This paper investigates age-related differences in ICP across day- and nighttime. Changing normal values with age may have implications for shunt valve selection and design.
BackgroundNo true reference values for intracranial pressure (ICP) in humans exist; current values are estimated from measurements in adults who undergo treatment in order to correct ICP. We report ICP values in a “pseudonormal” group of children and adults to examine if age affects ICP.
MethodsWe analyzed data from all nonshunted patients undergoing a 24-hour ICP monitoring as part of a diagnostic work-up and included patients with no subsequent suspicion of increased ICP and no need for pressure-relieving treatment with a minimum follow-up period of 3 years.
ResultsFrom February 2008 to November 2014, a 24-hour ICP monitoring was performed in 221 patients. Of these patients, 35 (14 children, 21 adults) met the inclusion criteria. Follow-up time to confirm absence of ICP-related disease was 3-9 years. Daytime ICP was 2.8 mmHg ± 2.2 in children and 1.9 mmHg ± 4.2 in adults (P = 0.39). Of 35 patients, 32 had higher nighttime ICP. The difference between daytime and nighttime ICP was similar in children (ΔICP = 5.8 mmHg ± 4.0, P < 0.0001) and adults (ΔICP = 6.1 mm Hg ± 3.3, P < 0.0001). ICP could be described as a decreasing function of age, with an ICP decrement of 0.69 mmHg per decade (P = 0.015).
ConclusionsWe found similar differences in daytime and nighttime ICP between children and adults with no ICP-related disease. ICP seems to decrease with age across all ages. This has implications for therapeutic interventions (e.g., shunt valve selection or resistance in external ventricular drainage).
Read the full paper in World Neurosurg (click here).