Abordaje retrosigmoideo para clipaje de aneurisma distal de la AICA / Retrosigmoid approach for clipping a distal aneurysm of the AICA

Introducción: Los aneurismas cerebrales de la circulación posterior, representan solo del 8 al 10 % del total de los aneurismas cerebrales, y de estos los de la arteria cerebelosa anteroinferior (AICA) son muy poco frecuentes, por lo que no hay algoritmo de manejo para estas lesiones, se requieren conocimientos anatómicos de vascular y de base de cráneo para el tratamiento de estos, hablando del abordaje quirúrgico, podemos mencionar, el extremo lateral, retrosigmoideo, orbitozigomatico y presigmoideo, que depende del tamaño y localización del aneurisma, ya sea distal o proximal. Presentamos este caso, que tratamos mediante un abordaje retrosigmoideo convencional, el cual nos ofreció un corredor quirúrgico suficiente, sin necesidad de un abordaje mas amplio, en este caso fue un aneurisma distal de la AICA, localizado en el segmento meatal, que se encontró en el complejo neurovascular medio del ángulo pontocerebeloso, muy próximo a los nervios craneales V, VII y VIII. Objetivos: Demostrar que los aneurismas distales de la AICA se pueden manejar mediante un abordaje retrosigmodeo convencional con éxito. Materiales y métodos: El paciente se colocó en posición park bench, bajo fijación esquelética de 3 puntos, con el asterion como punto mas elevado. Se realizo una incisión en forma de C en la mastoides y se realizo un abordaje dirigido hacia el ángulo pontocerebeloso. Resultados: Se logró realizar el clipaje del aneurisma de forma satisfactoria, con un buen resultado clínico del paciente, quien fue egresada a los 4 días sin déficit neurológico. Conclusión: El abordaje retrosigmoideo es una opción terapéutica para el manejo de los aneurismas ubicados en el ángulo pontocerebeloso, específicamente del AICA distal y también se puede usar incluso para los aneurismas distales del PICA.

Background: Cerebral aneurysms of the posterior circulation, representing only 8 to 10% of the total cerebral aneurysms, but the aneurysms of the anteroinferior cerebellar artery (AICA) are very rare, so there is no management algorithm for these lesions, anatomical knowledge of vascular and skull base are known for the treatment of these lesions, in relation of the surgical approach, we can identify, the far lateral, retrosigmoid, orbitozigmatic or presigmoid approaches, which depends on the size and location of aneurysm, either distal or proximal. We present this case, which we treated through a conventional retrosigmoid approach, which offers us a sufficient surgical corridor, without the need for a broader approach, in this case it was a distal AICA aneurysm, located in the meatal segment, which was found in the middle neurovascular complex of the pontocerebellar angle, very close to the cranial nerves V, VII and VIII. Objective: Demonstrate that distal aneurysms of AICA can be managed using a successful conventional retrosigmoid approach. Results: The clipping of the aneurysm was achieved satisfactorily, with a good clinical result of the patient, who was discharged at 4 days without neurological deficit. Conclusion: The retrosigmoid approach is a therapeutic option for the management of aneurysms located in the pontocerebellar angle, specifically of the distal AICA and can also be used even for distal aneurysms of the PICA.

Reconstruction of anterior inferior cerebellar artery by occipital artery through extended retrosigmoid approach / 中华显微外科杂志

Objective To explore the feasibility of occipital artery(OA) to anterior inferior cerebellar artery (AICA) through the extended retrosigmoid approach,also perform a systemic microanatomical study of OA and AICA with the exposure of extended retrosigmoid approach,find the easy way to perform the procedure.Methods From September,2016 to January,2017,5 adult cadaveric heads injected with colored latex (total 10 sides) were performed the extended retrosigmoid approach,and measured the caliber of distal occipital artery (OA),the final length of the OA harvest,the reliable landmark of the OA harvest,and the distance from the flocculonodular segment of anterior inferior cerebellar artery (AICA) to the OA,the diameter of AICA flocculonodular segment branch.Whole procedure of OA to IACA bypass also be performed.Statistical analysis was performed.Results By the extended retrosigmoid approach,AICA flocculonodular segment could be easily exposure,the average diameter was 1.2 mm,the OA branch could be harvested in average was (72.3±3.3)mm in length from the occipital sulcus,and the average distance between occipital sulcus and AICA flocculonodular segment was (47.6±l.9)mm.The bypass procedure also could be performed through the proper corridor.Conclusion The Extended retrosigmoid approach is a safe and efficient way to perform the OA-AICA bypass procedure,and the procedure is easier to be performed than other surgical approaches.

Ruptured Total Intrameatal Anterior Inferior Cerebellar Artery Aneurysm

Among the distal anterior inferior cerebellar artery (AICA) aneurysms, a unique aneurysm at the meatal loop inside the internal auditory meatus is extremely rare. The authors report a case of surgically treated total intrameatal AICA aneurysm. A 62-year-old female patient presenting with sudden bursting headache and neck pain was transferred to our department. Computed tomography and digital subtraction angiography showed subarachnoid hemorrhage at the basal, prepontine cistern and an aneurysm of the distal anterior inferior cerebellar artery inside the internal auditory meatus. Surgery was performed by retrosigmoid craniotomy with unroofing of the internal auditory meatus. The aneurysm was identified between the seventh and eighth cranial nerve in the meatus and was removed from the canal and clipped with a small straight Sugita clip. After operation the patient experienced transient facial paresis and tinnitus but improved during follow up.

Effect of temporal lakes on avifaunal composition at the Southeast of Isthmus of Tehuantepec, Oaxaca, Mexico / Efecto de las lagunas temporales sobre la composición de la avifauna al Sureste del Istmo de Tehuantepec, Oaxaca, México

Oaxaca hosts one of the greatest biodiversity in México, occupying first place in avian diversity compared to other regions of the country. However, the area is undergoing serious problems such as high deforestation rates, soil erosion and over exploitation and extinction of species. These factors have all contributed to the current loss of biodiversity. Also, biological inventories are still incomplete. One of the least explored sites is the semiarid zone of Tehuantepec isthmus, around the locality of Santa Maria del Mar, Oaxaca, México. The area includes floodable grasslands, mangrove areas and dry forest, providing a range of potential habitats for different species. Our objective was to evaluate the effect of temporal lakes on spatial and temporal composition of the avifauna in Santa Maria del Mar, in order to generate information regarding this group within the region and the state, and to understand the importance of flood areas for resident and transitory birds. We conducted 12 avifauna surveys between July 2006 and June 2008, and established two transects of 2km length in each of four habitat types (beach, grassland, dry forest, and mangrove). We found a total of 75 species, corresponding to 16 orders and 30 families. Within an area of 26km², we significantly found 10.1% of the total number of bird species recorded for the entire state, and 6.6% of the total reported in Mexico. The families most represented were: Ardeidae, Laridae and Scolopacidae. Over the entire study period, dry forest was the most diverse habitat; followed by mangrove, grassland and the beach. Of all the species recorded, 38.6% were found at the edge or in the temporal lakes. We found a significant difference in species composition between seasons in the grassland, but no difference in the other habitats. Our results showed a significant effect of temporary lakes on avian diversity during the wet season; it also demonstrated the importance of grassland conservation given its relevance for presence of waterbirds. We suggested a continued and more intense monitoring; and proposed the designation of the area as an important Conservation Bird Area (AiCA).

Oaxaca alberga una biodiversidad de las más grandes en México, ocupando el primer lugar en diversidad de aves si se le compara con otras regiones del país. Sin embargo, el área sufre serios problemas tales como altas tasas de deforestación, erosión de suelo y sobre explotación y extinción de especies. Todos estos factores han contribuido con la actual pérdida de diversidad biológica. Además, los inventarios biológicos aún están incompletos. Una de las zonas menos exploradas es la parte semiárida del istmo de Tehuantepec, en los alrededores de la localidad de Santa María del Mar, Oaxaca, México. El área incluye pastizales inundables, áreas de manglar y de selva seca, y provee de una gama de hábitat potenciales para diversas especies. Nuestro objetivo fue evaluar el efecto de las lagunas temporales en la composición espacial y temporal de la avifauna en Santa María del Mar, con el propósito de generar información relacionada con este grupo dentro de la región y del estado, además de comprender la importancia de las áreas inundables para las aves residentes y migratorias. Entre julio 2006 y junio 2008 realizamos 12 monitoreos de la avifauna, y establecimos dos transectos de 2km de longitud para cada uno de los cuatro tipos de hábitat (playa, pastizal, selva seca y manglar). Encontramos un total de 75 especies, correspondendiendo a 16 órdenes y 30 familias. Dentro de un área de 26km², de manera significativa registramos el 10.1% del total de aves registradas para todo el estado y el 6.6% del total de especies registradas para México. Las familias mejor representadas fueron: Ardeidae, Laridae y Scolopacidae. Para todo el periodo de estudio, la selva seca fue el hábitat más diverso, seguido por el manglar, el pastizal abierto y la playa. Del total de especies registradas, el 38.6% se encontraron en el borde o dentro de lagunas temporales. Encontramos una diferencia significativa en la composición de especies entre temporadas en el pastizal, pero no se encontró diferencia entre el resto de los hábitat. Nuestros resultados muestran un efecto significativo de las lagunas temporales sobre la diversidad de la avifauna durante la temporada lluviosa; también evidencian la importancia de la conservación de los pastizales, dada su relevancia para la presencia de aves acuáticas. Sugerimos realizar un monitoreo continuo e intensivo, y proponemos que la zona sea designada como un área de importancia para la Conservación de las Aves (AiCA).

Aves de Quindicocha - Valle de Sibundoy, Putumayo - Colombia: Potencial área de conservación / Birds from Quindicocha - Sibundoy Valley, Putumayo - Colombia: Potential Conservation Area / Aves Quindicocha - Vale do Sibundoy, Putumayo-Colômbia: Área Potencial de Conservação

La base para la conservación es el conocimiento de la biodiversidad. Para establecer Áreas de Importancia para la Conservación de Aves (AICA) en el valle de Sibundoy (departamento de Putumayo, territorio Quindicocha, sudoeste de Colombia), se realizaron 21 jornadas de observación de aves en 11 zonas entre mayo y junio de 2013. Fueron registradas 164 especies de aves, nueve de estas corresponden a amplitudes o confirmaciones de distribución en la región. Los resultados obtenidos apoyan la propuesta de nominar esta región como un AICA independiente a AICA Laguna de la Cocha; ya que cumple con los criterios propuestos por BirdLife International en cuanto a presencia de especies amenazadas - A1 (Hapalopsittaca amazonina; Grallaria rufocinerea; Doliornis remseni; Sericossypha albocristata; Buthraupis wetmorei; Hypopyrrhus pyrohypogaster); presencia de siete aves restringidas a cinco Áreas de Endemismo de Aves (EBAs) - A2; y la presencia de 27 especies de aves restringidas al bioma Norte de los Andes - A3. Algunas de las especies no incluidas para el AICA Laguna de la Cocha.

Knowledge of the existing biodiversity is the basis of conservation. To establish Area of Important Bird Area (IBA) in the valley of Sibundoy (department of Putumayo, Quindicocha territory, in the southwest of Colombia). I conducted 21 days of birding in 11 areas between May and June 2013. I recorded 164 bird species; nine of these species correspond to distribution amplitudes or confirmations in the region. The results support the request to designate this region as an IBA, independent to IBA Laguna de la Cocha. It meets the BirdLife International criteria regarding the presence of endangered species - A1 (Hapalopsittaca amazonina; Grallaria rufodnerea; Doliornis remseni; Sericossypha albocristata; Buthraupis wetmorei;Hypopyrrhuspyrohypogaster), the presence of seven birds restricted to five Endemic Bird Areas (EBAs) - A2, and the presence of 27 species of birds restricted to the North Andes biome - A3. Some of the species not included for IBA Laguna de la Cocha.

A base para a conservação é o conhecimento da biodiversidade. Para estabelecer Áreas de Importância para a Conservação das Aves (IBA), no vale do Sibundoy (departamento de Putumayo, território Quindicocha, sudoeste da Colômbia), realizaram-se 21 dias de observação de pássaros em 11 áreas, entre maio e junho de 2013. Foram registadas 164 espécies de aves, nove delas correspondem a amplitudes ou confirmações de distribuição na região. Os resultados apoiam a proposta de nomear esta região como um AICA independente a AICA Lagoa da Cocha; pois cumpre com os critérios propostos pela BirdLife International para a presença de espécies ameaçadas de extinção - A1 (Hapalopsittaca amazonina; Grallaria rufocinerea; Doliornis remseni;albocristata Sericossypha; Buthraupis wetmorei; Hypopyrrhus pyrohypogaster); presença de sete aves restritas a cinco Áreas endémicas de pássaros (EBAS) - A2, bem como a presença de 27 espécies de aves restritas ao bioma Norte dos Andes - A3 . Algumas das espécies não incluídas para a AICA Lagoa da Cocha.

The effect of 5-aminoimidazole-4-carboxamide-ribonucleoside was mediated by p38 mitogen activated protein kinase signaling pathway in FRO thyroid cancer cells

BACKGROUND/AIMS: 5'-Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is a cellular energy sensor that monitors intracellular AMP/adenosine triphosphate (ATP) ratios and is a key regulator of the proliferation and survival of diverse malignant cell types. In the present study, we investigated the effect of activating AMPK by 5-aminoimidazole-4-carboxamide-ribonucleotide (AICAR) in thyroid cancer cells. METHODS: We used FRO thyroid cancer cells harboring the BRAF(V600E) mutation to examine the effect of AICAR on cell proliferation and cell survival. We also evaluated the involvement of mitogen-activated protein kinase (MAPK) pathways in this effect. RESULTS: We found that AICAR treatment promoted AMPK activation and suppressed cell proliferation and survival by inducing p21 accumulation and activating caspase-3. AICAR significantly induced activation of p38 MAPK, and pretreatment with SB203580, a specific inhibitor of the p38 MAPK pathway, partially but significantly rescued cell survival. Furthermore, small interfering RNA targeting AMPK-alpha1 abolished AICAR-induced activation of p38 MAPK, p21 accumulation, and activation of caspase-3. CONCLUSIONS: Our findings demonstrate that AMPK activation using AICAR inhibited cell proliferation and survival by activating p38 MAPK and proapoptotic molecules in FRO thyroid cancer cells. These results suggest that the AMPK and p38 MAPK signaling pathways may be useful therapeutic targets to treat thyroid cancer.

5-aminoimidazole-4-carboxamide Riboside Induces Apoptosis Through AMP-activated Protein Kinase-independent and NADPH Oxidase-dependent Pathways

It is debatable whether AMP-activated protein kinase (AMPK) activation is involved in anti-apoptotic or pro-apoptotic signaling. AICAR treatment increases AMPK-alpha1 phosphorylation, decreases intracellular reactive oxygen species (ROS) levels, and significantly increases Annexin V-positive cells, DNA laddering, and caspase activity in human myeloid cell. AMPK activation is therefore implicated in apoptosis. However, AMPK-alpha1-knockdown THP-1 cells are more sensitive to apoptosis than control THP-1 cells are, suggesting that the apoptosis is AMPK-independent. Low doses of AICAR induce cell proliferation, whereas high doses of AICAR suppress cell proliferation. Moreover, these effects are significantly correlated with the downregulation of intracellular ROS, strongly suggesting that AICAR-induced apoptosis is critically associated with the inhibition of NADPH oxidase by AICAR. Collectively, our results demonstrate that in AICAR-induced apoptosis, intracellular ROS levels are far more relevant than AMPK activation.

Activation of AMP-activated protein kinase stimulates the nuclear localization of glyceraldehyde 3-phosphate dehydrogenase in human diploid fibroblasts

In addition to its well-known glycolytic activity, GAPDH displays multiple functions, such as nuclear RNA export, DNA replication and repair, and apoptotic cell death. This functional diversity depends on its intracellular localization. In this study, we explored the signal transduction pathways involved in the nuclear translocation of GAPDH using confocal laser scanning microscopy of immunostained human diploid fibroblasts (HDFs). GAPDH was present mainly in the cytoplasm when cultured with 10% FBS. Serum depletion by culturing cells in a serum-free medium (SFM) led to a gradual accumulation of GAPDH in the nucleus, and this nuclear accumulation was reversed by the re-addition of serum or growth factors, such as PDGF and lysophosphatidic acid. The nuclear export induced by the re-addition of serum or growth factors was prevented by LY 294002 and SH-5, inhibitors of phosphoinositide 3-kinase (PI3K) and Akt/protein kinase B, respectively, suggesting an involvement of the PI3K signaling pathway in the nuclear export of GAPDH. In addition, 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR), an activator of AMP-activated protein kinase (AMPK), stimulated the nuclear translocation of GAPDH and prevented serum- and growth factor-induced GAPDH export. AMPK inhibition by compound C or AMPK depletion by siRNA treatment partially prevented SFM- and AICAR-induced nuclear translocation of GAPDH. Our data suggest that the nuclear translocation of GAPDH might be regulated by the PI3K signaling pathway acting mainly as a nuclear export signal and the AMPK signaling pathway acting as a nuclear import signal.

The Preconditioning with AICAR Protects Against Subsequent Renal Ischemia Reperfusion Injury / 대한신장학회지

PURPOSE:Preconditioning due to activation of AMPK might reduce ischemia-reperfusion (I/R) injury in the kidney, based on the key role of AMPK in preserving ATP. To evaluate this possibility, the effect of preconditioning with 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR), AMPK activator, before sustained ischemia was investigated. METHODS:Adult male Sprague-Dawley rats weighing approximately 220-250 g were used. To induce renal ischemia, a laparotomy was performed under ketamine and xylazine hydrochloride, and the blood supply to both kidneys was interrupted by placement of vessel clamps at the level of the renal pedicles. Reflow was initiated by removing the clamps. The following experimental groups were defined 1. Acute renal ischemia 0 sec, 10 min, 15 min, 2. AICAR treatment, 3. Sham group (S), 4. Ischemia/ Reperfusion group (I/R), 5. AICAR+I/R group (A+I/R), 6. AraA (Adenine-9-b-D-arabinofuranoside, an AMPK) inhibitor+AICAR+I/R group (AraA+A+I/R) RESULTS:There was only faint AMPK phosphorylation in the sham group. After 10 minutes of ischemia, or AICAR preconditioning however, Thr172 phosphorylation of AMPK was increased (p<0.05). The serum levels of BUN and creatinine were significantly decreased in AICAR preconditioning group (A+I/R). (128.0+/-7.33 mg/dL, 4.18+/-0.27 mg/dL vs. 90.2+/-11.13 mg/dL, 2.58+/-0.7 mg/dL, p<0.05), but these effects were attenuated by AMPK inhibitor, AraA (AraA+A+I/R group). In quantitative analysis of tubular injury, tubular injury score in AICAR preconditioning group significantly decreased (p<0.05). CONCLUSION:The AMPK activator AICAR has a protective effect against renal I/R injury.

Two Cases of Sudden Hearing Loss With Vertigo as an Isolated Symptom of Anterior Inferior Cerebellar Artery Infarction

Isolated sudden hearing loss with vertigo is usually peripheral origin. We report two cases with anterior inferior cerebellar artery infarction (AICA) manifesting sudden hearing loss with vertigo as an isolated symptom. Patient 1 was a 64-year-old man presented with right sided sudden hearing loss and vertigo accompanying horizontal beating nystagmus to the left. He had no other neurologic symptoms. MRI showed right AICA infarction involving lateral pons and middle cerebellar peduncle. Patient 2 was a hypertensive 56-year-old man. Left sided sudden hearing loss with vertigo was as an initial manifestation. Two days later, left sided facial palsy developed and MRI showed acute infarction in left lateral pons, middle cerebellar peduncle, and cerebellum. AICA infarction can be presented the hearing loss and vertigo as an isolated symptom and mimic the syndrome of peripheral origin.

A Case of Vestibular and Facial Nerve Root Entry Zone Infarction in AICA Territory Presenting with Vertigo Which Mimics Labyrinthine Lesion

Vertigo mimicking labyrinthine lesions may have resulted from ischemic insult to the inner ear or the vestibular nerve and nucleus in the AICA infarction syndrome. A 56-year-old female was admitted to the emergency room with vertigo and hearing loss in right ear. On neurological examination, she had left beating jerky torsional and horizontal nystagmus with falling and past pointing to right side. Brain magnetic resonance images showed high signal intensity in anterolateral portion of inferior pons on T2- weighted images. Severe right facial palsy of peripheral type developed 24 hours after admission. Audiometry and electronystagmography documented absent auditory and vestibular function on the affected side. We argue that vertigo of the acute infarction in AICA territory can be involved the eight and seventh nerve root entry zoon and mimic labyrinthine lesions

Sudden deafness caused by acute anterior inferior cerebellar artery infarction : A case report / 대한이비인후과학회지

A rare case, 49 year old man, of cerebellar infarction with occurrence of the sudden deafness was reported. On the otoneurological examination, hearing test and calroric test showed deafness and 19% vestibular hypofunction on the right side respectively. Mild vertigo was noticed, but spontaneous nystagmus was not observed. Cerebellar function test was intact. Magnetic resonance imaging (MRI) showed the acute cerebellar infarction in the area of the anterior inferior cerebellar artery (AICA) on the right side. After 7 days heparinization treatment, hearing threshold was much improved. An early recovery of hearing loss may be attributable to the recanalized circulation disturbance or the developement of collateral circulation.

Incomplete AICA Syndrome Presented with Peripheral Facial Palsy; A Variant of Gasperini Syndrome

Acute infarcts of the anterior inferior cerebellar artery (AICA) territory are unusual. Furthermore incomplete AICA infarcts are perplexing because of its variations of vascular anatomy and inconsistent clinical features. We present a case with clinical features of AICA infarction, which consist of ipsilateral peripheral-type facial palsy, vertigo, and contralateral facial and upper limb sensory changes without motor weakness. The patient had hypertension and was a current smoker. The high signal intensity on inferior pontine tegmental area was found on MRI and the R2 interneuronal dysfunction was note on Blink reflex. The angiographic findings didn't show any focal vascular lesions, which is contrary to the pathogenesis of AICA infarction published previously. On the clinical ground, the present case reserves to attention in that patients with peripheral-type facial palsy should be properly evaluated and with thorough neurological examination and we could differentiate between the incomplete AICA infarcts such as Gasperini syndrome and Bell's palsy.

Changes in Cochlear Blood Flow by Anterior Inferior Cerebellar Artery Occlusion in Guinea Pigs / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Cochlear blood flow is considered important as one of many causes of various inner ear diseases. Many studies have been performed to prove the decrease in cochlear blood flow as a cause of those diseases. This study was performed to determine the effects of cochlear ischemia induced by AICA occlusion on the relation of cochlear blood flow (CBF) in guinea pigs. MATERIALS AND METHODS: In 3 guinea pigs, the AICA was exposed through the basal portion of the skull with stable systemic blood pressure. The CBF of the basal area was monitored with laser Doppler flowmetry (LDF). The AICA was clamped for several minutes. With different durations, the LDF was measured under systemic blood pressure monitoring. RESULT: The vascular conductance in preocclusion state was 0.09+/-0.04 TPU (tissue perfusion unit)/mmHg. During occlusion of AICA for above 1 minute, abrupt decrease and following slow increase of CBF was observed. CONCLUSION: The autoregulation of CBF was identified, but it was incomplete even under the stable blood pressure. This study can be a good model for evalulation of hearing function during partial cochlear ischemia, but occulusion of labyrinthine artery will be a better choice for complete cochlea ischemia model.