Correlation of palpation anterior fontanometry and cerebrospinal fluid opening pressure in early childhood hydrocephalus.

Background: The anterior fontanelle (AF) tension has been a traditional clinical method of indirect assessment of intracranial pressure (ICP). How does this time-tested bedside assessment technique compare with an objective ventricular cerebrospinal fluid (CSF) opening pressure?

Objective: To determine the correlation of palpation anterior fontanometry and CSF opening pressure in early childhood hydrocephalus.

Materials And Methods: Children diagnosed with hydrocephalus who were planned for CSF diversion using ventriculo-peritoneal (V-P) shunt were prospectively studied over 18 months. The AF tension was assessed by palpation preoperatively and graded. The CSF opening pressure was measured using sterile disposable plastic manometers after ventricular cannulation intraoperatively.

Statistical Analysis: Data obtained were analysed using SPSS version 21. Student's t-test, Mann-Whitney U test and ANOVA were used to determine associations based on normality tests. A P < 0.05 was considered significant for associations.

Results: Fifty-two children were operated on with AF patency rate of 88.5%. Their age ranged between 2 weeks and 18 months with a mean age of 7.1 ± 5.1 months. The fontanelle tension was tense, full and normal in 63.0%, 26.1% and 10.9% of patients, respectively. The mean CSF opening pressure of 20.5 ± 8.5 cm of HO was higher than the expected ICP for the age group (t-test 4.754, P = 0.000). All 28 patients with CSF opening pressure >15 cm of HO had a tense fontanelle, but 10.9% of children with raised ICP have normal AF tension.

Conclusion: The mean ICP increases as palpation AF tension increases, but a normal AF tension does not rule out raised ICP.