Background: In patients with migraine, an abnormally large haemodynamic response to epileptogenic visual stimulation has previously been observed, consistent with the hypothesis of a cortical hyperexcitability. Ophthalmic filters have been used in the treatment of migraine, and they reduce the haemodynamic response.

Methods: The present study used near-infrared spectroscopy (NIRS) to characterise the haemodynamic response to a range of visual stimuli in 20 patients with migraine (15 with aura and 5 without) and paired controls in order to assess the effect of ophthalmic treatment. In an initial study, the response to three stimuli (chequerboard, and two gratings of different spatial frequency) was measured. In a second study, using the mid-spatial frequency grating as stimulus, the response was compared when precision spectral filters (PSF), grey filters or filters of control colour were worn as ophthalmic lenses.

Results: In the first study the time course of the response differed between the groups. The difference was most distinct for the grating with mid-spatial frequency. In the second study the PSF broadened (normalised) the haemodynamic response in migraineurs relative to controls, consistent with fMRI BOLD findings and suggesting a physiological mechanism for their reported efficacy. In neither study were there differences in the amplitude of the response between migraine and control groups or indeed between filters.

Conclusion: The time course of the functional response as measured by NIRS may be an effective tool to track therapy with PSF and explore the mechanisms of visual stress in migraine.

Download full-text PDF

Source
http://dx.doi.org/10.1177/0333102412444474DOI Listing

Publication Analysis

Top Keywords

haemodynamic response
16
time course
12
response
9
visual stimulation
8
near-infrared spectroscopy
8
patients migraine
8
second study
8
mid-spatial frequency
8
migraine
6
study
6

Similar Publications

Background: The match physical demands placed on soccer referees are intrinsically connected to their capacity to make accurate judgments, becoming the second most studied theme in associate soccer refereeing.

Objective: This study aims to review the external and internal load performed by soccer referees in high-level competitions, to identify changes in these indicators over different periods as the competition progresses, and to analyze the standards for dividing speed zones and heart rate zones.

Methods: Web of Science, PubMed, Scopus, and EBSCOhost were thoroughly searched.

View Article and Find Full Text PDF

Purpose: To assess physiological metrics during the use of a commercially available bilateral active ankle exoskeleton during a challenging military-relevant task and if use of the exoskeleton during this task influences: metabolic load, physiological measures or rate of perceived exertion.

Methods: Nine healthy volunteers (5M, 4F) completed this randomized cross-over design trial, with a baseline visit and two randomized test sessions (with/without the exoskeleton). Variables included impact on time to exhaustion during walking on a treadmill at varying speeds and gradients (0-15%) at 26.

View Article and Find Full Text PDF

Police tactical group (PTG) officers respond to the most demanding and high-risk police situations. As such, PTG personnel require exceptional physical fitness, and selection for employment often evaluates fitness both directly and indirectly. While heart rate (HR) is often used to measure physical effort, heart rate variability (HRV) may be a valuable tool for measuring stress holistically.

View Article and Find Full Text PDF

The use of an alteplase (Activase) purge solution to address Impella ventricular assist device "thrombosis" or "purge system occlusion" has been mainly documented with earlier generation Impella devices (CP, 2.5, 5.0).

View Article and Find Full Text PDF

Purpose: This study aimed to evaluate the acute effects of beetroot extract and resveratrol supplementation (isolated and combined) on cardiac autonomic modulation and cardiovascular parameters recovery after exercise in individuals with coronary artery disease (CAD).

Methods: 14 males with CAD were submitted to 4 protocols consisting of 30 min (min) of rest, 30 min of aerobic exercise on a treadmill (60% of the heart rate reserve HRR), followed by 30 min of recovery. Before each protocol, the subjects consumed 500 mg of starch (placebo protocol), 500 mg of beetroot (beetroot protocol), or 500 mg of resveratrol (resveratrol protocol), or 500 mg of beetroot and 500 mg of resveratrol (combined protocol).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!