Introduction: Intracranial aneurysms are important causes of mortality.We observed high incidence of intracranial aneurysms among the tribal population of Northern kerala,south india.We did this study to confirm our observation.Tribals constitute 5 percent of population of northern kerala.They maintain a unique way of life not mingling with general population.The incidence of consanguineous marriage and substance abuse are very rampant among them.Studies reveal high incidence of genetic diseases like thalasemia and vasculitis among them.
Methods: Aim of study was to confirm high prevalence of intracranial aneurysm among tribal population of northern kerala,to study the clinical profile of these patients and to compare it with non tribal populations and histological study of cerebral vessel of tribal people.Study period from 2005 to 2012.Hospital data of tribal and non tribal patients,admitted with confirmed aneurismal subarachnoid hemorrhage analyzed.
Data of 100 patients,matched for age and sex,from both groups analyzed.Pathological aspect studied by
histopathological examination of a segment of middle cerebral artery of cadavers.
Results: Annual incidence of aneurismal SAH in non tribal population was 16/100,000,whereas 42/100,000 among tribal.Male to female ratio was 2:3 among non tribals vs 3:2 among tribals. Mean age of aneurismal bleeding was 63 among non tribals vs 42 among tribals.
High incidence of multiple aneurysm among tribals-20% vs 10% among non tribals. Pathological study revealed tunica media of vessel wall 30% less thick and Presence of inflammatory cell infiltrate in tribals.Defects in internal elastic lamina in 20% of tribals and 8%among non tribals.
Conclusions: The incidence of aneurysmal SAH is more common among tribal population of northern Kerala.Clinical profile of these patients is distinct.Young males are more affected.High prevalence of comorbid conditions like vasculitis,genetic predisposition-possibly related to consanguineous marriage,substance abuse etc may be the causative factors.Specific anatomical factors and inflammatory processes may be related to pathogenesis.Genetic study and Periodic screening for aneurysm may be relevant for these population.
Patient Care: It will help understand the distinct clinical features and genetic aspects of intracranial aneurysms among the Tribal population of Northern Kerala. These patients will benefit from periodic screening for intracranial aneurysms considering the increased prevalence among them.Moreover effective preventive strategies may be developed if we understand the exact causative factors.
Learning Objectives: The study revealed increased prevalence of intracranial aneurysms among the tribal population of Kerala,India.Study helped understand the distinct clinical profile of these patients as well as the pathological aspects.Importance of detailed genetic study and periodic screening also emphasized by the study.