Transcranial Doppler role in prediction of post-dural puncture headache in parturients undergoing elective cesarean section: prospective observational study

Cerebral Blood Flow in Low Intracranial Pressure Headaches—What Is Known?

“…After delivery, velocity progressively and rapidly increases in the first postpartum week, but this may be due to blood loss during delivery. The mechanism for these increases in the Vm might be also mild vasoconstriction, resulting from a sudden decrease in estrogen levels after delivery [45]. Only one doppler study examined intracranial veins.…”

Predictive performance of transcranial Doppler for PDPH

“…The standard deviation (SD) of mean velocity and pulsatility index is very narrow compared to the difference between the means of the groups [1]. Previous study suggests some overlap of the dispersion of those two parameters between the groups [1,3]. This peculiar dispersion may have led to a `significant` p value, very narrow AUC of ROC and a near ideal sensitivity and specificity.…”

“…I read with interest the article by Mowafy and Abd Ellatif and would like to bring a few points for due consideration [1].…”

“…Instead of using a predefined sensitivity/specificity or area under the curve (AUC) of receiver operating characteristic (ROC) curve, the authors chose to find an undisclosed difference of mean of cerebral artery velocity [1,2]. Moreover, the cited study does not report the values used by authors [1]. Thus, it is unclear whether their study was adequately powered to examine their primary aim.…”

“…3. The reported 95% Confidence Interval (CI) of AUC of ROC of PI is 1-1 [1]. It is extremely unlikely that the observed sample parameter will depict the population parameter with such outstanding confidence.…”