Association of cerebral perfusion pressure with headache in women with pre-eclampsia

Objective To study estimated cerebral perfusion pressure and its relation t o headache and scotomata in women with pre-eclampsia. Design Prospective, observational study. Setting University teaching hospitals. Population Seventy-nine pre-eclamptic women with (n = 42) and without (n = 37) headache. Patients with scotomata were also studied separately. Methods Transcranial Doppler ultrasound was used to estimate the resistance index, pulsatility index, and estimated cerebral perfusion pressure in the middle cerebral artery. eCPP data were plotted on the same axes as the mea n (and 5th and 95th% prediction limits) eCPP data from 63 normal pregnant w omen followed longitudinally through pregnancy. Data outside of the 95% pre diction limits were regarded as abnormal. Data from the pre-eclamptic women were also expressed in terms of the number of standard deviations from the mean value established for normal pregnancy (multiples of the standard dev iation: MOS). All studies were prior to labour, under similar conditions, a nd before volume expansion or treatment. Analysis of data was performed usi ng Student's t test, Mann-Whitney U test, ANOVA, and Fisher's exact test wi th two-tailed P < 0.05, and receiver operating characteristic curve analysi s with a one-tailed P < 0.05. Main outcome measures Resistance index, pulsatility index, and eCPP. Results Pre-eclamptic women with headache were much more likely to have abn ormal eCPP (34/42; 88%) than those without headache (18/37; 49%), P = 0.004 , OR 4.5 (95% CI 1.5 to 13.9). There were no differences in terms of MOS in the resistance index or pulsatility index between the two groups, but esti mated perfusion pressure, expressed as multiples of the standard deviation in the group with headache, was significantly higher than in the women with out. Headache was noted in both over-perfusion and under-perfusion states. Only women with headache had scotomata, and their presence was not related to the severity of the headache or any difference in resistance indices or eCPP. Conclusions Headache in women with pre-eclampsia is strongly associated wit h the presence of abnormal cerebral perfusion pressure. This information ma y be of use in clinical management. Prospective, observational study. Unive rsity teaching hospitals.