The tympanic membrane displacement analyser for monitoring intracranial pressure in children

Abstract

Purpose: Raised intracranial pressure (ICP) is a potentially treatable cause of morbidity and mortality but tools for monitoring are invasive. We sought to investigate the utility of the tympanic membrane displacement (TMD) analyser for non-invasive measurement of ICP in children. Methods: We made TMD observations on normal and acutely comatose children presenting to Kilifi District Hospital (KDH) at the rural coast of Kenya and on children on follow-up for idiopathic intracranial hypertension at Evelina Children's Hospital (ECH), in London, UK. Results: We recruited 63 patients (median age 3.3 (inter-quartile range (IQR) 2.0-4.3) years) at KDH and 14 children (median age 10 (IQR 5-11) years) at ECH. We observed significantly higher (more negative) TMD measurements in KDH children presenting with coma compared to normal children seen at the hospital's outpatient department, in both semi-recumbent [mean −61.3 (95 % confidence interval (95 % CI) −93.5 to 29.1) nl versus mean −7.1 (95 % CI −54.0 to 68.3) nl, respectively; P = 0.03] and recumbent postures [mean −61.4 (95 % CI −93.4 to −29.3) nl, n = 59) versus mean −25.9 (95 % CI −71.4 to 123.2) nl, respectively; P = 0.03]. We also observed higher TMD measurements in ECH children with raised ICP measurements, as indicated by lumbar puncture manometry, compared to those with normal ICP, in both semi-recumbent [mean −259.3 (95 % CI −363.8 to −154.8) nl versus mean 26.7 (95 % CI −52.3 to 105.7) nl, respectively; P < 0.01] and recumbent postures [mean −137.5 (95 % CI −260.6 to −14.4) nl versus mean 96.6 (95 % CI 6.5 to 186.6) nl, respectively; P < 0.01]. Conclusion: The TMD analyser has a potential utility in monitoring ICP in a variety of clinical circumstances.