磁共振脑径线测量对多系统萎缩的诊断价值

目的 研究磁共振脑径线测量对于多系统萎缩(MSA)的诊断价值.方法 11例MSA患者,可能MSA 2例,拟诊MSA 9例.其中以帕金森综合征为主要表现(MSA-P)5例,以小脑性共济失调为主要表现(MSA-C)6例.健康对照组6名,病例对照组9例(帕金森病1例、其他类型的帕金森综合征8例).选取反映脑干、小脑和基底节形态学的径线进行测量,计算全脑三维体积,比较各项参数的组间差异.结果 MSA组的脑桥横径(mm,下同)明显短于健康对照组和病例对照组(27.6±2.0、30.5±0.6、29.9±1.1),MSA患者的四脑室前后径(11.9±2.8)明显长于健康对照(9.0±2.1).MSA-C组的脑桥横径明显短于健康对照组和病例对照组(27.2±2.1、30.5±0.6、29.9±1.1).MSA-C患者的四脑室前后径和横径(12.8±2.6和9.0±2.1)明显长于健康对照(17.3±2.1和13.8±1.7).MSA-P患者的脑桥横径较健康对照组短(28.2±1.8、30.5±0.6).MSA-P患者的苍白球最长径(23.7±5.0)和红核直径(6.6±0.8)明显较MSA-C患者(29.7±2.4和8.2±0.4)短.MSA-C患者的第四脑室横径较MSA-P患者宽(17.3±2.1、12.6±2.7),小脑中脚宽度较MSA-P患者缩短(13.3±1.9、15.8±1.2).结论 磁共振脑体积径线测量对于MSA患者脑组织局部萎缩的程度提供了量化的手段.脑桥的横径缩短可以客观地反映MSA患者脑桥的萎缩,但不能用于区分MSA-P和MSA-C.MSA-C患者更易出现第四脑室的扩大和MCP的萎缩,MSA-P患者更易出现红核萎缩.     

Pontine veins. MRI cross-sectional anatomy

Summary The pons is covered by a rich venous network offering numerous vascular landmarks in MRI and during surgery. We present an original study of the veins as they appear on MR multiplanar scans after gadolinium IV injection. This prospective study is based on 40 consecutive patients with normal posterior fossa structures. One of the major venous collectors follows the pons: the superior petrosal v. was identified on MRI in 95% of our cases. Its hooklike extremity drains into the superior petrosal sinus. The inferior petrosal v. was never identifiable. The superficial pontine venous network are identified in 72.5% of cases in the axial plane and were organised in longitudinal and transverse collectors, whose MR aspects are presented here.

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Les veines du pont. Anatomie sectionnelle en IRM

Résumé Le pont, enveloppé des citernes subarachnoïdiennes, est parcouru à sa surface par de nombreux vaisseaux qui constituent autant de points de repère topographiques en IRM que de rapports chirurgicaux. Nous présentons une étude de l'anatomie veineuse en coupe telle que l'IRM la révèle après injection de Gadolinium. Cette étude prospective comporte 40 patients indemmes de lésion de la fosse crânienne postérieure. Le pont est longé par un des collecteurs majeurs du tronc cérébral : la v. pétreuse supérieure, identifiée dans 95 % des cas. Elle se jette par un crochet caractéristique dans le sinus pétreux supérieur. La v. pétreuse inférieure n'a jamais été reconnue. Les vv. pontiques forment un réseau maillé visible dans 72,5 % des cas en coupes axiales et comportant des axes transversaux et longitudinaux dont les critères d'identification sont présentés selon le plan de coupe.

     

Neuroanatomical Correlates of Skin Conductance Orienting in Normal Humans: A Magnetic Resonance Imaging Study

Although little is known about the neuroanatomical basis of skin conductance orienting in intact normal humans, the limited literature on animals and humans with neurological and clinical disorders implicate prefrontal, temporal/amygdala, and pons brain areas in mediating skin conductance orienting. This study relates area of these structures using magnetic resonance imaging techniques to skin conductance orienting responses in 17 normal humans in order to test hypotheses that larger area of these excitatory structures will be associated with more orienting responses. Left and right hand skin conductance orienting was significantly associated with left and right prefrontal area (r = .44-.60), area of the pons (r = .43-.54), and left but not right temporal/amygdala area (r = .47-.53). No relationships were observed with areas thought to be unrelated to skin conductance activity (cerebellum, nonfrontal cortical area), medial prefrontal cortex, or the third ventricle. This appears to be the first study relating brain structure to skin conductance orienting in intact normal humans. Although preliminary at the present time, these results implicate prefrontal, pons, and temporal/amygdala areas in the mediation of skin conductance orienting in normal humans.     

Leucoéncephalopathie multifocale progressive

Summary A young woman presented a mixed congenital and familial immunodeficiency syndrome consisting in an absence of IgA and lowered levels of IgG and IgM, with a defect in cellular immunity. She had a mild malabsorption syndrome with slight alterations of the jejunal mucosa. Non-caseating tuberculoid granulomata were found in skin lesions, in lymph nodes and in the spleen. At age 27 the patient died of a neurological disease of 4 months duration. Autopsy revealed a very widespread demyelinating process involving mainly the right cerebellar hemisphere but also most of the pons and left cerebellum, with the typical morphologic characters of PML. In the hemispheres lesions were limited to microscopical microglial nodules with discrete demyelination. A review of 86 published cases of PML revealed 9 other cases in which lesions showed a strong predilection for the subtentorial territories. This sampling allows for the assumption that some 11% of the cases of PML have this particular lesion distribution. Other pertinent features of this case are briefly discussed.

     

Ischaemia-induced sympathoexcitation in spinalyzed rats

Systemic ischaemia increases sympathetic activity via both reflex and direct effects on the nervous system, which include the hypothalamus and brainstem structures that provide excitatory drive to sympathetic pre-ganglionic motoneurones. Using an arterially perfused working heart-brainstem preparation (WHBP), we evaluated the sympathoexcitatory response recorded from the thoracic sympathetic chain (tSC) in response to systemic ischaemia (produced by arresting perfusion for 30 s) before and after transecting consecutively at both the ponto-medullary and medullary-spinal cord junctions. Ischaemia produced a striking increase in tSC activity that persisted after transecting at both the ponto-medullary and medullary-spinal cord levels (intact: 70+/-3%; ponto-medullary: 77+/-7%; medullary-spinal cord: 61+/-6%; n=9). In sino-aortic denervated (SAD) rats (n=4), sympathoexcitatory responses were smaller in both intact and ponto-medullary, but not in medullary-spinal cord transected versus intact rats. Following administration of a ganglionic blocker [hexamethonium (hex), 25 mg/kg] after medullary-spinal cord transection the ischaemia-induced sympathoexcitatory response was reduced (12+/-6% increase relative to control, n=4). In medullary-spinal cord transected preparations, intrathecal injection of N2-saturated saline increased tSC discharge (22+/-3%, n=4), which was attenuated by hex (5+/-1%). We propose that neural mechanisms within the cervical-thoracic segments can make a substantial contribution to the sympathoexcitatory response during systemic ischaemia.     

Ultrasonic measurements of the posterior cranial fossa structures in neonates and infants

The structures in the posterior cranial fossa of neonates and infants were visualized ultrasonically via the anterior fontanelle. The diamters of the cerebellar vermis, pons, fourth ventricle and cisterna vermis were measured in the midsagittal plane in neonates (n=76), 1-month-old infants (n=61) and 3-to-6-month-old infants (n=35). The normal values obtained will be useful for evaluation of morphological abnormalities in the posterior cranial fossa.     

Laryngeal effects of stimulation of rostral and ventral pons in the anaesthetized rat

In order to study the importance of two pontine regions modulating laryngeal resistance, electrical current or microinjections of glutamate (10-30 nl, 1-3 nmol) were made into the pontine parabrachial complex and the A5 region in spontaneously breathing anaesthetized rats. Two distinct patterns of laryngeal and respiratory responses were elicited. An increase of subglottal pressure was accompanied with an expiratory facilitatory response consisted of a decrease in both respiratory rate and phrenic nerve activity. A decrease of subglottal pressure was accompanied with an inspiratory facilitatory response consisted of an increase in both respiratory rate and phrenic nerve activity. The modification of laryngeal calibre occurred during both respiratory phases in most cases. The concomitant cardiovascular changes of these responses were also analyzed. Controls using guanethidine to block autonomic responses which might interact with respiratory control were also made. Histological analysis of stimulation sites showed a topographical organization of these responses: laryngeal constriction was evoked from K?lliker-Fuse, medial parabrachial nuclei and A5 region, whilst the laryngeal dilation was evoked from the lateral parabrachial nucleus.     

Pontocerebellar hypoplasia type 2: a neuropathological update

Pontocerebellar hypoplasia type 2 (PCH-2; MIM 277470), an autosomal recessive neurodegeneration with fetal onset, was studied in six autopsies with ages at death ranging between 1 and 22 years. Three patients were distantly related. A case of olivopontocerebellar hypoplasia (OPCH; MIM 225753) was studied for comparison. Typical findings are: short cerebellar folia with poor branching (“hypoplasia”), relative sparing of the vermis, sharply demarcated areas of full thickness loss of cerebellar cortex probably resulting from regression at an early stage of development, segmental loss of dentate nuclei with preserved islands and reactive changes, segmental loss in the inferior olivary nucleus with reactive changes, loss of ventral pontine nuclei with near absence of transverse pontine fibers and sparing of spinal anterior horn cells. Variable findings are: cystic cerebellar degeneration, found in two, with vascular changes limited to the cerebellum in one. Comparison to olivopontocerebellar hypoplasia (OPCH) strongly suggests a continuum of pathology between this disorder and PCH-2. Immunohistochemical evaluation of the endoplasmic reticulum stress response is negative. We conclude that the neuropathological findings in PCH-2 are sufficiently specific to enable an unequivocal diagnosis based on neuropathology.     

Fluctuating gustatory disturbance and ophthalmodynia heralding the onset of a paramedian pontine infarction

Lasting taste disturbance has been previously reported as a consequence of brainstem infarction, but there are no previous reports of transient gustatory sensations preceding the onset of stroke. Ophthalmodynia, presenting as “salt-and-pepper” eye pain, has been reported rarely. We present a 58-year-old right-handed woman who had fluctuating ophthalmodynia and taste disturbance immediately preceding a left paramedian pontine infarction. We discuss the neuroanatomical basis of taste in reference to this presentation.     

桥脑海绵状血管瘤的显微手术治疗:附12例报告

目的 分析桥脑海绵状血管瘤的显微外科手术治疗方法 和预后.方法 显微手术切除桥脑海绵状血管瘤12例.11例位于桥脑背侧的海绵状血管瘤,采用枕下正中经菱形窝入路切除;1例位于桥脑腹外侧的海绵状血管瘤,采用颞下经小脑幕入路切除.结果 均镜下全切除病灶,术后病理证实为脑海绵状血管瘤.术后临床表现改善6例,无变化3例,面瘫加重1例,出现外展神经瘫痪1例,死亡1例.术后平均随访时间3个月,复查MRI均未见病灶复发,脑干组织影像学修复良好,术后遗留的临床症状均有不同程度的恢复.结论 在正确选择手术适应症及手术方法 的前提下,桥脑海绵状血管瘤的手术治疗是安全和有效的.