NEUROVASCULAR COUPLING DURING AGEING AND INMIGRANEURS

• Main Author: Marjan Zaletel
• Format: Article
• Language: English
• Published: Slovenian Medical Association 2008-05-01
• Series: Zdravniški Vestnik
• Online Access: http://vestnik.szd.si/index.php/ZdravVest/article/view/874

A noninvasive assessment of neurovascular coupling using visually evoked cerebral bloodflow velocity responses (VEFR) and visual evoked potentials (VEP), during normal ageingand in migraneurs, would be of great importance for interpretation of functional neuroimaging methods. According to the recent findings neurovascular coupling could bealtered in older subjects and in migraneurs.The records were made from a group of healthy younger (37.5±9.4 years; 20 subjects) andolder subjects (69.5±5.9 years; 20 subjects) as well as from patients with migraine (36.6 ±10.4 years) interictally. The stimulus was a black-and-white checkerboard with visual contrasts of 1 %, 10 % and 100 %. The VEFR were measured in the posterior cerebral arteryusing transcranial Doppler (TCD), and the VEP were recoded from occipital leads. To testthe relationship between the VEFR, the VEP and the visual contrast, a linear regressionanalysis was performed.A significant increase of the VEFR and the VEP to graded visual contrasts (p < 0.01) wasfound both in the younger and older subjects. The linear regression showed a significantpositive association between the VEP in the VEFR (r = 0.66, p < 0.01) of the younger andolder subjects (r = 0.74, p < 0.01). The regression coefficient of the younger subjects wassignificantly higher (b = 0.54; SE = 0.07) than that of the older ones (b = 0.40; SE = 0.05)(p < 0.01). Also, we found an increase of VEFR and VEP within group of migraneurs(p < 0.01). VEFR were significantly higher in migraneurs (p < 0.01) compared to controls,while VEP did not significantly differ between the groups (p > 0.05). The regression showeda significant association between VEP and VEFR migraneurs (r = 0.63, p < 0.01). Theregression coefficient of migraneurs (b = 0.88, SE = 0.08) was significantly higher than ofhealthy subjects (b = 0.55, SE = 0.07) (p = 0.04).We concluded that a simultaneous recording of VEFR and VEP at graded visual contrastsindicates diminished neurovascular coupling in older subjects and it is increased in migraneurs interictally.