Tracking down the White Plague. Chapter two: The role of endocranial abnormal blood vessel impressions and periosteal appositions in the paleopathological diagnosis of tuberculous meningitis.
Although endocranial abnormal blood vessel impressions (ABVIs) and periosteal appositions (PAs) have been considered as paleopathological diagnostic criteria for tuberculous meningitis (TBM) based on findings of previous studies, they are not pathognomonic for tuberculosis (TB). Therefore, their utilization in the paleopathological practice can be questioned, especially in consideration that most of the previous studies were not performed on identified skeletal collections but on osteoarchaeological material and did not include statistical data analysis. To fill the aforementioned research gap, for the first time, a macroscopic investigation was conducted on identified pre-antibiotic era skeletons from the Terry Collection. A sample set of 234 individuals who died of TB (TB group) and 193 individuals who died of non-tuberculous causes (NTB group) were examined. The frequency of ABVIs and PAs, as well as other probable TB-related lesions was recorded. To determine the significance of difference (if any) in the frequencies of ABVIs and PAs between the two groups, χ2 testing of our data was performed. We found that ABVIs, PAs, and their co-occurrence with each other and with other probable TB-related lesions were more common in the TB group than in the NTB group. In addition, the χ2 comparative frequencies of ABVIs and PAs revealed a statistically significant difference between individuals who died of TB and individuals who died of NTB causes. Our findings strengthen those of previous studies that ABVIs and PAs are not specific to TBM but can be of tuberculous origin. Therefore, they do have a diagnostic value in the identification of TB in human osteoarchaeological material, especially when they simultaneously occur with other probable TB-related lesions. Their prudent utilization provides paleopathologists with a stronger basis for diagnosing TB and consequently, a more sensitive means of assessing TB frequency in past human populations.