Transcranial Doppler and cerebral tomodensitometry scan in the predictivity of intracranial hypertension

ABSTRACT

To compare transcranial Doppler ultrasonography [TCD] and cerebral tomodensitometry [CT], in the predictivity of intracranial hypertension [ICH]. Sixteen patients, with a median age of 47 years, under continuous monitoring of intracranial pressure [ICP] were included in a double blinded prospective study. Each time a CT was performed the left and right middle cerebral arteries were insonated. With TCD, ICH is noted if the worst mean blood flow diastolic velocity was less than 25 cm/s, associated with a pulsatility index value larger than 1.2. Cerebral tomodensitometry was analysed and the ICH noted if one or more of the following radiographic signs was present [disappearance of sulci, effacement of ventricles, reduction of the white-grey matter differentiation, basal cistern compression, hydrocephalus and midline shift higher to 5 mm]. The median initial Glasgow Coma Score was 8 +/- 3. Intracranial pressure monitoring was undertaken in the following situations 10 severe head injury, 4 strokes and 2 cerebral tumours. A total of 30 CT were carried out. Fourteen patients presented at least one episode of ICH. During episodes of ICH, TCD correlated with ICP in 64% of the cases, whereas CT correlated with ICP in 68% of the cases. In the absence of ICH the correlation of TCD and ICP decreased to 37.5%. In 4 cases of ICH, data of CT were not in favour of ICH while TCD correlated with ICP. Associating TCD and CT allows to detect ICH in 86% of cases vs. 68% only with CT [p=0.15] and vs. 64% only with TCD [p=0.08]. Transcranial Doppler ultrasonogrpahy is equivalent to CT in the predictivity of an ICH. This predictability is better in cases of ICH [ICP > 20 mmHg]. Associating TCD to CT allows to recover the majority of the cases of ICH not detected by CT alone