Eletrophysiology

BACKGROUD: Cavo- tricuspid isthmus dependent atrial flutter (CTI- AFL) is a common atrial arrhythmia in patients with prior cardiac surgery (postsurgical AFL) and without prior cardiac surgery (nonsurgical AFL). However, there is only limited data regarding the eletrophysiological differences between the CTI- AFL in the postsurgical patients and the nonsurgical patients. HYPOTHESIS: We aimed to investigate the differences in clinical and electrophysiological characteristics between the postsurgical group and nonsurgical group and to evaluate the acute and long-term outcomes after ablation guided by robotic magnetic navigation (RMN) in both the groups...

Introduction  Knowledge about the positive effects that music and dance bring, in its various forms, to the healthy human brain, is important not only in the context of basic neuroscience but may also strongly affect practices in neurorehabilitation. Objective  To verify the relationship between hearing and movement and, specifically, to analyze the interference of professional dance practice and formal musical training in the magnitude of the vestibule-cervical and vestibular reflexes. Method  The sample consisted of 92 subjects, aged between 18 and 35 years old, 31 professional musicians, 31 ballet dancers, and 30 control subjects...

Available evidence suggests that emotions influence arithmetic, and explicit emotion regulation modulates the effect of anxiety on arithmetic performance. However, neural mechanisms by which implicit emotion regulation affects these phenomena remain unclear, particularly under distinct affective priming contexts. Twenty-two college students were required to perform multiple tasks in sequence, including an idioms matching task, a multiplication computational estimation task (MCE task), an emotion judgement task (EJ task), and an emotion assessment task (EA task)...

OBJECTIVE: Simultaneous recording of the electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) allows a combination of eletrophysiological and haemodynamic information to be used to form a more complete picture of cerebral dynamics. However, EEG recorded within the MRI scanner is contaminated by both imaging artifacts and physiological artifacts. The majority of the techniques used to pre-process such EEG focus on removal of the imaging and balistocardiogram artifacts, with some success, but don't remove all other physiological artifacts...

We propose to investigate brain electrophysiological alterations associated with Parkinson's disease through a novel adaptive dynamical model of the network of the basal ganglia, the cortex and the thalamus. The model uniquely unifies the influence of dopamine in the regulation of the activity of all basal ganglia nuclei, the self-organised neuronal interdependent activity of basal ganglia-thalamo-cortical circuits and the generation of subcortical background oscillations. Variations in the amount of dopamine produced in the neurons of the substantia nigra pars compacta are key both in the onset of Parkinson's disease and in the basal ganglia action selection...

Numerous processes of neuronal development and synaptic plasticity in the brain rely on the palmitoyl acyltransferase ZDHHC7, as it palmitoylates various synaptic and extrasynaptic proteins such as neural cell adhesion molecule (NCAM) or gamma-aminobutyric acid (GABAA ) receptors. In addition, ZDHHC7 palmitoylates sex steroid hormone receptors and is, therefore, indirectly linked to mental disorders that often occur because of or in conjunction with stress. In this work, we investigated how ZDHHC7 affects stress responses in mice...

BACKGROUND: There is emerging evidence that ultrasound elastography may provide additional diagnostic information in peripheral neuropathies. OBJECTIVE: To investigate the use of ultrasound elastography to evaluate median nerve stiffness in patients with carpal tunnel syndrome (CTS), as well as the relationship between the elastographic stiffness and electrophysiological severity. DESIGN: Case control study. SETTING: Tertiary hospital outpatient neurophysiology clinic...

Early growth response-1 (Egr-1), defined as a zinc finger transcription factor, is an upstream master switch of the inflammatory response, and its expression can be used to investigate the spatial and temporal extent of inflammatory changes in the brain. Cortical spreading depression (CSD) is characterized as a slowly propagating (2-5 mm/min) depolarization wave through neurons and astrocytes in humans that contributes to migraines and possibly to other brain pathologies. In rodents, CSD can be induced experimentally, which involves unilateral depolarization that is associated with microglial and astrocyte responses...

OBJECTIVES: Dorsal root ganglion (DRG) stimulation has been demonstrated to be effective in treating painful diabetic polyneuropathy in a small case series. However, diabetic polyneuropathy only accounts for 41% of all polyneuropathies and the efficacy of DRG on other types of polyneuropathy is unclear. The objective of this study is to evaluate the efficacy of DRG stimulation in treating painful hereditary and idiopathic axonal polyneuropathy. MATERIALS AND METHODS: This is a monocentric retrospective case series...

The aim of the study was to evaluate the incidence of different personality types and state and trait anxiety levels in patients with paroxysmal supraventricular tachycardia and their association with patients age, gender and the mechanism of the paroxysmal SVT. 62 patients with documented paroxysmal supraventricular tachycardia who underwent endocardial eletrophysiological study and catheter ablation of the paroxysmal SVT were included in the study. The patients were asked to fill out the Myers-Brigss Type Indicator and State-Trait Anxiety Inventory questionnaires and the results were analyzed and correlated with the arrhythmia mechanism determined during electrophysiological study and catheter ablation procedure, and the patients' demographics (age and gender)...

It has been suggested that the brain pre-empts changes in the environment through generating predictions, although real-time electrophysiological evidence of prediction violations in the domain of visual perception remain elusive. In a series of experiments we showed participants sequences of images that followed a predictable implied sequence or whose final image violated the implied sequence. Through careful design we were able to use the same final image transitions across predictable and unpredictable conditions, ensuring that any differences in neural responses were due only to preceding context and not to the images themselves...

INTRODUCTION: Complete denervation of transplanted heart exerts protective effect against postoperative atrial fibrillation; various degrees of autonomic denervation appear also after transection of ascending aorta during surgery for aortic aneurysm. OBJECTIVE: This study aimed to evaluate if the level of cardiac denervation obtained by resection of ascending aorta could exert any effect on postoperative atrial fibrillation incidence. METHODS: We retrospectively analysed the clinical records of 67 patients submitted to graft replacement of ascending aorta (group A) and 132 with aortic valve replacement (group B); all episodes of postoperative atrial fibrillation occurred during the 1-month follow-up have been reported...

BACKGROUND: Concussion, particularly in relation to sports and combat activities, is increasingly recognized as a potential cause of both short- and long-term neurologic sequelae. This review will focus on the neuro-ophthalmologic findings associated with concussion, the current tests for concussion, and the potential for visual performance measures to improve our detection and assessment of concussions. EVIDENCE ACQUISITION: A PubMed search using the specific key words "concussion," "mild traumatic brain injury," "neuro-ophthalmological findings," and "diagnostic and management tests" was performed...

A double-cone coil with large angled windings has been developed to modulate deeper brain areas such as the anterior cingulate cortex (ACC). Abnormal resting state activity in the pregenual ACC (pgACC), dorsal ACC (dACC) and subgenual ACC (sgACC) has been observed in depression. A patient with medication resistant chronic depression received ten sessions of transcranial magnetic stimulation (TMS) (10 Hz, 2000 stimuli/session) using a double-cone coil placed over the supplementary motor area, targeting the anterior cingulate...

OBJECTIVE: To clarify the clinical features and mechanism of the transience of myoclonus in patients with a transient myoclonic state with asterixis (TMA). METHODS: We investigated the clinical and eletrophysiological profiles of 6 patients with TMA (age: 84±3 years). During an asymptomatic period, somatosensory evoked potentials (SEPs) were recorded in all 6 patients and motor evoked potentials (MEPs) were examined in 1 patient. SEPs were recorded and jerk-locked back averaging (JLA) was performed in 2 patients while symptomatic...

PURPOSE: To non-invasively study the sensory nerve conduction of the caudal nerve of normal developing rats. METHODS: Twenty normal Wistar male rats served as subjects. Caudal nerve conduction studies were performed at 60 days from birth and weekly at end of six consecutive weeks. The caudal nerve was stimulated distally and nerve potentials were recorded proximally on the animal's tail using common 'alligator' clips as surface electrodes. RESULTS: The amplitude and the conduction velocity of the caudal nerve sensory action potential increased linearly from 29+/-6 microV to 85+/-13 microV and from 34+/-3 m/s to 44+/-4 m/s, respectively, between the 8th and the 15th week of life...

Rett syndrome, an autism spectrum disorder with prominent motor and cognitive features, results from mutations in the gene for methyl-CpG-binding protein 2 (MeCP2). Here, to identify cortical circuit abnormalities that are specifically associated with MeCP2 deficiency, we used glutamate uncaging and laser scanning photostimulation to survey intracortical networks in mouse brain slices containing motor-frontal cortex. We used in utero transfection of short hairpin RNA constructs to knock down MeCP2 expression in a sparsely distributed subset of layer (L) 2/3 pyramidal neurons in wild-type mice, and compared input maps recorded from transfected-untransfected pairs of neighboring neurons...

BACKGROUND: stuttering is a speech fluency disorder. Auditory evoked potentials (AEP) are electrophysiological tests that are being used as an instrument to establish the diagnosis of several disorders as well as to assess therapeutic outcomes. AIM: 1 - to characterize the AEP of individuals with stuttering in comparison to a control group; 2 - to verify the amelioration of these potentials post speech-language treatment. METHOD: the research sample was composed by 8 adult males with stuttering - research group (RG), with ages ranging from 18 to 30 years, and 8 normally fluent adult males - control group (CG), within the same age range...

The aim of this study was to investigate the effect of spider toxins on brain injury induced by oxygen deprivation and low glucose (ODLG) insult on slices of rat hippocampus. After ODLG insult cell viabilility in hippocampal slices was assessed by confocal microscopy and epifluorescence using the live/dead kit containing calcein-AM and ethidium homodimer and CA1 population spike amplitude recording during stimulation of Schaffer collateral fibers. Spider toxins Tx3-3 or Tx3-4 and conus toxins, omega-conotoxin GVIA or omega-conotoxin MVIIC are calcium channel blockers and protected against neuronal damage in slices subjected to ODLG insult...

Dropped head sign is characterized by the gradual forward sagging of the head due to weakness of neck extensor muscles. This may be a prominent sign of several neuromuscular disorders and may be an isolated feature of myasthenia gravis (MG). We describe a patient with isolated neck extensor weakness, eletrophysiological findings suggesting myasthenia gravis and positive MuSK antibodies. This case supports that finding anti-MuSK antibodies may be extremely helpful in dropped head patients and negative acetylcholine receptor antibodies especially if needle EMG does not reveal myopathic or neurogenic patterns...