Vascular Dementia and Multiple Lacunar Infarcts
Yes, vascular dementia can be characterized by multiple lacunar infarcts, which represent one of the classic imaging findings and pathological patterns of this disease. 1
Imaging Findings in Vascular Dementia
Multiple lacunar infarcts are explicitly recognized as a hallmark feature of vascular dementia on neuroimaging:
Classic MRI findings in vascular dementia include encephalomalacia from multiple cortical and subcortical infarcts, small but strategically placed lacunar infarcts, microhemorrhages, and white matter disease. 1
MRI with T2 FLAIR imaging can distinguish lacunar infarcts from perivascular spaces, both of which are associated with vascular risk factors and small vessel disease. 1
The presence of multiple lacunar infarcts, particularly when combined with white matter signal changes in the corpus callosum, anterior temporal lobes, and external capsule, may indicate specific diagnoses like CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy). 1
Clinical Subtypes and Pathological Patterns
The Canadian Stroke Best Practice Recommendations recognize that vascular cognitive impairment encompasses multiple presentations, including small-vessel disease with white matter lesions and lacunar infarcts as a predominant etiology. 1
Four clinical patterns of vascular cognitive impairment are now recognized:
- Subcortical ischemic vascular dementia (which includes multiple lacunar infarctions as a defining feature) 1, 2, 3
- Post-stroke dementia 1
- Multi-infarct dementia 1
- Mixed dementia 1
Pathological Definition
From a neuropathological standpoint, lacunar infarcts are defined as cystic lesions smaller than 1 cm in size located in the basal ganglia, brain stem, or deep white matter (but not the cerebral cortex). 1
Subcortical vascular dementia specifically results from lacunar infarcts or multiple microinfarcts in the basal ganglia, thalamus, brainstem, and white matter, and is associated with more than 50% of vascular dementia cases. 3
Underlying Mechanisms
Multiple lacunar infarcts in vascular dementia typically result from:
- Hypertensive small vessel changes causing arteriolosclerosis and lipohyalinosis 2, 4
- Small vessel disease affecting subcortical brain regions 1, 3
- Less commonly, cholesterol emboli can cause lacunar infarctions, though this is rare 5
Clinical Significance
The presence of multiple lacunar infarcts disrupts neuronal networks involved in cognition, memory, and behavior (thalamo-cortical, striato-subfrontal, cortico-subcortical, and limbic systems), leading to the characteristic cognitive profile of subcortical vascular dementia. 6
The main clinical features include decreased motor performance, early impairment of attention and executive function with slowing of information processing. 3
Important Caveat
Mixed pathology is extremely common, with vascular disease frequently coexisting with Alzheimer's disease pathology in up to 38% of cases. 1, 7 Therefore, the presence of multiple lacunar infarcts does not exclude concurrent neurodegenerative processes, and comprehensive evaluation is essential. 1