracellular recording respectively. Results Compared with control group ,the nerve ending of muscle spindle in SW-14d was distorted, degenerated and dissolved; the diameters of intrafusal fibers and capsule in equatorial region of soleus muscle spindles were diminished(P＜0.05). The spontaneous cell activity and discharge of RN neurons (spikes/s) induced by afferent firing from muscle spindles after injection of succinylcholine were reduced after 2 weeks' simulated weightlessness respectively (18.44±5.96 vs. 10.19±6.88, 32.50±8.08 vs. 16.86±5.97, P＜0.01). Conclusion The degeneration of muscle spindle induced by simulated weightlessness may be one of the causes that led to alterations in discharges of RN.
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Objective Whether combination of ganoderma spore and L-NNA(NOS inhibitor) could promote the neuronal survival and axonal regeneration in Clarke's nucleus(CN) and red nucleus(RN) following spinal cord hemisection was explored. Methods Thirty adult female rats were divided into control group,L-NNA group,low dosage of ganoderma spore group,low dosage of ganoderma spore+L-NNA group,high dosage of ganoderma spore group and high dosage of ganoderma spore+L-NNA group.L-NNA was intraperitoneally injected and high dosage of ganoderma spore was irrigated into the rat's stomach after hemisection of T11 spinal cord segment in high dosage of ganoderma spore+L-NNA group. Results Thirty days after spinal cord hemisection,the number of CN neurons was decreased and some neurons were expressing NOS on lesioned side of L1 spinal cord in control group.The number of CN neurons on lesioned side of L1 spinal cord was increased in L-NNA group and low dosage of ganoderma spore group,but the number of NOS-positive neurons was decreased.In low dosage of ganoderma spore+L-NNA group and high dosage of ganoderma spore group,the number of CN neurons was significantly increased and NOS-positive neurons were also significantly decreased on lesioned side of L1 spinal cord.In high dosage of ganoderma spore+L-NNA group,there were most CN neurons surviving and least NOS-positive CN neurons,and some neurons were labeled by flourogold on lesioned side of LI spinal cord.The density of RN neurons on lesioned side was decreased in control group and L-NNA group.The density of RN neurons on lesioned side was increased in low dosage of ganoderma spore group and low dosage of ganoderma spore+L-NNA group.The density of RN neurons on lesioned side was significantly increased in high dosage of ganoderma spore group and high dosage of ganoderma spore+L-NNA group.Conclusion Ganoderma spore or L-NNA can promote the survival of injuried CN neurons after spinal cord hemisection.Combination of ganoderma spore and L-NNA can better promote injuried CN neuronal survival and axonal regeneration.Ganoderma spore can also enhance injuried RN neuronal survival.
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After a injection of kainic acid or WGA-HRP into the red nucleus, the degenerated or HRP labeled terminals in lamina V of the contralateral trigeminal subnucleus caudalis (Vc) were examined electron microscopically. It was found that the degenerated and HRP labeled terminals contained vesicles of spherical or mixed type, and formed symmetrical synapses with medium- or small-sized dendrites. These findings suggested that the descending rubral fibers might be inhibitory in regulating the activity of the neurons, and supposed to be sensory in nature. Thus the red nucleus might play certain role in modulation of the oro-facial somatosensory transmission (including pain) in lamina V of Vc, besides the rubrospinal influence on the involuntary motor functions of the spinal anterior horn. The technique for tracing neural connections with electron microscope was discussed as well.
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In the present study the projections were traced from the red nucleus and the region of the griseum centrale mesencephali to the inferior olivary complex (IOC) by using the method of anterograde transport of the WGA-HRP in the cat. The results has led to the following conclusions: 1.Both injected regions have positive projections to the ipsilateral IOC. No labeled cells were found in the IOC. 2. The projections from the red nucleus to the IOC terminated in the dorsal lamina of the principal olive and the dorsal end of the caudal half of the medial accessory olive. The projections from the region of the griseum centrale mesencephali to the IOC terminated in the whole medial accessory olive, ventral lamina of the principal olive and the connecting part between the ventrolateral end of ventral lamina and dorsal lamina of the principal olive. The most heavily labeled regions were the dorsal lamina of the principal olive among the regions receiving projection from the red nucleus and the medial accessory olive among those receiving fibers from the griseum centrale mesencephali region, the other regions were more lightly labeled.3. Some labeled regions of the IOC in the present study overlapped with those regions receiving fibers from the spinal cord reported by others. In the present study the labeled area is more extensive than those reported in the literature.