No abstract

The prevalence of neurological diseases and cranial pathologies in sub-Saharan Africa remains a very little investigated field. This study aims at providing an imaging-based overview of cranial pathologies in two Tanzanian hospitals and at identifying possible differences in the spectrum of diseases between rural and urban African populations. At rural Haydom Lutheran Hospital (Manyara region) the data of 726 patients were included in a retrospective survey. At urban Aga Khan Hospital (Dar es Salaam) the data of 1975 patients who had undergone Computed Tomography (CT) and of 537 Magnetic Resonance Imaging (MRI) patients were obtained. All three surveys showed a clear male preponderance within the populations. The median age of the patients was higher in the city (urban CT 48 years; range 0-95/MRI 39 years; 0.1-89; rural CT 32 years; 0-102). In the urban series stroke, extracranial infections, cerebral atrophy and tumours formed the main groups of diagnoses. Amongst rural patients traumatic pathologies, followed by stroke and cerebral infections/infestations were the most common diagnoses. The most striking differences were noticed with cases compatible with cerebral infections/infestations and hydrocephalus being reported more frequently in the rural population. On the other hand stroke and cerebral atrophy were more frequent amongst urban patients. In the rural catchment area the data of 51 HIV-positive CT patients could be obtained, showing a clear female preponderance. Within the urban HIV-positive subgroup of CT patients (n = 57), the gender distribution was almost equal. Furthermore, in both HIV-positive populations the proportion "compatible with cerebral infections/infestations" was higher than amongst the overall study populations. In conclusion, cranial pathologies seem to differ widely in rural and urban areas of Tanzania in particular with respect to cerebral infections and vascular disease.

The prevalence of spinal pathologies in sub-saharan Africa has received little attention so far. The aim of the survey was to investigate and compare the prevalence pattern of spinal lesions in two different populations of Tanzania, one coming from the urban and semi-urban catchment area of Aga Khan Hospital in Dar es Salaam and the other coming from the rural catchment area of Haydom Lutheran Hospital in Mbulu, northern Tanzania. At the Aga Khan Hospital a total number of 1163 patients were included in the survey. In 50 cases (4.3%) no radiological findings were available and 150 patients (12.9%) showed no pathological abnormality. 90.4% (n = 1051) of screened population were classified in the category of extradural-extramedullary pathologies. Intradural-extramedullary lesions were observed in only three cases (0.3%). Intramedullary pathologies accounted for 2.1% (n = 24). Mean age of the screened population was 46.6 years, male-female ratio 1.08:1. At the Haydom Lutheran Hospital 105 cases were included into the study. Twenty-six patients (24.8%) showed no pathological abnormalities. Extradural-extramedullary pathologies occurred in 72.4% (n = 76) of overall cases. However, intradural-extramedullary pathologies were not seen in Haydom. Intramedullary pathologies were diagnosed in two patients (1.9%). Mean age was with 39.8 years clearly younger compared to urban areas, male-female ratio being 1.21:1, only non-significantly higher than in the Aga Khan Hospital's population. Beside this, one of the main goals of this study was to assess the frequency of infections to the spinal cord and vertebral column in rural and urban Tanzania. Surprisingly there were only few radiological findings at the Aga Khan Hospital, which suggested diagnoses consistent with tropical diseases, a striking difference from rural Haydom Lutheran Hospital, where nearly 30% of all patients showed changes on radiograph consistent with infections/infestations.