Value of overnight monitoring of intracranial pressure in hydrocephalic children.
OBJECTIVE
Exaggerated nocturnal intracranial pressure (ICP) dynamics are commonly observed in hydrocephalic children with a compromise of CSF compensatory reserve capacity. Successful shunting restores this cerebrospinal reserve. We used ICP overnight monitoring combined with positional maneuvers in complex hydrocephalic children with a suspected shunt malfunction for the assessment of shunt function.


METHODS
In 32 hydrocephalic children, we performed 65 computerized overnight recordings and 25 positional maneuvers. Baseline ICP was considered abnormal if it exceeded the operating pressure of the shunt by more than 2.5 mm Hg. The maximum ICP (normal = <25 mm Hg), RAP coefficient (the correlation coefficient between pulse amplitude and mean intracranial pressure, which indicates pressure volume compensatory reserve; normal = <0.6), magnitude of slow waves (SLOW) and ICP pulse amplitude (AMP) were calculated for each night.


RESULTS
Using baseline ICP, maximum ICP and RAP, 19 recordings were classified as 'normal' (group 1), 13 as 'questionable' (group 2), and 33 as 'pathological' (group 3) indicating shunt dysfunction or active hydrocephalus. ICP, AMP, RAP and SLOW were significantly different between groups and significantly elevated in group 3 compared to group 1. Positional tests identified shunt overdrainage in 5 of 25 occasions. In patients of group 1, who underwent revision, shunts turned out to be functional. All patients of group 3 eventually underwent shunt revision with improvement of symptoms thereafter.


CONCLUSIONS
Computerized ICP monitoring can benefit the assessment of shunt function, and can accurately characterize the status of CSF compensation in shunted children with a complex presentation.
Schuhmann
Martin U
MU
Department of Pediatric Neurosurgery, Children's Hospital of Michigan, Wayne State University School of Medicine, Detroit, Mich., USA. martin.schuhmann@med.uni-tuebingen.de
Sood
Sandeep
S
McAllister
James P
JP
Jaeger
Matthias
M
Ham
Steven D
SD
Czosnyka
Zofia
Z
Czosnyka
Marek
M
D000293:Adolescent; D000328:Adult; D002557:Cerebrospinal Fluid Shunts; D002648:Child; D002675:Child, Preschool; D004868:Equipment Failure; D006801:Humans; D006849:Hydrocephalus / Q000503:physiopathology*; D007427:Intracranial Pressure; D008991:Monitoring, Physiologic; D011187:Posture