The number of circulating monocytes increases after stroke. In this study, we assessed the time course and phenotype of monocyte subsets and their relationship with the clinical course and outcome in 46 consecutive stroke patients and 13 age-matched controls. The proportion of the most abundant ‘classical’ CD14^highCD16 monocytes did not change after stroke, whereas that of CD14^highCD16+ monocytes increased and CD14^dimCD16+ monocytes decreased. CD14^highCD16 + monocytes had the highest expression of TLR2, HLA-DR and the angiogenic marker, Tie-2; CD14^dimCD16+ monocytes had the highest expression of costimulatory CD86 and adhesion molecule CD49d. Platelet-monocyte interactions were highest in CD14^highCD16 monocytes and lowest in CD14^dimCD16+ monocytes. In adjusted models, 1/CD14^highCD16 monocytes were associated with poor outcome (OR: 1.38), higher mortality (OR: 1.40) and early clinical worsening (OR: 1.29); 2/CD14^highCD16+ monocytes were inversely related to mortality (OR: 0.32); and 3/CD14^dimCD16+ monocytes were inversely related to poor outcome (OR: 0.74) and infarction size ( r= 0.45; P = 0.02). These results illustrate that the predominant monocyte subtype conveys harmful effects after stroke, which include stronger interaction with platelets. Alternatively, rarer subpopulations of monocytes are beneficial with a phenotype that could promote tissue repair and angiogenesis. Therefore, monitoring of monocyte subtypes may emerge as a useful tool at the bedside for stroke patients.

This article describes the imaging appearances of white matter diseases and the pathologic substrate responsible for the various imaging features. White matter diseases include a wide spectrum of disorders that have in common impairment of normal myelination, either by secondary destruction of previously myelinated structures (demyelinating processes) or by primary abnormalities of myelin formation (dysmyelinating processes). The pathogenesis of many white matter diseases remains poorly understood. Demyelinating disorders are the object of this review and will be further divided into autoimmune, infectious, vascular, and toxic-metabolic processes. Autoimmune processes include multiple sclerosis and related diseases: tumefactive demyelinating lesions, Balo concentric sclerosis, Marburg and Schilder variants, neuromyelitis optica (Devic disease), acute disseminated encephalomyelitis, and acute hemorrhagic leukoencephalopathy (Hurst disease). Infectious processes include Lyme disease (neuroborreliosis), progressive multifocal leukoencephalopathy, and human immunodeficiency virus (HIV) encephalopathy. Vascular processes include different types of small-...