Outbreak of cryptosporidiosis in a child day-care centre in Gipuzkoa, Spain, October to December 2011.

From October to December 2011, an outbreak of 26 cases of cryptosporidiosis occurred in a day-care centre in Gipuzkoa, Spain. The infection spread from person to person and affected 24 children under two years of age (attack rate: 38%) and two caregivers. Cryptosporidium oocysts were observed in 10 of 15 samples. During 2010, only four cases of cryptosporidium were detected in Gipuzkoa, and 27 overall in Spain.

Real-time G-protein-coupled receptor imaging to understand and quantify receptor dynamics.

Understanding the trafficking of G-protein-coupled receptors (GPCRs) and their regulation by agonists and antagonists is fundamental to develop more effective drugs. Optical methods using fluorescent-tagged receptors and spinning disk confocal microscopy are useful tools to investigate membrane receptor dynamics in living cells. The aim of this study was to develop a method to characterize receptor dynamics using this system which offers the advantage of very fast image acquisition with minimal cell perturbation. However, in short-term assays photobleaching was still a problem. Thus, we developed a procedure to perform a photobleaching-corrected image analysis. A study of short-term dynamics of the long isoform of the dopamine type 2 receptor revealed an agonist-induced increase in the mobile fraction of receptors with a rate of movement of 0.08 µm/s For long-term assays, the ratio between the relative fluorescence intensity at the cell surface versus that in the intracellular compartment indicated that receptor internalization only occurred in cells co-expressing G protein-coupled receptor kinase 2. These results indicate that the lateral movement of receptors and receptor internalization are not directly coupled. Thus, we believe that live imaging of GPCRs using spinning disk confocal image analysis constitutes a powerful tool to study of receptor dynamics.

Measles genotypes D4 and G3 reintroduced by multiple foci after 15 years without measles virus circulation, Gipuzkoa, the Basque Country, Spain, March to June 2011.

During a three-month period in spring 2011, 23 cases of measles occurred in seven independent outbreaks in a region in Spain with around 700,000 inhabitants, where the disease had been eliminated since 1997. High vaccination coverage and rapid diagnosis allowed implementation of containment measures and this prevented spread of the disease. Except for the first outbreak which affected 10 cases, each of the other six outbreaks caused a maximum of three secondary cases.

Changes in subthalamic activity during movement observation in Parkinson's disease: is the mirror system mirrored in the basal ganglia?

OBJECTIVE: The observation of a voluntary movement executed by another person is associated with an alpha and beta EEG desynchronization over the motor cortex, thought to reflect activity from the human "mirror neuron" system. The aim of our work was to study the changes in local field potentials (LFP) recorded from the subthalamic nucleus (STN) and their relationship with cortical activity, during movement observation. METHODS: Bilateral EEG and STN LFP recordings were acquired in 18 patients with Parkinson's disease, through surgically implanted electrodes for deep brain stimulation. Oscillatory changes during movement execution and movement observation were compared with two different control conditions (simple stimulus and rotating stimulus observation), in "off" and "on" motor states. Time-frequency transforms and event-related coherence were used for the analysis. RESULTS: Movement observation was accompanied by bilateral beta reduction in subthalamic power and cortico-STN coherence, which was smaller than the decrease observed during movement execution, but significant when compared with the two control conditions. CONCLUSIONS: Movement observation is accompanied by changes in the beta oscillatory activity of the STN, similar to those observed in the EEG. SIGNIFICANCE: These changes suggest that the basal ganglia might be engaged by the activity of the human mirror system.

La neurofisiología clínica: pasado, presente y futuro / Clinical Neurophysiology: past, present, future

La Neurofisiología Clínica es una especialidad médica cuyo objeto es el estudio del sistema nervioso y muscular con fines diagnósticos, pronósticos y terapéuticos. En este artículo se analiza el objetivo básico que pretende esta disciplina, las técnicas que utiliza y su reconocimiento como especialidad médica. Se hace un pequeño recorrido por su definición y alcance de la misma, cómo se estructura hoy día y las posibilidades de futuro que ofrece (AU)

Clinical Neurophysiology is a medical speciality whose aim is the study of the nervous and muscular system for diagnostic, prognostic and therapeutic purposes. This article analyses the basic objective pursued by this discipline, the techniques it employs and its recognition as a medical speciality. The article briefly reviews its definition and scope, how it is structured at present and the future possibilities it offers (AU)

Oscilaciones cerebrales: papel fisiopatológico y terapéutico en algunas enfermedades neurológicas y psiquiátricas / Brain oscillations: pathophysiological and therapeutic role in some neurological and psychiatric diseases

Se usa el término «oscilación o actividad oscilatoria» para referirse a las fluctuaciones rítmicas de los potenciales postsinápticos de un grupo neuronal (potenciales de campo local) o de una región cortical (EEG, electrocorticografía) y también al patrón de descarga rítmico de los potenciales de acción de una neurona o un grupo neuronal. La actividad oscilatoria posibilita la sincronización entre grupos neuronales de la misma área cortical o de áreas distantes entre sí que intervienen en una acción motora, tarea cognitiva o perceptiva. Con frecuencia es motivo de confusión asociar la presencia de actividad oscilatoria con fenómenos de sincronización, ya que ambos fenómenos aunque relacionados no son equivalentes. En patologías neurológicas o psiquiátricas tan distintas como la enfermedad de Parkinson u otros movimientos anormales, la epilepsia o la esquizofrenia se han descrito anomalías de la actividad oscilatoria de distintas estructuras cerebrales o de su sincronización que podrían jugar un papel relevante en su fisiopatología. En esta revisión se discuten estos aspectos haciendo hincapié en su importancia por ser un mecanismo básico del funcionamiento cerebral y un nuevo mecanismo fisiopatólogico de la sintomatología de algunas enfermedades cerebrales (AU)

The terms «oscillations» or «oscillatory activity» are frequently used not only to define the rhythmic fluctuations of the postsynaptic potentials of a neuronal group (local field potentials) or a cortical region (EEG, MEG), but also to indicate the rhythmic discharge pattern of action potentials from a neuron or a small group of neurons. Oscillatory activity makes possible the synchronization of different neuronal groups from nearby or distant cortical regions that participate in the same motor, sensory or cognitive task. The presence of oscillatory activity is usually associated to the existence of synchronization, but both phenomena are not necessarily always equivalent. Abnormalities of oscillatory activities or synchronization within or between different brain structures have been described in several neurological and psychiatric diseases; these abnormalities might play a relevant pathophysiological role in Parkinson´s disease (and other movement disorders), schizophrenia or epilepsy. This review discusses all these aspects, with emphasis on their potential role both as a basic mechanism in brain function and as a pathophysiological substrate for some of the symptoms and signs observed in several diseases (AU)

Vídeo-electroencefalografía: una necesidad / Video-electroencephalography: a necessity

El vídeo-EEG es una herramienta diagnóstica habitual. Los avances técnicos de la última década la han simplificado de tal modo que con poco más de un ordenador y una cámara de vídeo pueden conseguirse registros de calidad. Se requiere personal preparado para su ejecución e interpretación. Es muy útil para el diagnóstico de episodios paroxísticos, para la clasificación y caracterización de crisis epilépticas y para la cuantificación de crisis o grafoelementos epileptiformes. Dada la importancia de un diagnóstico exacto, certero, ante un episodio paroxístico, no cabe duda de que esta herramienta debe ser cada vez más asequible para evitar el mal trato a muchos enfermos neurológicos. A pesar del paso de los años, un 20-30% de pacientes diagnosticados de epilepsia no son realmente epilépticos, lo cual sigue siendo excesivo e inaceptable (AU)

The video-EEG is a common diagnostic tool nowadays. The technical achievements of the last decade have brought a simplification of the equipment required to obtain good quality recordings, with little more than a computer and a video camera being necessary. However, the medical and technical staff must be well trained to execute and interpret the study. It is very useful in the diagnosis of paroxysmal events, for the classification and characterization of epileptic seizures and to quantify epileptiform discharges. Due to the importance of a correct diagnosis to avoid mistreating many neurological patients, this tool should be accessible to clinicians. In spite of the advances of recent years, 20-30% of patients diagnosed with epilepsy are not really epileptic, a fact that it is excessive and unacceptable (AU)

What can man do without basal ganglia motor output? The effect of combined unilateral subthalamotomy and pallidotomy in a patient with Parkinson's disease.

We have studied motor performance in a man with Parkinson's disease (PD) in whom thermolytic lesions of the left subthalamic and left globus pallidus nuclei interrupted the basal ganglia (BG)-thalamo-cortical motor circuit in the left hemisphere. This allowed us to study remaining motor capabilities in the absence of aberrant BG activity typical of PD. Movements of the left arm were slow and parkinsonian whereas movement speed and simple reaction times (RT) of the right (operated) arm were within the normal range with no obvious deficits in a range of daily life activities. Two main abnormalities were found with the right hand. (a) Implicit sequence learning in a probabilistic serial reaction time task was absent. (b) In a go/no-go task when the percent of no-go trials increased, the RT superiority with the right hand was lost. These deficits are best explained by a failure of the cortex, deprived of BG input, to facilitate responses in a probabilistic context. Our findings confirm the idea that it is better to stop BG activity than allowing faulty activity to disrupt the motor system but dispute earlier claims that interrupting BG output in PD goes without an apparent deficit. From a practical viewpoint, our observations indicate that the risk of persistent dyskinesias need not be viewed as a contraindication to subthalamotomy in PD patients since they can be eliminated if necessary by a subsequent pallidotomy without producing deficits that impair activities of daily life.

Complex modular structure of large-scale brain networks.

Modular structure is ubiquitous among real-world networks from related proteins to social groups. Here we analyze the modular organization of brain networks at a large scale (voxel level) extracted from functional magnetic resonance imaging signals. By using a random-walk-based method, we unveil the modularity of brain webs and show modules with a spatial distribution that matches anatomical structures with functional significance. The functional role of each node in the network is studied by analyzing its patterns of inter- and intramodular connections. Results suggest that the modular architecture constitutes the structural basis for the coexistence of functional integration of distant and specialized brain areas during normal brain activities at rest.

Abnormalities in brain synchronization are correlated with cognitive impairment in multiple sclerosis.

BACKGROUND: Cognitive functions are supported by brain networks and they are highly dependent on the integrity of long white matter tracts that mediate the information flow between such distant cortical areas. Brain damage in multiple sclerosis (MS) may produce cognitive impairment by preferentially damaging these tracts, thereby impairing brain synchrony. Auditory amplitude modulation following responses (AMFR), are oscillatory steady-state responses to rhythmic auditory stimuli that indirectly measure brain synchrony. OBJECTIVE: To study the effect of MS lesions in brain synchrony and its relationship with cognitive function. METHODS: We assessed the correlation between cognitive performance, as assessed with the brief repeatable battery-neuropsychology (BRB-N), and the AMFR in a group of 27 MS patients and 22 healthy controls. RESULTS: The maximal AMFR frequency - but not the amplitude - in the 30-60 Hz range was lower in patients with cognitive impairment than in patients with no cognitive impairment or the healthy controls (39.79 Hz, 43.85 Hz, and 43.84 Hz, respectively, P < 0.05). Indeed, the frequency of the AMFR was negatively correlated with the scores obtained in verbal memory, attention, and executive function. The multiple regression analysis indicates that the AMFR was the best predictor of the BRB-N scores after controlling for potential confounding factors such as age, education, disability, and years of disease evolution. CONCLUSIONS: These results suggest that the loss of synchronization in different central nervous system (CNS) pathways caused by demyelinating lesions might involve both the slowing of brain oscillatory activity and less efficient cognitive processing.

A swimming pool-related outbreak of pharyngoconjunctival fever in children due to adenovirus type 4, Gipuzkoa, Spain, 2008.

An outbreak of pharyngoconjunctival fever affecting 59 children was detected in a municipality of northern Spain in July 2008. The outbreak was related to insufficient doses of water disinfectant in the municipal swimming pool.

[Clinical Neurophysiology: past, present, future]. / La neurofisiología clínica: pasado, presente y futuro.

Clinical Neurophysiology is a medical speciality whose aim is the study of the nervous and muscular system for diagnostic, prognostic and therapeutic purposes. This article analyses the basic objective pursued by this discipline, the techniques it employs and its recognition as a medical speciality. The article briefly reviews its definition and scope, how it is structured at present and the future possibilities it offers.

[Brain oscillations: pathophysiological and potentially therapeutic role in some neurological and psychiatric diseases]. / Oscilaciones cerebrales: papel fisiopatológico y posiblemente terapéutico en algunas enfermedades neurológicas y psiquiátricas.

The terms "oscillations" or "oscillatory activity" are frequently used not only to define the rhythmic fluctuations of the postsynaptic potentials of a neuronal group (local field potentials) or a cortical region (EEG, MEG), but also to indicate the rhythmic discharge pattern of action potentials from a neuron or a small group of neurons. Oscillatory activity makes possible the synchronization of different neuronal groups from nearby or distant cortical regions that participate in the same motor, sensory or cognitive task. The presence of oscillatory activity is usually associated to the existence of synchronization, but both phenomena are not necessarily always equivalent. Abnormalities of oscillatory activities or synchronization within or between different brain structures have been described in several neurological and psychiatric diseases; these abnormalities might play a relevant pathophysiological role in Parkinson's disease (and other movement disorders), schizophrenia or epilepsy. This review discusses all these aspects, with emphasis on their potential role both as a basic mechanism in brain function and as a pathophysiological substrate for some of the symptoms and signs observed in several diseases.

[Video-electroencephalography: a necessity]. / Vídeo-electroencefalografía: una necesidad.

The video-EEG is a common diagnostic tool nowadays. The technical achievements of the last decade have brought a simplification of the equipment required to obtain good quality recordings, with little more than a computer and a video camera being necessary. However, the medical and technical staff must be well trained to execute and interpret the study. It is very useful in the diagnosis of paroxysmal events, for the classification and characterization of epileptic seizures and to quantify epileptiform discharges. Due to the importance of a correct diagnosis to avoid mistreating many neurological patients, this tool should be accessible to clinicians. In spite of the advances of recent years, 20-30% of patients diagnosed with epilepsy are not really epileptic, a fact that it is excessive and unacceptable.

Memantine induces reversible neurologic impairment in patients with MS.

BACKGROUND: Cognitive dysfunction is very common in multiple sclerosis (MS) and it severely impairs patients' quality of life. Thus, we explored whether memantine might improve cognitive performance in patients with MS. METHODS: We conducted a pilot trial with memantine (30 mg/day) in patients with MS with cognitive impairment. The trial was designed as a 1-year, randomized, double-blind, crossover study comparing memantine against a placebo in 60 patients with MS and cognitive impairment. Cognitive impairment was defined as the performance 1.5 standard deviations below the normative data in at least two tests of two cognitive domains in the Brief Repeatable Battery-Neuropsychology. The primary endpoint was improvement of verbal memory and the secondary endpoints were safety and improvements in the other cognitive domains, disability and quality of life. The trial was registered at www.clinicaltrials.org: NCT00638833. RESULTS: Although 19 patients had been included, the trial was halted after nine patients reported a worsening of their neurologic symptoms that deteriorated their quality of life. Seven of the nine patients in the memantine arm had blurred vision, fatigue, severe headache, increased muscle weakness, walking difficulties, or unstable gait. Only two patients in the placebo group reported neurologic symptoms and in both cases they were related with changes in their disease-modifying therapy. The adverse events only occurred on reaching the maximum dose (30 mg/day). After stopping medication, the patients reverted to their baseline disability within a few days. CONCLUSIONS: Memantine at a dose of 30 mg/day may induce transient worsening of neurologic symptoms of multiple sclerosis.

Chirp-evoked potentials in the awake and anesthetized rat. A procedure to assess changes in cortical oscillatory activity.

Steady-state potentials are oscillatory responses generated by rhythmic stimulation of a sensory pathway. The frequency of the response, which follows the frequency of stimulation and potentially indicates the preferential working frequency of the auditory neural network, is maximal at a stimulus rate of 40 Hz for auditory stimuli in humans, but may be different in other species. Our aim was to explore the responses to different frequencies in the rat. The stimulus was a tone modulated in amplitude by a sinusoid with linearly-increasing frequency from 1 to 250 Hz ("chirp"). Time-frequency transforms were used for response analysis in 12 animals, awake and under ketamine/xylazine anesthesia. We studied whether the responses were due to increases in amplitude or to phase-locking phenomena, using single-sweep time-frequency transforms and inter-trial phase analysis. A progressive decrease in the amplitude of the response was observed from the maximal values (around 15 Hz) up to the limit of the test (250 Hz). The high-frequency component was mainly due to phase-locking phenomena with a smaller amplitude contribution. Under anesthesia, the amplitude and phase-locking of lower frequencies (under 100 Hz) decreased, while the phase-locking over 200 Hz increased. In conclusion, amplitude-modulation following responses differ between humans and rats in response range and frequency of maximal amplitude. Anesthesia with ketamine/xylazine modifies differentially the amplitude and the phase-locking of the responses. These findings should be taken into account when assessing the changes in cortical oscillatory activity related to different drugs, in healthy rodents and in animal models of neurodegenerative diseases.

Oscillatory changes related to the forced termination of a movement.

OBJECTIVE: Stimulus-induced movements are accompanied by a definite pattern of oscillatory changes, that include a frontal 15 Hz synchronization, a central peri-movement desynchronization, and a contralateral beta rebound after the movement. Our aim was to study the oscillatory changes related to the forced termination of a single complex motor program (signature) and compare them with those observed after the normal termination of the movement. METHODS: Fifty-eight reference-free EEG channels were analyzed in 10 healthy subjects. A 2000 Hz tone (S1, go signal) indicated the subject to begin to write his/her complete signature. A second 2000 Hz tone 0.8 s afterwards (50% probability: S2, stop signal) indicated the subject to stop immediately. Movement-related energy changes were evaluated by means of time-frequency (Gabor) transforms. RESULTS: A frontal 15 Hz synchronization was observed after S1, but not after S2. The amplitude of the post-movement beta increase was significantly lower when the movement was abnormally terminated (p=0.005), while the peri-movement decrease was similar. CONCLUSIONS: The forced termination of a motor program reduces significantly the amplitude of the post-movement beta increment, conserving its temporal pattern. Also, the presence of the 15 Hz frontal synchronization only after S1, together with the results of previous studies, suggests that the frontal mechanisms involved in go/no go and stop signals are very different. SIGNIFICANCE: Our results indicate that the beta rebound is an active process, independent of the peri-movement beta decrease, which is influenced by how the movement is terminated.

Marked decrease in the incidence and prevalence of hepatitis A in the Basque Country, Spain, 1986-2004.

The aim of this study was to determine changes in the epidemiology of hepatitis A virus (HAV) infection in the Basque Country, Spain, and to evaluate their implications for vaccination strategies. A total of 1356 persons were enrolled in a study of the prevalence of anti-HAV in 2004 and compared with two previous studies (1986-1987 and 1992). The selection method and the characteristics of the population were similar in the three studies. A marked decline in the seroprevalence in all age groups (P<0.001) and in the incidence of cases/100,000 inhabitants (from 38.0 in 1986-1988 to 2.9 in 2002-2004) were observed. The mean age of patients with hepatitis A increased from 17.7 years in 1986-1992 to 21.2 years in 1993-1998 and 25.3 years in 1999-2004 (P<0.001). Between 1997 and 2004, 20% of patients were hospitalized. The changes observed have occurred rapidly causing a change in the epidemiological pattern from middle-high endemicity (1986) to low endemicity (2004).