Visually evoked blood flow responses and vasoneuronal coupling in partial epilepsy.

OBJECTIVES

Increased metabolic demand is coupled with increased regional blood flow. The decreased vasoreactivity in epileptic patients however, prompts an impact of epileptic dysfunction on vasoneuronal coupling.

MATERIAL AND

METHODS

Blood flow velocities during visual stimulation were monitored by TCD in both posterior cerebral arteries in 20 epileptic patients and 20 control persons, response-amplitudes (RA) and pulsatility indices (PI) were analyzed.

RESULTS

The RAs were significantly smaller in patients than in controls (28.4 +/- 5.7% vs 38.4 +/- 10.2%; P < 0.001). RAs were larger in the right side and these right-sided responses were significantly smaller in patients with right-sided vs left-sided epileptic foci (27.9 +/- 5.5% vs 36.1 +/- 4.5%; P < 0.005). The PI during stimulation was significantly larger in patients than in controls (0.92 +/- 0.11 vs 0.74 +/- 0.15; P < 0.001).

CONCLUSION

Our data suggest an impaired vasoneuronal coupling in focal epilepsy, and support the view that the right hemisphere might be more important for color processing.