Comparative Stereological Analysis of Intracranial Volume fractions among Patients with Brain Atrophy and Normal Pressure Hydrocephalus from a Nigerian Population

Background: Differentiation between symptoms of normal pressure hydrocephalus (NPH) and other neurodegenerative disorders such as Brain Atrophy (BA) are usually confusing. Available diagnostic methods are invasive while the few non-invasive methods did not take care of potential factors known to influence intracranial volumes. We, therefore, aim to determine and compare the intracranial volume fractions among patients with NPH and BA. Methods: This was a prospective, cross-sectional age-matched control study among consenting patients that were diagnosed with NPH, BA and healthy control in Aminu Kano Teaching Hospital from March 2018 to November 2020. Each patient was routinely examined with CT-Scan; However, control participants were from other reasons. Participants with a medical history known to influence the intracranial volume were excluded. Volume estimation was based on a stereological Cavalieri method and three volume fractions were determined mathematically for each of the group. Test-point computing was facilitated through a locally developed software (voXas_2018). Ethical approval was sort prior to the study. Results: Patients with NPH have higher total CSF: brain ratio, intraventricular volume: brain ratio and extra-ventricular: brain ratio. Similar pattern was exhibited according to age grouping, except in the older age category where BA volume fractions were higher. Conclusion: Age, gender and statue are known to influence intracranial volumes. We controlled their potential effects through age-matched control of participants between groups and the use of intracranial volume ratios for objective diagnosis of NPH and BA. However, Tcsf:Br and InV:Br volume fraction ratios were found to be reliable indices for distinguishing patients with NPH and BA.