From the Guidelines
Dilated periventricular spaces in the brain are typically caused by enlarged perivascular spaces, which can be a normal finding, especially with aging.
Causes of Dilated Periventricular Spaces
- Enlarged perivascular spaces: These are a common cause of dilated periventricular spaces and can be a normal finding, especially with aging 1.
- Multiple sclerosis: Periventricular lesions are a hallmark of multiple sclerosis, and these lesions can cause the periventricular spaces to appear dilated on imaging 1.
- Ischaemic small-vessel disease: This condition can cause lesions in the deep white matter, including the periventricular region, leading to dilated periventricular spaces 1.
- Migraine: White matter lesions, including those in the periventricular region, can be seen in patients with migraine, although these are typically not as extensive as those seen in multiple sclerosis 1.
- Other conditions: Such as neuromyelitis optica spectrum disorders, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and Susac syndrome, can also cause dilated periventricular spaces, although the appearance and distribution of lesions may differ from those seen in multiple sclerosis 1.
Important Considerations
- Lesion morphology: The shape, size, and orientation of lesions can help distinguish between different conditions, with ovoid or round lesions perpendicular to the ventricles being more suggestive of multiple sclerosis 1.
- Lesion distribution: The distribution of lesions, including the presence of periventricular, juxtacortical, and infratentorial lesions, can also help distinguish between different conditions 1.
- Imaging sequences: The use of specific imaging sequences, such as T2-FLAIR, can help detect and characterize periventricular lesions 1.
From the Research
Causes of Dilated Periventricular Space
The causes of a dilated periventricular space in the brain can be attributed to several factors, including:
- Cerebral small vessel disease, as evidenced by studies that show an association between enlarged perivascular spaces and lacunar stroke subtype, white matter hyperintensities, and vascular risk factors 2, 3
- Arteriolosclerosis, which is characterized by an increased ratio between wall thickness and external diameter of arterioles, leading to demyelination and axonal loss 4
- Age, as the prevalence of enlarged perivascular spaces increases with age 3
- Cognitive impairment, as seen in a case report where a patient with widespread enlarged perivascular spaces presented with progressive memory impairment and other cognitive deficits 5
- Location and size of the dilated perivascular space, as symptoms can vary depending on the location and size of the space, with larger spaces causing more severe neurological deficits 6
Associated Factors
Other factors that may be associated with dilated periventricular spaces include:
- White matter lesions, which are often seen in conjunction with enlarged perivascular spaces 2, 3
- Cerebral atrophy, which has been linked to basal ganglia-enlarged perivascular spaces 3
- Previous stroke, which has been associated with total enlarged perivascular spaces 3
- Vascular risk factors, such as hypertension and diabetes, which may contribute to the development of cerebral small vessel disease and enlarged perivascular spaces 2, 3