From the Guidelines
Periventricular white matter lesions are indicative of multiple sclerosis, particularly when they are ovoid in shape, perpendicular to the lateral ventricles, and located in the corpus callosum, as described in the study published in the journal Brain in 2019 1. These lesions appear as T2-hyperintense cerebral white matter lesions in direct contact with the lateral ventricles, without intervening white matter. The study highlights that periventricular multiple sclerosis lesions are typically distributed along the deep medullary veins, thus having their main axis perpendicular to the lateral ventricles, and are generally defined as ‘Dawson’s fingers’. Some key characteristics of periventricular white matter lesions include:
- Ovoid shape on the axial plane
- Location in the corpus callosum
- Perpendicular orientation to the lateral ventricles
- Presence of ‘Dawson’s fingers’ It is essential to distinguish periventricular lesions from other conditions, such as migraine, ischaemic small-vessel disease, neuromyelitis optica spectrum disorders, and anti-MOG-IgG disease, which can also present with white matter lesions. The study emphasizes the importance of using T2-FLAIR sequences to detect periventricular lesions and to distinguish them from enlarged perivascular spaces 1. Red flags for periventricular lesions include the presence of lacunar infarcts or microbleeds, suggestive of ischaemic small-vessel disease, or confluent and symmetric white matter abnormalities, indicative of genetic or metabolic leukodystrophies. Periventricular lesions with predominantly temporal pole involvement can suggest cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) or other inherited conditions 1.
From the Research
Periventricular White Matter Lesions
A periventricular white matter (PVM) lesion can indicate several conditions, including:
- Cerebral small vessel disease (CSVD) 2, 3, 4
- Multiple sclerosis (MS) 3
- Periventricular leukomalacia (PVL) in preterm infants 5, 6
- Ischemic injury to the brain 2, 3, 4, 6
- Infection and inflammation 3, 6
Characteristics of PVM Lesions
PVM lesions are often characterized by:
- Low cerebral blood flow (CBF) 2
- Hypoxia and oxygen desaturation 3
- Microvessel stenosis and enlarged perivascular spaces 4
- Fibrinogen deposition and blood-brain barrier dysfunction 4
- Demyelination and axonal injury 3, 5, 6
Risk Factors
Risk factors for developing PVM lesions include: