RESUMEN
OBJECTIVE: To provide new evidence of the existence of basal forebrain amnesia, as a different entity from hippocampal or diencephalic amnesia. BACKGROUND: Some authors consider that the characteristics of amnesia do not depend on lesion site, although others claim there are neuropsychologic differences between amnesias due to hippocampal, diencephalic, and basal forebrain lesions. As to the latter, literature is scarce and controversial. The opportunity to thoroughly study J.S., a man with a high IQ and amnesia, enabled us to reinforce the second hypothesis. METHODS: J.S. is a 47-year-old man who underwent surgery for a pituitary adenoma, the resulting lesion involving only the basal forebrain. We gave him a complete neuropsychologic battery for amnesia and executive functions. RESULTS: J.S. showed severe amnesia with a flat learning curve, a rapid forgetting rate and good recognition, a temporal gradient of several years for remote memory, preserved semantic and procedural memory. Most of the tests for executive functions were normal, although he did have a significant personality change after surgery. CONCLUSIONS: This patient is different from patients with hippocampal or diencephalic lesions, and is similar to other patients reported with basal forebrain lesions. The main difference is the relation between his flat learning curve and preserved recognition, both for visual and verbal material.
Asunto(s)
Amnesia/clasificación , Amnesia/patología , Ganglios Basales/patología , Retención en Psicología , Aprendizaje Verbal , Adenoma/complicaciones , Adenoma/cirugía , Amnesia/etiología , Aprendizaje por Asociación , Ganglios Basales/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Reconocimiento Visual de Modelos , Neoplasias Hipofisarias/complicaciones , Neoplasias Hipofisarias/cirugía , Reconocimiento en Psicología , Valores de ReferenciaRESUMEN
Cobalamin deficiency may cause cognitive deficits and even dementia. In Alzheimer's disease, the most frequent cause of dementia in elderly persons, low serum levels of vitamin B12, may be misleading. The aim of this work was to characterize the cognitive pattern of B12 deficiency and to compare it with that of Alzheimer's disease. Nineteen patients with low levels of vitamin B12 were neuropsychologically evaluated before treatment and a year later. Results were compared with those of 10 healthy control subjects. Final results suggest that there is a different pattern in both diseases. Twelve elderly patients with dementia improved with treatment. Seven elderly demented patients did not improve; they deteriorated after 1 year although their levels of cobalamin were normal. Analysis of the initial evaluation showed that the 2 groups of patients had a different neuropsychological profile. The group that improved had initially more psychotic problems and more deficits in concentration, visuospatial performance, and executive functions. They did not show language problems and ideomotor apraxia, which were present in the second group. Their memory pattern was also different. These findings suggest that cobalamin deficiency may cause a reversible dementia in elderly patients. This dementia may be differentiated from that of Alzheimer's disease by a thorough neuropsychological evaluation.
Asunto(s)
Demencia/diagnóstico , Demencia/etiología , Deficiencia de Vitamina B 12/complicaciones , Deficiencia de Vitamina B 12/psicología , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/diagnóstico , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Trastornos de la Memoria/etiología , Pruebas Neuropsicológicas , Deficiencia de Vitamina B 12/diagnósticoRESUMEN
Myasthenia gravis (MG) is a T cell-dependent, antibody-mediated autoimmune disease. A dual altered peptide ligand (APL) that is composed of the tandemly arranged two single amino acid analogs of two myasthenogenic peptides was demonstrated to downregulate in vitro and in vivo murine MG associated autoreactive responses. Furthermore, treatment with the dual APL ameliorated the clinical manifestations of an established experimental autoimmune MG in mice. This study was undertaken in order to investigate the ability of the dual APL to immunomodulate MG-associated responses of peripheral blood lymphocytes (PBL) of patients with MG to the native autoantigen acetylcholine receptor (AChR). PBL of 22 of 27 patients with MG tested responded by proliferation to torpedo AChR. The proliferative responses of PBL of 21 of 22 responders were significantly inhibited by the dual APL. The inhibition was specific because a control peptide did not inhibit these proliferative responses. The dual APL also downregulated the levels of the secreted pathogenic cytokine IFN-gamma in supernatants of stimulated PBL of 80% of the tested patients. The latter inhibitions correlated with an upregulated production of the immunosuppressive cytokine, tumor growth factor beta. Thus, the results of our study demonstrate that the dual APL is capable of downregulating in vitro autoreactive responses of patients with MG and suggest that this peptide is a potential candidate for a novel specific treatment of patients with MG.