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Duplex color ultrasound study of infantile progressive ventriculomegaly
1Department of Pediatrics, National Cheng Kung University Hospital, Tainan, Taiwan, Republic of China.
Insights
The Pourcelot index (PI) helps differentiate hydrocephalus from atrophy in infants with enlarged ventricles. An elevated PI before shunting indicates a better outcome, suggesting shunts are less beneficial for infants with normal PI values.
Area of Science:
- Pediatric Neurology
- Neuroimaging
- Cerebrovascular Physiology
Background:
- Ventriculomegaly in infants can result from various causes, including meningitis and hemorrhage.
- Assessing cerebrovascular resistance is crucial for managing hydrocephalus.
- Duplex color ultrasound offers non-invasive monitoring of cerebral blood flow and ventricular size.
Purpose of the Study:
- To evaluate the utility of Doppler variables, specifically the Pourcelot index (PI), in differentiating types of ventriculomegaly in infants.
- To correlate PI with ventricular size changes and clinical outcomes after shunt placement.
- To determine if PI can predict shunt responsiveness in ventriculomegalic infants.
Main Methods:
- Sequential duplex color ultrasound measurements of ventricular sizes and anterior cerebral artery (ACA) Doppler variables were performed on 14 infants with ventriculomegaly.
- Infants were categorized into two groups based on frontal horn radius (FHR) changes post-shunt placement.
- Pourcelot index (PI) and other Doppler parameters were analyzed before and after shunting, with intracranial pressure monitored.
Main Results:
- Infants with greater FHR reduction post-shunt (Group I) had higher pre-shunt PI compared to those with minimal reduction (Group II).
- A significant correlation between cerebrovascular resistance and ventricular dilation was observed only in Group I.
- Post-shunt, significant improvements in end-diastolic velocity, velocity-time integral, and PI were noted exclusively in Group I, which also showed better outcomes.
Conclusions:
- The Pourcelot index (PI) is valuable in distinguishing between hydrocephalic and atrophic ventriculomegaly in infants.
- Infants with ventriculomegaly and an unelevated PI are less likely to benefit from ventricular shunting.
- Pre-shunt PI measurements can aid in predicting shunt efficacy and guiding treatment decisions for pediatric hydrocephalus.
Abstract:
Sequential measurements of ventricular sizes and Doppler variables of anterior cerebral artery (ACA) by duplex color ultrasound were performed on 14 ventriculomegalic infants (mean age: 3.4 months): 9 were postmeningitic, 3 posthemorrhagic, and 2 congenital. According to changes of the frontal horn radius (FHR) after shunts, the FHR was decreased greater than 30% (n = 9) in group I and less than or equal to 10% (n = 5) in group II. Before shunting, Pourcelot index (PI) in group I was greater than in group II (P less than 0.01), but FHR in group II was higher than in group I (P less than 0.01). The intracranial pressure did not vary between groups. Serial preshunt examinations showed a significant correlation between the degree of cerebrovascular resistance and the degree of ventricular dilation only in group I. After surgery, significant changes of end-diastolic velocity, the area under the velocity curve, and PI were found only in group I. The reservoir pumping test performed on 2 cases of recurrent ventriculomegaly in group I and 3 cases in group II showed a decreased PI only in group I, in which the outcome was better. PI is useful in differentiating between hydrocephalic and atrophic ventriculomegaly. These data suggest that a ventriculomegalic infant with an unelevated PI value hardly benefits from a ventricular shunt.