Establishment of Three-Dimensional Finite Element Model of Medulla Oblongata-Upper Cervical Spinal Cord Based on Pathological Section and Biomechanical Analysis of Related Injury / 医用生物力学

Objective The three-dimensional (3D) solid model of medulla oblongata-upper cervical spinal cord based on specimen pathological section data was established, and the stress and strain levels of medulla oblongata-upper cervical spinal cord under dentate process compression were obtained by finite element analysis, so as to provide references for clinical research. Methods Mimics was used to process the slice data, so as to establish the point cloud model. SolidWorks was used to locate, edit and optimize the point cloud model, so as to establish the 3D solid model. HyperMesh was used to establish the finite element model and ANSYS was used for finite element analysis. Results The medulla oblongata-upper cervical spinal cord model with clear boundary between gray matter and white matter and white matter fiber bundle was established. The stress and strain levels and stress-strain curves of white matter and gray matter under different compression degrees were obtained. Conclusions Combined with pathological sections of specimens and reverse engineering, the 3D medulla oblongata-upper cervical spinal cord model with clear morphology and structure of gray/white matter can be established. When the medulla oblongata-upper cervical spinal cord is compressed, the stress level of gray matter is lower than that of white matter, and about 20% of compression is the critical state of white matter. When the disease develops beyond the critical state, the biomechanical properties of white matter may fail, resulting in gray matter damage.

El verdadero origen aparente de los nervios glosofaríngeo, vago y accesorio / The true apparent origin of glossopharyngeal, vagus and accessory nerves

Resumen Introducción. Existe un vacío conceptual asociado con los sitios precisos por donde emergen las raíces de los nervios glosofaríngeo, vago y accesorio, un conocimiento que es de suma importancia para los neurocirujanos. Objetivo. Determinar el sitio preciso por donde las raíces de los nervios glosofaríngeo, vago y accesorio emergen como origen aparente en la médula oblongada. Materiales y métodos. Se valoraron 67 troncos encefálicos humanos que con anterioridad habían sido fijados en solución de formalina al 10%. Mediante inspección directa, luego de retirar las meninges, se examinó y registró el sitio preciso por donde emergen las raíces de tales nervios y se comparó con lo registrado en la literatura. Resultados. En el 100% de los troncos encefálicos estudiados se encontró que las raíces nerviosas emergen entre 2mm a 3mm por detrás del surco retro-olivar, distinto a lo reportado en la literatura consultada. Conclusión. Hay disparidad de criterios en cuanto al origen aparente de los nervios glosofaríngeo, vago y accesorio, lo que amerita un estudio más amplio que permita llegar a un consenso generalizado sobre el sitio preciso por donde las raíces de tales nervios hacen su aparición.

Abstract Introduction: There is a conceptual gap associated with the sites where the roots of the glossopharyngeal, vagus and accessory nerves emerge, which is information of utmost importance for neurosurgeons. Objective: To determine the exact site where the roots of the glossopharyngeal, vagus and accessory nerves emerge, considering the medulla oblongata as their apparent place of origin. Materials and methods: 67 human brainstems that had previously been fixed in 10% formalin solution were examined. After removing the meninges, the precise site where the roots of these nerves emerged was analyzed by direct inspection and the results recorded and compared to the literature. Results: In 100% of the brainstems studied, it was found that the nerve roots emerge between 2mm and 3mm behind the retro-olivary groove, which differs from the reports of the consulted literature. Conclusion: There are different opinions about the apparent origin of the glossopharyngeal, vagus and accessory nerves. This requires a deeper study that allows reaching a general consensus on the precise place where the roots of these nerves originate.

Setting-up of the calculation model for sagittal diameter of bulbo-medullary junction / 中华骨科杂志

Objective@#To develop a calculation model for normal sagittal diameter (SD) of bulbo-medullary junction with the change of distance above the measurement baseline(the line connecting the anterior lower margin of the C2 vertebral body and the posterior upper margin of the C3 vertebral body), and to investigate its calculation error.@*Methods@#All of 164 patients with cervical disc herniation or cervical spinal stenosis who underwent cervical MRI between April 2018 and August 2018 in Beijing Jishuitan Hospital were included in this study. The normal bulbo-medullary junction was divided into two parts from top to bottom, and the dividing line was defined factitiously (the line parallel to the measurement baseline and through the lower margin of cancellous bone of the anterior arch of atlas). On the middle sagittal MRI images of 100 cases of normal bulbo-medullary junction, the change rate of the SD along the distance above the measurement baseline was counted on the upper and lower segments separately. The calculation model for SD of bulbo-medullary junction was established, with the SD of spinal cord at level of the lower margin of axis and the distance above the measurement baseline as independent variables. After setting-up of the calculation model, the actual SD at the lower margin of the C1 anterior arch and 10 mm above and below it was measured on other 64 cases of normal bulbo-medullary junction. The actual SD and calculation value were compared for calculating the error and error rate. The SD at the dividing line was estimated using the substituted estimation (the actual SD at level of the lower margin of axis) and mean-value estimation (the mean SD of the first 100 cases). Calculation value, substituted estimation and mean-value estimation were compared, and their calculation error and the occurrence rate of significant error (no less than 1 mm) were also compared.@*Results@#Calculation formula for SD of bulbo-medullary junction: (below the dividing line) SD=sagittal diameter at level of the lower margin of axis (SDA)+0.0472×height above the measurement baseline (HAB), (above the dividing line) SD=SDA+0.0472×height of dividing line above the measurement baseline (HDL)+0.298×(HAB-HDL). The error of calculation model increased with the distance above the measurement baseline. The error at the topmost level was 1.06±0.72 mm, and the error rate was 10.52%± 8.26%. Compared with the estimation method using the mean value, the calculation model was accompanied with a significantly lower ratio of significant error (Z=-3.527, P<0.001). Compared with the estimation method using a substitute, the error of the calculation model was significantly smaller (Z=-4.88, P<0.001) and the ratio of significant errors was significantly lower (Chi-Square= 6.015, P=0.024).@*Conclusion@#The SD calculation model could accurately estimate the SD of a normal bulbo-medullary junction, and has great significance for the quantitative imaging assessment and decompression strategy in patients with atlantoaxial instability.

A case of unilateral hypertrophic olivary degeneration following bilateral medial medullary infarction / 中华神经科杂志

Bilateral medial medullary infarction is a rare type of stroke. Hypertrophic olivary degeneration (HOD) is usually secondary to the lesion involving the Guillain-Mollaret triangle with vacuolar degeneration of inferior olivary nucleus neurons and enlargement of inferior olivary nucleus. The primary lesions involving the Guillain-Mollaret triangle are usually located in midbrain, pons and cerebellum. A case of unilateral HOD secondary to bilateral medial medullary infarction is reported and the clinical characteristics, diagnosis and treatment are analyzed in order to improve the understanding of HOD.

Analysis of clinical characteristics of 13 patients with bilateral medial medullary infarction / 中国神经精神疾病杂志

Objective To investigate the clinical characteristics of bilateral medial medullary infarction (BMMI). Methods The clinical data, cranial magnetic resonance imaging (MRI) and prognosis at 3 months follow-up of 13 patients with BMMI were analyzed, retrospectively. Results The common symptoms and signs of BMMI were quadriplegia in 13 cases), dizzy in 10 cases, dysarthria in 8 cases, hypoglossal nerve palsy in 8 cases)and dyspnea in 3 severe cases. The disease had an acute onset with rapid progress and reached peak between day 3 and 6. There were ten cases with moderate to severe disability at 3 months follow-up. The risk factors were hypertension, hyperlipidemia and diabetes. MRI diffusion weighted imaging showed hyperintense signals in the bilateral medial medulla with classical "heart-"shape (6 cases) and "Y-" shape (6 cases). Magnetic resonance angiography showed unilateral vertebral artery stenosis or occlusion in most patients. Conclusion BMMI is a rare cerebrovascular disease with a poor outcome. MRI diffusion weighted imaging is of great value in the early diagnosis.

X-linked spinal and bulbar muscular atrophy (Kennedy's disease): the first case described in the Brazilian Amazon / Atrofia muscular bulboespinhal ligada ao cromossomo X (doença de Kennedy): o primeiro caso descrito na Amazônia brasileira

ABSTRACT The X-linked spinal and bulbar muscular atrophy (Kennedy's disease) is a rare X-linked, recessive, lower motor neuron disease, characterized by weakness, atrophy, and fasciculations of the appendicular and bulbar muscle. The disease is caused by an expansion of the CAG repetition in the androgen receptor gene. Patients with Kennedy's disease have more than 39 CAG repetitions. We report a case of 57-year-old man, resident of Monte Dourado (PA, Brazil) who complained of brachiocrural paresis evolving for 3 years along with fasciculations and tremors of extremities. In addition, he also developed dysarthria, dysphagia, and sexual dysfunction. The patient clinical picture included gait impairment, global hyporeflexia, proximal muscle atrophy of upper limbs, deviation of the uvula to right during phonation and tongue atrophy with fasciculations. The patient reported that about 30 years ago he had undergone gynecomastia surgery. His electroneuromyography suggested spinal muscular atrophy, and nuclear magnetic resonance imaging showed tapering of the cervical and thoracic spinal cord. Patient's creatine kinase level was elevated. In view of the findings, an exam was requested to investigate Kennedy's disease. The exam identified 46 CAG repetitions in the androgen receptor gene, which confirmed the diagnostic suspicion. This was the first case of Kennedy's disease diagnosed and described in the Brazilian Amazon. To our knowledge only other four papers were published on this disease in Brazilian patients. A brief review is also provided on etiopathogenic, clinical and diagnostic aspects.

RESUMO A atrofia muscular bulboespinhal ligada ao cromossomo X (doença de Kennedy) é uma rara doença de neurônio motor inferior, recessiva, ligada ao X, e caracterizada por fraqueza, atrofia e fasciculações da musculatura apendicular e bulbar. É causada por uma expansão da repetição CAG no gene do receptor de androgênio. Pacientes com doença de Kennedy apresentam mais de 39 repetições CAG. O paciente deste relato era do sexo masculino, 57 anos, morador de Monte Dourado (PA, Brasil), com queixa de paresia braquiocrural há 3 anos, acompanhada de fasciculações e tremores de extremidades. Em seguida, ele desenvolveu disartria, disfagia e disfunção sexual. Também apresentava comprometimento da marcha, hiporreflexia global, atrofia muscular proximal dos membros superiores, desvio da úvula para direita à fonação e atrofia de língua com fasciculações. Foi realizada cirurgia para tratamento de ginecomastia há 30 anos. A eletroneuromiografia sugeriu quadro de atrofia muscular espinhal. Imagens de ressonância magnética demonstraram afilamento da medula espinhal cervical e torácica. A creatina quinase estava elevada. Diante dos achados, solicitou-se investigação para doença de Kennedy, e foram identificadas 46 repetições CAG no gene do receptor de androgênio, o que confirmou a suspeita diagnóstica. Este foi o primeiro caso de doença de Kennedy diagnosticado e descrito na Amazônia brasileira. Existem, além deste relato, apenas outros quatro trabalhos publicados sobre a doença em pacientes do Brasil. Também realizamos breve revisão de aspectos etiopatogênicos, clínicos e diagnósticos.

Advances in Dysphagia after Medullary Infarction (review) / 中国康复理论与实践

@#Dysphagia is most common after medullary infarction, characterized by aspiration, residual pharynx and poor esophageal sphincter opening. The existence and severity of dysphagia can be preliminarily determined according to the site of infarction, and it is more likely to cause dysphagia on rostral, dorsal and lateral part of the medulla oblongata. High resolution manometry can be used to understand the biomechanical characteristics of the pharynx and upper segment of esophagus, and helps to evaluate dysphagia, especially combined with videofluoroscopic swallowing study, to guide the rehabilitation. Compensatory posture, electrical stimulation, transcranial magnetic stimulation and balloon dilatation are effective for the treatment.

Medullary Infarction Presenting as Sudden Cardiac Arrest: Report of Two Cases and Review of the Literature

The causes of sudden death after medullary infarction involve arrhythmia, central respiratory failure, and dysautonomia. Sudden cardiac arrest in a medullary infarction is uncommon. Most of these cases experienced sudden cardiopulmonary arrest within 2 weeks from stroke onset as the extent of lesion increased. Here, we report two cases of medullary infarction presenting as sudden cardiac arrest. These cases indicate that medullary infarction could be one of the causes of sudden cardiac arrest.

Síndrome de Opalski, una variante del síndrome de Wallenberg: reporte de caso y revisión de la literatura / Opalski Syndrome, a variant of Wallenberg Syndrome: Case report and literature review

RESUMEN Se presenta un caso local de la variante de Opalski, del síndrome medular lateral (síndrome de Wallenberg) y se hace una revisión de la literatura sobre los síntomas de este cuadro clínico, así como las posibles razones que explican esta modificación en la expresión clínica. La variante de Opalski fue descrita en 1948, ochenta y nueve años después de la descripción original del síndrome por Adolf Wallenberg, su principal característica es la presencia de hemiparesia o hemiplejía del cuerpo del mismo lado de la lesión del bulbo raquídeo. La etiología es vascular en la mayoría de casos, por obstrucción de la arteria cerebelosa postero-inferior o de los ostium de vasos penetrantes que se originan en la arteria. No hay estudios que reporten la incidencia exacta de este cuadro clínico a nivel mundial, sin embargo, su presentación no es tan infrecuente. Lo más interesante al analizar cada caso, es que los hallazgos semiológicos son una muestra de la profunda organización del sistema nervioso.

SUMMARY A clinical case of the Opalski variant of the lateral medullary syndrome (Wallenberg's syndrome) is presented and a literature review about the symptoms of this clinical picture is done, as well as the possible reasons explaining this modification in the clinical expression. The Opalski variant was described in 1948, eighty-nine years after the original description of the syndrome by Adolf Wallenberg, its main feature is the presence of hemiparesis or hemiplegia of the ipsilateral side of the injury in the medulla oblongata. In most cases the etiology is vascular when the postero-inferior cerebellar artery is occluded or there is an obstruction of the ostium of penetrating vessels originating in the artery. There are no studies that accurately report the worldwide incidence of this clinical variant, however, its presentation is not uncommon. The most interesting discovery of each case is that semiological findings are a good example of the profound organization of the nervous system.

Medullary infarction / 国际脑血管病杂志

Medulla oblongata is precise in structure and the blood supply is complicated. After its infarction, it is easy to be misdiagnosed or missed because of its various clinical manifestations and lack of specificity. This article reviews the pathogenesis, clinical manifestations, and prognosis of medullary infarction in different sites.

"A case of typical""Y""-shaped medullary infarction" / 天津医药

The medulla oblongata is located at the lower end of the brain stem, and it has abundant blood supply. The incidence of medial medullary infarction is low in cerebrovascular diseases. Bilateral medial medullary infarction is even rare. Bilateral medial medullary infarction is mainly characterized by paralysis. The respiratory failure can occur in severe cases. Magnetic resonance diffusion imaging can present aheartorYshaped lesion. We treated 1 patient with a typicalYshaped bilateral medial medullary infarction.

Microsurgical treatment of solid hemangioblastoma in medulla oblongata / 中华显微外科杂志

Objective To report the clinical features,microsurgical techniques and outcomes of 5 patients admitted in our hospital,who had solid hemangioblastoma in medulla oblongata in the last 5 years.Methods 5 consecutive cases of solid hemangioblastoma in medulla oblongata operated from March,2011 to May,2016 were reviewed and fl lowed up.Results All patients suffered headache,dizziness and cerico-occipital pain from the beginning plus one was found because of obstructive hydrocephalus.The mean duration before operation was 6.7 months.The mean maximum diameter of tumor was (33.7±3.4)mm.The suboccipital posterior midline approach was performed and gross total resection was achieved in all 5 cases.After operation,endotracheal tube was removed in all 5 patients,but 3 received tracheotomy,and all patients can take food freely now through rehabilitation exercise.Followed up until September 2016,all patients lived a normal life.Conclusion The operation of solid hemangioblastoma in medulla oblongata is full of huge risk,but microsurgical resection is the only cure means for the tumor.

Neurocysticercosis, unusual manifestations / Neurocisticercosis, manifestaciones inusuales

Abstract Neurocysticercosis is the most common parasitic infection in the central nervous system. This disease is presented when a person ingests Taenia solium eggs excreted in feces from another individual infected with taeniasis. In 50% of the cases, neurocysticercosis takes place in the brain parenchyma, and its appearance is less frequent in the posterior fossa and the spinal cord. The case of a patient with an atypical location of the parasite at the medulla oblongata, between parenchymal and spinal areas, is presented. The initial symptoms were common but its subsequent manifestations were similar to those of Bruns syndrome. Furthermore, the epidemiological profile of neurocysticercosis in Colombia, its control measures and prevention strategies were reviewed in this study.

Resumen La neurocisticercosis es la infección parasitaria más frecuente en el sistema nervioso central; esta enfermedad se desarrolla cuando los huevos de Taenia solium excretados en heces de un individuo con teniasis son ingeridos por otra persona. La presentación de la neurocisticercosis tiene lugar en el parénquima cerebral en 50% de los casos, mientras que en la fosa posterior y en la médula espinal es menos frecuente. Se presenta el caso de un paciente que tuvo una ubicación exótica del parásito a nivel del bulbo raquídeo concomitando con la forma parenquimatosa y medular; las manifestaciones clínicas iniciales fueron las comunes, pero sus síntomas posteriores se caracterizaron por el síndrome de Bruns. Además, durante la investigación se revisó el perfil epidemiológico de la neurocisticercosis en Colombia y las medidas de control y de prevención.

A Wide Spectrum of Axial Mesodermal Dysplasia Complex With Rhombencephalic Anomaly: A Case Report

Axial mesodermal dysplasia complex (AMDC) arises in variable combinations of craniocaudal anomalies such as musculoskeletal deformities, neuroschisis, or rhombencephalic developmental disorders. To the best of our knowledge, the co-existence of AMDC with associated musculoskeletal anomalies, medullary neuroschisis with mirror movements, and cranial nerve anomalies has not yet been reported. Here, we report the case of a 4-year-old boy whose clinical features were suggestive of Goldenhar syndrome and Poland syndrome with Sprengel deformity. Moreover, he showed mirror movements in his hands suspected of rhombencephalic malformation, and infranuclear-type facial nerve palsy of the left side of his face, the opposite side to the facial anomalies of Goldenhar syndrome. After conducting radiological studies, he was diagnosed with medullary neuroschisis without pontine malformations and Klippel-Feil syndrome with rib anomalies. Based on these findings, we propose that clinical AMDC can be accompanied by a wide variety of musculoskeletal defects and variable degrees of central nervous system malformations. Therefore, in addition to detailed physical and neurological examinations, imaging studies should be considered in AMDC.

Surgical Outcome of Adult Idiopathic Chiari Malformation Type 1

OBJECTIVE: The pathophysiology of idiopathic Chiari malformation (CM) type 1 is disturbance of free cerebrospinal fluid (CSF) flow and restoration of normal CSF flow is the mainstay of treatment. Additional migration of the medulla oblongata in pediatric patients is referred to as CM type 1.5, but its significance in adult patients is unknown. This study is to compare surgical outcomes of adult idiopathic CM type 1.5 with that of type 1. METHODS: Thirty-eight consecutive adult patients (M : F=11 : 27; median, 33.5; range, 18–63) with syringomyelia due to idiopathic CM type 1 were reviewed. Migration of the medulla oblongata was noted in 13 patients. The modified McCormick scale (MMS) was used to evaluate functional status before and one year after surgery. All patients underwent foramen magnum decompression and duroplasty. Factors related to radiological success (≥50% decrease in the diameter of the syrinx) were investigated. The follow-up period was 72.7±55.6 months. RESULTS: Preoperative functional status were MMS I in 11 patients and MMS II in 14 of CM type 1 and MMS I in 8 and II in 5 of CM type 1.5. Of patients with MMS II, 5/14 patients in group A and 3/5 patients in group B showed improvement and there was no case of deterioration. Radiological success was achieved in 32 (84%) patients and restoration of the cisterna magna (p=0.01; OR, 46.5) was the only significant factor. CONCLUSION: Migration of the medulla oblongata did not make a difference in the surgical outcome when the cisterna magna was restored.

Sudden Unexpected Death after Lateral Medullary Infarction

The prognosis of lateral medullary infarction is mostly benign, but unexpected sudden death can occur even when the initial symptoms are benign. An 81-year-old man visited the emergency room with whirling-type dizziness and right-veering tendency. Brain magnatic resonance imaging (MRI) revealed a right lateral medullary infarction accompanied by a right cerebellar infarction. He died suddenly at 1 day after admission with only slight lesion progression on MRI. This case suggests that patients with a lateral medullary infarction should be carefully monitored during the acute period.

Isolated Tongue Paralysis as Presentation of Seropositive Neuromyelitis Optica Spectrum Disorder

Neuromyelitis optica spectrum disorder (NMOSD) is characterized by a characteristic clinical presentation or positivity for the anti-aquaporin-4 antibody. Lesions involving the dorsal medulla are typical of NMOSD, but isolated tongue paralysis has not been reported previously. We report a rare case of NMOSD presenting with isolated tongue paralysis and swelling due to intrinsic tongue muscle paralysis, which was caused by bilateral involvement of the hypoglossal nuclei in the lower dorsal medulla oblongata.

Analysis of clinical and imaging characteristics of bilateral medial medullary infarction / 中国脑血管病杂志

Objective To investigate the clinical and imaging characteristics of bilateral medial medullary infarction. Methods The clinical data of 3 patients with bilateral medial medullary infarction admitted to Shengjing Hospital of China Medical University were analyzed retrospectively. The related literature was reviewed. Results Three patients in this group were all males. Their main clinical manifestations were quadriplegia, dysarthria, and paresthesia, and 1 of them complicated with respiratory failure. One patient was suspected of having Guillain-Barre syndrome. The hyperintensities of heart-shape,Y- shape,and V- shape were its imaging features of typical MRI diffusion weighted imaging. Conclusion Bilateral medial medullary infarction is a rare posterior circulation ischemic lesion in clinical practice. Its early symptoms are not typical and easy to be misdiagnosed and missed. MRI diffusion weighted imaging is its main imaging examination method.

A case that Goshuyuto was effective for intractable hiccups caused by the medulla oblongata dissemination of the cerebellum melanoma

<b>Introduction:</b> Goshuyuto was effective in a case with intractable hiccups caused by the medulla oblongata dissemination of the cerebellum melanoma. <b>Case:</b>A 54-yearold male patient was diagnosed cerebellum malignant melanoma. He suffered from intractable hiccups caused by the medulla oblongata dissemination lesion of this melanoma. He was treated with some Western medicines such as Baclofen, Metoclopramide, Chlorpromazine and Clonazepam, which are usually used for the treatment of hiccups, but they were not effective. Therefore we gave him Goshuyuto which is Kampo medicine and his hiccups subsided immediately. Since then, he continues taking Gosyuyuto about a year and there has been no recurrence of hiccups thus far. <b>Conclusion:</b> Taking of Kampo medicine is the useful choice for a patient whom Western medicine is ineffective.

Effect of Exercise on micro-Opioid Receptor Expression in the Rostral Ventromedial Medulla in Neuropathic Pain Rat Model

OBJECTIVE: To investigate the effects of aerobic exercise on neuropathic pain and verify whether regular treadmill exercise alters opioid receptor expression in the rostral ventral medulla (RVM) in a neuropathic pain rat model. METHODS: Thirty-two male Sprague-Dawley rats were used in the study. All rats were divided into 3 groups, i.e., group A, sham group (n=10); group B, chronic constriction injury (CCI) group (n=11); and group C, CCI+exercise group (n=11). Regular treadmill exercise was performed for 30 minutes a day, 5 days a week, for 4 weeks at the speed of 8 m/min for 5 minutes, 11 m/min for 5 minutes, and 22 m/min for 20 minutes. Withdrawal threshold and withdrawal latency were measured before and after the regular exercise program. Immunohistochemistry and Western blots analyses were performed using antibodies against micro-opioid receptor (MOR). RESULTS: Body weight of group C was the lowest among all groups. Withdrawal thresholds and withdrawal latencies were increased with time in groups B and C. There were significant differences of withdrawal thresholds between group B and group C at 1st, 2nd, 3rd, and 4th weeks after exercise. There were significant differences of withdrawal latencies between group B and group C at 3rd and 4th weeks after exercise. MOR expression of group C was significantly decreased, as compared to that of group B in the RVM and spinal cord. CONCLUSION: In neuropathic pain, exercise induced analgesia could be mediated by desensitization of central MOR by endogenous opioids, leading to the shift of RVM circuitry balance to pain inhibition.