Cognitive Impairment in Lacunar Strokes

Abstract

Vascular cognitive impairment is closely related to stroke. Each condition is a risk factor for the other. Cognitive impairment is a symptom that makes it difficult for a stroke patient to live at home. In this review paper, different types of vascular cognitive impairment are discussed, with emphasis on cognitive impairment related to lacunar strokes (LACS). Symptoms, diagnostics, epidemiology, treatment, and prognosis are surveyed. LACS are often associated with leukoaraiosis, which is related to subcortical ischemic vascular dementia. Even if LACS often are mild, they may therefore be associated with cognitive impairment on longer term. KeywordsStroke, vascular cognitive impairment, leukoaraiosis, small vessel disease Disclosure: The author has no conflicts of interest to declare. DefinitionsAccording to ICD-10, a diagnosis of dementia requires: (1) impairment in short-and long-term memory; (2) impairment in abstract thinking, judgement, higher cortical function, or personality change; (3) memory impairment and intellectual impairment, which cause significant social and occupational impairments; and (4) the occurrence of these traits when patients are not in a state of delirium.Cognitive impairment is a continuum, affecting different cognitive domains at different rates, from different causes. 4 The definition of dementia requires memory impairment plus involvement of at least one other cognitive domain. This definition is less appropriate for vascular cognitive impairment (VCI), because in VCI memory is often less affected than executive functions. In this paper, the terms cognitive impairment and VCI are used whenever possible.Delirium, or confusional state, is a more or less acute disorder of attention and global cognition (memory and perception), which is reversible. 5 Delirium is almost always caused by a provoking event, such as an infection, a metabolic condition, or a psychotropic drug.People with pre-existing cognitive impairment are at higher risk for developing delirium.LACS result from occlusion of the penetrating arteries that provide blood to the brain's deep structures. A corresponding infarction is often small, within 10 mm and affects the deep nuclei of the brain or different neural pathways to and from the cortex. 6,7 Compared to larger infarctions that involve the cortex, patients with LACS often have a lower grade of stroke severity 1 and a better short-time prognosis. 8 Therefore, LACS have been considered as relatively benign. 7On the other hand, LACS are often seen together with leukoaraiosis or cerebral white matter changes. 9,10 These are radiologic findings with bilateral patchy or diffuse areas of hyperintensities of the cerebral white matter on T2-weighted MRI. Leukoaraiosis is probably caused by chronic ischemia in the white matter, leading to loss of myelin and axons, and ultimately to gliosis and atrophy. 11 Leukoaraiosis is related to cognitive impairment. 12,13 Classification of Cognitive ImpairmentNot so many years ago, a rather strict distinction was made between th...