Vasoreactivity in patients with periventricular white matter lucency.

OBJECTIVES: Cerebral hypoperfusion has been evidenced in patients with periventricular white matter lucency (PWML), however, our knowledge is limited regarding vasoreactivity (VR) changes in these patients. Therefore, we compared the cerebral blood flow velocity (CBFV) responses during different vasoregulatory challenges in healthy volunteers, to those in patients with PWML.
MATERIAL AND METHODS: In 20 patients with PWML and in 20 healthy volunteers the VR of the middle cerebral artery (MCA) system was measured by analyzing the changes of CBFV during different stimulation paradigms (ventilation, tilting and acetazolamide tests). During transcranial Doppler (TCD) registration the systemic blood pressure, the expiratory partial CO(2) pressure (pCO(2)) and the electroencephalograph (EEG) were monitored.
RESULTS: The relative velocity change was significantly smaller in the PWML group than in the normal control group during hypercapnia (16 +/- 12% vs 32 +/- 17%; P < 0.001) and this finding was confirmed by assessment of pCO(2)-corrected velocity change (4.7 +/- 3.7 cm/s/kPa vs 18.4 +/- 6.8 cm/s/KPa; P < 0.001). Although CBFV measurements during acetazolamide test tended to support these findings, the changes of other parameters measured did not reach the level of significance. One patient showed considerable orthostatic reaction (mean arterial blood pressure decrease by 70 mmHg) but it was not associated with significant changes in CBFV.
CONCLUSION: Patients with PWML showed an impaired VR in the MCA flow territory supporting the concept of the microangiopathic origin of leukoaraiotic changes.