Periventricular leukomalacia - the clinical-imaging challenge. A narrative review

Abstract

Periventricular leukomalacia (PLM) is a term used to describe white matter damage to the brain of premature infants, with both a focal and diffuse component. The aim of the study was to analyze bibliographic data with reference to the causes, risk factors, clinical presentation and imaging criteria for the differential diagnosis of periventricular leukomalacia with other pathologies. The methodology for selecting bibliographic sources included accessing the medical databases PubMed - Medline, Hinari, using the keywords: “periventricular leukomalacia”, “magnetic resonance imaging”, “multiple sclerosis”, “cerebral microangiopathy”, “differential diagnosis”, for the last 25 years. From about 2000 publications, 25 scientific sources in English relevant to the studied subject were selected.Results: The word “leucomalacia” is derived from the greek “leukos” meaning white and “malacia” meaning softening. Periventricular leucomalacia is morphologically defined by 2 histopathological components - a focal necrotic component in the periventricular region of the cerebral white matter and a diffuse component characterized by reactive gliosis in thesurrounding white matter. The “watershed” vascularization of the periventricular region determines increased sensitivity to hypoxic-ischemic events, with the subsequent development of periventricular lesions with ventricular wall deformation that can be diagnosed by transcranial ultrasonography in newborns or by magnetic resonance imaging (MRI) in patients of different ages. Periventricular lesions in T2w hypersignal are not characteristic only for periventricular leukomalacia, they are also evidenced in pathologies such as multiple sclerosis, cerebral microangiopathy, but can exist as a variant of the norm in the terminal myelination areas of the white matter. The challenges of the differential diagnosis of periventricular leukomalacia arise especially in cases when patients did not present clinical manifestations characteristic of the pathology in childhood, but being examined by cerebral MRI in adulthood for other reasons, imaging changes apparently similar to those in multiple sclerosis, cerebral lacunar infarcts, etc. are highlighted. When discrepancies appear between clinical and imaging manifestations, they should be treated with caution and require additional investigations.Conclusions: Knowledge of the typical radiological manifestations of PLM with changes in the periventricular region, associated with ventricular wall traction and local atrophy of the affected white matter, will allow avoiding the wrong diagnosis of this pathology. For a more accurate interpretation of the characteristic PLM lesions in the differential diagnosis with periventricular changes of other genesis, it is important to collaborate between the clinician and the imaging physician in order to provide data from the patient’s disease history, including data related to the antenatal and early postnatal period, for a correct therapeutic decision for the benefit of the patient.