[Developmental amnesia and early brain damage: neuropsychology and neuroimaging]. / Amnesia del desarrollo y daño cerebral temprano: neuropsicologia y neuroimagen.

ABSTRACT

AIM: To contribute to neuropsychological profiling of developmental amnesia subsequent to bilateral damage to both hippocampi in early age. SUBJECTS AND METHODS: The total sample of 24 schoolchildren from both sexes is distributed in three groups perinatal hypoxic-ischaemic encephalopathy and everyday complaints of memory in school age (n = 8); perinatal hypoxic-ischaemic encephalopathy without memory complaints (n = 7); and a group of typically developing (n = 9). All participants in every groups did have normal general intelligence and attention. Both clinical groups had, as another clinical consequence, spastic cerebral palsy (diplegia). Neuropsychological exam consisted on tests of general intelligence, attentional abilities, declarative memory and semantic knowledge. All participants had a brain magnetic resonance image and spectroscopy of hippocampi. Scheltens criteria were used for visual estimation of hippocampal atrophy. Parametric and non-parametric statistical contrasts were made. RESULTS: Despite preservation of semantic and procedural learning, declarative-episodic memory is impaired in the first group versus the other two groups. A significant proportion of bilateral hippocampal atrophy is only present in the first group versus the other two non-amnesic groups using Scheltens estimation on MRI. Two cases without evident atrophy did have diminished NAA/(Cho + Cr) index in both hippocampi. CONCLUSIONS: Taken together, these results contribute to delineate developmental amnesia as an specific impairment due to early partial bihippocampal damage, in agreement with previous studies. After diagnosis of developmental amnesia, a specific psychoeducational intervention must be made; also this impairment could be candidate for pharmacological trials in the future.

RESUMEN

TITLE Amnesia del desarrollo y daño cerebral temprano neuropsicologia y neuroimagen.Objetivo. Contribuir a la descripcion de la amnesia del desarrollo como sindrome especifico en niños que sufrieron agresion temprana, pero no masiva, de ambos hipocampos. Sujetos y metodos. Muestra de 24 escolares de ambos sexos, de 6-16 años de edad. Se distribuye en tres grupos pacientes afectos de encefalopatia hipoxico-isquemica perinatal, con paralisis cerebral espastica, inteligencia normal y fallos de memoria (n = 8); pacientes con similares caracteristicas, pero sin quejas de memoria (n = 7); y escolares sanos sin antecedentes de riesgo (n = 9) como grupo control. Se aplican escalas y tests para comprobar la normalidad intelectual y atencional, y para medir el perfil de rendimiento en tareas de memoria. En todos los sujetos, mediante resonancia magnetica, se estima la presencia y grado de atrofia hipocampica con la escala de Scheltens, y se calcula el indice espectroscopico NAA/(Cho + Cr). Resultados. El perfil neuropsicologico de los ocho pacientes del primer grupo es claramente sugestivo de amnesia del desarrollo, que contrasta con la normalidad en los otros grupos. En siete escolares con amnesia se constata bilateralmente algun grado de atrofia bihipocampica o disminucion significativa del indice NAA/(Cho + Cr). Conclusiones. La amnesia del desarrollo se caracteriza por afectacion de la memoria episodica con preservacion del aprendizaje semantico y procedimental. Se explica por daño parcial bihipocampico temprano. El correcto diagnostico permite una intervencion psicoeducativa especifica. En el futuro cabria ensayar terapias farmacologicas asociadas a la intervencion psicoeducativa.