gms | German Medical Science

Objective: Many intracranial neurosurgical pathologies are associated with increased intracranial pressure. Influences of raised ICP on global brain perfusion in pediatric patients are poorly investigated. Color-duplex sonography of all four brain supplying arteries can be used to measure total cerebral blood flow volume (CBFV). This study investigates CBFV before and after therapy in conditions associated with raised ICP to elucidate the impact of raised ICP on global brain perfusion in children.

Methods: 15 children, aged between 0.5 and 11 years were included. 8 patients had a posterior fossa tumor with obstructive hydrocephalus, 2 patients had hydrocephalus of other origin and 5 children were treated for sagittal synostosis with intraoperatively confirmed raised ICP. Investigations were performed using a 12 Mhz linear transducer. CBFV was determined as the sum of flow volumes in both internal carotid and vertebral arteries. Each intravascular flow volume was calculated as the product of time-averaged flow velocity and the cross-sectional area of the insonated vessel segment as described previously [1].

Results: Mean global CBFV before surgery was reduced to 646.9±156.3 ml/min compared to age-dependent normal values (821±116ml/min). After surgery CBFV increased significantly to the normal range (839.7±226.1 ml/min; p<0.01). The increase of CBFV was independent of the underlying cause of raised ICP. The strongest increase was found in patients after treatment of posterior fossa tumor (mean difference: 305.9±113.6 ml/min). The preoperative reduction of CBFV fully recovered after surgery in each individual case.

Conclusion: Raised intracranial pressure of various origin seems to compromise global brain perfusion in children, even if they are not obviously symptomatic for raised ICP like children with sagittal synostosis or moderate hydrocephalus. These data provide first impressions and more patients with different underlying pathologies need to be examined to gain insights into physiology and pathophysiology of the relation between ICP and global brain perfusion. CBFV measurements might thus evolve as a further, non-invasive diagnostic tool in pediatric neurosurgery patients.