Predictors of poor functional outcomes in adults with type I Chiari Malformation: Clinical and surgical factors assessed with the Chicago Chiari Outcome Scale over long-term follow-up.

OBJECTIVE: This study aimed to identify clinical and surgical features associated with poor long-term postoperative outcomes in patients diagnosed with Type I Chiari Malformation (CMI) treated with posterior fossa decompression with duroplasty (PFDD), with or without tonsillar coagulation. METHODS: This retrospective, single-center study included 107 adult patients with CMI surgically treated between 2010 and 2021. The surgical technique involved a midline suboccipital craniectomy, C1 laminectomy, durotomy, arachnoid dissection, duroplasty, and tonsillar coagulation until 2014, after which tonsillar coagulation was discontinued. Postoperative outcomes were assessed using the Chicago Chiari Outcome Scale (CCOS) at a median follow-up of 35 months. Clinical, surgical, and neuroimaging data were analyzed using the Wilcoxon signed-rank test, Cox regression analysis, and Kaplan-Meier survival curves to identify predictors of poor functional outcomes. RESULTS: Of the 107 patients (mean age 43.9 years, SD 13), 81 (75.5 %) showed functional improvement, 25 (23.4 %) remained unchanged, and 1 (0.9 %) experienced worsened outcomes. Cephalalgia, bilateral motor weakness, and bilateral paresthesia were the most frequent initial symptoms. Tonsillar coagulation was performed in 31 cases (28.9 %) but was clinically associated with higher rates of unfavorable outcomes. The Wilcoxon signed-rank test indicated that long-term follow-up CCOS was significantly higher than postoperative CCOS (Z = -7.678, p < 0.000). Multivariate Cox analysis identified preoperative bilateral motor weakness (HR 6.1, 95 % CI 1.9-18.9; p = 0.002), hydrocephalus (HR 3.01, 95 % CI 1.3-6.9; p = 0.008), and unilateral motor weakness (HR 2.99, 95 % CI 1.1-8.2; p = 0.033) as significant predictors of poor outcomes on a long-term follow-up. CONCLUSION: This study highlights the high rate of functional improvement in CMI patients following PFDD. Preoperative motor weakness and hydrocephalus were significant predictors of poor long-term outcomes. Tonsillar coagulation did not demonstrate a clear clinical benefit and may be associated with worse outcomes. Our findings suggest that careful preoperative assessment and selection of surgical techniques are crucial for optimizing patient outcomes.

Evolution from microscopic transoral to endoscopic endonasal odontoidectomy.

OBJECT: The goal of this study was to compare the indications, benefits, and complications between the endoscopic endonasal approach (EEA) and the microscopic transoral approach to perform an odontoidectomy. Transoral approaches have been standard for odontoidectomy procedures; however, the potential benefits of the EEA might be demonstrated to be a more innocuous technique. The authors present their experience with 12 consecutive cases that required odontoidectomy and posterior instrumentation. METHODS: Twelve consecutive cases of craniovertebral junction instability with or without basilar invagination were diagnosed at the National Institute of Neurology and Neurosurgery in Mexico City, Mexico, between January 2009 and January 2013. The EEA was used for 5 cases in which the odontoid process was above the nasopalatine line, and was compared with 7 cases in which the odontoid process was beneath the nasopalatine line; these were treated using the transoral microscopic approach (TMA). Odontoidectomy was performed after occipital-cervical or cervical posterior augmentation with lateral mass and translaminar screws. One case was previously fused (Oc-C4 fusion). The senior author performed all surgeries. American Spinal Injury Association scores were documented before surgical treatment and after at least 6 months of follow-up. RESULTS: Neurological improvement after odontoidectomy was similar for both groups. From the transoral group, 2 patients had postoperative dysphonia, 1 patient presented with dysphagia, and 1 patient had intraoperative CSF leakage. The endoscopic procedure required longer surgical time, less time to extubation and oral feeding, a shorter hospital stay, and no complications in this series. CONCLUSIONS: Endoscopic endonasal odontoidectomy is a feasible, safe, and well-tolerated procedure. In this small series there was no difference in the outcome between the EEA and the TMA; however, fewer complications were documented with the endonasal technique.

Operative technique for en bloc resection of upper cervical chordomas: extended transoral transmandibular approach and multilevel reconstruction.

Anterior exposure for cervical chordomas remains challenging because of the anatomical complexities and the restoration of the dimensional balance of the atlanto-axial region. In this report, we describe and analyze the transmandibular transoral approach and multilevel spinal reconstruction for upper cervical chordomas. We report two cases of cervical chordomas (C2 and C2-C4) that were treated by marginal en bloc resection with a transmandibular approach and anterior-posterior multilevel spinal reconstruction/fixation. Both patients showed clinical improvement. Postoperative imaging was negative for any residual tumor and revealed adequate reconstruction and stabilization. Marginal resection requires more extensive exposure to allow the surgeon access to the entire pathology, as an inadequate tumor margin is the main factor that negatively affects the prognosis. Anterior and posterior reconstruction provides a rigid reconstruction that protects the medulla and decreases axial pain by properly stabilizing the cervical spine.

Knowledge of skull base anatomy and surgical implications of human sacrifice among pre-Columbian Mesoamerican cultures.

Human sacrifice became a common cultural trait during the advanced phases of Mesoamerican civilizations. This phenomenon, influenced by complex religious beliefs, included several practices such as decapitation, cranial deformation, and the use of human cranial bones for skull mask manufacturing. Archaeological evidence suggests that all of these practices required specialized knowledge of skull base and upper cervical anatomy. The authors conducted a systematic search for information on skull base anatomical and surgical knowledge among Mesoamerican civilizations. A detailed exposition of these results is presented, along with some interesting information extracted from historical documents and pictorial codices to provide a better understanding of skull base surgical practices among these cultures. Paleoforensic evidence from the Great Temple of Tenochtitlan indicates that Aztec priests used a specialized decapitation technique, based on a deep anatomical knowledge. Trophy skulls were submitted through a stepwise technique for skull mask fabrication, based on skull base anatomical landmarks. Understanding pre-Columbian Mesoamerican religions can only be realized by considering them in their own time and according to their own perspective. Several contributions to medical practice might have arisen from anatomical knowledge emerging from human sacrifice and decapitation techniques.

Imaging features of sellar cysticercosis.

Cases of sellar involvement of neurocysticercosis (NCC) are rare. Little is known about the mechanisms by which the parasite can compromise the pituitary gland. Although NCC damages sellar structures with direct compression by large cysts, extension through the basal cisterns and third ventricle with focal arachnoiditis can result as an inflammatory response. Evaluation for hypophyseal lesions in patients with NCC may allow for the diagnosis of unexplained loss of visual acuity and hormonal disturbances.

Ventriculostomia endoscópica del tercer ventrículo / Endoscopyc third ventriculostomy

Las complicaciones asociadas a las cirugías de derivación ventricular han renovado el interés en buscar alternativas para el manejo de la hidrocefalia. La ventriculostomía endoscópica del tercer ventrículo es un procedimiento efectivo en el manejo de ciertos tipos de hidrocefalia como la secundaria a estenosis acueductal congénita o adquirida, compresión del sistema ventricular debida a tumores, lesiones en fosa posterior. Reportes recientes incluyen otros tipos de hidrocefalia tanto comunicante como no comunicante. El objetivo de este artículo es revisar la ventriculostomía endoscópica, sus complicaciones, indicaciones y fallas. Este es un procedimiento seguro con baja morbilidad y buenos resultados. Sin embargo, es necesario definir los candidatos ideales para el procedimiento.

Evaluación funcional del músculo temporal en el abordaje pterional / Funtional evaluation of temporal muscle in the pterional approach

La craneotomía pterional es uno de los abordajes más comunes dentro de la neurocirugía, tienen inconvenientes tales como la sección del músculo temporal que ocasiona defectos estéticos importantes. Se realizó un estudio comparativo para evaluar las técnicas de disección del músculo temporal en el abordaje pterional y definir cuál es la que presenta menor lesión al músculo, así como a la rama frontotemporal del nervio facial. Las tres técnicas evaluadas fueron: I. La sección muscular transversal, II. Disección subfacial, y III. Craneotomía osteoplástica. En todos los pacientes se valoró un procedimiento quirúrgico unilateral, con evolución neurológica favorable y participación voluntaria. Se encontraron los mejores resultados cosméticos para el grupo 2, con un hundimiento de la fosa temporal de 1.08 mm contra 2.6 mm para los del grupo 1 (p=0.0020) y 2 mm para el grupo 3 ( p=0.033). En ningún caso hubo datos clínicos de lesión a la rama frontotemporal del nervio facial. La electromiografía tuvo pocos cambios en el grupo 2. Se concluyó que el abordaje subfacial tiene los mejores resultados estéticos y funcionales, es una técnica que ofrece un adecuado corredor quirúrgico sin que la disección y reparación de la fascia del músculo temporal modificaran de manera significativa el tiempo quirúrgico.

Frequency of motor neuron diseases in a Mexico City referral center

Objetivo. Analizar la incidencia y características clínicas de las enfermedades de neurona motora (ENM) en una institución mexicana. Material y Métodos. Es un estudio retrospectivo de las principales características clínicas de 274 casos de ENM diagnosticados en el Instituto Nacional de Neurología /INNN) de la ciudad de México, de 1965 a 1995, como casos definitivos de ENM con base en los criterios de El Escorial (248 casos de esclerosis lateral amiotrófica, 15 de parálisis bulbar progresiva, 8 de esclerosis lateral primaria y 3 de atrofia espinal progresiva). Resultados. La frecuencia de la enfermedad en el INNN se incrementó gradualmente durante los 31 años revisados. La edad promedio de inicio de la enfermedad fue de 48 años, en contraste con una edad de inicio mayor encontrada en el resto del mundo. Las características clínicas del grupo estudiado fueron similares a las de otros informes. Conclusiones. Hubo un notable incremento en la frecuencia de la ENM en el INNN, en forma similar a lo observado a nivel mundial del padecimiento, salvo por una aparente edad de inicio menor. Es necesaria la realización de estudios prospectivos poblacionales para conocer la incidencia de las ENM en México