Raúl Carlos Rey

Differences in Stroke Subtypes Among Natives and Caucasians in Boston and Buenos Aires

Background and Purpose Several issues regarding ethnic-cultural factors, sex-related variation, and risk factors for stroke have been described in the literature. However, there have been no prospective studies comparing ethnic differences and stroke subtypes between populations from South America and North America. It has been suggested that natives from Buenos Aires, Argentina, may have higher frequency of hemorrhagic strokes and penetrating artery disease than North American subjects. The aim of this study was to validate this hypothesis. Methods We studied the database of all consecutive acute stroke patients admitted to the Ramos Mejia Hospital (RMH) in Buenos Aires and to the Beth Israel Deaconess Medical Center (BIMC) in Boston, Massachusetts, from July 1997 to March 1999. Stroke subtypes were classified according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. All information on patients (demographic, clinical, and radiographic) was recorded prospective to the assessment of the stroke subtype. Results Three hundred sixty-one and 479 stroke patients were included at RMH and BIMC stroke data banks, respectively. Coronary artery disease was significantly more frequent in BIMC (P <0.001), whereas tobacco and alcohol intake were significantly more frequent in RMH (P <0.001). Intracerebral hemorrhage (P <0.001) and penetrating artery disease (P <0.001) were significantly more frequent in the RMH registry, whereas large-artery disease (P <0.02) and cardioembolism (P <0.001) were more common in the BIMC data bank. Conclusions Penetrating artery disease and intracerebral hemorrhage were the most frequent stroke subtypes in natives from Buenos Aires. Lacunar strokes and intracerebral hemorrhage were more frequent among Caucasians from Buenos Aires than Caucasians from Boston. Poor risk factor control and dietary habits could explain these differences.

Diagnosis of mitochondrial disorders applying massive pyrosequencing

Mitochondrial disorders are a frequent cause of neurological disability affecting children and adults. Traditionally, molecular diagnosis of mitochondrial diseases was mostly accomplished by the use of Sanger sequencing and PCR–RFLP. However, there are particular drawbacks associated with the use of these methods. Recent multidisciplinary advances have led to new sequencing methods that may overcome these limitations. Our goal was to explore the use of a next generation sequencing platform in the molecular diagnosis of mitochondrial diseases reporting our findings in adult patients that present with a clinical-pathological diagnosis of a mitochondrial encephalomyopathy. Complete genomic sequences of mitochondrial DNA were obtained by 454 massive pyrosequencing from blood samples. The analysis of these sequences allowed us to identify two diagnostic pathogenic mutations and 74 homoplasmic polymorphisms, useful for obtaining high-resolution mitochondrial haplogroups. In summary, molecular diagnosis of mitochondrial disorders could be efficiently done from readily accessible samples, such as blood, with the use of a new sequencing platform.

Epidemiology of amyotrophic lateral sclerosis patients in a centre in Buenos Aires

UNLABELLED Sporadic amyotrophic lateral sclerosis (sALS) is considered a multifactorial disease with genetic and environmental factors causing motor neuron degeneration. OBJECTIVE To describe the epidemiological and occupational characteristics of patients with sALS who attended the Ramos Mejía Hospital at Buenos Aires, Argentina. METHOD We analyzed the medical records of sALS patients diagnosed between 2001 and 2008. All occupations were coded according to the International Standard Classification of Occupation (ISCO). RESULTS 187 patients were assessed, 38.5% were women and 61.5% men. Mean age at diagnosis was 55 years. 16% of them came from rural areas; 68% of the studied population had no health insurance. 40% were employed in elementary occupations, 19 were technicians and 8 handicraftsmen. CONCLUSION The most represented profession was elementary occupation. A large proportion of patients came from rural areas, which might suggest an increased risk of environmental exposure to an unknown agent in those regions.

Normatization of the Symbol Digit Modalities Test-Oral Version in a Latin American Country

The aim of this study was to standardize the Symbol Digit Modalities Test (SDMT)-Oral version in a healthy population living in Argentina and to analyze the influence that age, gender, and education have on the SDMT. Secondarily, it is intended to analyze the performance of patients with multiple sclerosis (MS) on this test. Two hundred ninety-seven healthy participants were evaluated; they had an average age of 39.28 years and 13.87 years of schooling; 77.8% were women. The sample was segmented according to age in three groups: younger than 35 years old, 36 to 50 years old, and 51 to 70 years old. The sample was also segmented according to years of schooling in three groups: 11 years or less, 12 to 16 years, and more than 16 years. All participants were evaluated with the oral version of the SDMT. A clinical sample of 111 patients with MS was also assessed. The mean on the SDMT for the total sample was 51.34 (SD = 12.76). The differences were significant between all groups, p < .05, according to age. The participants with a higher level of education performed better than did those with moderate education and those with less schooling, p < .05. There was a significant difference between patients with MS and healthy controls, p < .01. The SDMT is influenced by age as well as by schooling, although not by gender. The norms displayed here will be useful to accurately evaluate the yield of the patients in the neuropsychological clinic when comparing them with their group of reference. It was also demonstrated that the SDMT can discriminate between patients with MS and healthy people.

Atención del stroke agudo en una unidad de stroke y una sala general

Resumen Introduccion el stroke es una de las principales causas de discapacidad y muerte. Las Unidades de Stroke (US) mejoraron el tratamiento de la enfermedad cerebrovascular. Objetivo comparar la atencion del stroke agudo en una sala de Neurologia general (SNe) y en una US. Pacientes y metodo retrospectivamente se reviso la atencion de pacientes con stroke agudo en la SNe en el periodo comprendido entre agosto de 1997 a agosto de 1998 (previo a la apertura de US) y la atencion en la US en el lapso de tiempo desde agosto de 2004 a agosto de 2005. Se evaluaron los tiempos en llegar al hospital, en pasar a la sala apropiada y el tiempo de internamiento en el hospital. Resultados hubo 164 pacientes; 69 (42,09%) en la SNe y 95 (57,93%) en US. El 86,32% de los casos en US fueron stroke isquemico, en SNe fueron el 72,46%. El tiempo en llegar al hospital fue similar para ambas salas. El lapso en ingresar en la sala especializada fue de 4 horas 19 minutos en US y de 3 dias 43 minutos en Neurologia (p= 0,003). El tiempo medio de estancia hospitalaria fue 7 dias 16 horas en US y 23 dias 13 horas en la sala de Neurologia general (p= 0,001). Conclusiones en la US con un equipo multidisciplinario hubo un menor tiempo de internamiento que en la SNe. La presencia de un medico neurologo entrenado en patologia cerebrovascular, junto con una US, acelero el ingreso en una sala especializada. No hubo diferencias en las complicaciones ni en la mortalidad.

Diagnostico y tratamiento de la myasthenia gravis estudio de una poblacion hospitalaria

Between 1974 and 1987 we have examined 50 patients with the diagnosis of myasthenia gravis. Female preponderance (2.5: 1) was found. Also, it was observed that most of the patients were aged between 20 and 49 years. Beside the clinical examination, the following tests were performed: (1) edrofonium test, (2) supramaximal repetitive nerve stimulation, (3) serum acetylcholine antibodies titers and (4) intraperitoneal passive transference of patients sera to mice and recording of meepps amplitude in the phrenic-diaphragm preparation in vitro. These four tests gave positive values for myasthenia in 90 to 100% of the cases. Thymus radiological examination was carried out by pneumomediastinography, which proved to correlate with the histological picture of the gland, and computed tomography, which disclosed some discrepances with the histology. Treatment was based on anticholinesterase drugs, corticosteroids and thymectomy, being the corticosteroids the most valuable therapeutical tool. Nine patients treated with steroids disclosed transitory worsening of their signs and symptoms at very early stages after onset of corticosteroid therapy, 6 of them had a disfavorable course in their follow-up. This observation seem to have value in the early prognosis of the disease.

Estudio electrofisiologico de las variactones en la inervacion de los musculos de la mano

An electrophysiological study was carried out searching for variations in the innervation of the muscles of the hand. For this purpose a simple and non time-consuming technique was designed for stimulating the ulnar and median nerves at the elbow and wrist. Recordings were performed with surface electrodes at the abductor pollicis brevis, adductor digiti minimi and first dorsal interosseus muscles. Several anomalous innervation patterns of the intrinsic muscles of the hand were found, and the innervation of the first dorsal interosseus by the median nerve was the most frequent.