Annals of African Medicine

ORIGINAL ARTICLE
Year
: 2014  |  Volume : 13  |  Issue : 4  |  Page : 157--160

Benin stroke score in the diagnosis of acute brain infarct: A pilot study in Senegalese Africans


Imarhiagbe Frank Aiwansoba1, Okaka Enajite Ibiene2, Ugiagbe Rose Ashinedu2, Ogunrin Akindele Olubunmi2, Ndiaye Mansour Mohammadu3,  
1 Neurology Unit, Department of Medicine, University of Benin Teaching Hospital, Benin City, Nigerian; West African Health Organisation's 2012 PEPL Research Fellow, CHNU, Dakar, Senegal
2 Neurology Unit, Department of Medicine, University of Benin Teaching Hospital, Benin City, Nigerian
3 Department of Neurology, Centre Hospitalier National Universitaire, Dakar, Senegal

Correspondence Address:
Imarhiagbe Frank Aiwansoba
Neurology Unit, Department of Medicine, University of Benin Teaching Hospital, P.O.BOX 7184, GPO, Benin City, Nigeria

Abstract

Background: The Benin stroke score (BSS) is a validated tool in the diagnosis of intracerebral hemorrhage (ICH) but not in the diagnosis of brain infarct. The aim of this report is to specifically validate the BSS in the clinical diagnosis of acute brain infarct. Materials and Methods: A total of 60 participants with a presumptive diagnosis of acute stroke in a busy tertiary neurologic care centre in Francophone West Africa were evaluated within 48 h of onset of symptoms with the BSS after basic data were obtained, before computed tomography or magnetic resonance imaging scans was used as gold standard. BSS is a three-item tool that scores age, supine diastolic blood pressure, and Glasgow coma scale with a minimum score of 0 and a maximum score of 3.5. A score of 2.5 or less is diagnostic for a brain infarct. Results: The sensitivity, specificity, positive predictive value, negative predictive value, positive and negative likelihood ratios of BSS in the diagnosis of brain infarct were 83.78%, 69.56%, 81.57%, 72.72%, 2.75, and 0.23, respectively. BSS agreed with neuroimaging in the diagnosis of all stroke subtypes significantly on kappa statistics (k = 0.538, P < 0.001) and interrater and intrarater reliability between two cadres of medical personnel in the use of BSS were significant (r = 0.9. 0.95, 0.95, P < 0.001, <0.001, <0.001), respectively. Conclusion: BSS as a simple clinical tool could be used with appreciable levels of accuracy in the clinical diagnosis of acute brain infarct where neuroimaging may not be available or immediately inaccessible, much the same way it is being used for ICH.



How to cite this article:
Aiwansoba IF, Ibiene OE, Ashinedu UR, Olubunmi OA, Mohammadu NM. Benin stroke score in the diagnosis of acute brain infarct: A pilot study in Senegalese Africans.Ann Afr Med 2014;13:157-160


How to cite this URL:
Aiwansoba IF, Ibiene OE, Ashinedu UR, Olubunmi OA, Mohammadu NM. Benin stroke score in the diagnosis of acute brain infarct: A pilot study in Senegalese Africans. Ann Afr Med [serial online] 2014 [cited 2021 Oct 27 ];13:157-160
Available from: https://www.annalsafrmed.org/text.asp?2014/13/4/157/142278


Full Text

 Introduction



The Benin stroke score (BSS) is a three-item diagnostic tool previously validated in the diagnosis of spontaneous intracerebral hemorrhage (ICH) with an appreciable level of accuracy; however, its use in the diagnosis of brain infarct at present rests on the exclusion of spontaneous parenchymal hemorrhage in a presumptive case of acute stroke. [1]

It may be argued that the exclusion of a hemorrhage shores up the chances that a stroke subtype is an infarct except where they coexist or where an infarct transforms into a hemorrhage, but it is pertinent to mention that the usefulness of a diagnostic tool for acute stroke would be better appreciated if it is validated in the diagnosis of both infarct and hemorrhage.

Clinical diagnostic tools for acute stroke perform differently when compared with neuroimaging as the gold standard; however, their usefulness is particularly brought to bear where there is a dearth of neuroimaging modalities like computed tomography (CT) or magnetic resonance imaging (MRI) in the triage of acute stroke patients in the emergency room. [1] Clinimetric tools generally are more user friendly if they have few items and are easy to use. [1],[2]

This study pilot tested the use of the BSS in the diagnosis of acute brain infarct to complement its previous use in the diagnosis of spontaneous ICH.

 Materials and Methods



A total of 60 patients seen in the busy emergency department and outpatient clinics in a tertiary neurologic care hospital in Francophone West Africa in February-March 2012, within 48 h of onset of stroke symptoms had their basic data of age and sex captured by a proforma and all were administered the test instrument-the BSS, translated first into French language and back translated into English language and again to French language to ensure content validity before cranial CT and/or MRI was ordered.

BSS is a previously validated instrument for the diagnosis of spontaneous ICH that scores age of the patient, supine diastolic blood pressure and Glasgow Coma scale on an assigned score of 0, 1, or 1.5. Age above or equal to 80 scores 0, below 80 years scores 1, diastolic blood pressure above or equal to 110 mm Hg scores 1 and 120 mm Hg or above scores 1.5, Glasgow Coma scale score of less than 13 or less than or equal to 9 in aphasic patients scores 1 and above or equal to 13 or above 9 in aphasia scores 0. A total score of less than 2.5 was considered diagnostic for acute brain infarct and results were compared with cranial CT or MRI as gold standard. The use of BSS was compared between a first and a 3 rd year resident doctors in the study center to test for intra- and interrater reliability. Patients who presented after 48 h of onset of stroke symptoms or neuroimaging evidence of hemorrhage coexisting with infarct or diagnosis other than stroke were exclusion criteria. CT was done with a 16 slice machine and MRI was ordered only when CT was inconclusive with a 1.5 Tesla machine at the study center. Study was approved by the institutional review board (ethics committee) of the center.

Statistics

Basic data were expressed as means, standard deviations, and percentages. Sensitivity, specificity, likelihood ratios, positive and negative predictive values of BSS in the diagnosis of brain infarct were determined. Symmetric agreement between BSS and CT or MRI was tested on kappa statistics and intrarater and interrater reliability between two cadres of medical personnel in the use of BSS was tested with Pearson's correlation. SPSS version 17 was used for analysis and P value of less than 0.05 was taken as significant for all tests.

 Results



A total of 60 patients were studied, mean age was 60.58 (16.58) years, range 19-95, comprising 23 (38.4%) females and 37 (61.6%) males. Mean BSS and diastolic blood pressure were 1.86 (0.883) and 98.40 (22.28) mm Hg, respectively. Stroke subtype was made up of 37 (61.7%) infarct and 23 (38.3%) spontaneous ICH [Table 1].{Table 1}

The sensitivity and specificity of BSS for brain infarct were 83.78% and 69.56%, respectively. The positive and negative predictive values of BSS for infarct were 81.57% and 72.72% and the positive and negative likelihood ratios were 2.75 and 0.23, respectively. BSS compared significantly with neuroimaging (cranial CT and MRI) for all stroke subtypes with a kappa value of 0.538 (P < 0.001) [Table 2].{Table 2}

The intrarater and interrater reliability of BSS between two cadres of resident doctors in the diagnosis of brain infarct were 0.9, 0.9, and 0.95 (P < 0.001, 0.001, and 0.001), respectively [Table 3].{Table 3}

 Discussion



The mean age and gender distribution of study participants are similar to findings in related studies and the elevated mean diastolic blood pressure suggests the strong association between hypertension and acute stroke as shown earlier in other sub-Saharan African populations. [3],[4],[5],[6],[7] The mean BSS value of less than 2.5 is consistent with the preponderance of infarct in the distribution of stroke subtypes compared to hemorrhage. [1]

Remarkably, BSS is sensitive and specific in the diagnosis of acute brain infarct, with values comparable to some other diagnostic stroke scores with more items. [8],[9],[10],[11],[12] Its predictive values are also appreciable.

Importantly, BSS compares significantly with neuroimaging for all stroke subtypes. The significant reliability between two cadres of medical personnel in the application of BSS underscores the simplicity of its application. [1] It bears reiteration that the BSS is a three-item tool and that clinimetric tools generally are more appealing when the items are whittled to as few as possible devoid of redundant items. [13]

It is safe to conclude that the BSS as a simple clinimetric tool could as well be used in the diagnosis of brain infarct as it is for ICH with appreciable levels of accuracy. [1] BSS could be easily applied in other populations with similar sociodemographic features and resource constrain as in most parts of sub-Saharan Africa with a huge dearth of the gold standard diagnostic equipment to aid early detection and triage of acute stroke subtypes.

The relatively small sample size may be a limitation in this study as well as the dearth of related citations, but this is extenuated by the fact that the BSS is a new tool being pilot tested in the diagnosis of brain infarct, thereby broadening its scope as a tool in the clinical diagnosis of stroke.

 Acknowledgement



We appreciate the doctors and staff at service de Neurologie, Centre Hospitalier National Universitaire, Fann, Dakar, Senegal.

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