Sporadic hemangioblastoma of cauda equina: An atypical case report.

BACKGROUND: Hemangioblastomas account for about 1%-3% of all central nervous system tumors. They are usually associated with the Von Hippel-Lindau syndrome and typically occur in the posterior fossa, or throughout the spinal neuraxis. Here, we report the unusual case of a sporadic cauda equina hemangioblastoma. CASE DESCRIPTION: A 28-year-old Caucasian female patient presented with progressive low back pain of 2 months duration. The magnetic resonance (MR) revealed a heterogeneous intradural and extramedullary lesion at the L2 level; with intravenous contrast, there were vascular flow voids and surrounding vasogenic edema (i.e., measuring 4.1 cm × 3.5 cm). The patient underwent an L2 right hemilaminectomy under intraoperative neurophysiological monitoring. She was discharged the 4th postoperative day, neurologically intact. Literature describes 21 previous reports of sporadic isolated spinal hemangioblastomas. CONCLUSION: Although rare, sporadic, and isolated hemangioblastomas of the cauda equina should be included among the differential diagnoses of intradural spinal lesions, particularly when enhanced MR studies document serpentine flow voids.

Diffuse spinal spreading following previous intracranial intradural chordoma resection: A rare case report.

INTRODUCTION: Chordoma is a malignant tumor that usually involves the axial skeleton. Intradural chordomas are even rarer and 37 cases have been reported to the best of our knowledge. We present a case of a patient with an atypical metastatic diffuse intradural spinal involvement. CASE DESCRIPTION: We present a 33-year-old woman previously submitted to five brain surgeries to treat a posterior fossa intradural chordoma since December 2012. Currently, she presented almost with right and left hemiplegia (grade 2 bilaterally) and also left oculomotor, adbucent and facial nerve paresis. We performed neuroaxis magnetic resonance MR which disclosed stability of posterior fossa tumor which was previously irradiated. However, there were new intradural lesions at the level of C3, T11/T12 and L4/L5/S1 vertebrae. DISCUSSION: With the advent of contemponaeous surgery, radiotherapy options and even available chemotherapy to treat Chordomas (Imatinib), patients may experience enlarged survival and thus face complications such as drop metastases along neuroaxis. Our case illustrates a late (6 years) follow-up presentation of an initial posterior fossa intradural chordoma. It suggests that whole neuraxis involvement may be the final presentation of all patients harbouring chordomas and surviving after adequate initial treatment.

Intraoperative Ultrasonography for Definition of Less Invasive Surgical Technique in Patients with Chiari Type I Malformation.

INTRODUCTION: Chiari malformation type I (CM) is the main congenital malformation disease of the craniovertebral junction. The ideal surgical treatment is still controversial. Invasive procedures inside the cerebrospinal fluid (CSF) space and associated with dural repair are considered the gold standard; however, less invasive surgery with isolated bone decompression without dural opening may be possible in selected patients. Our study evaluates the efficacy of intraoperative CSF flow measurement with ultrasonography (USG) as a determining parameter in the selection of these patients. METHODS: We analyzed prospectively 49 patients with CM operated on at the Hospital das Clínicas, College of Medicine, University of São Paulo. Patients underwent decompressive surgery with or without opening of the dura mater after intraoperative USG measuring flow rate. A value of 3 cm/second was considered a cutoff. Quality of life before and after surgery and the improvement of neck pain and headache were evaluated. RESULTS: Among 49 patients enrolled, 36 patients (73%) had CSF flow >3 cm/second and did not undergo duraplasty. In 13 patients (27%) with initial flow <3 cm/second, dural opening was performed together with duraplasty. All patients improved when preoperative and postoperative scores were compared, and all clinical parameters evaluated did not differ between both surgical groups. Patients submitted to bone decompression alone had a lower complication rate. CONCLUSIONS: Intraoperative USG with measurement of CSF allows the proper selection of patients with CM for less invasive surgery with bone decompression without duraplasty.

Reliability and safety of a new upper cervical spine injury treatment algorithm.

METHODS: Thirty cases, previously treated according to the new algorithm, were presented to four spine surgeons who were questioned about their personal suggestion for treatment, and the treatment suggested according to the application of the algorithm. After four weeks, the same questions were asked again to evaluate reliability (intra- and inter-observer) using the Kappa index. RESULTS: The reliability of the treatment suggested by applying the algorithm was superior to the reliability of the surgeons' personal suggestion for treatment. When applying the upper cervical spine injury treatment algorithm, an agreement with the treatment actually performed was obtained in more than 89% of the cases. CONCLUSION: The system is safe and reliable for treating traumatic upper cervical spine injuries. The algorithm can be used to help surgeons in the decision between conservative versus surgical treatment of these injuries.

Reliability and safety of a new upper cervical spine injury treatment algorithm / Avaliação de reprodutibilidade e segurança de um novo algoritmo de tratamento das lesões cervicais altas

ABSTRACT In the present study, we evaluated the reliability and safety of a new upper cervical spine injury treatment algorithm to help in the selection of the best treatment modality for these injuries. Methods Thirty cases, previously treated according to the new algorithm, were presented to four spine surgeons who were questioned about their personal suggestion for treatment, and the treatment suggested according to the application of the algorithm. After four weeks, the same questions were asked again to evaluate reliability (intra- and inter-observer) using the Kappa index. Results The reliability of the treatment suggested by applying the algorithm was superior to the reliability of the surgeons’ personal suggestion for treatment. When applying the upper cervical spine injury treatment algorithm, an agreement with the treatment actually performed was obtained in more than 89% of the cases. Conclusion The system is safe and reliable for treating traumatic upper cervical spine injuries. The algorithm can be used to help surgeons in the decision between conservative versus surgical treatment of these injuries.

RESUMO Avaliamos a reprodutibilidade e segurança do algoritmo Upper Cervical Spine Injuries Treatment Algorithm (UCITA) recém proposto para a escolha do tratamento das lesões traumáticas da junção crânio-cervical. Métodos Trinta casos previamente tratados de acordo com o algoritmo foram apresentados a quatro cirurgiões de coluna, sendo questionada a conduta pessoal dos mesmos e a conduta segundo a aplicação do algoritmo. Após 4 semanas, foram refeitas as mesmas perguntas para avaliar a reprodutibilidade (intra e interobservador) do algoritmo, através do índice estatístico “Kappa”. Resultados A reprodutibilidade da conduta com o uso do algoritmo foi superior a reprodutibilidade da conduta pessoal dos cirurgiões. Com o uso do UCITA, a concordância do tratamento realmente efetivado foi encontrada em mais de 89% dos casos. Conclusão O uso do UCITA foi seguro e reprodutível, podendo ser usado como ferramenta auxiliar na tomada de decisão entre tratamento cirúrgico versus conservador dos traumatismos da junção crâniocervical.

Survival score scales of patients operated with spinal metastases: retrospective application in a Brazilian population / Escalas de prognóstico em pacientes operados com metástases vertebrais: aplicação retrospectiva em população brasileira

ABSTRACT Spinal cord epidural metastasis (SEM) is a common complication of systemic cancer. Predicting these patient’s survival is a key factor to select the proper treatment modality, but the three most used score scales to predict their survival (Tokuhashi revised score, Tomita score and Bauer modified score) were designed in single institutions and their reliability to predict correctly the patient’s survival were first tested only in those specific populations. This prognostication issue is addressed in this article, evaluating retrospectively the survival of 17 patients with SEM from a Brazilian general hospital with these score scales. Our results show that the actual survival of those patients were worse than the predicted of all three score scales, suggesting that differences between the different populations might have affected their reliability and alert that their usage as a major factor to select the most appropriate treatment have to be done with caution.

RESUMO Metástases vertebrais são uma complicação comum em pacientes com câncer sistêmico. Avaliar o prognóstico e a sobrevida desses pacientes é um fator de grande importância para escolher o tratamento mais adequado, porém as três escalas mais usadas atualmente para prever a sobrevida deles (Tokuhashi revisada, Tomita e Bauer modificada) foram desenhadas em instituições isoladas, e sua habilidade em estimar corretamente a sobrevida desses pacientes foram testadas primeiramente apenas nessas populações específicas. Essa questão de estimar o prognóstico é abordada nesse artigo, analisando retrospectivamente a sobrevida de 17 pacientes com metástase vertebral provenientes de um hospital geral no Brasil com essas escalas. Nossos resultados apontam que a sobrevida real desses pacientes foi menor que a prevista pelas três escalas, sugerindo que as diferenças entres as diferentes populações podem ter afetado a aplicabilidade delas. Assim, alertamos que o uso dessas escalas em populações diferentes das estudadas originalmente deve ser feito com cuidado.

Survival score scales of patients operated with spinal metastases: retrospective application in a Brazilian population.

Spinal cord epidural metastasis (SEM) is a common complication of systemic cancer. Predicting these patient's survival is a key factor to select the proper treatment modality, but the three most used score scales to predict their survival (Tokuhashi revised score, Tomita score and Bauer modified score) were designed in single institutions and their reliability to predict correctly the patient's survival were first tested only in those specific populations. This prognostication issue is addressed in this article, evaluating retrospectively the survival of 17 patients with SEM from a Brazilian general hospital with these score scales. Our results show that the actual survival of those patients were worse than the predicted of all three score scales, suggesting that differences between the different populations might have affected their reliability and alert that their usage as a major factor to select the most appropriate treatment have to be done with caution.

Immunohistochemical expression of cyclin D1 is higher in supratentorial ependymomas and predicts relapses in gross total resection cases.

Ependymomas are tumors of the CNS. Although cyclin D1 overexpression has been related to several cancers, its prognostic value in ependymomas has not yet been fully established. We evaluated cyclin D1 expression by an immunohistochemistry analysis of 149 samples of ependymomas, including some relapses, corresponding to 121 patients. Eighty-one patients were adults, 60 were intracranial cases and 92 tumors were grade II. Gross total resection (GTR) was achieved in 62% of cases, and relapse was confirmed in 41.4% of cases. Cyclin D1 protein expression was analyzed by immunohistochemistry and scored with a labeling index (LI) calculated as the percentage of positively stained cells by intensity. We also analyzed expression of CCND1 and NOTCH1 in 33 samples of ependymoma by quantitative real-time PCR. A correlation between cyclin D1 LI score and anaplastic cases (P < 0.001), supratentorial location (P < 0.001) and age (P = 0.001) were observed. A stratified analysis demonstrated that cyclin D1 protein expression was strong in tumors with a supratentorial location, independent of the histological grade or age. Relapse was more frequent in cases with a higher cyclin D1 LI score (P = 0.046), and correlation with progression-free survival was observed in cases with GTR (P = 0.002). Only spinal canal tumor location and GTR were suggestive markers of PFS in multivarite analyses. Higher expression levels were observed in anaplastic cases for CCND1 (P = 0.002), in supratentorial cases for CCND1 (P = 0.008) and NOTCH1 (P = 0.011). There were correlations between the cyclin D1 mRNA and protein expression levels (P < 0.0001) and between CCND1 and NOTCH1 expression levels (P = 0.003). Higher cyclin D1 LI was predominant in supratentorial location and predict relapse in GTR cases. Cyclin D1 could be used as an immunohistochemical marker to guide follow-up and treatment in these cases.

XI cranial nerve cervical schwannoma - case report / Schwannoma do nervo acessório cervical- relato de caso

Cisternal spinal accessory schwannoma are still a rare condition without neurofibromatosis with only 32 cases reported so far. We describe a cisternal accessory schwannoma presented in a 36-year-old woman with posterior cervical pain and cervical mieolopaty, defined by grade IV tetraparesia. A suboccipital craniectomy with C1 posterior arch resection was performed. During microsurgical dissection together with electrophysiological monitoring and nerve stimulation tumor was identified as having the spinal accessory root as its origins. Carefully intraneural dissection was then performed with complete lesion removal, histopatological examination confirmed the hypothesis of schwannoma. The patient was free from pain and improved her neurological status with no accessory nerve palsy. Complete surgical resection is indicated for such lesions and can be achieved with good outcome.

O schwannoma do ramo espinhal do nervo acessório em sua porção cisternal, quando não associado à neurofibromatose, é uma condição rara, com apenas 32 relatos de caso na literatura. O diagnóstico diferencial da lesão deve ser atentado, principalmente no que diz respeito à preservação da função motora do nervo acessório. Este é um relato de caso de uma paciente do sexo feminino de 36 anos com queixa de cervicalgia associada à mielopatia cervical compressiva secundária à lesão expansiva intradural, extramedular, estendendo-se do forame magno até a porção superior da lâmina de C2. A paciente foi submetida a uma craniectomia de fossa posterior e ressecção do arco posterior de C1. Durante exploração cirúrgica, auxiliada por monitoração eletrofisiológica e estimulação neural, foi identificado que a lesão tinha origem no ramo espinhal do nervo acessório direito. Foi então ressecada de forma completa com preservação dos fascículos íntegros do nervo de origem. O exame anatomopatológico confirmou a hipótese de schwannoma. A paciente evoluiu sem dor e com melhora do quadro neurológico, sendo preservada a função do nervo acessório. O schwannoma do ramo espinhal do nervo acessório é uma condição rara. A ressecção cirúrgica total é o tratamento de escolha para esses pacientes e pode ser alcançada sem lesões neurológicas significativas secundárias ao ato cirúrgico.

The history of neurosurgery at the University of Sao Paulo.

The history of neurosurgery at University of São Paulo comes from 1918, since its origins under the Department of Neurology from Chair of Psychiatric Clinic and Nervous Diseases. Professor Enjolras Vampré was the great inspiration for such medical specialty in the State of Sao Paulo. In 1929, the first neurosurgical procedures were performed in the recently (at time) organized Section of Neurosurgery. The official inauguration of the Division of Functional Neurosurgery occurred at June 1977, with the presence of worldwide well-known neuroscientists. The division suffered a deep streamlining under the leadership of Professor Raul Marino Jr., between the decades of 1990 and 2000. At this time, it was structured with the sections of neurological surgery, functional neurosurgery and neurosurgical emergency. Since 2008, Professor Manoel Jacobsen Teixeira is the Chairman of the Division and has provided the Division with the best available technological resources, performing more than 3,000 surgeries a year and training professionals who will, certainly, be some of the future leaders of brazilian neurosurgery.

The history of neurosurgery at the University of Sao Paulo / A historia da neurocirurgia na Universidade de Sao Paulo

The history of neurosurgery at University of São Paulo comes from 1918, since its origins under the Department of Neurology from Chair of Psychiatric Clinic and Nervous Diseases. Professor Enjolras Vampré was the great inspiration for such medical specialty in the State of Sao Paulo. In 1929, the first neurosurgical procedures were performed in the recently (at time) organized Section of Neurosurgery. The official inauguration of the Division of Functional Neurosurgery occurred at June 1977, with the presence of worldwide well-known neuroscientists. The division suffered a deep streamlining under the leadership of Professor Raul Marino Jr., between the decades of 1990 and 2000. At this time, it was structured with the sections of neurological surgery, functional neurosurgery and neurosurgical emergency. Since 2008, Professor Manoel Jacobsen Teixeira is the Chairman of the Division and has provided the Division with the best available technological resources, performing more than 3,000 surgeries a year and training professionals who will, certainly, be some of the future leaders of brazilian neurosurgery.

A história da neurocirurgia na Universidade de São Paulo remonta a 1918, quando surge sob o Departamento de Neurologia da cadeira de Clínica Psiquiátrica e Doenças Nervosas. O Professor Enjolras Vampré foi o grande inspirador da especialidade no estado de São Paulo. Em 1929, foram realizadas as primeiras intervenções neurocirúrgicas na então recentemente organizada Seção de Neurocirurgia. A fundação oficial da Divisão de Neurocirurgia Funcional data de junho de 1977 e contou com a participação de diversos cientistas de renome internacional. A Divisão passou por profunda reorganização sob a direção do Professor Raul Marino Jr. entre as décadas de 1990 e 2000, quando foi estruturada com os setores de neurocirurgia geral, neurocirurgia funcional e emergência neurocirúrgica. Desde 2008, o Professor Manoel Jacobsen Teixeira é responsável pela Divisão, que conta com os melhores recursos tecnológicos disponíveis, realizando mais de 3.000 cirurgias por ano e formando profissionais que certamente serão futuros líderes na neurocirurgia brasileira.

Avaliação das técnicas cirúrgicas para tratamento da mielorradiculopatia espondilótica cervical / Evaluación de las técnicas quirúrgicas para el tratamiento de la mielorradiculopatía cervical espondilótica / Evaluation of surgical techniques for treatment of cervical spondylotic myeloradiculopathy

OBJETIVO: Avaliar a eficácia do tratamento cirúrgico da mielorradiculopatia espondilótica cervical na produção de melhora neurológica pós-operatória, aferida em pontos pela escala da JOA e taxa de recuperação e as complicações do tratamento. MÉTODOS: Análise dos prontuários e os exames de imagem de 200 indivíduos submetidos a tratamento cirúrgico da mielorradiculopatia cervical no HC-FMUSP, no período de janeiro de 1993 a janeiro de 2007. A avaliação clínica foi quantificada pela escala da JOA, com média de segmento de 06 anos e 08 meses. RESULTADOS: Evidenciou-se melhora neurológica pós-operatória nas vias anterior e posterior, exceto nas laminectomias sem fusão, onde houve piora neurológica tardia. A via anterior mostrou um significante maior índice de complicações, relacionados a déficit de fusão intervertebral, deslocamento de enxerto, síndrome de disco adjacente, disfonia, disfagia, o mau posicionamento de enxerto e placas, lesão de raiz nervosa e significativo maior índice de re-intervenção cirúrgica. Na via posterior maior ocorrência de instabilidade em cifose pós-operatória na laminectomia, não sendo observada na laminoplastia, esta última com índices semelhantes aos encontrados na via anterior. Não houve melhora da dor axial nas laminoplastias e houve piora nas laminectomias, enquanto que nas discectomias e corpectomias houve significativa melhora do sintoma. CONCLUSÃO: As vias anterior e posterior foram eficazes em produzir melhora neurológica, exceto as laminectomias sem fusão. A via anterior produziu mais complicações, mas trata melhor a dor.

OBJECTIVE: To evaluate the efficacy of surgical treatment of cervical spondylotic myeloradiculopathy in the production of postoperative neurological improvement, measured in points by the scale of JOA (Japanese Orthopaedic Association) and the recovery rate and complications of therapy. METHODS: Analysis of medical records and imaging studies of 200 patients undergoing surgical treatment of cervical myeloradiculopathy in HC-FMUSP, from January 1993 to January 2007. Clinical evaluation was quantified by the scale of the JOA, with an average follow-up of 6 years and 8 months. RESULTS: There was post-operative neurological improvement in the anterior and posterior approach, except in laminectomy without fusion, where late neurological deterioration was observed. The anterior approach showed a significantly higher rate of complications related to poor fusion, intervertebral displacement of the graft, adjacent disc syndrome, dysphonia, dysphagia, poor positioning of the graft and plates, nerve root injury and significant higher rate of re-operation. In the posterior approach, increased occurrence of instability and kyphosis in the postoperative, in laminectomy were found, whereas in laminoplasty these conditions were not observed, presenting similar rates to those found for the anterior approach. There was no improvement in axial pain in the laminoplasties and worsening in laminectomies, whereas in discectomias and corpectomias there was significant relief of symptoms. CONCLUSION: The anterior and posterior routes were effective in producing neurological improvement, except for laminectomy without fusion. The anterior approach produced more complications, but is better for pain treatment.

OBJETIVO: Evaluar la eficacia del tratamiento quirúrgico de la mielorradiculopatía cervical espondilótica en la producción de la mejoría neurológica posoperatoria, medida en puntos en la escala de la JOA y la tasa de recuperación y las complicaciones de la terapia. MÉTODOS: Análisis de los registros médicos y de los exámenes de imagen de 200 pacientes sometidos a tratamiento quirúrgico de la mielorradiculopatía cervical en el HC-FMUSP, desde enero de 1993 a enero de 2007. La evaluación clínica se cuantificó mediante la escala de la JOA, con un segmento promedio de 06 años y 08 meses. RESULTADOS: Se observó una mejoría neurológica posoperatoria en las vías anterior y posterior, con excepción de las laminectomías sin fusión, donde hubo deterioro neurológico tardío. La vía anterior mostró una tasa significativamente mayor de complicaciones relacionadas con el déficit de fusión intervertebral, desplazamiento del injerto, síndrome de disco adyacente, disfonía, disfagia, o mala posición de injerto y placas, lesión de la raíz del nervio y tasa significativamente mayor de nueva intervención quirúrgica. En la vía posterior, mayor incidencia de inestabilidad en la cifosis posoperatoria, en la laminectomía, y en la laminoplastia no se observó esto, teniendo esta última tasas similares a las encontradas en la vía anterior. No hubo mejoría en el dolor axial en las laminoplastias y se agravó en las laminectomías, mientras que en las discectomías y las corpectomías se produjo una mejoría significativa de los síntomas. CONCLUSIÓN Las vías anterior y posterior fueron eficaces en la producción de mejoría neurológica, con excepción de las laminectomías sin fusión. La vía anterior produjo más complicaciones, pero el dolor es mejor tratado.

Fatores prognósticos associados ao tratamento cirúrgico da mielorradiculopatia espondilótica cervical / Factores pronósticos asociados con el tratamiento quirúrgico de la mielorradiculopatía cervical espondilótica / Prognostic factors associated with surgical treatment of cervical spondylotic myeloradiculopathy

OBJETIVO: Identificar os fatores clínicos dos indivíduos, fatores sociais, ambientais e dos exames de imagem que se correlacionam ao resultado final de melhora neurológica em pacientes submetidos ao tratamento cirúrgico da mielopatia espondilótica cervical. MÉTODOS: A avaliação clínica foi quantificada pela escala deficitária da JOA. Analisamos 200 casos de mielorradiculopatia cervical, operados no HC-FMUSP, no período de janeiro de 1993 a janeiro de 2007. A média de segmento foi de 06 anos e 08 meses. A análise radiológica foi baseada nos critérios de instabilidade de White e scala de Kellgren. RESULTADOS: Em 80% houve melhora, 14% estabilização e em 6% piora do quadro neurológico. A piora neurológica não foi associada com nenhum fator clínico, ambiental ou de imagem. A melhora neurológica foi diretamente proporcional a menor idade na cirurgia, ausência de co-morbidade, sinal de Hoffman, atrofia muscular, hipersinal medular na RNM, menor período de evolução pré-operatório, melhor status neurológico pré-operatório e inversamente proporcional ao diâmetro AP do canal medular e multiplicidade de compressões. Identificou-se associação com o tabagismo. Mais de 70 anos, evolução superior a 24 meses, atrofia muscular, pontuação JOA igual ou inferior a sete pontos e diâmetro AP do canal inferior ou igual a seis mm não foram associado à melhora.

OBJECTIVE: Identify the individual, social, environmental clinical factors and also imaging studies which correlate to the final result of neurological improvement in patients undergoing surgical treatment of cervical spondylotic myelopathy. METHODS: The clinical assessment was quantified by the deficit in JOA scale. We analyzed 200 cases of cervical myeloradiculopathy surgically treated in HC-FMUSP, from January 1993 to January 2007. The mean follow-up was 6 years and 8 months. The analysis was based on radiological criteria of instability by White and Kellgren scale. RESULTS: 80% had improved, 14% stabilized and 6% had worsened. The neurological deterioration was not associated with any clinical, environmental or imaging factor. The neurological improvement was directly proportional to the lower age at surgery, absence of co-morbidity, Hoffman sign, muscular atrophy, spinal cord hyperintensity on MRI, the shortest period of preoperative evolution, better preoperative neurological status and was inversely proportional to the AP diameter of the spinal canal and to multiple cord compressions. An association with smoking was observed. Over 70 years of age, evolution superior to 24 months, muscle atrophy, JOA score equal to or less than seven points and AP canal diameter less than or equal to 6mm were not associated with improvement.

OBJETIVO: Identificar los factores clínicos de los pacientes, factores sociales, ambientales y de exámenes de imagen que se correlacionan con el resultado final de mejoría neurológica en pacientes sometidos a tratamiento quirúrgico de la mielopatía cervical espondilótica. MÉTODOS: La evaluación clínica fue cuantificada por la escala de JOA. Se analizaron 200 casos de mielorradiculopatía cervical, operados en el HC-FMUSP, desde enero de 1993 a enero de 2007. El promedio del segmento fue de 06 años y 08 meses. El análisis radiológico se basó en los criterios de inestabilidad de White y en la escala de Kellgren. RESULTADOS: El 80% había mejorado, el 14% tuvo estabilización y el 6% presentó deterioro del cuadro neurológico. El empeoramiento neurológico no se asoció con ningún factor clínico, ambiental ni de imagen. La mejoría neurológica fue directamente proporcional a edad menor para la cirugía, ausencia de comorbilidad, signo de Hoffman, atrofia muscular, hiperintensidad de la medula espinal en la RM, período más corto de la evolución preoperatoria, mejor estado neurológico preoperatorio, y siendo inversamente proporcional al diâmetro AP del canal espinal y a las compresiones múltiples. Identificada una asociación con el tabaquismo. Más de 70 años de edad, la evolución superior a 24 meses, la atrofia muscular, la puntuación JOA igual o inferior a siete puntos y el diámetro AP del canal menor o igual a seis mm no se asociaron con a mejoría.