AGBGA. Artículos de Investigación

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Anatomía general, histología y morfometría del sistema digestivo del pez pterophyllum scalare (Perciformes: cichlidae)
(2020-12-05) Ramírez-Espitia, Edith Juliana; Hurtado-Giraldo, Hernan; Gómez-Ramírez, Edwin; Neurociencias
Introduction: Ornamental Angel fish (Pterophyllum scalare) is one of the main commercialized species from South America, with an important number of national and international dealers. Objective: To make a histological and morphometric description of P. scalare digestive tract. Methods: Nineteen adult individuals were used. Intestinal coefficient values were obtained, and a macroscopic and microscopic description of esophagus, stomach, and intestine (anterior, middle and posterior) was carried out. Samples were processed for paraffin embedding, and 5 µm sections were stained with H&E and P.A.S. Positive P.A.S. cells were counted. Lumen area and tissue area were measured in representative digitalized sections from each region. Results: P. scalare exhibited a short esophagus, followed by a blind bag shaped, scarcely muscular stomach, and a short intestine (intestinal coefficient 1.66 +/- 0.52). Four constitutive tissue layers were identified: mucosa, submucosa, muscular and in some areas also a serosa layer. Esophagus exhibit abundant globet P.A.S. + cells and shows the larger tisular area was observed. Luminal area and perimeter are larger in anterior intestinal region. Conclusions: the intestinal coefficient value (1.66 +/- 0.52), and the histological and morphometric characteristics of the evaluated organs, suggest that P. scalare is omnivorous with soft prey preferences.
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Aqueductal Cerebrospinal Fluid Stroke Volume Flow in a Rodent Model of Chronic Communicating Hydrocephalus: Establishing a Homogeneous Study Population for Cerebrospinal Fluid Dynamics Exploration
(2019-08-05) Vivas-Buitrago, Tito; Lokossou, Armelle; Jusué-Torres, Ignacio; Pinilla-Monsalve, Gabriel; Blitz, Ari M.; Herzka, Daniel A.; Robison, Jamie; Xu, Jiadi; Guerrero-Cazares, Hugo; Mori, Susumu; Quiñones-Hinojosa, Alfredo; Baledént, Olivier; Rigamonti, Daniele; Neuro Ciencias
Background Idiopathic normal pressure hydrocephalus (iNPH) is a cause of dementia that can be reversed when treated timely with cerebrospinal fluid (CSF) diversion. Understanding CSF dynamics throughout the development of hydrocephalus is crucial to identify prognostic markers to estimate benefit/risk to shunts. Objective To explore the cerebral aqueduct CSF flow dynamics with phase-contrast magnetic resonance imaging (MRI) in a novel rodent model of adult chronic communicating hydrocephalus. Methods Kaolin was injected into the subarachnoid space at the convexities in Sprague-Dawley adult rats. 11.7-T Bruker MRI was used to acquire T2-weighted images for anatomic identification and phase-contrast MRI at the cerebral aqueduct. Aqueductal stroke volume (ASV) results were compared with the ventricular volume (VV) at 15, 60, 90, and 120 days. Results Significant ventricular enlargement was found in kaolin-injected animals at all times (P < 0.001). ASV differed between cases and controls/shams at every time point (P = 0.004, 0.001, 0.001, and <0.001 at 15, 60, 90, and 120 days, respectively). After correlation between the ASV and the VV, there was a significant correlation at 15 (P = 0.015), 60 (P = 0.001), 90 (P < 0.001), and 120 days. Moreover, there was a significant positive correlation between the VV expansion and the aqueductal CSF stroke between 15 and 60 days. Conclusions An initial active phase of rapid ventricular enlargement shows a strong correlation between the expansion of the VV and the increment in the ASV during the first 60 days, followed by a second phase with less ventricular enlargement and heterogeneous behavior in the ASV. Further correlation with complementary data from intracranial pressure and histologic/microstructural brain parenchyma assessments are needed to better understand the ASV variations after 60 days.
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Brain Circuitry Supporting Multi-Organ Autonomic Outflow in Response to Nausea
(2016-02) García, Ronald G.; Kim, Jieun; Sheehan, James D.; Beissner, Florian; Bianchi, Anna M.; Cerutti, Sergio; Kuo, Braden; Barbieri, Riccardo; Napadow, Vitaly; Sclocco, Roberta
While autonomic outflow is an important co-factor of nausea physiology, central control of this outflow is poorly understood. We evaluated sympathetic (skin conductance level) and cardiovagal (high-frequency heart rate variability) modulation, collected synchronously with functional MRI (fMRI) data during nauseogenic visual stimulation aimed to induce vection in susceptible individuals. Autonomic data guided analysis of neuroimaging data, using a stimulus-based (analysis windows set by visual stimulation protocol) and percept-based (windows set by subjects’ ratings) approach. Increased sympathetic and decreased parasympathetic modulation was associated with robust and anti-correlated brain activity in response to nausea. Specifically, greater autonomic response was associated with reduced fMRI signal in brain regions such as the insula, suggesting an inhibitory relationship with premotor brainstem nuclei. Interestingly, some sympathetic/parasympathetic specificity was noted. Activity in default mode network and visual motion areas was anti-correlated with parasympathetic outflow at peak nausea. In contrast, lateral prefrontal cortical activity was anticorrelated with sympathetic outflow during recovery, soon after cessation of nauseogenic stimulation. These results suggest divergent central autonomic control for sympathetic and parasympathetic response to nausea. Autonomic outflow and the central autonomic network underlying ANS response to nausea may be an important determinant of overall nausea intensity and, ultimately, a potential therapeutic target.
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Complexity Variability Assessment of Nonlinear Time-Varying Cardiovascular Control
(2017-02-20) García, Ronald G.; Citi, Luca; NoggleTaylor, Jessica; Toschi, Nicola; Barbieri, Riccardo; Valenza, Gaetano
The application of complex systems theory to physiology and medicine has provided meaningful information about the nonlinear aspects underlying the dynamics of a wide range of biological processes and their disease-related aberrations. However, no studies have investigated whether meaningful information can be extracted by quantifying second-order moments of time-varying cardiovascular complexity. To this extent, we introduce a novel mathematical framework termed complexity variability, in which the variance of instantaneous Lyapunov spectra estimated over time serves as a reference quantifier. We apply the proposed methodology to four exemplary studies involving disorders which stem from cardiology, neurology and psychiatry: Congestive Heart Failure (CHF), Major Depression Disorder (MDD), Parkinson’s Disease (PD), and Post-Traumatic Stress Disorder (PTSD) patients with insomnia under a yoga training regime. We show that complexity assessments derived from simple time-averaging are not able to discern pathology-related changes in autonomic control, and we demonstrate that between-group differences in measures of complexity variability are consistent across pathologies. Pathological states such as CHF, MDD, and PD are associated with an increased complexity variability when compared to healthy controls, whereas wellbeing derived from yoga in PTSD is associated with lower time-variance of complexity.
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Cross-frequency phase-amplitude coupling between hippocampal theta and gamma oscillations during recall destabilizes memory and renders it susceptible to reconsolidation disruption
(2020-08-12) Radiske, Andressa; Gonzalez, Maria Carolina; Conde-Ocazionez, Sergio A.; Rossato, Janine I.; Köhler, Cristiano A.; Cammarota, Martín; Neuro Ciencias
Avoidance memory reactivation at recall triggers theta-gamma hippocampal phase amplitude coupling (hPAC) only when it elicits hippocampus-dependent reconsolidation. However, it is not known whether there is a causal relationship between these phenomena. We found that in adult male Wistar rats, silencing the medial septum during recall did not affect avoidance memory expression or maintenance but abolished hPAC and the amnesia caused by the intrahippocampal administration of reconsolidation blockers, both of which were restored by concomitant theta burst stimulation of the fimbria–fornix pathway. Remarkably, artificial hPAC generated by fimbria–fornix stimulation during recall of a learned avoidance response naturally resistant to hippocampus-dependent reconsolidation made it susceptible to reactivation-dependent amnesia. Our results indicate that hPAC mediates the destabilization required for avoidance memory reconsolidation and suggest that the generation of artificial hPAC at recall overcomes the boundary conditions of this process.
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Cross-tolerance between nitric oxide synthase inhibition and atypical antipsychotics modify nicotinamide-adenine-dinucleotide phosphate-diaphorase activity in mouse lateral striatum
(2019-01) Prieto, Sonia G.; Silva, João C.S.; De Lima, Mairon O.; Almeida, Maria C.; Echeverry, Marcela B.
Previous research indicates that the subchronic administration of NG-nitro-L-arginine (L-NOARG) produces tolerance to haloperidol-induced catalepsy in Swiss mice. The present study aimed to further investigate whether intermittent subchronic systemic administration of L-NOARG induces tolerance to the cataleptic effects of haloperidol as well as olanzapine or clozapine (Clz) in C57Bl mice after subchronic administration for 5 consecutive days. Striatal FosB protein expression was measured in an attempt to gain further insights into striatal mechanisms in antipsychotic-induced extrapyramidal symptoms side effects. An nicotinamide-adeninedinucleotide phosphate-diaphorase histochemical reaction was also used to investigate whether tolerance could neurons. Subchronic administration of all antipsychotics produced catalepsy, but cross-tolerance was observed only between L-NOARG (15 mg/kg, intraperitoneally) and Clz (20 mg/kg, intraperitoneally). This cross-tolerance effect was accompanied by decreased FosB protein expression in the dorsal striatum and the nucleus accumbens shell region, and reduced icotinamideadenine-dinucleotide phosphate-diaphorase activity in the dorsal and ventral lateral striatum. Overall, these results suggest that interference with the formation of nitric oxide, mainly in the dorsal and ventral lateral-striatal regions, appears to improve the cataleptic effects induced by antipsychotics acting as antagonists of low-affinity dopamine D2 receptor, such as Clz.
Acceso abierto
Cross-tolerance between nitric oxide synthase inhibition and atypical antipsychotics modify nicotinamide-adenine-dinucleotide phosphate-diaphorase activity in mouse lateral striatum
(2019-02-05) Prieto, Sonia G.; Silva, João C.S.; De Lima, Mairon O.; Almeida, Maria C.; Echeverry, Marcela B.; Neuro Ciencias
Previous research indicates that the subchronic administration of NG-nitro-L-arginine (L-NOARG) produces tolerance to haloperidol-induced catalepsy in Swiss mice. The present study aimed to further investigate whether intermittent subchronic systemic administration of L-NOARG induces tolerance to the cataleptic effects of haloperidol as well as olanzapine or clozapine (Clz) in C57Bl mice after subchronic administration for 5 consecutive days. Striatal FosB protein expression was measured in an attempt to gain further insights into striatal mechanisms in antipsychotic-induced extrapyramidal symptoms side effects. An nicotinamide-adenine-dinucleotide phosphate-diaphorase histochemical reaction was also used to investigate whether tolerance could induce changes in the number of nitric oxide synthase-active neurons. Subchronic administration of all antipsychotics produced catalepsy, but cross-tolerance was observed only between L-NOARG (15 mg/kg, intraperitoneally) and Clz (20 mg/kg, intraperitoneally). This cross-tolerance effect was accompanied by decreased FosB protein expression in the dorsal striatum and the nucleus accumbens shell region, and reduced icotinamide-adenine-dinucleotide phosphate-diaphorase activity in the dorsal and ventral lateral striatum. Overall, these results suggest that interference with the formation of nitric oxide, mainly in the dorsal and ventral lateral-striatal regions, appears to improve the cataleptic effects induced by antipsychotics acting as antagonists of low-affinity dopamine D2 receptor, such as Clz.
Acceso abierto
Cyclic Vomiting Syndrome is characterized by altered functional brain connectivity of the insular cortex : A cross-comparison with migraine and healthy adults
(2018-06) Ellingsen, Dan-Mikael; García, Ronald G.; Lee, Jeungchan; Lin, Richard L.; Kim, Jieun; Thurler, Andrea H; Castel, Shahar; Dimisko, Laurie; Rosen, Bruce R.; Hadjikhani, Nouchine; Kuo, Braden; Napadow, Vitaly
Cyclic Vomiting Syndrome (CVS) has been linked to episodic migraine, yet little is known about the precise brain-based mechanisms underpinning CVS, and whether these associated conditions share similar pathophysiology. We investigated the functional integrity of salience (SLN) and sensorimotor (SMN) intrinsic connectivity networks in CVS, migraine and healthy controls using brain functional Magnetic Resonance Imaging. CVS, relative to both migraine and controls, showed increased SLN connectivity to middle/posterior insula, a key brain region for nausea and viscerosensory processing. In contrast, this same region showed diminished SMN connectivity in both CVS and migraine. These results highlight both unique and potentially shared pathophysiology between these conditions, and suggest a potential target for therapeutics in future studies.
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Dengue in Santander State, Colombia: fluctuations in the prevalence of virus serotypes are linked to dengue incidence and genetic diversity of the circulating viruses
(2019-11-05) Carreño, María Fernanda; Jiménez-Silva, Cinthy Lorena; Rey-Caro, Luz Aida; Conde-Ocazionez, Sergio A.; Flechas-Alarcón, María Camila; Velandia, Sindi Alejandra; Ocazionez, Raquel Elvira; Neuro Ciencias
objectiveTo investigate the link between fluctuations in the prevalence of dengue virus (DENV)serotypes and the number of dengue cases in the metropolitan area of Bucaramanga, Santander State,Colombia, in the 2007–2010 and 2014–2017 periods.methodViruses were isolated from febrile patient samples by direct application to C6/36-HT cellsand typed using monoclonal antibodies. We performed autocorrelation and cross-correlation analysesto determine whether fluctuations in the prevalence of DENV serotypes and dengue cases werecorrelated. Full envelope (E) gene sequences were employed to examine the genetic diversity ofserotypes circulating by using a phylogenetic approach.resultsAll four dengue virus serotypes were detected. DENV-1 was the dominant serotype in bothperiods followed by DENV-3 or DENV-2 depending on the period; DENV-4 was the least prevalentvirus in both periods. Cross-correlation analyses suggest a temporal relation between the fluctuationsin the prevalence of DENV serotypes, which were almost simultaneous (lag=0) or related to recentpast fluctuations (lag>1.0) in the number of dengue cases. Data suggest that a sustainedpredominance of DENV-1, an increase of the DENV-4 prevalence, and a switch from DENV-3 toDENV-2 could be linked to an outbreak. Circulating viruses were grouped into Genotype V, Asia/American III and II for DENV-1, -2, -3 and -4, respectively; intragenotypic diversity was detected.conclusionsThe present work highlights the need of comprehensive studies on dynamics of DENV inColombia to understand transmission of dengue and evaluate the effectiveness of a vaccination programme.
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Desmoplastic infantile ganglioglioma with late presentation : A clinical, radiological and histopathological analysis
(2013-12) Romero Rojas, Alfredo E.; Diaz Perez, Julio A.; Lozano Castillo, Alfonso
Desmoplastic infantile ganglioglioma (DIG) is a rare supratentorial tumor in the central nervous system. Definitive diagnosis of this neoplasm is based on histopathologic analysis evaluating distinctive findings such as the fibroblastic differentiation. Here we present a clinical case of DIG with a long follow-up in an eight-year-old boy with a six-month history of recurrent emesis, psychomotor hyperactivity and generalized tonic-clonic seizures. Computed tomography scan and magnetic resonance imaging (MRI) showed a cystic, heterogeneous, mass on the right temporal uncus. A histopathological diagnosis of late presentation DIG was made. We documented the immunohistochemical expression of a molecular soft tissue / muscle differentiation marker (h-CaD) in addition to a low proliferative index (Ki-67) in this case. After surgical intervention, a control MRI showed changes of right frontal-temporal craniotomy and a persistent mass in the anterior and medial temporal lobe with basal extension. Further surgical intervention was performed, completely removing the tumor, which had the same characteristics. The patient is asymptomatic while receiving anticonvulsant therapy (phenytoin) with no evidence of tumor recurrence on MRI after a follow-up of five years. The low grade and soft tissue appearance in images are correlated with the histopathologic and immunohistochemical profile of this tumor, but the rarity of this tumor makes a presumptive diagnosis by images a challenge. The above-mentioned molecular markers or new ones could be used as molecular targets for molecular imaging studies to increase the probability of a pre-operative diagnosis based on molecular features through images.
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Dimensionality and homogeneity of the Colombian version of the Cocaine Craving Questionnaire (CCQ-N-10)
(2022-06-20) Cassiani-Miranda, Carlos Arturo; Scoppetta, Orlando; Quintero-Gómez, Tito Cesar; Arraut-Camargo, Eduard; Castaño-Pérez, Guillermo; Cabanzo-Arenas, Diego Fernando; Campo-Arias, Adalberto; Neurociencias
Background It is essential to have a validated instrument to measure craving for cocaine use. The study’s objective was to understand the dimensionality and homogeneity of the Cocaine Craving Questionnaire (CCQ-N-10) among Colombian cocaine users. Methods A sample of 102 hospitalized or outpatient adults diagnosed with cocaine use disorders attending addiction units in Bucaramanga, Colombia. Internal consistency and construct validity were estimated by confirmatory factor analysis and correlation analysis with scales with similar objectives. Results An omega coefficient of 0.93 was obtained, and adjustment indicators of the confirmatory model were acceptable (RMSEA of 0.08, CFI and TLI of 0.99) when two of the original scale items were removed from the original scale analysis. Conclusion This study shows that the craving scale reduced to eight items can be helpful to assess the construct in the Colombian population; however, the small sample size makes it challenging to carry out other analysis to corroborate its psychometric properties.
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Distribution of somatostatin-28 (1-12), calcitonin gene-related peptide, and substance P in the squirrel monkey brainstem : An immunocytochemical study
(2019-01) Duque Díaz, Ewing Rafael; Coveñas, Rafael
Using an immunocytochemical technique, we have studied the distribution of fibers and cell bodies containing somatostatin-28 (1-12) [SOM-28 (1-12)], calcitonin gene-related peptide (CGRP), and substance P (SP) in the brainstem of Saimiri sciureus. The distribution of the peptidergic cell bodies was very restricted: perikarya containing SOM-28 (1-12) were only observed in the substantia grisea centralis, while no immunoreactive cell bodies containing CGRP or SP were visualized. Fibers containing SOM-28 (1-12), CGRP, or SP were widely distributed in the brainstem: immunoreactive fibers containing SOM-28 (1-12) showed the most widespread distribution and were the most abundant. The distribution of SOM-28 (1-12)-, CGRP- or SP-immunoreactive fibers was very similar. Colocalization of immunoreactive fibers containing SOM-28 (1-12), CGRP or SP was observed in many brainstem nuclei. A neuroanatomical relationship between CGRP- and SP-immunoreactive fibers was observed, although this relationship was less marked for SOM-28 (1-12) and SP and lower still for SOM-28 (1-12) and CGRP. The widespread distribution of the peptidergic fibers suggests that the studied neuropeptides are involved in many physiological actions.
Acceso abierto
Distribution of somatostatin-28 (1-12), calcitonin gene-related peptide, and substance P in the squirrel monkey brainstem: an immunocytochemical study
(2019-01-25) Duque-Diaz, Ewing Rafael; Coveñas, R.; Nuero Ciencias
Using an immunocytochemical technique, we have studied the distribution of fibers and cell bodies containing somatostatin-28 (1-12) [SOM-28 (1-12)], calcitonin gene-related peptide (CGRP), and substance P (SP) in the brainstem of Saimiri sciureus. The distribution of the peptidergic cell bodies was very restricted: perikarya containing SOM-28 (1-12) were only observed in the substantia grisea centralis, while no immunoreactive cell bodies containing CGRP or SP were visualized. Fibers containing SOM-28 (1-12), CGRP, or SP were widely distributed in the brainstem: immunoreactive fibers containing SOM-28 (1-12) showed the most widespread distribution and were the most abundant. The distribution of SOM-28 (1-12)-, CGRP- or SP-immunoreactive fibers was very similar. Colocalization of immunoreactive fibers containing SOM-28 (1-12), CGRP or SP was observed in many brainstem nuclei. A neuroanatomical relationship between CGRP- and SP-immunoreactive fibers was observed, although this relationship was less marked for SOM-28 (1-12) and SP and lower still for SOM-28 (1-12) and CGRP. The widespread distribution of the peptidergic fibers suggests that the studied neuropeptides are involved in many physiological actions.
Acceso abierto
Dose-Optimization of Respiratory-Gated Auricular Vagal Afferent Nerve Stimulation (RAVANS) for Blood Pressure Modulation in Hypertensive Patients
(2019-09-05) Stowell, Jessica; Garcia, Ronald G.; Staley, Rachel; Sclocco, Roberta; Fisher, Harrison; Napadow, Vitaly; Goldstein, Jill; Barbieri, Riccardo
The objective of this study was to determine the optimal frequency of respiratory-gated auricular vagal afferent nerve stimulation (RAVANS) for the modulation of blood pressure in hypertensive patients. Twelve hypertensive subjects (52.5±6.0 years, 8 females) underwent five randomized stimulation sessions, during which they received exhalatory-gated stimulation at frequencies of 2, 10, 25, and 100 Hz or sham stimulation. A continuous blood pressure signal was collected during a 30-minute stimulation period and a 10-minute recovery period using a Finometer device (Finapress Medical System, the Netherlands). LabChart (ADInstruments, Colorado Springs, CO, USA) was used to process and compute blood pressure responses. A significantly greater reduction of systolic blood pressure values during stimulation was observed in the 100 Hz session compared to sham (p=0.02). In addition, significant reductions in diastolic blood pressure (p=0.04) and mean arterial pressure (p=0.04) values were observed during RAVANS stimulation compared to baseline during the 100 Hz session. Evaluation of other stimulation frequencies did not reveal significant results. RAVANS exhibits a frequency-dependent effect on the modulation of arterial blood pressure levels of hypertensive subjects.
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Dysfunctional chemosensation in myasthenia gravis : A systematic review
(2013-09) Leon Sarmiento, Fidias E.; Leon Ariza, Daniel S.; Doty, Richard L.
Myasthenia gravis has traditionally been viewed as a disorder that solely affects the neuromuscular junction within the peripheral nervous system. However, there is now evidence that the cholinergic dysfunction of this disorder may be more widespread than previously believed. This article provides a systematic review of the studies that examined smell and taste function in myasthenia gravis. Methods: We analyzed studies that reported chemosensory function alterations in patients with myasthenia gravis. PubMed, MEDLINE, Web of Science, EMBASE, and SciELO, searched to identify articles published from January 1950 through December 2012, were supplemented by relevant articles. The following information was identified from each article: the number of patients, number of controls (if any), clinical stage of patients, neurological involvement, serological state, taste or smell involvement, chemosensory test used, and country of publication. Results: Ten studies reporting smell and taste function and dysfunction in patients with myasthenia gravis were identified, most of which were case reports commenting on apparent abnormalities in the taste system. The sole empirical study that investigated taste function, however, was negative, suggesting that some reports of taste loss may reflect olfactory loss. One study clearly documented olfactory dysfunction in patients with myasthenia gravis, dysfunction most likely attributable to altered central nervous system cholinergic function. Conclusions: Chemosensory dysfunction has been reported in a number of patients with myasthenia gravis. Given the close association between complaints of taste dysfunction and loss of flavor sensations secondary to olfactory system damage, quantitative testing should be used to accurately assess the nature and degree of the dysfunction present in this debilitating disorder.
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Effects of Polybrominated Diphenyl Ethers on Hormonal and Reproductive Health in E-Waste-Exposed Population: A Systematic Review
(2022-06-25) Singh, Vishal; Cortes-Ramirez, Javier; Toms, Leisa-Maree; Sooriyagoda, Thilakshika; Karatela, Shamshad; Neurociencia
Electronic waste management is a global rising concern that is primarily being handled by informal recycling practices. These release a mix of potentially hazardous chemicals, which is an important public health concern. These chemicals include polybrominated diphenyl ethers (PBDEs), used as flame retardants in electronic parts, which are persistent in nature and show bioaccumulative characteristics. Although PBDEs are suspected endocrine disruptors, particularly targeting thyroid and reproductive hormone functions, the relationship of PBDEs with these health effects are not well established. We used the Navigation Guide methodology to conduct a systematic review of studies in populations exposed to e-waste to better understand the relationships of these persistent flame retardants with hormonal and reproductive health. We assessed nineteen studies that fit our pre-determined inclusion criteria for risk of bias, indirectness, inconsistency, imprecision, and other criteria that helped rate the overall evidence for its quality and strength of evidence. The studies suggest PBDEs may have an adverse effect on thyroid hormones, reproductive hormones, semen quality, and neonatal health. However, more research is required to establish a relationship of these effects in the e-waste-exposed population. We identified the limitations of the data available and made recommendations for future scientific work.
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Endoscope-assisted contralateral transmaxillary approach to the clivus and the hypoglossal canal : Technical case report
(2019-05) Pamias Portalatin, Eva; Mahato, Deependra; Rincón Torroella, Jordina; Vivas Buitrago, Tito; Quinones Hinojosa, Alfredo; Owusu Boahene, Kofi Derek
Clival lesions are still considered surgically complex due to their anatomical location. Critical structures, such as the internal carotid arteries (ICAs), cavernous sinuses, cranial nerves, and brainstem, may be encased within the lesion. Although advances in endoscopic endonasal approaches have provided new routes to these lesions, exposure and resection of clival tumors through the endonasal route remain a technical challenge. Here, the authors report a left-sided endoscopic transmaxillary approach to access the right aspect of the clivus and the hypoglossal canal. A 35-year-old woman presented with progressive right 6th cranial nerve palsy. MRI revealed a contrast-enhancing right petroclival chondrosarcoma that involved Meckel’s cave and extended into the right hypoglossal canal. An endoscopiccontralateral-transmaxillary approach through a left sublabial incision was used to access the right petroclival region and right hypoglossal canal. A left maxillary osteoplastic flap was elevated to expose the left maxillary sinus. This was followed by a left medial maxillectomy, gaining access to the left posterior nasal cavity. The posterior third of the left inferior turbinate and nasal septum were removed to access the right side of the petroclival region. Near-total resection was achieved without any vascular or neurological complications. A thin shell of residual tumor was left behind due to involvement of vital structures, such as the ICA, and further treated with proton-beam radiotherapy. The endoscopic-contralateral-transmaxillary approach provides a direct surgical corridor and good lateral visualization of the skull base vasculature. This approach allows wide maneuverability around the ICA and hypoglossal canal, which, in this case, allowed maximal tumor resection with full preservation of neurological function.
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Endoscope-assisted contralateral transmaxillary approach to the clivus and the hypoglossal canal: Technical case report
(2019-05-05) Pamias-Portalatin, Eva; Mahato, Deependra; Rincon-Torroella, Jordina; Vivas-Buitrago, Tito; Quiñones-Hinojosa, Alfredo; Boahene, Kofi O.; Neuro Ciencias
Clival lesions are still considered surgically complex due to their anatomical location. Critical structures, such as the internal carotid arteries (ICAs), cavernous sinuses, cranial nerves, and brainstem, may be encased within the lesion. Although advances in endoscopic endonasal approaches have provided new routes to these lesions, exposure and resection of clival tumors through the endonasal route remain a technical challenge. Here, the authors report a left-sided endoscopic transmaxillary approach to access the right aspect of the clivus and the hypoglossal canal.A 35-year-old woman presented with progressive right 6th cranial nerve palsy. MRI revealed a contrast-enhancing right petroclival chondrosarcoma that involved Meckel's cave and extended into the right hypoglossal canal. An endoscopic-contralateral-transmaxillary approach through a left sublabial incision was used to access the right petroclival region and right hypoglossal canal. A left maxillary osteoplastic flap was elevated to expose the left maxillary sinus. This was followed by a left medial maxillectomy, gaining access to the left posterior nasal cavity. The posterior third of the left inferior turbinate and nasal septum were removed to access the right side of the petroclival region. Near-total resection was achieved without any vascular or neurological complications. A thin shell of residual tumor was left behind due to involvement of vital structures, such as the ICA, and further treated with proton-beam radiotherapy.The endoscopic-contralateral-transmaxillary approach provides a direct surgical corridor and good lateral visualization of the skull base vasculature. This approach allows wide maneuverability around the ICA and hypoglossal canal, which, in this case, allowed maximal tumor resection with full preservation of neurological function.
Acceso abierto
Evaluación neurofuncional del tallo cerebral. Parte I : Reflejo del parpadeo
(2009-10) Leon Sarmiento, Fidias E.; Gutiérrez, Claudia; Bayona Prieto, Jaime
The blink reflex is the neural response elicited in the orbicular oculi muscle after single or paired supraorbital nerve stimulation, by either electrical, mechanical, acoustic, thermal, chemical or magnetic stimulation. It is made up of three responses called R1, R2 and R3. R1 is an early response that follows A beta fibers, and does not habituate. R2 is a middle-latency response that follows A beta and A delta fibers, tends to habituate and is modulated by sensorimotor suprasegmental structures. R3 is a long-latency response, generated by stimulation of a multisynaptic chain of neurons that involve type C fibers belonging to a complex pontothalamic-amigdalo-cerebellar pathway. It is also possible to record three silent periods if the blink reflex is obtained while the subject makes a voluntary facial muscle effort. The functional study of this reflex allows to define with certainty whether the lesion is in afferent or efferent pathways or if it involves an abnormal sensorimotor integration due to disorders of the central, autonomic or peripheral nervous systems. A correct execution of these studies, and their appropriate interpretation, based on the underlying mechanisms of neural plasticity, will guide toward better neurorehabilitation protocols.
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Evidences in Neurological Surgery and a Cutting Edge Classification of the Trigeminocardiac Reflex : A Systematic Review
(2018-08) Leon Ariza, Daniel S.; Leon Ariza, Juan S.; Nangiana, Jasvinder; Vargas Grau, Gabriel; Leon Sarmiento, Fidias E.; Quiñones Hinojosa, Alfredo
The trigeminocardiac reflex (TCR) is characterized by bradycardia, decrease of mean arterial blood pressure, and sometimes, asystole during surgery. We critically reviewed TCR studies and devised a novel classification scheme for assessing the reflex. Methods A comprehensive systematic literature review was performed using PubMed, MEDLINE, Web of Science, EMBASE, and Scielo databases. Eligible studies were extracted based on stringent inclusion and exclusion criteria. Statistical analyses were used to assess cardiovascular variables. TCR was classified according to morphophysiologic aspects involved with reflex elicitation. Results A total of 575 patients were included in this study. TCR was found in 8.9% of patients. The reflex was more often triggered by interventions made within the anterior cranial fossa. The maxillary branch (type II in the new classification) was the most prevalent nerve branch found to trigger the TCR. Heart rate and mean arterial blood pressure were similarly altered (P = 0.06; F = 0.3912809), covaried with age (P = 0.012; F = 9.302), and inversely correlated to each other (r = −0.27). Conclusions TCR is a critical cardiovascular phenomenon that must be quickly identified and efficiently classified and should trigger vigilance. Prompt therapeutic measures during neurosurgical procedures should be carefully addressed to avoid unwanted complications. Accurate categorization using the new classification scheme will help to improve understanding and guide the management of TCR in the perioperative period.

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