Intracranial arteriopathy in young patients with ischaemic stroke

Abstract

In young patients with stroke, there is a considerable delay to the correct diagnosis and awareness among both the general population and health care professionals is low. Improved knowledge about the mode of presentation, stroke mimics, causes and risk factors for stroke in the young, may lead to earlier diagnosis and treatment. With the studies described in this thesis, we tried to further elucidate the clinical course, outcome, radiological evolution, and haemodynamic consequences of intracranial arteriopathies in young patients with arterial ischaemic stroke (AIS). Patients included in the studies were aged between 1 month and 18 years (children) and between 18 and 50 years (young adults). Of 372 children with AIS, 34% had a unilateral intracranial arteriopathy in the anterior circulation. We investigated the course of this arteriopathy subtype in 79 previously healthy children who underwent repeated vascular imaging. Only five children (6%) were shown to have progressive arteriopathy. In 94%, the course of arteriopathy was non-progressive and these children fulfilled the diagnostic criteria of transient cerebral arteriopathy (TCA). When we repeated vascular imaging in 14 young adults with AIS and a unilateral intracranial arteriopathy, none showed progression of arteriopathy after a median follow-up duration of 8.8 years. We found that TCA also exists in young adults. During follow-up, 18% of children with TCA had recurrent ischaemic symptoms and 41% had a good neurological outcome. Children with a progressive arteriopathy had significantly more recurrences than those with TCA (p=0.007) and none had a good outcome. Fourteen percent of the young adults had recurrent ischaemic symptoms and functional outcome was good in 71% of patients. However, outcome between both age groups cannot be compared readily, since different outcome measures have been used in the paediatric and adults series. We found that cortical infarct localization in children with AIS and a unilateral intracranial arteriopathy was significantly associated with poor neurological outcome (OR 6.14, 95% CI 1.29–29.22, P=0.02). Unfortunately, there is limited knowledge on other predictors of outcome in children and young adults with AIS. Little is known about the effect of an intracranial arteriopathy on cerebral blood flow (CBF) in young patients with AIS. When we investigated CBF with Arterial Spin Labelling perfusion MRI, we found that CBF can be compromised in non-infarcted cortical areas of the symptomatic hemisphere. However, we found a discrepancy between the quantified CBF and the visual assessment of CBF, probably due to vascular artefacts. If follow-up vascular imaging in children with AIS demonstrates a non-progressive arteriopathy, clinical outcome is better and stroke recurrence rates are lower than in patients with progressive intracranial arteriopathy. TCA also exists in young adults. Perfusion deficits in brain tissue that is not primarily affected by ischaemic stroke can be measures with ASL perfusion MRI and might in the future help to identify young stroke patients who are at risk of poor outcome or stroke recurrence.