BackgroundThe variations of the circle of Willis (CW) are clinically important as patients with effective collateral circulations have a lower risk of transient ischemic attack and stroke than those with ineffective collaterals. The aim of the present cadaveric study was to investigate the anatomical variations of the CW and to compare the frequency of prevalence of the different variations with previous autopsy studies as variations in the anatomy of the CW as a whole have not been studied in the Indian subcontinent.MethodsThe external diameter of all the arteries forming the CW in 225 normal Sri Lankan adult cadaver brains was measured using a calibrated grid to determine the prevalence in the variation in CW. Chisquared tests and a correspondence analysis were performed to compare the relative frequencies of prevalence of anatomical variations in the CW across 6 studies of diverse ethnic populations.ResultsWe report 15 types of variations of CW out of 22 types previously described and one additional type: hypoplastic precommunicating part of the anterior cerebral arteries (A1) and contralateral posterior communicating arteries (PcoA) 5(2%). Statistically significant differences (p < 0.0001) were found between most of the studies except for the Moroccan study. An especially notable difference was observed in the following 4 configurations: 1) hypoplastic precommunicating part of the posterior cerebral arteries (P1), and contralateral A1, 2) hypoplastic PcoA and contralateral P1, 3) hypoplastic PcoA, anterior communicating artery (AcoA) and contralateral P1, 4) bilateral hypoplastic P1s and AcoA in a Caucasian dominant study by Fisher versus the rest of the studies.ConclusionThe present study reveals that there are significant variations in the CW among intra and inter ethnic groups (Caucasian, African and Asian: Iran and Sri Lanka dominant populations), and warrants further studies keeping the methods of measurements, data assessment, and the definitions of hypoplasia the same.

Objective:To determine the extent of hypoplasia of the component vessels of the circle of Willis (CW) and the anatomical variations in the anterior communicating artery (AcomA) in the subjects who have died of causes unrelated to the brain and compare with previous autopsy studies.Materials and Methods:The external diameter of all the arteries forming the CW in 225 normal Sri Lankan adult cadaver brains was measured using a calibrated grid to determine the occurrence of “typical” CWs, where all of the component vessels had a diameter of more than 1 mm. Variations in the AcomA were classified into 12 types based on Ozaki et al., 1977.Results:193 (86%) showed “hypoplasia”, of which 127 (56.4%) were with multiple anomalies. Posterior communicating artery (PcoA) was hypoplastic bilaterally in 93 (51%) and unilaterally in 49 (13%). Precommunicating segment of the posterior cerebral arteries (P1) was hypoplastic bilaterally in 3 (2%), unilaterally in 14 (4%), and AcomA was hypoplastic in 91 (25%). The precommunicating segment of the anterior cerebral arteries (A1) was hypoplastic unilaterally in 17 (5%). Types of variations in the AcomA were: single 145 (65%), fusion 52 (23%), double 22 (10%) [V shape, Y shape, H shape, N shape], triplication 1 (0.44%), presence of median anterior cerebral artery 5 (2%), and aneurysm 1 (0.44%).Conclusion:The occurrence of “typical” CW in autopsy brains was rare. Further studies would be necessary to determine if these anatomical variations could predispose to cerebral ischemia and premature stroke in the Sri Lankan population.

This study reveals that the internal carotid artery (ICA) provided the major supply to the PCA in 4.4% of foetal and 2.2% of transitional configurations. The adult configuration was present in 220 (93.3%), the highest recorded in the literature. This finding may be of relevance to vertebrobasilar ischaemia and infarcts in the territory of the PCA.

Background Diagnostic delay (DD) in Ankylosing Spondylitis (AS) remains a challenge, averaging 8.6 years1. Chronic back pain comprises 2.6million GP consultations per year, of which 5% have AS2. Identifying this “needle in a haystack” is compounded by poor appreciation of inflammatory back pain and lack of appropriate use of MRI early in diagnosis. The advent of biologic therapy with potential to induce remission makes early diagnosis increasingly important. There is paucity of data on the impact of DD on disease burden in AS. Published data suggests DD correlates to high disease activity, functional impairment, poor metrology and work disability (WD)3,4. DD and WD correlate to reduced survival in AS5. Objectives Primarily to assess the impact of DD on Bath AS Metrology Index (BASMI) and current work status (cWS) Secondarily to assess the impact of DD on Bath AS disease activity Index (BASDAI), Bath AS Functional Index (BASFI) and current Tumour Necrosis Factor inhibitor use (cTNFU) Methods This was a retrospective cohort study of AS patients meeting modified New York criteria. Time from symptom onset to diagnosis (DD) was correlated to BASMI, BASDAI and BASFI within a year of diagnosis, cWS in those under 60 years and cTNFU. The confounding effects of age, HLA B27 status, family history of AS and smoking were accounted for by statistical modelling Results Data on 106 patients was analysed. 79% were male. Mean age at symptoms onset was 24.5years (±SD 9.8) and at diagnosis was 35.5 (±14.0). Mean DD was 10.5 (±11.9). Gender made no significant difference to DD (p=0.4) BASMI score increased by 0.06 for each year of DD (p=0.0002) and age at diagnosis (p=0.015) when measured independently. However when DD was corrected for age the BASMI rise was not significant, indicating that age remained a significant predictor (p=0.039) 33% of patients were Work disabled (WD). Gender had no significant impact on cWS (p=0.1). The Work enabled (WE) had significantly shorter DD than the WD (median 7.8 vs.16.6 years, p=0.005). The risk of being WD increased by 6.6% for each year of DD (OR=1.067, CI=1.03–1.1; p=0.0009) Age at diagnosis was a significant predictor of cWS (p=0.008). The risk of being WD increased to peak at 38.5 years and declined thereafter. HLA B27 positive patients had 6 fold higher odds of being WE (OR=6.2, CI=1.6–24.8) DD did not have a significant effect on BASDAI (p=0.8), BASFI (p=0.6) or cTFNU (p=0.9) Conclusions DD caused significantly worse mobility and WD. Both outcomes were highly dependent on age at diagnosis. The peak risk of WD was in the age group that contributes the most to family and national economy. Unlike the published data, we did not find a significant impact of DD on BASDAI, BASFI or cTNFU. Our findings underpin the importance of minimising DD in AS. References Hamilton L et al. Services for people with Ankylosing Spondylitis in the UK-a survey of Rheumatologists and patients. Rheum 2011;50:1991-8 Underwood MR et al. Inflammatory Back pain in primary care. Br J Rheum 1995;34(11):1074...

Objective:The purpose of this study was to examine the degree of contribution from the vertebrobasilar and carotid systems to the origin of the PCA in fetal autopsy brains of last trimester of pregnancy and to compare with published data on the configuration of adult and fetal brains in a population of Sri Lankan origin.Materials and Methods:The external diameter of the PcomA, pre-communicating part (P1), and the post-communicating part (P2) of posterior cerebral artery (PCA) of 34 fetal brain in the last trimester of pregnancy (30 to 40 weeks of gestation) was measured using a stereomicroscope equipped with a micrometer calibrator.Results:The blood supply to the occipital lobe mainly via the PCA was seen in 25 (59%) of fetal brains as compared to that in the literature 220 (93%) in adults brains and the blood supply to the occipital lobe mainly via the internal carotid artery (ICA) was seen in 16 (34%) of fetal brains as compared to 25 (7%) of adults brains (P < 0.0001), transitional configuration where the PcomA is equal in diameter to P1 segment of the PCA was seen in 5 (7.4%) of fetal brains and 8 (2%) of adults brains.Conclusions:The present study reveals that from the newborn to the adult there is shift from carotid system to the vertebrobasilar system, this justifies further studies on different racial and geographic regions which may give a clearer picture about the cerebral hemodynamics from childhood to adult.