RESUMEN
The development of transcranial colour-coded duplex sonography (TCCS) has resurrected the hope of safe, real time bedside brain imaging beyond childhood. This review article provides an overview of the role of TCCS in the management of patients with stroke. The objective is to stimulate interest in the field of neurosonology as a potential means of improving neurological outcome for stroke patients and a area for stroke research endeavors in Africa. Literature search was done on MEDLINE, Cochrane library, and Google Scholar databases with the following keywords: transcranial colour Doppler, Transcranial duplex sonography, transcranial colour-coded Doppler sonography, stroke, infarct and haemorrhage. We also identified relevant articles from the references section of studies produced by our literature search. We discussed the roles of TCCS to discriminate ischaemic from haemorrhagic forms; unravel the mechanism of stroke; monitor temporal evolution of stroke and predictors of stroke outcome; and promote better understanding of the epidemiology of stroke. Its emerging role as a potent point-of-care imaging modality for definitive treatment in ischaemic stroke within and outside the hospital setting is also highlighted. Comparison of TCCS with alternative modalities for neuroimaging in stroke is also discussed. A root cause analysis of the untenable high cost of neuroimaging for stroke patients in Africa is presented vis-à-vis the potential economic relief which widespread adoption of TCCS may provide. We advocate capacity building for TCCS and suggest some action plans required to achieve safe, cheap, affordable and reliable ultrasound based neuroimaging for stroke patients in resource limited areas of Africa.
RESUMEN
BACKGROUND: Neuroimaging features associated with vascular cognitive impairment have not been examined in sub-Saharan Africans. We determined magnetic resonance imaging (MRI) features associated with cognitive impairment in a sample of Nigerian stroke survivors. METHODS: Stroke survivors underwent brain MRI with standardized assessment of brain volumes and visual rating of medial temporal lobe atrophy (MTA), and white matter hyperintensities (WMH) at 3 months post-stroke. Demographic, clinical and psychometric assessments of global cognitive function, executive function, mental speed and memory were related to changes in structural MRI. RESULTS: In our pilot sample of 58 stroke survivors (60.1 ± 10.7 years old) MTA correlated significantly with age (r = 0.525), WMH (r = 0.461), memory (r = -0.702), executive function (r = -0.369) and general cognitive performance (r = -0.378). On univariate analysis, age >60 years (p = 0.016), low educational attainment (p < 0.001 to p < 0.003), total brain volume (p < 0.024 and p < 0.025) and MTA (p < 0.003 to p < 0.007) but not total WMH (p < 0.073, p = 0.610) were associated with cognitive outcome. In a two-step multivariate regression analysis, MTA (p < 0.035 and p < 0.016) and low educational attainment (p < 0.012 and p < 0.019) were sustained as independent statistical predictors of cognitive outcome. CONCLUSIONS: Medial temporal lobe atrophy was a significant neuroimaging predictor of early post-stroke cognitive dysfunction in the Nigerian African stroke survivors. These observations have implications for a vascular basis of MTA in older stroke survivors among sub-Saharan Africans.