Cerebral Artery Hypoplasia in a Select Adult Kenyan Population

Abstract

Background Hypoplasia of cerebral arteries predisposes to stroke and cerebral aneurysms which have an increased incidence in sub-Saharan Africa. The frequency and pattern of cerebral artery hypoplasia, however, shows population variations, and data from the African population remain scanty. Objectives This study aimed to determine the percentage of hypoplasia in the anterior, middle, and posterior cerebral, anterior and posterior communicating, basilar, and vertebral arteries. Materials and Methods Sections of the basilar, vertebral, posterior, and anterior communicating arteries and anterior, middle, and posterior cerebral arteries were taken, processed for histology, and examined with a light microscope at ×40. The images of the vessels were taken by a photomicroscope and circumference analyzed with the aid of Scion image analyzer. The average diameter of 10 sections was taken to be the diameter of the artery in analysis. Hypoplasia was then defined as internal diameter ≤1 mm. Photographs of representative samples of asymmetry were taken, data were analyzed using SPSS, and gender differences were analyzed using the Student's test. Results were presented in tables. Results Two hundred and eighteen formalin-fixed brains of adult Kenyans at the Department of Human Anatomy, University of Nairobi, were studied. Of the 218, 48 brains (22%) did not have vessels with any form of hypoplasia while 170 (78%) did have vessels. Of these, anterior circulation hypoplasia (anterior cerebral artery and posterior communicating artery) was seen in 100 brains (46%) and posterior circulation hypoplasia (middle and posterior cerebral, basilar, and vertebral arteries) in 69 brains (32%). Conclusion Cerebral arterial hypoplasia is frequent in the select adult Kenyan population.

Cerebral Artery Hypoplasia among Black Kenyans

“…The “Charcot artery of cerebral hemorrhage,” which is a branch of the middle cerebral artery, is the most common artery to bleed. Here, in this study from the Kenyan population, Ogengo et al 4 observed that the middle cerebral artery is least commonly affected with the hypoplasia. This suggests that the middle cerebral artery is prone for hemorrhagic stroke than ischemic.…”

“…In this Kenyan African study, 4 the authors observed that the posterior communicating artery, which connects the carotid and vertebral arterial system, is more prone for hypoplasia. This factor may hinder the effective anastomosis between the major arterial inputs of brain.…”

“…2 The cerebral blood flow of different anatomical variations can be of help for the understanding of collateral circulation. 3 In this study by Ogengo et al, 4 the authors made an attempt to observe the cerebral artery hypoplasia in the East African sample population. The “Charcot artery of cerebral hemorrhage,” which is a branch of the middle cerebral artery, is the most common artery to bleed.…”

Asymmetry of P1 and vertebral arteries is not related to basilar tip aneurysm development or rupture

“…[ 15 ] Besides, BTAs also present a unique anatomic configuration and it is well known that the supply and discharge vessels of the basilar artery are often subject to anatomical asymmetries. [ 7 , 14 , 19 , 21 ] Nowadays, it is unclear to what extent this asymmetry of the vertebral arteries (VAs) and the PCAs affects the local flow dynamics or if it is a risk factor for aneurysm rupture or aneurysm growth in BTAs.…”