Autopsy survey of histopathological features and immunohistochemical markers of dementia in medico-legal deaths at Mulago hospital and KCCA mortuaries, Uganda

Abstract

Background: Dementia is a neurodegenerative disorder characterized by an irreversible cognitive decline. Although previously associated with old age, in people aged 65 and above, recent studies have reported early-onset disease occurring in people as young as 40 years. There is limited literature on the prevalence of dementia and its neuropathological findings in Uganda. Objective: To determine the prevalence of histopathological and immunohistochemical features of dementia among persons aged 40 years and above as seen at autopsy at KCCA and Mulago Hospital mortuaries. Methods: This was a cross-sectional study on forensic and medical autopsies at the KCCA and Mulago Hospital mortuaries. The data was collected over nine months. The brain specimens were collected using a consecutive sampling method, and examined macroscopically and microscopically in the Laboratory at the Department of Pathology, Makerere University College of Health Sciences. Standard diagnostic criteria were used to assess the neuropathological substrates of major types of dementia. Data collected were entered into REDCap software and exported to STATA 16 software for statistical analysis. The variables analyzed were age, sex, the weight of the brain, atrophy, neuronal loss, neurofibrillary tangles, plaques, Lewy bodies, and positivity for phosphorylated Tau and α- Synuclein. Results: A total of 106 cases were included in the study, the majority being male at 77.4% (82/106), and between 40 to 44 years of age at 30.2% (32/106). On microscopic examination, 13.2% (14/106) had histopathology features suggestive of dementia, 25.5% (27/106) of these had neuritic plaques, 15.1% (16/106) had neurofibrillary tangles (NFTs) and 10.4% (11/106) had neuronal loss. Also, 6.6% (7/106) and 11.3% (12/106) were positive for Congo red and Beilschowsky's Silver stain respectively, but there were no Lewy bodies. No tissue section was positive for anti-alpha Synuclein while 12.3% (13/106) were positive for antiphosphorylated Tau. Conclusion: Despite the limited diagnosis of dementia in our settings, histopathological and immunological features indicate its occurrence among medical-legal autopsies, as early as 40 years