[Memory evaluation using functional magnetic resonance: applications in preoperative patients and in Alzheimer s disease]. / Evaluacion de la memoria mediante resonancia magnetica funcional: aplicaciones en pacientes prequirurgicos y en la enfermedad de Alzheimer.

The assessment of memory functions related to medial temporal lobe has become one of the most important issues on current neuropsychology. On this communication, we review the results which our research group has achieved using two functional magnetic resonance Image procedures to assess memory function: Hometown walking task and an encoding/retrieval task using complex images. Nine patients with tumoural temporal lesions performed the hometown walking task. The results of these patients showed either a bilateral or contralesional representation of memory function. These results confirm those obtained by Jokeit, Okujava y Woermann (2001), and they seem to prove that this protocol is useful to determine the preservation of memory function in the non damaged hemisphere. On the other hand, the images encoding/retrieval task has been run by two groups of four patients diagnosed as Alzheimer disease and mild cognitive impairment, and another group of five patients who participated as a control group. According to our hypothesis, the results have shown a lower activation at the left parahippocampal gyrus in mild cognitive impairment and Alzheimer disease patients than controls, just as a lower bilateral activation in the same structure for the Alzheimer group than the control group. As a whole, our results show how important may become functional magnetic resonance image for neuropsychological assessment of memory, and as a diagnostic tool for CNS diseases.

Evaluación de la memoria mediante resonancia magnética funcional: aplicaciones en pacientes prequirúrgicos y en la enfermedad de Alzheimer / Memory evaluation using functional magnetic resonance: applications in preoperative patients and in alzheimer's disease

La evaluación de las funciones de memoria relacionadas con estructuras del lóbulo temporal medial se ha convertido en uno de los pilares más importantes en la Neuropsicología actual, dada su extrema relevancia en enfermedades como las demencias y las epilepsias temporales. En esta comunicación revisaremos los resultados que nuestro grupo de investigación ha obtenido con la utilización de sendos protocolos de evaluación de la memoria mediante resonancia magnética funcional (RMf): la tarea de `Paseo por tu Ciudad' (PPTC) y la tarea de `codificación/recuerdo' de imágenes complejas. La tarea de PPTC se ha aplicado a un grupo de nueve pacientes candidatos a neurocirugía por lesiones en el lóbulo temporal, y se obtuvo en todos ellos una representación bilateral o contralesional de la memoria. Los resultados coinciden con los obtenidos en el estudio original de Jokeit, Okujava y Woermann (2001) y parecen mostrar que este protocolo sirve para determinar la preservación o no de la función mnésica en el hemisferio lesionado. Por su parte, la tarea de codificación/recuerdo de imágenes se ha administrado a un grupo de cuatro pacientes con enfermedad de Alzheimer, cuatro con deterioro cognitivo leve y cinco participantes controles. De acuerdo con nuestras hipótesis, los resultados han mostrado una menor activación en la circunvolución parahipocampal izquierda en el grupo con deterioro cognitivo leve que en el grupo control, así como una menor activación bilateral en esas estructuras en el grupo con enfermedad de Alzheimer, si se compara con el grupo control. Nuestros resultados, en conjunto, muestran la importancia que en el futuro tendrá la RMf en la evaluación neuropsicológica de la memoria, y en el diagnóstico de las enfermedades del sistema nervioso central (AU)

he assessment of memory functions related to medial temporal lobe has become one of the most important issues on current neuropsychology. On this communication, we review the results which our research group has achieved using two functional magnetic resonance Image procedures to assess memory function: ‘Hometown walking’ task and an ‘encoding/retrieval’ task using complex images. Nine patients with tumoural temporal lesions performed the hometown walking task. The results of these patients showed either a bilateral or contralesional representation of memory function. These results confirm those obtained by Jokeit, Okujava y Woermann (2001), and they seem to prove that this protocol is useful to determine the preservation of memory function in the non-damaged hemisphere. On the other hand, the images encoding/retrieval task has been run by two groups of four patients diagnosed as Alzheimer disease and mild cognitive impairment, and another group of five patients who participated as a control group. According to our hypothesis, the results have shown a lower activation at the left parahippocampal gyrus in mild cognitive impairment and Alzheimer disease patients than controls, just as a lower bilateral activation in the same structure for the Alzheimer group than the control group. As a whole, our results show how important may become functional magnetic resonance image for neuropsychological assessment of memory, and as a diagnostic tool for CNS diseases (AU)

[Applications of functional magnetic resonance imaging in pre-surgical patients: motor, mnemonic and linguistic functions]. / Aplicaciones de la resonancia magnética funcional en pacientes prequirúrgicos: funciones motora, de memoria y lingüística.

AIMS: This paper reviews and describes cases involving useful protocols for pre-surgical evaluation in functional magnetic resonance imaging (fMRI) of the motor, mnemonic and linguistic functions. DEVELOPMENT: The application of fMRI in pre-surgical evaluation allows us to pinpoint the anatomical location of a function in relation to the lesion. This technique therefore appears as an alternative to the classical intraoperative tests, which are more aggressive and costly. The paper describes aspects and considerations of fMRI with regard to the methodology and procedure employed in its application, as well as the control of contaminating variables that can affect results. The language protocols are described in terms of lateralisation and localisation, and are divided into expressive and receptive language protocols, together with linguistic protocols for overall stimulation that allow the localisation of both expressive and receptive areas. Concerning the motor protocols, we describe the procedures for patients with and without difficulties in their movement. Lastly, we review and describe the memory protocols that give rise to bilateral stimulation in the mesial temporal areas, which allows both lateralisation and localisation of the hippocampal and parahippocampal areas that are functionally significant for the patients' memory. Each of the protocols is illustrated with cases carried out by our work team. CONCLUSIONS: The development of new protocols for pre-surgical evaluation must be guided by greater delimitation and consistency in functional stimulation, as well as analysis of the behaviour displayed.

Aplicaciones de la resonancia magnética funcional en pacientes prequirúrgicos: funciones motora, de memoria y lingüística / Applications of functional magnetic resonance imaging in pre-surgical patients: motor, mnemonic and linguistic functions

Objetivo. Este artículo revisa y presenta casos sobre protocolos útiles de evaluación prequirúrgica en resonancia magnética funcional (RMf) de las funciones motoras, mnésicas y lingüísticas. Desarrollo. La aplicación de la RMf en la evaluación prequirúrgica permite referenciar la localización anatómica de una función en relación con la lesión. En este sentido, esta técnica se plantea como alternativa a las pruebas clásicas intraoperatorias, que son más invasivas y costosas. El artículo reseña aspectos y consideraciones propias de la RMf en relación con su metodología y procedimiento de aplicación, además del control de variables contaminantes que pueden afectar a los resultados. Los protocolos de lenguaje se describen en términos de lateralización y localización, y se distinguen protocolos de lenguaje expresivo y receptivo, además de protocolos lingüísticos de activación global que permiten localizar tanto áreas expresivas como receptivas. En relación con los protocolos motores, se describen los procedimientos para pacientes con y sin dificultades de movimiento. En último lugar, se revisan y describen los protocolos de memoria que producen una activación bilateral en las áreas temporales mesiales, que permiten tanto la lateralización como la localización de las áreas hipocampales y parahipocampales funcionalmente elocuentes para la memoria de los pacientes. Cada uno de los protocolos se ilustra con casos llevados a cabo por nuestro equipo de trabajo. Conclusiones. La mayor delimitación y consistencia en la activación funcional, así como el análisis de la conducta manifiesta, deben guiar el desarrollo de nuevos protocolos de evaluación prequirúrgica (AU)

Aims. This paper reviews and describes cases involving useful protocols for pre-surgical evaluation in functional magnetic resonance imaging (fMRI) of the motor, mnemonic and linguistic functions. Development. The application of fMRI in presurgical evaluation allows us to pinpoint the anatomical location of a function in relation to the lesion. This technique therefore appears as an alternative to the classical intraoperative tests, which are more aggressive and costly. The paper describes aspects and considerations of fRMI with regard to the methodology and procedure employed in its application, as well as the control of contaminating variables that can affect results. The language protocols are described in terms of lateralisation and localisation, and are divided into expressive and receptive language protocols, together with linguistic protocols for overall stimulation that allow the localisation of both expressive and receptive areas. Concerning the motor protocols, we describe the procedures for patients with and without difficulties in their movement. Lastly, we review and describe the memory protocols that give rise to bilateral stimulation in the mesial temporal areas, which allows both lateralisation and localisation of the hippocampal and parahippocampal areas that are functionally significant for the patients’ memory. Each of the protocols is illustrated with cases carried out by our work team. Conclusions. The development of new protocols for pre-surgical evaluation must be guided by greater delimitation and consistence in functional stimulation, as well an analysis of the behaviour displayed (AU)