Conectividad funcional a partir de la perfusión cerebral en pacientes epilépticos y con enfermedad de Parkinson / Functional connectivity from cerebral perfusion in patients with epilepsy and Parkinson's disease

Introducción: La epilepsia y la enfermedad de Parkinson han sido descritos como trastornos de redes neurales. El estudio de la conectividad por modalidades moleculares puede ser más relevante fisiológicamente que los basados en señales hemodinámicas. Objetivo: Proponer una metodología para la descripción de patrones de conectividad funcional a partir de la perfusión cerebral por tomografía por emisión de fotón único. Métodos: La metodología incluye cuatro pasos principales: preprocesamiento espacial, corrección del volumen parcial, cálculo del índice de perfusión y obtención de la matriz de conectividad funcional mediante el coeficiente de correlación de Pearson. Se implementó en 25 pacientes con distintos trastornos neurológicos: 15 con epilepsia farmacorresistente y 10 con enfermedad de Parkinson. Resultados: Se encontraron diferencias significativas entre los índice de perfusión de varias regiones de los hemisferios ipsilateral y contralateral tanto en pacientes con epilepsia del lóbulo frontal como en pacientes con epilepsia del lóbulo temporal. Igual resultado se obtuvo en los pacientes con enfermedad de Parkinson con distintos estadios de la enfermedad. Para cada grupo se identificaron patrones de conectividad funcional que involucran a regiones relacionadas con la patología en estudio. Conclusiones: Con el desarrollo de esta metodología se ha demostrado que la tomografía por emisión de fotón único aporta información valiosa para estudiar la organización de las redes funcionales del cerebro. Futuras investigaciones con mayor número de pacientes contribuirían a hacer inferencias sobre los correlatos neurales de los distintos trastornos cerebrales(AU)

Introduction: Epilepsy and Parkinson's disease have been described as disorders of neural networks. The study of connectivity by molecular modalities may be more physiologically relevant than those based on hemodynamic signals. Aim: The aim of the present work is to propose a methodology for the description of functional connectivity patterns from brain perfusion by single photon emission tomography. Methods: The methodology includes four main steps: spatial preprocessing, partial volume correction, calculation of the perfusion index and obtaining the functional connectivity matrix using Pearson's correlation coefficient. It was implemented in 25 patients with different neurological disorders: 15 with drug-resistant epilepsy and 10 suffering Parkinson's disease. Results: Significant differences were found between the perfusion indexes of various regions of the ipsilateral and contralateral hemispheres in both patients with frontal lobe epilepsy and patients with temporal lobe epilepsy. The same result was obtained in Parkinson's disease patients with different stages of the disease. For each group, functional connectivity patterns involving regions related to the pathology under study were identified. Conclusions: With the development of this methodology, it has been demonstrated that single photon emission tomography provides valuable information to study the organization of functional brain networks. Future research with a larger number of patients would contribute to make inferences about the neural correlates of the different brain disorders(AU)

Análisis de los riesgos radiológicos en la medicina nuclear diagnóstica del Instituto de Hematología e Inmunología de Cuba / Analysis of radiological risks in diagnostic nuclear medicine of the Institute of Hematology and Immunology of Cuba

Introducción: Para el inicio de las operaciones en el servicio de medicina nuclear del Instituto de Hematología e Inmunología, se realizó el análisis de los riesgos radiológicos. Objetivos: Determinar la contribución individual de las etapas del proceso y de los elementos de control en el riesgo radiológico. Métodos: Se desarrolló el modelo del proceso a partir del método de la matriz de riesgo. Las medidas que se adicionaron estuvieron dirigidas a eliminar las secuencias accidentales con riesgo de nivel medio y consecuencias altas para los pacientes. Se determinaron los elementos de control más importantes por su participación porcentual e incidencia en el cambio del nivel de riesgo al ser eliminados. Resultados: Las etapas más contribuyentes al riesgo fueron por orden de importancia; la preparación de radiofármacos, la adquisición de las imágenes y la administración. Se destacan las medidas siguientes: carga de trabajo moderada, capacitaciones al oficial de protección radiológica y al que realiza las administraciones, el procedimiento de contrastar los datos de la dosis que será administrada al paciente con lo establecido en la prescripción del estudio, las pruebas de control de calidad de radiofármacos, el análisis de los resultados de la dosimetría realizada periódicamente a los trabajadores y las auditorías externas e internas con equipamiento diferente. Conclusiones: Se incluyeron todas las medidas identificadas en la obtención del riesgo residual y en el análisis de sensibilidad en el Plan de mejora de la seguridad y calidad, como garantía de la seguridad radiológica de las operaciones(AU)

Introduction: For the start of operations in the nuclear medicine service of the Institute of Hematology and Immunology, the analysis of radiological risks carried out. Objectives: To determine the individual contribution of the stages of the process and of the control elements in the radiological risk. Methods: The developed process model was from the risk matrix method. The added measures were at eliminating accidental sequences with medium risk and high consequences for the patients. The most important control elements were by their percentage participation and incidence in the change in the level of risk when they eliminated. Results: The stages most contributing to the risk were, in order of importance, the preparation of the radiopharmaceuticals, the acquisition of the images and the administration. Highlighted measures are the following: a moderate workload, the training for the radiation protection officer and the one who performs the administrations and the procedure of contrasting the data of the dose that will administer to the patient against what is in the study prescription. Besides are the tests quality control of radiopharmaceuticals, the analysis of the results of the dosimetry performed on the workers periodically and the external and internal audits with different equipment. Conclusions: All the measures identified in obtaining the residual risk and in the sensitivity analysis, were included in the Safety and Quality Improvement Plan, as a guarantee of the radiological safety of the operations(AU)

HaNDL syndrome: Correlation between focal deficits topography and EEG or SPECT abnormalities in a series of 5 new cases. / Síndrome HaNDL: correlación entre la topografía del déficit neurológico y las alteraciones en electroencefalograma y SPECT en una serie de 5 nuevos casos.

INTRODUCTION: Transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL) is characterised by migraine-like headache episodes accompanied by neurological deficits consisting of motor, sensory, or aphasic symptoms. Electroencephalogram (EEG) and single photon emission computed tomography (SPECT) may show focal abnormalities that correspond to the neurological deficits. We aim to evaluate the correlation between focal deficit topography and EEG or SPECT abnormalities in 5 new cases. PATIENTS: We retrospectively reviewed patients attended in a tertiary hospital (January 2010-May 2014) and identified 5 patients (3 men, 2 women) with a mean age of 30.6 ± 7.7 (21-39) years. They presented 3.4 ± 2.6 episodes of headache (range, 2-8) of moderate to severe intensity and transient neurological deficits over a maximum of 5 weeks. Pleocytosis was detected in CSF in all cases (70 to 312 cells/mm3, 96.5-100% lymphocytes) with negative results from aetiological studies. RESULTS: At least one EEG was performed in 4 patients and SPECT in 3 patients. Patient 1: 8 episodes; 4 left hemisphere, 3 right hemisphere, and 1 brainstem; 2 EEGs showing left temporal and bilateral temporal slowing; normal SPECT. Patient 2: 2 episodes, left hemisphere and right hemisphere; SPECT showed decreased left temporal blood flow. Patient 3: 3 left hemisphere deficits; EEG with bilateral frontal and temporal slowing. Patient 4: 2 episodes with right parieto-occipital topography and right frontal slowing in EEG. Patient 5: 2 episodes, right hemisphere and left hemisphere, EEG with right temporal slowing; normal SPECT. CONCLUSION: The neurological deficits accompanying headache in HaNDL demonstrate marked clinical heterogeneity. SPECT abnormalities and most of all EEG abnormalities were not uncommon in our series and they did not always correlate to the topography of focal déficits.

Sentinel lymph node biopsy in paediatric melanoma. A case series.

The incidence of melanoma in children is uncommon, being particularly rare in children under 10 years-old. However, this disease is increasing by a mean of 2% per year. As in adults, the lymph node status is the most important prognostic factor, crucial to performing the selective sentinel lymph node biopsy (SLNB). We report 3 cases of paediatric patients of 3, 4 and 8 years-old, in which SLNB was performed for malignant melanoma. Paediatric age implies greater technical difficulty to the scintigraphy scan due to poor patient cooperation, with mild sedation required in some cases, and only being able to acquire planar images in other cases. SPECT/CT was only performed in the oldest patient. In our cases, SLNB was useful for selecting the least invasive surgery in order to reduce morbidity.