Development of a simulation platform for the evaluation of PET neuroimaging protocols in epilepsy

Monte Carlo simulation of PET studies is a reference tool for the evaluation and standardization of PET protocols. However, current Monte Carlo software codes require a high degree of knowledge in physics, mathematics and programming languages, in addition to a high cost of time and computational resources. These drawbacks make their use difficult for a large part of the scientific community. In order to overcome these limitations, a free and an efficient web-based platform was designed, implemented and validated for the simulation of realistic brain PET studies, and specifically employed for the generation of a wellvalidated large database of brain FDG-PET studies of patients with refractory epilepsy

Introducción a las técnicas de neuroimagen

La tomografía por emisión de positrones (PET) y la resonancia magnética (RM) ofrecen la posibilidad de estudiar la anatomía del cerebro y su plasticidad, y de detectar las zonas que se activan o las redes que tienen su actividad sincronizada al realizar determinadas tareas. Se hará una breve introducción de distintas técnicas de neuroimagen con ejemplos de aplicación.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Beneficial effects of pharmacological treatment in post-stroke dynamic aphasia: a behavioural and neuroimaging study

Introduction : Dynamic Aphasia (DA) is a rare form of language disorder characterized by reduced spontaneous speech with preservation of other language functions. Two types of DA have been described: language-specific type (type I DA) and domain-general type (type II DA). In type I DA, deficits are selective for word and sentence generation, whereas in type II DA impairments affect discourse generation, narrative, fluency, and non-verbal generation tasks. There is little information on the treatment of DA. Although treatment with a cognitive enhancing drug (bromocriptine) improved outcome in previous studies, pharmacological interventions combining two drugs acting on other neurotransmitter systems in DA have not been reported so far. Methods : We report an open-label pharmacological single case study (n = 1) in a male patient with a chronic type I/II DA secondary to an ischemic infarction in the left fronto-opercular and insular regions. After baseline evaluation, the patient received donepezil 5 mg/day (2 months), donepezil 10 mg/day (2 months), donepezil 10 mg/day plus memantine 20 mg/day (4½ months) followed by a washout period (1½ months). No speech-language therapy was used. A comprehensive cognitive and language evaluation was carried out at baseline and at different endpoints. 18FDG-PET was performed at the four timepoints. Results : Donepezil (5 mg/day) significantly improved type I DA features (normalization of verbs generation, p = 0.01), whereas donepezil (10 mg/day) improved some type II features (normalizing spontaneous speech, verbal fluency and improving generation of novel thoughts, p = 0.004), along with improvement of executive-attentional functioning. Combined therapy further enhanced cognitive function, but did not additionally improved DA. 18 FDG-PET revealed significant reductions of perilesional hypometabolic activity mainly after donepezil (10 mg/day) and washout. Discussion : Treatment with donepezil improved language deficits in a patient with chronic post-stroke type I/II DA. Combined therapy (donepezil plus memantine) further enhanced executive-attentional functioning. Beneficial changes were associated with improvements in perilesional metabolic activity. References : Luria AR et al.Acta Neurologica et Psychiatrica (1967). Robinson G et al. Brain (1998). Keywords : Language; patients; single case study; adults; cerebrovascular; behavioural, functional imaging.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Diagnóstico del servicio al cliente en cadenas hoteleras en Santa Marta D.T.C.H. – caso de Xarm Hotels

En el presente estudio de caso se analiza por medio de una serie de entrevistas al personal, encuestas a los clientes y observación directa e indirecta a través de portales web, la manera en que la cadena hotelera Xarm Hotels ubicada en la ciudad de Santa Marta D.T.C.H. realiza los procesos relacionados con el servicio al cliente. Se realiza una descripción detallada de los pasos ejecutados desde que el cliente hace su reserva hasta que el servicio es consumado, así como se proporcionan una serie de hallazgos sobre la percepción de los huéspedes acerca de la satisfacción, confort, seguridad y comportamiento del personal. Los datos analizados sugieren una relación entre motivación, capacitaciones y productividad de los empleados. Se describen 4 propuestas de mejoramiento: la utilización de un sistema de gestión de servicio al cliente para facilitar los procesos de fidelización y recompra, un programa de capacitaciones periódico, un programa de motivación para el personal de la Cadena, así como recomendaciones específicas para cada uno de los establecimientos que la conforman

Brain structural and functional correlates of the heterogenous progression of mixed transcortical aphasia

Mixed transcortical aphasia (MTCA) is characterized by non-fluent speech and comprehension deficits coexisting with preserved repetition. MTCA may evolve to less severe variants of aphasias or even to full language recovery. Mechanistically, MCTA has traditionally been attributed to a disconnection between the spared left perisylvian language network (PSLN) responsible for preserved verbal repetition, and damaged left extrasylvian networks, which are responsible for language production and comprehension impairments. However, despite significant advances in in vivo neuroimaging, the structural and functional status of the PSLN network in MTCA and its evolution has not been investigated. Thus, the aim of the present study is to examine the status of the PSLN, both in terms of its functional activity and structural integrity, in four cases who developed acute post-stroke MTCA and progressed to different types of aphasia. For it, we conducted a neuroimaging- behavioral study performed in the chronic stage of four patients. The behavioral profile of MTCA persisted in one patient, whereas the other three patients progressed to less severe types of aphasias. Neuroimaging findings suggest that preserved verbal repetition in MTCA does not always depend on the optimal status of the PSLN and its dorsal connections. Instead, the right hemisphere or the left ventral pathway may also play a role in supporting verbal repetition. The variability in the clinical evolution of MTCA may be explained by the varying degree of PSLN alteration and individual premorbid neuroanatomical language substrates. This study offers a fresh perspective of MTCA through the lens of modern neuroscience and unveils novel insights into the neural underpinnings of repetition.Funding for open access publishing: Universidad Málaga/CBUA. This work was supported by the Spanish Ministry of Economy, Industry and Competitiveness, Instituto de Salud Carlos III under Grant: PI16/01514 (MLB and GD) and by the Junta de Andalucía under Grant: P20_00501 (GD). MLB was funded by the European Social Fund (FEDER). DL-B was supported by the Ayuda RYC2020-029495-I Ramón y Cajal funded by the MCIN/AEI/10.13039/501100011033 and by El FSE invierte en tu futuro; and by the Grant PID2021-127617NA-I00 Proyecto de Generación de Conocimiento 2021 funded by MCIN/AEI /10.13039/501100011033/ and FEDER Una manera de hacer Europa. JP-P was funded by a PhD scholarship (FPU16/05198) from the Spanish Ministry of Education, Culture and Sport under the FPU program. MJT-P was supported by a Margarita Salas postdoctoral fellowship by the University of Malaga, funded by the European Union– NextGenerationEU – and the Spanish Ministerio de Universidades, and by a mobility grant from the Spanish Ministry of Universities under the José Castillejo program

Language as a Threat: Multimodal Evaluation and Interventions for Overwhelming Linguistic Anxiety in Severe Aphasia

Linguistic anxiety (LA) is an abnormal stress response induced by situations that require the use of verbal behavior, and it is accentuated during language testing in persons with aphasia (PWA). The presence of LA in PWA may jeopardize the interpretation of cognitive evaluations, leading to biased conclusions about the severity of the language alteration and the effectiveness of the treatments. In the present study, we report the case of a woman (Mrs. A) with severe chronic mixed transcortical aphasia due to left frontal and parietal hemorrhages that partially spared the perisylvian area. Mrs. A was treated with the dopamine agonist Rotigotine alone and combined with Intensive Language-Action Therapy (ILAT). Complementary evaluations included autonomic reactivity during the performance of different language tasks, resting state functional magnetic resonance imaging (rs-fMRI) and [18F]-fluorodeoxyglucose positron emission tomography (18F-FDG-PET). We found that formal language testing in a clinical setting triggered a dramatic increase of automatic echolalia, perseverations and frustration, making the task completion difficult. The treatment improved aphasia, but gains were more robust when evaluation was performed by Mrs. A’s husband at home than by clinicians. Autonomic evaluation under Rotigotine revealed higher reactivity during tasks tapping an impaired function in comparison with a task evaluating a preserved function (verbal repetition). Baseline 18F-FDG-PET analysis showed decreased metabolic activity in left limbic-paralimbic areas, whereas rs-fMRI revealed compensatory activity in the right hemisphere. We also analyzed the different factors (e.g., premorbid personality traits, task difficulty) that may have contributed to LA in Mrs. A during language testing. Our findings emphasize the usefulness of implicating adequately trained laypersons in the evaluation and treatment of PWA showing LA. Further studies using multidimensional evaluations are needed to disentangle the interplay between anxiety and abnormal language as well as the neural mechanisms underpinning LA in PWA

Ecolalia mitigada y conducta de aproximación: plasticidad compensatoria en los circuitos cerebrales de lenguaje

Introducción. Las descripciones tradicionales de afasia atribuyen las alteraciones lingüísticas a daño de tejido cerebral, principalmente en el hemisferio izquierdo. Esta es una explicación lógica para aquellos síntomas que implican alteración de las funciones lingüísticas previas (capacidad de comprensión reducida, anomia, etc.). Sin embargo, los síntomas caracterizados por errores (parafasias, perseveraciones, etc.) o repetición verbal excesiva (ecolalia), no pueden emanar de áreas totalmente disfuncionales. Dentro de estos, hay dos síntomas que se observan con frecuencia en personas con afasia (PcA): conduite d´approach (aproximaciones sucesivas a la palabra objetivo, [CdA]) y ecolalia mitigada (EM). Objetivo. Explorar los mecanismos funcionales y estructurales que sustentan la CdA y EM, y cómo estos se relacionan con cambios plásticos dentro de la red del lenguaje. Para este fin, presentamos datos comportamentales y de neuroimagen de 3 PcA crónica. El paciente 1 presentaba un lenguaje caracterizada por múltiples instancias de CdA, el paciente 2 presentaba predominantemente EM y el paciente 3 instancias de ambos síntomas. Conclusiones. La CdA parece reflejar actividad de la vía ventral del lenguaje tras daño de la vía dorsal, mientras que la EM refleja hiperactividad de la vía dorsal en un intento por compensar un daño en la vía ventral.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Is the emergence of speech errors in chronic post-stroke aphasia a result of ongoing compensatory brain plasticity mechanisms?

Traditional descriptions of aphasia have ascribed language disturbances to tissue damage but symptoms expressed as repetitive verbal behaviors such as echolalia, perseverations and so forth, cannot emanate from fully dysfunctional. We propose that in aphasia, repetitive verbal behaviors (such as conduite d’approche (CdA) and mitigated echolalia (ME)) may be compensatory behaviors emerging from ongoing plastic changes occurring in the preserved tissue. CdA is the repetitive and self-initiated approximation to a target word during spontaneous speech or naming tasks. ME refers to the echoing of a just heard sentence introducing a subtle change. At brain level, language deficits usually result from lesions affecting the dorsal and the ventral streams. Damage to the main dorsal pathway is related to deficits in verbal repetition and fluency, while lesions affecting the ventral pathway are related to comprehension deficits. Thus, we propose that ME may emerge from spared dorsal stream when the ventral system is compromised, while CdA may result as an attemp of the ventral stream to compensate dorsal damage. In this study we analysed three cases of aphasia at linguistic and structural (MRI and PET) levels. In patient 1, speech was predominantly characterized by instances of CdA, patient 2 presented predominantly ME instances, and patient 3 had both CdA and ME. Results showed that patient 1 had a disconnection pattern that greatly overlapped with the dorsal language pathway, while patient 2 ́s lesion location bisected the ventral pathway discontinuing the projection of fibers that run through it. Patient 3 presented a disconnection pattern in-between the two previous ones. These findings suggest that symptoms as CdA and ME, that frequently appear in the chronic stage of aphasia may represent the behavioral expression of plastic changes occurring within the preserved language network in an attempt to compensate the linguistic functions associated to the damaged pathway.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Estudio de la activación cerebral de los turistas ante la personalidad de los destinos turísticos.

El objetivo de este estudio es conocer cuál es la activación cerebral del turista ante las diferentes dimensiones de la personalidad del destino, identificar si esa activación de regiones del cerebro difiere entre dimensiones y explorar la relación entre la activación cerebral y la intención de visita. Para ello se emplea la resonancia magnética funcional, con el objetivo de medir la respuesta de los turistas ante la presentación de imágenes que representan diferentes dimensiones de la personalidad de los destinos. Los resultados preliminares de este trabajo en curso muestran que las dimensiones activan regiones cerebrales asociadas a características relacionadas con el significado de la dimensión y que las regiones activadas varían entre las dimensiones, aunque aún no se dispone de datos para analizar su relación con la intención de visita. El presente trabajo representa una importante contribución a la literatura del neuromarketing y a la gestión de las estrategias de marketing de los destinos.Programa Operativo FEDER de Andalucía 2014-2020, Consejería de Transformación Económica, Industria, Conocimiento y Universidades (Proyecto P20_00457), y Ministerio de Educación, Cultura y Deporte del Gobierno de España (FPU20/00235)

Correlatos cerebrales y cognitivos de la potenciación farmacológica en un caso de afasia dinámica

Introducción. La afasia dinámica (AD) es un tipo raro de alteración del lenguaje caracterizada por una reducción del habla espontánea. La AD tipo lingüístico (AD I) se caracteriza por dificultades en la generación de palabras/frases, mientras que la AD tipo general (AD II) se caracteriza por problemas en la generación del discurso y la fluencia. Nuestro objetivo fue evaluar el efecto de dos fármacos combinados (donepezilo y memantina) que actúan sobre los sistemas de neurotransmisión colinérgico y dopaminérgico, respectivamente, en la recuperación de la AD. Descripción y resultados. Reportamos un estudio abierto de caso único de un paciente con AD I/II post-ictus. Se realizaron 5 evaluaciones cognitivas/lingüísticas y 18FDG-PET en 5 momentos: línea base, donepezilo-5mg/día (2 meses) , donepezilo-10mg/día (2 meses9, donepezilo-10mg/día más memantina-20mg/día (4½ meses) y período de lavado (1½ mes). Donepezilo-5mg/día mejoró la sintomatología de la AD I, mientras que el donepezilo-10mg/día mejoró la sintomatología AD II y las funciones ejecutivas/atencionales. El 18FDG-PET mostró un restablecimiento de la actividad metabólica perilesional después del donepezilo-10mg/día y del periodo de lavado. Conclusiones. El tratamiento con donepezilo mejoró los déficits lingüísticos en un paciente con AD I/II post-ictus. La terapia combinada produjo mejorías principalmente en funciones ejecutivas/atención, y estos beneficios, estaban asociados a mejorías de la actividad metabólica perilesional.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech