[Biology and mechanobiology of the intervertebral disc]. / Biología y mecanobiología del disco intervertebral.

The intervertebral disc (IVD) is noted for its low cell content, and being the largest avascular structure of human body. The low amount of cells in the disc have to adapt to an anaerobic metabolism with low oxygen pressure and acidic pH. Apart from surviving in an adverse microenvironment, they are exposed to a high level of mechanical stress. The biological adaptation of cells to acidosis and hyperosmolarity conditions are regulated by mechanoproteins, which are responsible for converting a mechanical signal into a cellular response, thus modifying its gene expression. Mechanobiology helps us to better understand the pathophysiology of IVD and its potential biological repair.

Does aqueductal stenosis influence the lumbar infusion test in normal-pressure hydrocephalus?

BACKGROUND: Late-onset idiopathic aqueductal stenosis may present with clinical features indistinct from idiopathic normal-pressure hydrocephalus (NPH). Moreover, aqueductal stenosis (AS) is not always detected by conventional magnetic resonance imaging (MRI). The aim of this study was to compare the hydrodynamic pattern among NPH patients according to the patency of the aqueduct. METHODS: Fifty-six consecutive lumbar infusion tests were performed in patients with NPH syndrome. Precipitating causes of hydrocephalus were excluded, and aqueductal patency was examined through high-resolution, T2-weighted 3D MRI. Patients were classified into two groups: non-patent aqueduct and patent aqueduct. Mean values of pressure and pulse amplitude were obtained from basal and plateau stages of infusion studies. RESULTS: Twelve of 56 patients with NPH-like symptoms presented with morphological AS (21.4 %). Patent aqueduct and non-patent aqueduct groups had similar values of mean opening lumbar pressure (8.2 vs. 8.1 mmHg), and mean opening pulse amplitude (3.1 vs. 2.9 mmHg). Mean pressure in the plateau stage (28.6 vs. 23.2 mmHg), and mean pulse amplitude in the plateau stage (12.5 vs. 10.6 mmHg) were higher in the patent aqueduct group. These differences were not statistically significant. Only Rout was significantly higher in the patent aqueduct group (13.6 vs. 10.1 mmHg/ml/min). One-third of NPH patients with AS presented Rout >12 mmHg/ml/min. CONCLUSIONS: No differences in mean pressure or pulse amplitude during basal and plateau epochs of the lumbar infusion test in NPH patients were detected, regardless of aqueductal patency. However, Rout was significantly higher in patients with patent aqueduct.

[Orbital leiomyoma. Case report and review of the literature]. / Leiomioma intraorbitario. Caso clínico y revisión de la literatura.

Leiomyoma are slowly growing lesions arising from smooth muscle. Orbital location has been reported in 25 cases. Histological findings and no recurrence after total resection support their benign behaviour. We report an intraconal orbital haemangioleiomyoma in a 55-year-old female treated by total resection through fronto-orbital craniotomy, with no recurrence after 15 months of follow-up. Radiological and pathological features are discussed, emphasising the prognostic role of the surgery.

[Innervation of the intervertebral disc]. / La inervación del disco intervertebral.

Until very recently, intervertebral disc innervation was a subject of considerable debate. Nowadays, the introduction of inmunohistochemical techniques associated to specific antibodies and studies with retrograde tracers in nerves have allowed greater understanding of disc innervation in physiological and pathological conditions and also endings characteristics and their patterns of distribution in both situations. The existing controversies regarding structural basis of discogenic pain, have raised the interest of knowing the influence of innervation in back pain from discal origin and its characteristics. Today, we know that pathologic neoinnervation accompanying radial fissures is an important factor in the genesis of discogenic pain; within a complex mechanism in which other neurobiomechemical, inflammatory and biomechanical factors are involved.

[Minimally invasive approach of extramedullary intradural spinal tumours. Review of 30 cases]. / Abordaje mínimamente invasivo de las lesiones espinales intradurales extramedulares. Revisión de 30 casos.

OBJECTIVE: To analyse the safety and effectiveness of a microsurgical unilateral approach in minimally invasive surgery of extramedullary, intradural spinal tumours. MATERIALS AND METHODS: This was a retrospective study of 29 patients with 30 extramedullary, intradural spinal tumours approached through unilateral laminectomy -hemilaminectomy. Epidemiological data, location and histology of the lesions and radiological and clinical evolution of the patients were recorded. The Nurick scale was used in the preoperative and postoperative functional assessment conducted during the last follow-up consultation. The mean age of patients was 60 years and there was a predominance of the female gender. The mean time elapsed from the onset of symptoms to diagnosis was 11.6 months. Sensitive and motor deficits were the most common symptoms. Meningioma was the most frequent lesion, followed by neurinoma and ependymoma. The most commonly affected level was the dorsal, followed by the lumbar and cervical. RESULTS: Total resection was performed in all cases except for one cervical neurinoma with extraforaminal extension. Three patients presented postoperative complications -cerebrospinal fluid fistula, asymptomatic pseudomeningocele and postoperative functional worsening- which were resolved with conservative treatment. The mean time of clinical and radiological follow-up was 33.4 months, with no tumoural recurrences being observed except for two cases of meningiomas. After the follow-up period, patients without functional disorders remained stable and all patients with functional disorders presented a clinical improvement of at least one point in the Nurick scale. CONCLUSIONS: We consider that the microsurgical unilateral approach is a safe and effective technique for the resection of most extramedullary, intradural spinal tumours.

Brown tumor of the orbital roof as an initial and isolated manifestation of secondary hyperparathyroidism.

Brown tumors appear in advanced stages of hyperparathyroidism. Only 17 cases have been documented in the orbit. We report a case of a young woman with a brown tumor in the orbital roof. Secondary hyperparathyroidism due to chronic renal disease was detected during the preoperative study. The pathogenesis, diagnosis and management of the brown tumor are discussed.

Endoscopic endonasal superomedial orbitectomy: How far is safe and possible?

OBJECTIVES: During the endoscopic endonasal approach (EEA) to the anterior cranial base, the lateral boundaries are the lamina papyracea (medial orbital walls) bilaterally but further extension in the coronal plane is possible by performing a superomedial orbitectomy. The aims of this study are to describe the technique of the endoscopic endonasal transethmoidal supraorbital approach to the anterior cranial base and to calculate the extension in the coronal plane added with the superomedial orbitectomy. METHODS: Thirty superomedial orbitectomies via EEA were completed in 15 fresh-frozen heads. After finishing the procedure, a bifrontal craniotomy with removal of both frontal lobes was performed in order to measure the width of the supraorbital EEA in the coronal plane. We divided the anterior cranial base into five zones related to distinct anatomical segments: sinusal zone, post-sinusal zone, anterior ethmoidal, inter-ethmoidal zone, and posterior ethmoidal zone. Measurements of each segment of the anterior cranial base were taken. RESULTS: In all specimens, it was possible to perform a superomedial orbitectomy without excessive retraction of the orbital contents. The inter-ethmoidal zone is the segment where the lateral extension was widest. The mean total width in this area was 45.4 mm. The superomedial orbitectomy added a mean of 8 mm on each side to the total anterior skull base exposure. CONCLUSION: The endoscopic endonasal superomedial orbitectomy added important extension in the coronal plane during an EEA to the anterior cranial base. The inter-ethmoidal zone has shown the greatest lateral extension. LEVEL OF EVIDENCE: N/A Laryngoscope, 130:1151-1157, 2020.

Giant-cell granuloma of the axis.

Giant-cell granuloma is a benign and nonneoplastic lesion with an expansive and locally destructive behavior. It typically involves the mandible and the maxilla. Only 1 case arising from the odontoid process of the axis has been reported previously. The authors report on a 64-year-old man with a giant-cell granuloma of the axis. They review this uncommon entity, emphasizing the complexity of differentiating between this lesion and other giant-cell tumors.

Comportamiento de la presión intrabdominal en el abdomen agudo quirúrgico / Behavior of intrabdominal pressure in the acute surgical abdomen

Introducción: la presión intrabdominal se define como el resultado de la tensión presente dentro del espacio anatómico abdominal y es un elemento clave en todos los procesos fisiopatológicos que se desarrollan en el abdomen agudo o en sus complicaciones. Objetivo: evaluar el comportamiento de la presión intrabdominal medida por vía transvesical en los pacientes con abdomen agudo quirúrgico. Método: se realizó una investigación de carácter cuasiexperimental del comportamiento de la presión intrabdominal, en 200 enfermos con cuadros de abdomen agudo quirúrgico, atendidos en el Hospital General Docente Comandante Pinares, durante el periodo comprendido de abril 2011 a octubre 2015. Se controlaron variables como la edad, sexo, presión intrabdominal, frecuencia respiratoria y cardiaca, así como diagnóstico etiológico. Resultados: la mayor incidencia de pacientes pertenece al sexo masculino, predominando las edades 40 - 49 años. El diagnóstico etiológico que más se presentó fue la apendicitis aguda con un valor de presión intrabdominal normal, entre 1 y 9 cm de agua. El incremento de la PIA modificó la frecuencia respiratoria (polipnea) y la frecuencia cardiaca (taquicardia). Después de realizar la laparotomía y descompresión abdominal la PIA regresa a valores normales en el postoperatorio. Conclusiones: la medición de la presión intrabdominal constituye una herramienta más para el diagnóstico del abdomen agudo quirúrgico y sus complicaciones(AU)

Introduction: intrabdominal pressure is defined as the result of the tension present within the abdominal anatomical space and is a key element in all the pathophysiological processes developed in the acute abdomen or in its complications. Objective: to evaluate the behavior of intrabdominal pressure measured by the transvesical approach in patients with acute surgical abdomen. Method: a quasiexperimental investigation was performed on the behavior of intrabdominal pressure in 200 patients with surgical acute abdomen, cared at Comandante Pinares General Teaching Hospital, during the period from April 2011 to October 2015. Some variables were controlled, such as age, sex, intrabdominal pressure, respiratory and cardiac frequency, as well as etiological diagnosis. Results: the highest incidence of patients belongs to the male sex, with ages ranging from 40 to 49 years old. The most frequent etiologic diagnosis was acute appendicitis with normal intrabdominal pressure, between 1 and 9 cm of water. The increase of intrabdominal pressure altered respiratory rate (polypnea) and heart rate (tachycardia). After performing abdominal laparotomy and decompression the intrabdominal pressure returned to normal postoperative values. Conclusions: the measurement of intrabdominal pressure is one more tool for the diagnosis of acute surgical abdomen and its complications(AU)

Biología y mecanobiología del disco intervertebral / Biology and mechanobiology of the intervertebral disc

El disco intervertebral (DIV) se caracteriza por su escasa celularidad y por constituir la estructura avascular más grande del cuerpo humano. Las escasas células del disco tienen que adaptarse a un metabolismo anaerobio con baja tensión de O2 y pH ácido. Además de sobrevivir a un microambiente adverso, están expuestas a un elevado estrés mecánico. La adaptación biológica de las células a las condiciones de acidosis e hiperosmolaridad está regulada por mecanoproteínas responsables de convertir una señal mecánica en respuesta celular, modificando su expresión génica. La mecanobiología nos ayuda a entender mejor la biopatología del DIV y su potencial reparación biológica

The intervertebral disc (IVD) is noted for its low cell content, and being the largest avascular structure of human body. The low amount of cells in the disc have to adapt to an anaerobic metabolism with low oxygen pressure and acidic pH. Apart from surviving in an adverse microenvironment, they are exposed to a high level of mechanical stress. The biological adaptation of cells to acidosis and hyperosmolarity conditions are regulated by mechanoproteins, which are responsible for converting a mechanical signal into a cellular response, thus modifying its gene expression. Mechanobiology helps us to better understand the pathophysiology of IVD and its potential biological repair

Leiomioma intraorbitario. Caso clínico y revisión de la literatura / Orbital leiomyoma. Case report and review of the literature

Los leiomiomas son lesiones de lento crecimiento originarias del músculo liso. La localización orbitaria solo ha sido descrita en 25 casos. Sus características histológicas y la ausencia de recurrencia tras la resección total apoyan su comportamiento benigno. Presentamos un caso de hemangioleiomioma intraconal en una mujer de 55 años tratado quirúrgicamente mediante craneotomía fronto-orbitaria con resección total y sin recurrencia de la lesión tras 15 meses de seguimiento. Se discuten los hallazgos histológicos y radiológicos, enfatizando en el papel pronóstico de la cirugía

Leiomyoma are slowly growing lesions arising from smooth muscle. Orbital location hasbeen reported in 25 cases. Histological findings and no recurrence after total resectionsupport their benign behaviour. We report an intraconal orbital haemangioleiomyoma ina 55-year-old female treated by total resection through fronto-orbital craniotomy, with norecurrence after 15 months of follow-up. Radiological and pathological features are discussed, emphasising the prognostic role of the surgery

La inervación del disco intervertebral / Innervation of the intervertebral disc

Hasta hace poco la inervación del disco intervertebral fue objeto de debate. La introducción de técnicas de inmunohistoquímica asociadas a anticuerpos específicos y los estudios con trazadores nerviosos retrógrados han permitido conocer mejor la inervación del disco en condiciones normales y patológicas así como las características de las terminaciones y sus patrones de distribución en ambas situaciones. Las controversias que existen acerca de las bases estructurales del dolor discogénico han despertado el interés por conocer la influencia de la inervación en el dolor lumbar de origen discal y sus características. Actualmente sabemos que la neoinervación patológica de las fisuras radiales es un factor importante en la génesis del dolor discogénico dentro de un complejo mecanismo en que están implicados factores neurobioquímicos, inflamatorios y biomecánicos (AU)

Until very recently, intervertebral disc innervation was a subject of considerable debate. Nowadays, the introduction of inmunohistochemical techniques associated to specific antibodies and studies with retrograde tracers in nerves have allowed greater understanding of disc innervation in physiological and pathological conditions and also endings characteristics and their patterns of distribution in both situations. The existing controversies regarding structural basis of discogenic pain, have raised the interest of knowing the influence of innervation in back pain from discal origin and its characteristics. Today, we know that pathologic neoinnervation accompanying radial fissures is an important factor in the genesis of discogenic pain; within a complex mechanism in which other neurobiomechemical, inflammatory and biomechanical factors are involved