Circulating gonadal and adrenal steroids in amyotrophic lateral sclerosis: possible markers of susceptibility and outcome.

Although changes of circulating steroids have been reported in patients with sporadic amyotrophic lateral sclerosis (ALS), a full comparison of the adrenal and gonadal steroid profile between control subjects and ALS patients is lacking. Considering that respiratory failure is the most frequent cause of death in ALS, we looked into whether a relationship emerged between circulating steroids and respiratory parameters. Serum levels of adrenal and gonadal steroids were measured in 52 age- and gender-matched subjects (28 ALS and 24 controls) using radioimmunoassay techniques. We also evaluated respiratory parameters in ALS patients, including forced vital capacity (FVC), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP). We found increased levels of testosterone in female ALS patients compared to healthy female subjects. Furthermore, control subjects showed a significant decline of testosterone, dehydroepiandrosterone and its sulfate, and a borderline decline of progesterone with increasing age. Instead, testosterone did not decline with increasing age in ALS patients. We also found that the dehydroepiandrosterone sulfate/cortisol ratio was positively associated with FVC, MIP, and MEP. Moreover, ALS patients showing higher testosterone levels and lower progesterone/free testosterone ratio presented a more rapid worsening of the monthly FVC. In conclusion, first our study revealed a differential steroid profile with age and gender in ALS patients relative to controls. Second, we demonstrated an association between some steroids and their ratios with respiratory function and disease progression. Thus, we hypothesize that the endogenous steroid profile could be a marker of susceptibility and prognosis in ALS patients.

Regional spread pattern predicts survival in patients with sporadic amyotrophic lateral sclerosis.

BACKGROUND AND PURPOSE: Sporadic amyotrophic lateral sclerosis (sALS) is a disease with a focal clinical onset and contiguous spread. We examined patterns of disease spread following symptoms onset in sALS and whether the pattern of spread predicted survival. METHODS: Review of medical records (2003-2009) at London Ontario and Buenos Aires clinic cohorts retrieved 318 patients with sporadic sALS. According to patient self-report, we determined eight spread patterns: rostro-caudal, caudo-rostral, crossed, circular, superior interposed, middle interposed, inferior interposed and isolated. The variables studied were as follows: age, gender, sALS phenotypes, time from onset to diagnosis and time and direction of the spreading to the first region. Survival from symptoms onset was analysed by Kaplan-Meier, Tarone-Ware and Cox proportional hazards methods. RESULTS: The direction of first spread was horizontal in 33%, rostral to caudal in 32% and caudal to rostral in 21%, whereas spread to remote regions was observed in 14% of patients. Survival curves and 3- and 5-year survival rates favoured patients with an isolated and caudo-rostral pattern of spread compared to patients progressing to distant regions without involvement in the intervening region, or 'superior and inferior interposed patterns' (Tarone-Ware P = 0.001, χ(2) = 0.002 and χ(2) = 0.006, respectively). Factors affecting survival were gender, time to diagnosis, flail arm phenotype and age at diagnosis. CONCLUSIONS: We have provided evidence that not all spread in ALS is contiguous and that the nature of symptom progression influences survival. Patients with sALS with 'interposed patterns' had a worse prognosis, whereas patients with caudo-rostral pattern fared better than the rest.

Endogenous progesterone is associated to amyotrophic lateral sclerosis prognostic factors.

UNLABELLED: Negative prognostic factors in amyotrophic lateral sclerosis include advanced age, shorter time from disease onset to diagnosis, bulbar onset and rapid progression rate. OBJECTIVE: To compare progesterone (PROG) and cortisol serum levels in patients and controls and ascertain its relationship to prognostic factors and survival. METHODS: We assessed serum hormonal levels in 27 patients and 21 controls. RESULTS: Both hormones were 1.4-fold higher in patients. PROG showed a negative correlation with age, positive correlation with survival and positive trend with time to diagnosis. Increased PROG was observed in spinal onset and slow progression patients. No correlation was demonstrated with cortisol. CONCLUSION: Increased hormonal levels in patients are probably due to hypothalamic-pituitary-adrenal axis activation. Nevertheless, in this preliminary report only PROG correlated positively with factors predicting better prognosis and survival. We hypothesize endogenous PROG and cortisol may be engaged in differential roles, the former possibly involved in a neuroprotective response.

In vitro neurotoxic properties and excitatory aminoacids concentration in the cerebrospinal fluid of amyotrophic lateral sclerosis patients. Relationship with the degree of certainty of disease diagnoses.

OBJECTIVE: To determine glutamate and aspartate levels in the cerebrospinal fluid (CSF) in patients with sporadic amyotrophic lateral sclerosis (SALS) grouped according to El Escorial diagnostic criteria, and to perform an in vitro assessment of the neurotoxicity of the CSF in murine cortical neurons. METHODS: SALS patients were sorted according to El Escorial diagnostic criteria. Glutamate and aspartate were measured in the CSF using high performance liquid chromatography. Cultured cortical neuron viability was determined after exposure to CSF for 24 h. RESULTS: Glutamate levels were elevated in 28 out of the 29 patients with definite, probable or possible SALS. There were no differences in glutamate concentrations when the three clinical forms of the disease were compared; neither there were significant variation across disease duration and clinical presentation. In agreement with previous reports, we concluded that CSF-SALS-induced in vitro neurotoxicity is mediated by ionotropic glutamate receptors. We found no relationship between the degree of in vitro neurotoxicity and glutamate concentration in the CSF. CONCLUSIONS: Glutamate but not aspartate CSF levels may contribute to ALS pathogenesis. However, glutamate levels may not influence the degree of diagnosis certainty or lesion extension.

Síntomas iniciales de esclerosis lateral amiotrófica / No disponible

No disponible

[Neuropsychological study of 12 patients with pure degenerative cerebellar disease]. / Evaluación cognitiva en 12 pacientes con enfermedad cerebelosa degenerativa pura.

INTRODUCTION: The cerebellum has been traditionally associated with motor control learning and performance. However, since 1970 a growing body of clinical and experimental evidences has suggested that the cerebellum may be involved in nonmotor cognitive functions as well. OBJECTIVE: To explore the presence of eventual cognitive impairment in non-demented patients with isolated degenerative cerebellar diseases. PATIENTS AND METHODS: Twelve patients with the diagnosis of selective degenerative cerebellar disorders, either inherited or sporadic, were selected (mean age: 40.42 +/- 13.49 years; mean education level: 9.92 +/- 3.99 years; duration of illness: 12.13 +/- 11.27 years, MMSE: 26.75 +/- 1.5) and evaluated through a standardized neuropsychological tests battery. Normalized Z scores were estimated and compared against 0, employing the t test for one sample. RESULTS: Significant cognitive deficits were found in the following domains: executive, visuo-spatial, memory and attention functions. Performance on the Wisconsin test showed a significative number of perseverative errors. Memory deficits included verbal learning and free recall difficulties, with good recognition of the material presented. CONCLUSIONS: The findings of this study are consistent with the role of the cerebellum as modulator of mental functions. The cognitive deficits resulting from cerebellar pathology may be related with the disruption of cerebello-cortical connexions involving a complex network which includes the prefrontal region, suggesting that the cerebellum may process cortical information coming from different areas linked with the control of cognition.

Evaluación cognitiva de 12 pacientes con enfermedad cerebelosa degenerativa pura / Neuropsychological study of 12 patients with pure degenerative cerebellar disease

Introducción. El cerebelo se ha asociado tradicionalmente con el aprendizaje y el control motor. Sin embargo, en las últimas tres décadas se ha obtenido evidencia clínica y experimental que sugiere que el cerebelo podría intervenir en el procesamiento cognitivo no motor. Objetivo. Estudiar el rendimiento neuropsicológico de pacientes con enfermedad cerebelosa degenerativa pura no dementes. Pacientes y métodos. Se evaluaron 12 pacientes con enfermedad cerebelosa degenerativa pura, de causa hereditaria o de presentación esporádica (edad: 40,42 13,49 años; educación: 9,92 3,99 años; tiempo de evolución: 12,13 11,27 años; MMSE: 26,75 1,5) por medio de una batería neuropsicológica estandarizada. Se calcularon puntuaciones normalizadas Z, que se compararon contra 0 mediante el empleo de pruebas de t de una muestra. Resultados. Se observaron alteraciones significativas en las pruebas de función ejecutiva, visuoespacial, memoria y atención. En el test de Wisconsin se registró un número significativo de errores perseverativos. Los fallos en memoria se caracterizaron por dificultades en el aprendizaje y la evocación diferida, con buen desempeño en el reconocimiento del material presentado. Los déficit cognitivos no se correlacionaron con la gravedad del déficit motor elemental. Conclusiones. Los datos obtenidos sugieren la participación del cerebelo en la modulación de las funciones mentales

Introduction. The cerebellum has been traditionally associated with motor control learning and performance. However, since 1970 a growing body of clinical and experimental evidences has suggested that the cerebellum may be involved in nonmotor cognitive functions as well. Objective. To explore the presence of eventual cognitive impairment in non-demented patients with isolated degenerative cerebellar diseases. Patients and methods. Twelve patients with the diagnosis of selective degenerative cerebellar disorders, either inherited or sporadic, were selected (mean age: 40.42 ± 13.49 years; mean education level: 9.92 ± 3.99 years; duration of illness: 12.13 ± 11.27 years, MMSE: 26.75 ± 1.5) and evaluated through a standardized neuropsychological tests battery. Normalized Z scores were estimated and compared against 0, employing the t test for one sample. Results. Significant cognitive deficits were found in the following domains: executive, visuo-spatial, memory and attention functions. Performance on the Wisconsin test showed a significative number of perseverative errors. Memory deficits included verbal learning and free recall difficulties, with good recognition of the material presented. Conclusions. The findings of this study are consistent with the role of the cerebellum as modulator of mental functions. The cognitive deficits resulting from cerebellar pathology may be related with the disruption of cerebello-cortical connexions involving a complex network which includes the prefrontal region, suggesting that the cerebellum may process cortical information coming from different areas linked with the control of cognition

[Amyotrophic lateral sclerosis: its relationship with thyroid function and phosphate calcium metabolism]. / Esclerosis lateral amiotrófica. Evaluacion de la función tiroidea y del metabolismo fosfocálcico.

INTRODUCTION: Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disease involving motor neurons of the spinal cord, brain stem, and motor cortex. Previous studies reported the coexistence of motor neuron disease with thyroid dysfunction and primary hyperparathyroidism. These findings suggested an eventual role of the previously mentioned endocrine disorders and the development of ALS. OBJECTIVE: Identify thyroid dysfunction and changes in mineral metabolism in patients affected by sporadic ALS. PATIENTS AND METHODS: We retrospectively analyzed data from 41 in ward patients from June 1998, to June 2001. All of them were diagnosed with sporadic ALS. The following laboratory test were performed: thyrotropin (TSH), thyroxine (T4), serum calcium, serum phosphate, parathyroid hormone (PTH) and ionic calcium concentrations. RESULTS: None of the studied patients was found to be hyperthyroid. Two patients had elevated TSH and normal T4, these findings suggested subclinical hypothyroidism. Elevated PTH was found in one patient; another had primary hyperparathyroidism. Low serum calcium was found in three patients and elevated phosphate was found in another four. CONCLUSIONS: All these findings do not allow us to assert a pathogenic association between thyroid dysfunction or alteration of phosphate calcium metabolism and ALS.

High affinity as a disease determinant factor in anti-GM(1) antibodies: comparative characterization of experimentally induced vs. disease-associated antibodies.

Elevated titers of serum anti-GM(1) antibodies of IgG isotype are found frequently in patients with Guillain-Barré syndrome. Much evidence indicates that these autoantibodies are involved in disease progression, but their exact function and the mechanism of their appearance are still unclear. In an attempt to reproduce "ganglioside syndrome", the experimental model of neuropathy developed by Nagai et al. (Neurosci. Lett. 2 (1976) 107), rabbits were intensively immunized with GM(1) in complete Freund adjuvant (CFA). High titers of anti-GM(1) antibodies were produced, with class switch and affinity maturation indicating an elaborate immune response. Unexpectedly, the rabbits did not show any clinical symptoms of neuropathy. Relatively affinities of both IgM and IgG antibodies were significantly lower than those of similar antibodies from neuropathy patients. These results suggest the existence of a threshold value above which affinity of anti-GM(1) antibodies becomes an important factor in disease induction. The absence of neuropathy symptoms in rabbits may be explained by absence of these high-affinity anti-GM(1) antibodies.

Hipofonía en ictus lacunar / Hypophonia in lacunar stroke

La hipofonía ha sido definida como una disminución en el volumen del habla. Es una manifestación infrecuente de ictus que se ha relacionado con infartos profundos múltiples. Caso clínico. Mujer de 82 años, con antecedentes de hipertensión arterial, que fue admitida en nuestro hospital por presentar debilidad en hemicuerpo derecho y un bajo nivel de voz. Presentaba hipofonía y era incapaz de elevar la voz. El lenguaje era fluente sin parafasias. La resonancia magnética con sequencia de difusión reveló una lesión pequeña hiperintensa en la corona radiata izquierda. No se detectaron otras lesiones. Conclusiones. Si bien la topografía lesional precisa que explique esta sintomatología no ha sido aún claramente definida, la hipofonía también podría asociarse a infartos lacunares aislados afectando arterias penetrantes en la corona radiata. Se requieren en estudios prospectivos para poder determinar la naturaleza y el pronóstico de este fenómeno (AU)

Southern Buenos Aires stroke project.

BACKGROUND: Ethnic differences and vascular risk factors are the major determinants of stroke subtypes. Nevertheless, specific data from undeveloped countries is difficult to obtain. Natives from South America may have a higher frequency of penetrating small vessel disease and hemorrhagic stroke. However, there are few studies in South America supporting these findings. OBJECTIVE: We analyze demographic, ethnic, risk factors, clinical characteristics, and stroke subtypes in all patients with acute stroke admitted to our hospital. METHODS: We studied all consecutive acute stroke patients admitted to the Ramos Mejia Hospital in Buenos Aires from 1997 to 1999. Our hospital serves a determined population of Southern Buenos Aires. Data were collected prospectively on patients' admission in a form especially designed for this study including vascular risk factors, clinical features, epidemiological characteristics, and neuroradiological findings. Stroke subtypes were determined according to the TOAST classification. RESULTS: Among 361 acute stroke patients, 31% had hemorrhagic stroke. It was more frequent among Natives (34%) than Caucasians (27%) (P<0.002). Ischemic stroke subtypes were as follows: 105 (42%) patients had lacunar, 31 (12%) atherosclerotic stroke, 53 (21%) cardioembolic infarction, and 16 (6%) other causes of stroke. Forty-five (18%) patients were classified as undetermined. Small vessel disease was higher among Caucasians (35%) than Natives (24%). CONCLUSIONS: Penetrating artery disease (42%) and intracranial hemorrhage (31%) were the most common stroke subtypes, being more frequent than reported in the literature. Natives had significantly higher frequency of hemorrhagic stroke than Caucasians.

Variable patterns of anti-GM(1) IgM-antibody populations defined by affinity and fine specificity in patients with motor syndromes: evidence for their random origin.

Elevated titers of serum antibodies against GM(1)-ganglioside are associated with a variety of autoimmune neuropathies. Although much evidence indicates that these autoantibodies play a primary role in the disease processes, the mechanism of their appearance is unclear. Low-affinity anti-GM(1) antibodies of the IgM isotype are part of the normal human immunological repertoire. In patients with motor syndromes, we found that in addition to the usual anti-GM(1) antibodies, the sera contain IgM-antibodies that recognize GM(1) with higher affinity and/or different specificity. This latter type of antibodies was not detected in other autoimmune diseases. We studied the fine specificity of both normal and motor disease-associated antibodies using HPTLC-immunostaining of GM(1) and structurally related glycolipids, soluble antigen binding inhibition, and GM(1) affinity columns. Normal low-affinity anti-GM(1) antibodies cross-react with GA(1) and/or GD(1b). In the motor syndrome patients, different populations of antibodies characterized by their affinity and cross-reactivity were detected. Although one population is relatively common (low affinity, not cross-reacting with GA(1) and GD(1b)), there are remarkably few sera having the same set of populations. These results suggest that the appearance of the new antibody populations is a random process. When the different antibody populations were analyzed in relation to the three-dimensional structure of GM(1), a restricted area of the GM(1) oligosaccharide (the terminal Galbeta1-3GalNAc) was found to be involved in binding of normal anti-GM(1) antibodies. Patient antibodies recognize slightly different areas, including additional regions of the GM(1) molecule such as the NeuNAc residue. We hypothesize that disease-associated antibodies may originate by spontaneous mutation of normal occurring antibodies.

[Partial non convulsive epileptic status as initial presentation of limbic encephalitis]. / Estado epiléptico no convulsivo como forma de presentación de encefalitis límbica.

INTRODUCTION: Limbic encephalitis is an unusual presentation of paraneoplastic syndrome, which includes among its symptoms seizures. CLINICAL CASE: We report a case with a rare presentation of limbic encephalitis as initial symptom of small cell lung carcinoma. A 69 year-old woman presented with partial non convulsive status epilepticus and neuropsychiatric disturbances. Chest radiography and computed tomography showed mediastinal lymphadenopathy and lung nodules. Subsequently, small cell lung carcinoma was diagnosed by lymph node biopsy. The cerebrospinal fluid study was normal. The electroencephalography and magnetic resonance imaging (MRI) findings had distinctive features compatible with temporo-limbic dysfunction. The anti-Hu antibodies were negative. The neuropsychiatric symptoms improved significantly after systemic chemotherapy and adjuvant radiotherapy. A serial follow-up MRI of the head showed no evidence of intracranial metastasis three months after the diagnosis of cancer. Limbic encephalitis may be an initial manifestation of lung cancer. Paraneoplastic limbic encephalitis is considered a remote effect of cancer commonly associated with anti-neuronal antibodies (anti-Hu) and small cell lung carcinoma. CONCLUSIONS: Status epilepticus could be an early sign of limbic encephalitis. The absence of anti-Hu antibodies does not rule out the presence of an underlying small cell lung carcinoma in patients with a clinical diagnosis of limbic encephalitis. Greater awareness for diagnosis and early treatment of the primary tumor offers the best chance for improvement in patients with lung cancer presenting with limbic encephalitis.

Multiple simultaneous intracerebral hemorrhages: clinical features and outcome.

BACKGROUND: The simultaneous occurrence of intracerebral hemorrhages in different arterial territories is an uncommon clinical event. Its predisposing factors and pathophysiological mechanisms are not clearly defined. OBJECTIVE: To analyze the frequency, risk factors, clinical features, neuroimaging findings, and outcome of multiple simultaneous intracerebral hemorrhages (SIHs). PATIENTS AND METHODS: We studied all patients with acute stroke admitted to our hospital from July 18, 1997, through December 18, 1999. Multiple SIHs were defined as the presence of 2 or more intracerebral hemorrhages affecting different arterial territories with identical computed tomographic density profiles. Patients with a history of traumatic brain injury were excluded from this study. Diagnostic investigation included routine blood and urine tests, coagulation studies, a chest radiograph, electrocardiogram, 2-dimensional transthoracic echocardiography, and computed tomography of the head without contrast medium. Disability was assessed using the National Institutes of Health Stroke Scale and Modified Rankin Scale. RESULTS: Among 142 patients with hemorrhagic stroke, we found 4 (2.8%) with SIHs. All 4 patients had a history of uncontrolled arterial hypertension. We excluded other potential causes of multiple SIHs by using appropriate diagnostic tests. The most common clinical manifestations were headache and weakness. Localization of hematomas was supratentorial, except for one patient who had both infratentorial and supratentorial hemorrhages. The mean National Institutes of Health score on admission was 15 and the Modified Rankin Scale score was higher than 4 at 3 months. CONCLUSIONS: In our study, all patients with multiple SIHs had arterial hypertension and a poor outcome. Additional analytic studies, including new imaging techniques, can help to elucidate the association between arterial hypertension and multiple SIHs, risk factors, and underlying mechanisms of this clinical condition.

[Magnetic resonance and clinical and electroencephalographical localization in focal epilepsy]. / Resonancia magnética y localización clínica y electroencefalográfica en la epilepsia focal.

Magnetic Resonance Imaging (MRI) is the method of choice to search for epileptogenic lesions. We correlated MRI findings with the epileptogenic zone (EZ) depicted by clinical and electroencephalographic (EEG) data. We studied 400 clinical records of patients who had been submitted to MRI studies and we analyzed, retrospectively, their ictal semiology, EEG characteristics and response to treatment. They were classified into 3 groups: A) temporal lobe epilepsy, B) frontal lobe epilepsy and C) parieto-occipital epilepsy. We included 155 patients: Group A) 68 cases (43.9%), 28 men (41.1%), mean age 32 +/- 11 years old, abnormal IMR in 44 (64.7%), refractory to treatment 48 (70.5%). Group B) 68 cases (43.9%), 38 men (55.8%), mean age 30 +/- 15 years old, abnormal IMR in 26 (38.2%), refractory to treatment 30 (44.1%). Group C) 19 cases (12.2%), 13 men (68.4%), mean age 27 +/- 11 years old, abnormal IMR in 11 (57.8%), refractory to treatment 12 (63.1%). Results showed that there were higher possibilities of detecting lesions which correlate with EZ in temporal than in frontal or parieto-occipital lobes epilepsy. The chances to find abnormalities on the MRI were 5 times higher in refractory patients than in those who were non-refractory.

Activated protein C resistance in patients with arterial ischemic stroke.

BACKGROUND: Activated C protein resistance (APC-R) has recently been reported to be a common cause of thrombophilia; it may be acquired or caused by a genetic defect (factor V Leiden mutation). It is clear that there is an association between APC-R and venous thrombosis. It has been suggested that there is a possible relationship of APC-R with arterial ischemic stroke (IS), but case-control studies have not given enough clues for considering APC-R as a main risk factor. OBJECTIVES: To assess the incidence of APC-R in patients with IS of several ethiologies in Buenos Aires. PATIENTS AND METHODS: Seventy-two patients with IS were assessed for signs or symptoms of previous clinical thrombophilia and the presence of vascular risk factors (RF). They were searched for APC-R (COATEST, APC resistance-V, with a predilution of the samples) test. Determinations were carried out between 1 to 4 months after the ischemic episode. The plasma of 50 healthy control subjects (blood donors) was used as controls. RESULTS: None of the patients had signs of previous thrombophilia; 57 (79.2%) had RF for IS, and 3 (4.2%) had APC-R (all of them with RF). One subject in the control group (2%) showed a low APC response (1/50). The occurrence of APC-R among patients with stroke was not significantly higher when compared with the occurrence of APC-R among the control subjects. CONCLUSIONS: In the present series, the incidence of factor V Leiden related APC-R in the group with IS was similar to the healthy population. Other risk factors were associated in patients showing APC-R.

[Hypophonia in lacunar stroke]. / Hipofonía en ictus lacunar.

INTRODUCTION: Hypophonia has been defined as a reduction in speech volume. It is an uncommon finding in acute stroke, mainly related to multiple deep infarcts. CLINICAL CASE: An 82 year old hypertensive woman was admitted to our hospital presenting acute right sided weakness and low speech volume. She was hypophonic and unable to yell. Language was fluent without paraphasic errors. A diffusion weighted magnetic resonance showed a small hyperintense lesion in the left corona radiata. No other lesions were detected. CONCLUSIONS: Although, the precise anatomic area involved in the brain has not been clearly precised yet, hypophonia may be also due to isolated lacunar affecting the penetrating arteries in the corona radiata. Further studies are necessary to better understand the nature and the prognosis of this phenomenon.

Resonancia magnética y localización clínica y electroencefalográfica en la epilepsia focal. / [Magnetic resonance and clinical and electroencephalographical localization in focal epilepsy]

Magnetic Resonance Imaging (MRI) is the method of choice to search for epileptogenic lesions. We correlated MRI findings with the epileptogenic zone (EZ) depicted by clinical and electroencephalographic (EEG) data. We studied 400 clinical records of patients who had been submitted to MRI studies and we analyzed, retrospectively, their ictal semiology, EEG characteristics and response to treatment. They were classified into 3 groups: A) temporal lobe epilepsy, B) frontal lobe epilepsy and C) parieto-occipital epilepsy. We included 155 patients: Group A) 68 cases (43.9

), 28 men (41.1

), mean age 32 +/- 11 years old, abnormal IMR in 44 (64.7

), refractory to treatment 48 (70.5

). Group B) 68 cases (43.9

), 38 men (55.8

), mean age 30 +/- 15 years old, abnormal IMR in 26 (38.2

), refractory to treatment 30 (44.1

). Group C) 19 cases (12.2

), 13 men (68.4

), mean age 27 +/- 11 years old, abnormal IMR in 11 (57.8

), refractory to treatment 12 (63.1

). Results showed that there were higher possibilities of detecting lesions which correlate with EZ in temporal than in frontal or parieto-occipital lobes epilepsy. The chances to find abnormalities on the MRI were 5 times higher in refractory patients than in those who were non-refractory.

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.