Transcriptomic analysis of subarachnoid cysts of Taenia solium reveals mechanisms for uncontrolled proliferation and adaptations to the microenvironment.

Subarachnoid neurocysticercosis (SANCC) is caused by an abnormally transformed form of the metacestode or larval form of the tapeworm Taenia solium. In contrast to vesicular parenchymal and ventricular located cysts that contain a viable scolex and are anlage of the adult tapeworm, the subarachnoid cyst proliferates to form aberrant membranous cystic masses within the subarachnoid spaces that cause mass effects and acute and chronic arachnoiditis. How subarachnoid cyst proliferates and interacts with the human host is poorly understood, but parasite stem cells (germinative cells) likely participate. RNA-seq analysis of the subarachnoid cyst bladder wall compared to the bladder wall and scolex of the vesicular cyst revealed that the subarachnoid form exhibits activation of signaling pathways that promote proliferation and increased lipid metabolism. These adaptions allow growth in a nutrient-limited cerebral spinal fluid. In addition, we identified therapeutic drug targets that would inhibit growth of the parasite, potentially increase effectiveness of treatment, and shorten its duration.

Postsurgical Outcomes of Mesial Temporal Lobe Epilepsy due to Hippocampal Sclerosis Associated with Calcified Neurocysticercosis.

The aim of this study was to analyze postsurgical outcomes for individuals with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) who underwent anterior temporal lobectomy, based on the presence of calcified neurocysticercosis (cNCC). A retrospective cross-sectional study was conducted on 89 patients with MTLE-HS who underwent anterior temporal lobectomy between January 2012 and December 2020 at a basic epilepsy surgery center located in Lima, Peru. We collected sociodemographic, clinical, and diagnostic information. The postsurgical results were analyzed using bivariate analysis according to the Engel classification. We included 89 individuals with a median age of 28 years (interquartile range [IQR]: 24-37), and more than half (55.1%) were male. Seventeen (19.1%) were diagnosed with cNCC. A greater number of patients with cNCC had lived in rural areas of Peru during their early life compared with those without cNCC (12 [70.6%] versus 26 [36.1%]; P = 0.010). Patients with cNCC exhibited a greater median frequency of focal to bilateral tonic-clonic seizures per month (1 [IQR: 0-2] versus 0 [0-0.5]; P = 0.009). Conversely, a lower proportion of patients with cNCC reported a history of an initial precipitating injury in comparison to the group without cNCC (4 [23.5%] versus 42 [58.3%]; P = 0.014). At the 1-year follow-up, most patients (82.4%) with cNCC were categorized as Engel IA. Similarly, at the 2-year follow-up, nine (75.0%) were classified as Engel IA. Our findings suggest that most patients diagnosed with cNCC exhibit favorable postsurgical outcomes, comparable to those without cNCC. Additionally, it can be postulated that cNCC may play a role as an initial precipitating injury.

The state of art of awake craniotomy in Latin American countries: a scoping review.

BACKGROUND AND OBJECTIVE: Awake craniotomy (AC) is a valuable technique for surgical interventions in eloquent areas, but its adoption in low- and middle-income countries faces challenges like limited infrastructure, trained personnel shortage, and inadequate funding. This scoping review explores AC techniques in Latin American countries, focusing on patient characteristics, tumor location, symptomatology, and outcomes. METHODS: A scoping review followed PRISMA guidelines, searching five databases in English, Spanish, and Portuguese. We included 28 studies with 258 patients (mean age: 43, range: 11-92). Patterns in AC use in Latin America were analyzed. RESULTS: Most studies were from Brazil and Mexico (53.6%) and public institutions (70%). Low-grade gliomas were the most common lesions (55%), most of them located in the left hemisphere (52.3%) and frontal lobe (52.3%). Gross-total resection was achieved in 34.3% of cases. 62.9% used an Asleep-Awake-Asleep protocol, and 14.8% used Awake-Awake-Awake. The main complication was seizures (14.6%). Mean post-surgery discharge time was 68 h. Challenges included limited training, infrastructure, and instrumentation availability. Strategies discussed involve training in specialized centers, seeking sponsorships, applying for awards, and multidisciplinary collaborations with neuropsychology. CONCLUSION: Improved accessibility to resources, infrastructure, and adequate instrumentation is crucial for wider AC availability in Latin America. Despite disparities, AC implementation with proper training and teamwork yields favorable outcomes in resource-limited centers. Efforts should focus on addressing challenges and promoting equitable access to this valuable surgical technique in the region.

Increased iron uptake in the bladder wall of racemose cysts of Taenia solium.

Racemose neurocysticercosis is an aggressive infection caused by the aberrant expansion and proliferation of the bladder wall of the Taenia solium cyst within the subarachnoid spaces of the human brain. The parasite develops and proliferates in a microenvironment with low concentrations of growth factors and micronutrients compared to serum. Iron is important for essential biological processes, but its requirement for racemose cyst viability and proliferation has not been studied. The presence of iron in the bladder wall of racemose and normal univesicular T. solium cysts was determined using Prussian blue staining. Iron deposits were readily detected in the bladder wall of racemose cysts but were not detectable in the bladder wall of univesicular cysts. Consistent with this finding, the genes for two iron-binding proteins (ferritin and melanotransferrin) and ribonucleotide reductase were markedly overexpressed in the racemose cyst compared to univesicular cysts. The presence of iron in the bladder wall of racemose cysts may be due to its increased metabolic rate due to proliferation.

Proliferative cells in racemose neurocysticercosis have an active MAPK signalling pathway and respond to metformin treatment.

Racemose neurocysticercosis is an aggressive infection caused by the aberrant expansion of the cyst form of Taenia solium within the subarachnoid spaces of the human brain and spinal cord, resulting in the displacement of the surrounding host tissue and chronic inflammation. We previously demonstrated that the continued growth of the racemose bladder wall is associated with the presence of mitotically active cells but the nature and control of these proliferative cells are not well understood. Here, we demonstrated by immunofluorescence that the racemose cyst has an active mitogen-activated protein kinases (MAPK) signalling pathway that is inhibited after treatment with metformin, which reduces racemose cell proliferation in vitro, and reduces parasite growth in the murine model of Taenia crassiceps cysticercosis. Our findings indicate the importance of insulin receptor-mediated activation of the MAPK signalling pathway in the proliferation and growth of the bladder wall of the racemose cyst and its susceptibility to metformin action. The antiproliferative action of metformin may provide a new therapeutic approach against racemose neurocysticercosis.

Identification and culture of proliferative cells in abnormal Taenia solium larvae: Role in the development of racemose neurocysticercosis.

Racemose neurocysticercosis is an aggressive disease caused by the aberrant expansion of the cyst form of Taenia solium within the subarachnoid spaces of the human brain and spinal cord resulting in a mass effect and chronic inflammation. Although expansion is likely caused by the proliferation and growth of the parasite bladder wall, there is little direct evidence of the mechanisms that underlie these processes. Since the development and growth of cysts in related cestodes involves totipotential germinative cells, we hypothesized that the expansive growth of the racemose larvae is organized and maintained by germinative cells. Here, we identified proliferative cells expressing the serine/threonine-protein kinase plk1 by in situ hybridization. Proliferative cells were present within the bladder wall of racemose form and absent from the homologous tissue surrounding the vesicular form. Cyst proliferation in the related model species Taenia crassiceps (ORF strain) occurs normally by budding from the cyst bladder wall and proliferative cells were concentrated within the growth buds. Cells isolated from bladder wall of racemose larvae were established in primary cell culture and insulin stimulated their proliferation in a dose-dependent manner. These findings indicate that the growth of racemose larvae is likely due to abnormal cell proliferation. The different distribution of proliferative cells in the racemose larvae and their sensitivity to insulin may reflect significant changes at the cellular and molecular levels involved in their tumor-like growth. Parasite cell cultures offer a powerful tool to characterize the nature and formation of the racemose form, understand the developmental biology of T. solium, and to identify new effective drugs for treatment.

Stereotactic surgery for neurocysticercosis of the 4th ventricle: illustrative cases.

BACKGROUND: Neurocysticercosis, caused by the larval stage of Taenia solium, affects the cerebral ventricles in 20-30% of cases and may lead to hydrocephalus and other neurological morbidity. Conventional treatment for cysts in the 4th ventricle includes open surgery (suboccipital approach) and neuroendoscopy, with the latter being the option of choice. Stereotactic surgery, minimally invasive, offers a good alternative for this type of deep lesion. OBSERVATIONS: The authors report the cases of two women, 30 and 45 years old, who presented with headache, dizziness, and ataxia and were diagnosed with 4th ventricle cysticercosis. Magnetic resonance imaging (MRI) revealed dilated 4th ventricles (approximately 2.5 cm in both cases, with cystic images inside the ventricular cavity). Both patients were treated with stereotactic surgery via a suboccipital transcerebellar approach. Cyst material was extracted, and the diagnosis was confirmed by pathological examination. The surgeries had no complications and resulted in clinical improvement. Control MRI scans showed reduction of the volume of the ventricle without residual cysts. LESSONS: Minimally invasive stereotactic surgery provided a safe alternative for 4th ventricle neurocysticercosis cysts, with more benefits than risks in comparison with conventional techniques.

Endoscopic endonasal surgery for massive subarachnoid neurocysticercosis: illustrative case.

BACKGROUND: Subarachnoid neurocysticercosis (NCC) is associated with high morbidity and mortality rates. Conventional transcranial approaches and transventricular endoscopy have been previously reported for extraparenchymal NCC and ventricular NCC, respectively. By October 2019, endonasal endoscopic approaches had not been used for the treatment of NCC. OBSERVATIONS: A 54-year-old-woman with NCC was admitted with acute neurological deterioration due to severe intracranial hypertension caused by massive subarachnoid NCC cysts, as evidenced on magnetic resonance imaging (MRI) with great brainstem compression. The case was discussed, and an endoscopic endonasal resection of the NCC cysts was scheduled. The diagnosis was confirmed by pathological anatomy. There were no complications in the surgery, with marked neurological improvement. Control MRIs demonstrated a significant reduction of NCC cysts. LESSONS: Minimally invasive approaches are an excellent alternative for skull-base tumoral and infectious pathology. Prior knowledge of the pathophysiology and the authors' experience in the management of patients with NCC allowed them to propose this approach, with optimal results.

Hemifacial Spasm Secondary to Arachnoiditis Due to Neurocysticercosis: Clinical Image.

Subarachnoid neurocysticercosis (NCC) is a form of NCC with cysticerci located in the subarachnoid space. This form of NCC can cause general and focal neurologic symptoms, and sometimes requires surgical intervention as a treatment. In this report, we present a rare case of hemifacial spasm secondary to arachnoiditis because of an NCC cyst in the cerebellopontine angle. The cysticercus was removed and the facial nerve was liberated via a retrosigmoidal approach. At 8-month follow-up, the patient reported no recurrence of symptoms. To our knowledge, this is the first case reported to surgically manage hemifacial spasm secondary to NCC arachnoiditis.

Establishment of epilepsy surgery in Peru.

Epilepsy surgery is a well-established treatment for certain types of intractable epilepsy. While there is a relatively high number of epilepsy surgery centers in Canada and the United States, the same cannot be said about many other parts of the world, such as South America. Although there are notable exceptions, such as Brazil and Colombia, formal epilepsy surgery centers have been lacking in many South American countries, including Peru. Although sporadic cases have been performed in Peru, there was no formal epilepsy surgery center in the country as of 2011. Beginning in 2008, with the support of the Partnering Epilepsy Centers in America program of the North American Commission of the International League Against Epilepsy, the Epilepsy Program at Western University in London, Canada, was partnered with the Department of Epilepsy at the Instituto Nacional de Ciencias Neurologicas in Lima. This was the beginning of a long-term relationship that culminated in the establishment of the first 2 formal epilepsy surgery centers in Peru. The purpose of this communication is to briefly summarize the establishment of 2 independent epilepsy surgery programs in Peru and to document the methods with which this accomplishment was achieved.

La cirugía de epilepsia y el establecimiento de programas quirúrgicos en el Perú: El proyecto de colaboración entre Perú y Canadá / Establishing epilepsy surgery programs in Peru: The Peru-Canada collaborative project

El presente artículo define y describe las características clínicas de epilepsia refractaria, la cirugía aplicable al manejo de la misma y la necesidad de establecer centros para el manejo integral de estos pacientes en el Perú. Además, describe los inicios de la cirugía de epilepsia en el Perú, su desarrollo paulatino y el proyecto de colaboración asistencial y educativo entre los programas de epilepsia de la Western University en London, Ontario, Canadá y el Instituto Nacional de Ciencias Neurológicas, así como el Hospital Edgardo Rebagliati en Lima, Perú.

The manuscript describes and defines the clinical characteristics of Refractory Epilepsy, applicable surgical procedures for its management and the need for the establishment of comprehensive epilepsy programs in Peru. It also describes the beginnings of epilepsy surgery in Peru, and the collaborative project between the Epilepsy programs at Western University in London, Canada and the National Neurological Institute and Rebagliati Hospital in Lima, Peru.

Actualización del reporte de biopsiapor aspiración con aguja fina de mama / Report of breast fine needle aspiration biopsy: an update

Las recomendaciones para la biopsia por aspiración con aguja fina de mama se desarrollaron y aprobaron en 1997 por el Instituto Nacional de Cáncer en Bethesda, Estados Unidos y fueron adaptadas a nuestro país en 2007, sin embargo, en los últimos años no se han realizado cambios formales en estas indicaciones. El objetivo de este módulo es presentar la actualización del reporte de biopsia por aspiración con aguja fina de mama, usando el sistema de reporte Bethesda, realizado por consenso con un grupo de patólogos, clínicos, radiólogos, cirujanos de mama y otros profesionales de la salud de Colombia y otros países, y con base en la experiencia realizando biopsia por aspiración con aguja fina de mama del Hospital Pablo Tobón Uribe y de Dinámica IPS.

Recommendations for breast fine needle aspiration biopsy were developed and approved in 1997 by The National Cancer Institute of Bethesda, United States, , and were adapted to our country on 2007, however, in last years these indications have not changed in a formal manner. The purpose of this review was to provide an update of the report for breast fine needle aspiration biopsy using the Bethesda system. This guide was made by consensus with pathologists, clinicians, radiologists, breast surgeons and other health professionals of Colombia and other countries. The update was basis on the experience of Hospital Pablo Tobon Uribe and Dinamica IPS in performing breast fine needle aspiration biopsy.

A collaborative effort to establish a comprehensive epilepsy program in Peru.

We report the achievements obtained, over a period of 4 years, by the collaborative partnering effort of the Epilepsy Program at Western University in Canada and the Instituto of Ciencias Neurologicas in Lima, Peru, building an epilepsy program in Peru.