RESUMO
La autoscopia, del griego autos (sí mismo) y skopeo (mirar), son alucinaciones complejas durante las cuales el paciente experimenta una duplicación visual de su cuerpo. El presente artículo discute algunos correlatos de conectividad cerebral obtenida por resonancia funcional en reposo, en una paciente con epilepsia refractaria y alucinaciones autoscópicas durante sus crisis. El objetivo es presentar los hallazgos por neuroimágenes funcionales de una paciente que presenta alucinaciones del tipo autoscópico. Como parte del protocolo de evaluación de pacientes con epilepsia refractaria se realiza examen de videomonitoreo electroencefalográfico, imágenes de tomografía por emisión de positrones e imágenes de resonancia magnética funcional en reposo a una paciente que sufre alucinaciones autoscópicas durante las crisis. La información obtenida por estos estudios se correlaciona con la información clínica. En la paciente, el estudio de tomografía por emisión de positrones y el videomonitoreo electroencefalográfico indican alteraciones en el lóbulo occipital derecho, hallazgos que coinciden con reportes en la literatura sobre autoscopia. La sincronización neuronal, medida por resonancia funcional, es anormal en la misma región alterada en la tomografía por emisión de positrones, permitiendo relacionar el fenómeno autoscópico con cambios de la conectividad cerebral. La paciente cuenta con características clínicas de alucinación autoscópica. La resonancia magnética indica zonas con alteraciones de la dinámica cerebral que, en el caso de la paciente, coinciden con regiones reportadas en la literatura. El presente estudio aporta evidencias sobre el papel de los mecanismos de sincronización neuronal y la percepción de alucinaciones.
Autoscopy, from Greek autos (self) and skopeo (looking at), are complex hallucinations wherein the patient feels a visual duplication of his body. The current paper presents some brain connectivity correlates, obtained from resting state functional magnetic resonance, in a patient with refractory epilepsy who suffers autoscopic hallucinations during her seizures. Introduce the functional neuroimaging findings in a patient with autoscopic hallucinations. As part of the evaluation protocol for patients with refractory epilepsy, electroencephalographic video monitoring, positron emission tomography and resting state functional magnetic resonance imaging, were done to a patient that suffers autoscopic hallucinations during her crisis. The information obtained from those studies are correlated with clinical information. In the patient, the positron emision tomography and the electroencephalographic video monitoring study indicate an injury in the right occipital lobe, findings that coincide with previous literature report about autoscopy. The neuronal synchronization, measured by functional resonance, is abnormal in the same region where is altered the positron emision tomography imaging, enabling to relate the autoscopy phenomena with brain connectivity alterations. The patient has clinical features of autoscopic hallucination. MRI indicates areas with altered brain dynamics in the case of the patient coincide with regions reported in the literature. This study provides evidence on the role of neuronal synchronization mechanisms and the perception of hallucinations.
RESUMO
BACKGROUND: Sun exposure and skin phototype are the most relevant risk factors for skin cancer. Colombia has high levels of ultraviolet radiation during the whole year, therefore, both, high UVI's and outdoor worker's daily activities, in our country are very important risk factors for the development of cutaneous cancer. To date no study has evaluated the usefulness of Fitzpatrick's skin phototype classification in Colombians and its correlation with the minimal erythema dose (MED) and constitutional skin color. Such information is gaining importance in other nations due to the fact that several country's population is becoming more ethnically diverse. OBJECTIVES: To determine the skin phototype, accumulated sun exposure, sun protection behavior, MED and phenotype in a Colombian school population. METHODS: Last year high school students from the western Antioquia were invited to participate by phone and letter through their respective school directors. A self-questionnaire was handled to each student. A representative sample of the universe was selected for a medical examination by a dermatologist in order to validate the results of the self-questionnaire. The constitutional skin color was determined with the chromameter CR 300 Minolta. The MED was defined as the minimal dose of UVB being able to induce erythema 24 h later. RESULTS: Eight schools of the area agreed to participate in the study, and a total of 911 students (58% girls and 42% boys) filled-out the self-questionnaire. Sun exposure in the majority of individuals was in a level between moderate and very high. Ninety percent of students do not use any sun protection device or cream. Only a 50% of concordance between self-assessed skin phototype vs. medical skin phototype was found, and the highest concordance corresponded to skin phototype II (82%). There was a marked difference in skin photosensitivity of Colombians compared with reports in Caucasians. We observed a marked overlapping in MED's and L* values in phototypes II and III. CONCLUSIONS: The Fitzpatrick's classification was not useful in Hispanic populations such as ours. Therefore, a new skin-phototype classification system is required. In our population the constitutional color was a good predictor of the MED but it did not correlate with skin phototype. The self-assessed questionnaire method was not useful to determine skin cancer risk in our population. The majority of this population has light skin phototypes and is highly exposed to solar UV radiation without proper protection.