Archibaldo Donoso

Platelet of Alzheimer patients: increased counts and subnormal uptake and accumulation of [14C]5-hydroxytryptamine.

Platelets are the main source of 5-hydroxytryptamine (5-HT) and amyloid precursor protein (APP) found in plasma. We studied a possible correlation between platelet markers and the clinical diagnosis of Alzheimer disease (AD). Our results indicate that in AD patients: (a) platelets are elevated, (b) their ability to accumulate 5-HT decreases and, (c) the kinetic parameters of 5-HT uptake are altered (decreased Km and Vmax), compared to non-demented healthy individuals. An aged Down syndrome patient presents even more deviant alterations. Our findings supports the idea that platelets may provide a systemic marker of AD, and eventually be useful for the clinical diagnosis of the disease.

Frequency and Determinants of Poststroke Cognitive Impairment at Three and Twelve Months in Chile

Background: A higher risk of poststroke cognitive impairment (CI) has been reported in Hispanics in a US cohort but has not been systematically studied in Latin America. Objectives: Our purpose was to investigate the frequencies and determinants of poststroke CI in the hispano-mestizo population of Santiago, Chile. Methods: A prospective study of hospitalized patients aged >60 years admitted with an ischemic or hemorrhagic stroke was conducted. The cognitive status was determined at 3 and 12 months after the stroke by informant questionnaires, neuropsychological testing and clinical diagnosis. Cardiovascular risk factors, brain imaging and stroke features were analyzed using regression models to establish determinants for poststroke CI. Results: A total of 164 patients (mean age = 72 ± 7.5 years) were recruited. Out of 122 patients (74%) evaluated at 3 months, 81 (66%) had CI. Out of 101 patients (62%) evaluated at 12 months, 39 (39%) had CI no dementia, and 22 (22%) were demented. The new-onset dementia frequency at 1 year was 16%. Independent determinants for dementia were higher functional impairment at hospital egress (OR = 4.0), left-hemisphere large-vessel infarction (OR = 6.9) and a larger amount of white matter changes (OR = 1.3). Conclusions: In this first study on poststroke CI in Latin America, the frequencies and determinants of poststroke CI were similar to those in other cohorts of different ethnic origin.

Deterioro cognitivo leve y enfermedad de Alzheimer inicial en adultos mayores

The early detection of dementia carries implications for clinical management of patients and their families, and it is of utmost concern if an effective pharmacological treatment is to be found. We report the final clinical diagnosis of 36 seniors who complained (or were accused) of forgetfulness. In the Initial Mini-Mental State Examination they scored 25 to 30 out of 30 points and could be diagnosed as having Mild Cognitive Impairment without dementia; preclinical Alzheimers disease was suspected. Clinical observation (from 6 to 70 months, mean 31) showed that the clinical condition of 15 patients clearly worsened; these were diagnosed as likely Alzheimers disease patients. Eleven suffered from emotional disturbances and improved with pharmacological and psychosocial treatment; ten of the patients had a static condition and remained in the Mild Cognitive Impairment category. We discuss the frontiers between normal aging, Mild Cognitive Impairment and Alzheimers disease; we remark the difficulties in the differential diagnosis. Most of the patients with Alzheimers disease were anosognosics with regard to the memory impairment; this could be a useful clinical point. We also underscore the usefulness of a neuropsychological assessment and the need for continued longitudinal evaluation of subjects with questionable dementia. In the next years, progress in neuropsychological, radiological and biological examinations will lead to improve diagnoses

Degeneración córtico-basal: 5 casos clínicos

Se presentan 5 pacientes con un cuadro clinico de degeneracion corticobasal (DCB); son los primeros casos publicados en nuestro pais. Todas eran mujeres en la 6a o 7a decada de vida; en 4 la distonia comenzo por el brazo derecho. El curso fue lentamente progresivo, con parkinsonismo (rigidez, akinesia, alteraciones posturales y disartria), demencia de tipo frontal y apraxias (constructiva en todas, ideomotora bilateral y oral en una, el defecto motor impidio su evaluacion en varios casos). En dos casos se comprobo una afasia no fluente. Cuatro pacientes presentaron alteraciones oculomotoras, con lentitud de los movimientos sacadicos y ausencia de nistagmo optokinetico. En una de ellas existio una agnosia visual aperceptiva y en el ultimo caso se comprobo un defecto del campo visual. En ningun caso fue posible una evaluacion fina de la sensibilidad, la sensibilidad dolorosa estuvo siempre conservada. La tomografia computada cerebral y la resonancia nuclear magnetica mostraron una atrofia asimetrica moderada; en 2 casos con SPECT se demostro una gran hipoperfusion asimetrica. La revision de la literatura permite concluir que la DCB es una entidad bien definida desde el punto de vista patologico, pero el cuadro clinico tradicional puede deberse a DCB propiamente tal, enfermedad de Pick, de Alzheimer, Jacob-Creutzfeldt, paralisis supranuclear progresiva, o infartos cerebrales. Por otra parte, casos comprobados con autopsia han sido diagnosticados en vida como enfermedad de Parkinson o Alzheimer, paralisis supranuclear progresiva, como demencia frontotemporal

Deterioro cognitivo leve: seguimiento de 10 casos

En una experiencia clinica inicial, de 36 sujetos diagnosticados como deterioro cognitivo leve (DCL), con un seguimiento clinico de 31 meses promedio, 15 evolucionaron a demencia de tipo Alzheimer, 11 mejoraron y se diagnosticaron como trastornos emocionales, y 10 permanecieron como DCL estables (Donoso et al. 2001). Un seguimiento de 2 anos adicionales del ultimo grupo permitio ver que 5 evolucionaron hacia una demencia (EA probable o mixta); uno mejoro, otro resulto ser una paralisis supranuclear progresiva, y solo 3 se mantuvieron estables. De estas experiencias se extraen dos conclusiones principales. Primero, que el diagnostico del DCL no es facil y puede confundirse con trastornos emocionales en adultos mayores. La segunda es que la mayoria de ellos corresponde a una fase inicial de la EA, sin demencia. Nuestros comentarios son dos. El primero es que no se necesitaria tener una demencia para sospechar o diagnosticar una EA probable. El segundo, que el diagnostico precoz del DCL permitiria tomar algunas medidas que tal vez impidan o posterguen la aparicion de la demencia.

Anosognosia en enfermedades cerebrales

Se analiza la falta de nocion de enfermedad y las confabulaciones en pacientes neurologicos con distintos defectos: hemiplejia, defectos visuales, defectos de la memoria, del lenguaje, traumatismos encefalocraneanos y demencias. Se discute la posible importancia de trastornos emocionales, de defectos focales y del deterioro cognitivo general como factores del desconocimiento de la enfermedad. Se concluye que existe una relacion psicopatologica entre tener un defecto, ser anosognosico, y confabular suponiendo un rendimiento normal. Ademas se plantea que existiria un sistema funcional del darse cuenta, constituido por diversas areas cerebrales importantes para el monitoreo de diferentes funciones y por las areas prefrontales

Trastornos del Lenguaje en el Adulto

The main purpose of the current review is to describe the language disorders in adult as a consequence of brain damage. The oral language disorders will be approached regarding the following topics: some basic linguistic concepts to describe language disturbances accurately; the functional language system involving perisylvian areas, right hemisphere and prefrontal areas; aphasia that represent a total or partial language impairment; the patient with aphasia, regarding their clinical background, their attitude towards the alteration, the cognitive impairment and other associated disorders; the aphasia treatment which has for purposes to achieve a functional communication and psychological and social adaptation considering their language impairment and, at last, the discourse impairment which affects their use and content. Regarding the reading and writing impairment, agraphia and alexia types will be described. Finally, it is important to mention two aspects: first, besides aphasia there are other language disorders and, second, language assessment is essential to the management and rehabilitation of the patient.