Influence of colors on habituation of visual evoked potentials in patients with migraine with aura and in healthy volunteers.

in Headache (2000), 40(1), 36-40

OBJECTIVE: To investigate whether colored glasses influence the habituation of visual evoked potentials. BACKGROUND: We have previously shown that during pattern-reversal stimulations lasting 2 minutes ... [more ▼]

OBJECTIVE: To investigate whether colored glasses influence the habituation of visual evoked potentials. BACKGROUND: We have previously shown that during pattern-reversal stimulations lasting 2 minutes the amplitude of the visual evoked potential increases in migraine with and without aura between attacks, whereas it decreases in healthy volunteers. Red light was found to increase visually evoked EEG fast activity only in children with migraine with aura. Wearing rose-tinted glasses for 4 months decreased attack frequency in parallel with a reduction of the visually evoked EEG fast activity. METHODS: We compared the change in amplitude of the visual evoked potential using five different tinted glasses in 12 patients with migraine with aura and in 10 healthy volunteers. During continuous stimulation at 3.1 Hz, five blocks of 50 responses were sequentially averaged using red, yellow, green, blue, and grey glasses and without glasses in a random order and analyzed in terms of latencies and N1-P1 amplitudes. Amplitude changes were calculated for each block by comparison with the first block in every condition and analyzed statistically using Zerbe's method. RESULTS: In healthy volunteers, the visual evoked potential amplitude increased with red glasses compared to without glasses (P = .05) or with green glasses (P = .03). In patients with migraine with aura, no significant difference was detected using colored glasses. Our findings in healthy volunteers are in line with earlier reports of increased excitability of the human visual cortex when exposed to red light. The lack of such a pattern in patients with migraine with aura suggests that the visual cortex is interictally hypoexcitable rather than hyperexcitable, which is consistent with studies of transcranial magnetic stimulation. [less ▲]

Familial influences on cortical evoked potentials in migraine.

in Neuroreport (1999), 10(6), 1235-8

Cortical information processing in migraine patients is impaired between attacks, showing deficient habituation of pattern-reversal visual evoked potentials (VEP), and strong intensity dependence of ... [more ▼]

Cortical information processing in migraine patients is impaired between attacks, showing deficient habituation of pattern-reversal visual evoked potentials (VEP), and strong intensity dependence of auditory cortical evoked potentials (IDAP). This could be a genetic trait as certain genetic patterns are known for evoked potentials in healthy subjects. We investigated VEP habituation and IDAP in 20 pairs of migraineurs made up of parents and their children. Using a Monte-Carlo statistical method, we selectively assessed vertical familial influences. VEP habituation and IDAP were abnormal in both parents and children. However, similarity was far more pronounced between related pairs than between unrelated pairs. Familial influences are highly significant in determinants of cortical information processing in migraineurs, hence supporting the important role of genetic factors. [less ▲]

Effect of potassium channel openers on the firing rate of hippocampal pyramidal cells and A10 dopaminergic neurons in vitro

in Archives of Physiology & Biochemistry (1997), 105

Potentiation instead of habituation characterizes visual evoked potentials in migraine patients between attacks

in European Journal of Neurology (1995), 2

Factors influencing between-laboratory variability of C-reactive protein results as evidenced by the Belgian External Quality Assessement (EQA) Scheme

in Scandinavian Journal of Clinical & Laboratory Investigation (1994), 54(6), 435-40

Based on results from the Belgian External Quality Assessment (EQA) Scheme, we studied the main factors affecting the between-laboratory variation of C-reactive protein determination. Participants using ... [more ▼]

Based on results from the Belgian External Quality Assessment (EQA) Scheme, we studied the main factors affecting the between-laboratory variation of C-reactive protein determination. Participants using homogeneous systems with several calibration points generally achieved better performance. Working temperatures influenced the results to a lesser extent. The present study stresses the importance for EQA organizers to collect more detailed information about CRP analytical methods used by the participants. It also suggests that manufacturers should be more involved in the management of quality, in particular by striving for standardization of the material (kit and calibrator) they produce for CRP assay. [less ▲]

Characteristics associated with early (less than or equal to 3 months) versus late (greater than 3 months to less than or equal to 3 years) mortality after acute myocardial infarction.

in American Journal of Cardiology (1989), 64(5), 315-8

To define the independent variables predictive of early versus late mortality after acute myocardial infarction (AMI), 420 consecutive patients were studied and divided into 3 groups: the 45 patients who ... [more ▼]

To define the independent variables predictive of early versus late mortality after acute myocardial infarction (AMI), 420 consecutive patients were studied and divided into 3 groups: the 45 patients who died within the initial 3 months (group 1), the 45 patients who died greater than 3 months and less than or equal to 3 years after AMI (group 2) and the 330 greater than 3-year survivors (group 3). The stepwise logistic discrimination method was applied to clinical and laboratory variables recorded during hospitalization to distinguish among the 3 groups. Six independent variables were found to be predictive of early mortality: left ventricular function score (chi-square 26.2; p less than 0.00001), ventricular fibrillation (chi-square 9.3; p = 0.002), bundle branch block (chi-square 9.0; p = 0.003), history of previous AMI (chi-square 8.7; p = 0.003), age (chi-square 5.8; p = 0.02) and atrioventricular block (chi-square 3.8; p = 0.05). Three independent variables were found predictive of late mortality: age (chi-square 13.8; p = 0.0002), anterior location of the AMI (chi-square 4.0; p = 0.04) and a low peak creatine kinase-MB level (chi-square 3.8; p = 0.05). Only 2 variables were able to distinguish between early and late nonsurvivors: peak creatine kinase-MB level (chi-square 8.7; p = 0.003) and ventricular fibrillation (chi-square 4.6; p = 0.03). Thus, the sets of independent risk factors for early and late mortality after AMI are substantially different--suggesting that differing mechanisms are responsible for outcome. [less ▲]

Does lactate dehydrogenase isoenzyme-5 contribute to the predictive power of total lactate dehydrogenase in myocardial infarction?

in Clinical Chemistry (1983), 29(5), 774-7

In 385 patients with acute myocardial infarction, lactate dehydrogenase (LD; EC 1.1.1.27) isoenzymes were determined electrophoretically 24, 48, and 72 h after admission. At those times, LD-1/LD-2 ratios ... [more ▼]

In 385 patients with acute myocardial infarction, lactate dehydrogenase (LD; EC 1.1.1.27) isoenzymes were determined electrophoretically 24, 48, and 72 h after admission. At those times, LD-1/LD-2 ratios exceeding 1 were recorded in 78.9, 88.8, and 92.2% of the cases, respectively. LD-1 ranged from 181 to 2674 U/L, or 21.9 to 66.1% of the total activity. On the first day of hospitalization, 27.3% of the patients demonstrated abnormal LD-5 (greater than 6% of total LD); this finding dropped to 20.5% and 17.4% in the two following days. Early increases in LD-5 were most frequently observed in patients associating inferior infarcts with posterior or lateral extension and having a previous history of myocardial infarction. On day 1, LD-5 was significantly increased in early deceased patients as compared to long-term survivors (9.7% vs 4.9% of total LD, p less than 0.01). LD-5 definitely contributes to the prognostic efficiency of total LD in acute myocardial infarction, but does not replace it as a risk predictor. This study confirms the superiority of total LD over the isoenzyme measurements to achieve short-term prognostication [less ▲]

Serum myoglobin determinations in the assessment of acute myocardial infarction.

in European Heart Journal (1982), 3(2), 122-9

Stepwise probit discrimination with specific application to short-term prognosis in acute myocardial infarction.

in Computers and Biomedical Research, an International Journal (1981), 14(5), 391-8

The prognostic significance of serum alpha 1-acid glycoprotein changes in acute myocardial infarction.

in Clinica Chimica Acta (1981), 115(2), 199-209

Serum alpha 1-acid glycoprotein and haptoglobin concentrations were evaluated in 151 patients with acute myocardial infarction (MI) during the first ten days of hospitalization. Maximum glycoprotein ... [more ▼]

Serum alpha 1-acid glycoprotein and haptoglobin concentrations were evaluated in 151 patients with acute myocardial infarction (MI) during the first ten days of hospitalization. Maximum glycoprotein concentrations were found to be related to myoglobin and enzyme peak levels. Glycoprotein levels recorded upon patients' admission did not vary for acute phase survivors and early deaths (15 patients), but the latter demonstrated significantly higher alpha 1-acid glycoprotein levels (p less than 0.05) on day 1. The maximum glycoprotein concentrations were, however, reached too long after the onset of acute MI to be of interest for short-term prognosis. Comparison of the evolution of the two glycoproteins investigated in late deaths (10 patients) and in 6-month survivors indicated increased alpha 1-acid glycoprotein levels in non-survivors, with a maximum discrimination occurring on day 8 (p less than 0.001). Haptoglobin was not significantly different in the two groups and even demonstrated lower concentrations from day 4 to day 10 in non-survivors. The decrease of haptoglobin levels in patients with hepatic dysfunction could explain the divergent results given by the serum concentrations of the two glycoproteins to predict mortality. We show in this study that alpha 1-acid glycoprotein measured at the end of hospitalization can give relevant prognostic information for the 6-month period following acute MI. [less ▲]