Search results for "Implanted"

Hippocampo-cerebellar theta band phase synchrony in rabbits.

2009

Hippocampal functioning, in the form of theta band oscillation, has been shown to modulate and predict cerebellar learning of which rabbit eyeblink conditioning is perhaps the most well-known example. The contribution of hippocampal neural activity to cerebellar learning is only possible if there is a functional connection between the two structures. Here, in the context of trace eyeblink conditioning, we show (1) that, in addition to the hippocampus, prominent theta oscillation also occurs in the cerebellum, and (2) that cerebellar theta oscillation is synchronized with that in the hippocampus. Further, the degree of phase synchrony (PS) increased both as a response to the conditioning sti…

Incidental finding of migrated pacing lead fragment into pulmonary artery detected with CT

2013

This case shows a rare complication of a migrated atrial lead into the pulmonary artery incidentally detected during a comprehensive evaluation of coronary CT angiography.

A Strange Case of Downward Displacement of a Deep Brain Stimulation Electrode 10 Years Following Implantation: The Gliding Movement of Snakes Theory.

2014

Background Despite the best efforts to ensure stereotactic precision, deep brain stimulation (DBS) electrodes can wander from their intended position after implantation. We report a case of downward electrode migration 10 years following successful implantation in a patient with Parkinson disease. Methods A 53-year-old man with Parkinson disease underwent bilateral implantation of DBS electrodes connected to a subclavicular 2-channel pulse generator. The generator was replaced 7 years later, and a computed tomography (CT) scan confirmed the correct position of both leads. The patient developed a gradual worsening affecting his right side 3 years later, 10 years after the original implantati…

Reward Unpredictability inside and outside of a Task Context as a Determinant of the Responses of Tonically Active Neurons in the Monkey Striatum

2001

Tonically active neurons (TANs) in the monkey striatum are involved in detecting motivationally relevant stimuli. We recently provided evidence that the timing of conditioned stimuli strongly influences the responsiveness of TANs, the source of which is likely to be the monkey's previous experience with particular temporal regularities in sequential task events. To extend these findings, we investigated the relationship of TAN responses to a primary liquid reward, the timing of which is more or less predictable to the monkey either outside of a task or during instrumental task performance. Reward predictability was indexed by the timing characteristics of the mouth movements. The responsive…

Hippocampal theta-band activity and trace eyeblink conditioning in rabbits.

2009

The authors examined the relationship between hippocampal theta activity and trace eyeblink conditioning. Hippocampal electrophysiological local field potentials were recorded before, during, and after conditioning or explicitly unpaired training sessions in adult male New Zealand White rabbits. As expected, a high relative power of theta activity (theta ratio) in the hippocampus predicted faster acquisition of the conditioned response during trace conditioning but, contrary to previous results obtained using the delay paradigm, only in the initial stage of learning. The presentation of the conditioned stimulus overall elicited an increase in the hippocampal theta ratio. The theta ratio dec…

Natural history of the Sprint Fidelis lead: survival analysis from a large single-center study.

2012

The purposes of our study were to: (1) determine lead failure rate in a large single-center cohort of Sprint Fidelis 6949 (Fidelis) leads, (2) define the risk of lead failure over time, (3) assess the impact of the Lead Integrity Alert (LIA) on lead failure presentation, and (4) identify independent predictors of Fidelis lead failure. All patients who underwent implantation of a Fidelis lead between September 2004 and July 2007 were included. Demographic, clinical, and device characteristics at the time of implant and prior to failure were collected and analyzed. A total of 971 Fidelis leads (706 men, 265 women, mean age 68.4 ± 12.8 years) were implanted. Over a mean follow-up of 46.3 month…

Is atrial sensing of ventricular far-field signals important in single-lead VDD pacing?

1998

UNLABELLED In single-lead VDD pacing the atrial sensitivity frequently is programmed to sensitive values. Atrial sensing of ventricular far-field signals should be reduced by differential atrial sensing. The aim of the study was to evaluate the effectiveness of this approach. METHODS The study included 10 patients with a single-lead VDD pacemaker (Thera 8948, Lead 5032). The atrial sensitivity was set to its most sensitive value of 0.18 mV and the telemetered intraatrial EGM was continuously recorded. After atrial tracked ventricular pacing, VVI pacing was performed with pacing rates from 100 to 160 beats/min in steps of 10 beats/min and up to 165 beats/min. The peak-to-peak amplitudes of P…

Right ventricular lead placement and ventricular dyssynchrony in a pacemaker population: An acute analysis from the evaluation of apical and non-apic…

2016

How Can We Identify the Best Implantation Site for an ECG Event Recorder?

2000

ZELLERHOFF, C., et al.: How Can We Identify the Best Implantation Site for an ECG Event Recorder? The aim of this study was to show how to find the preferable implantation site for an ECG event recorder (ECG-ER). We compared the quality of bipolar ECG recordings (4-cm electrode distance, vertical position) in 65 patients at the following sites: left and right subclavicular, left and right anterior axillary line (4th-5th interspace), left and right of the sternum (4th-5th interspace), heart apex, and subxyphoidal. The results were compared to the standard ECG lead II. In 30 patients, an additional comparison between vertical and horizontal ECG registrations was done using the same sites. ECG…

Role of the basolateral amygdala in retrieval of conditioned flavors in the awake rat.

2014

International audience; Learned association between odor, taste and further post-ingestive consequence is known as flavor nutrient conditioned preference. Amygdala is supposed to be one of the areas involved in these associations. In the present study, one flavor was associated with a 16% glucose (CS+) whereas another flavor was paired with less reinforcing 4% glucose (CS-). We showed that CS+ presentation after conditioning increased Fos expression in the basolateral nucleus of amygdala (BLA). Furthermore, we performed electrophysiological recordings in the BLA in free moving rats. After preference acquisition, rats were exposed to either the CS+ or the CS-. The proportion of neurons showi…