Association of Incidentally Discovered Covert Cerebrovascular Disease Identified Using Natural Language Processing and Future Dementia

Abstract

Background Covert cerebrovascular disease (CCD) has been shown to be associated with dementia in population‐based studies with magnetic resonance imaging (MRI) screening, but dementia risk associated with incidentally discovered CCD is not known. Methods and Results Individuals aged ≥50 years enrolled in the Kaiser Permanente Southern California health system receiving head computed tomography (CT) or MRI for nonstroke indications from 2009 to 2019, without prior ischemic stroke/transient ischemic attack, dementia/Alzheimer disease, or visit reason/scan indication suggestive of cognitive decline or stroke were included. Natural language processing identified incidentally discovered covert brain infarction (id‐CBI) and white matter disease (id‐WMD) on the neuroimage report; white matter disease was characterized as mild, moderate, severe, or undetermined. We estimated risk of dementia associated with id‐CBI and id‐WMD. Among 241 050 qualified individuals, natural language processing identified 69 931 (29.0%) with id‐WMD and 11 328 (4.7%) with id‐CBI. Dementia incidence rates (per 1000 person‐years) were 23.5 (95% CI, 22.9–24.0) for patients with id‐WMD, 29.4 (95% CI, 27.9–31.0) with id‐CBI, and 6.0 (95% CI, 5.8–6.2) without id‐CCD. The association of id‐WMD with future dementia was stronger in younger (aged <70 years) versus older (aged ≥70 years) patients and for CT‐ versus MRI‐discovered lesions. For patients with versus without id‐WMD on CT, the adjusted HR was 2.87 (95% CI, 2.58–3.19) for older and 1.87 (95% CI, 1.79–1.95) for younger patients. For patients with versus without id‐WMD on MRI, the adjusted HR for dementia risk was 2.28 (95% CI, 1.99–2.62) for older and 1.48 (95% CI, 1.32–1.66) for younger patients. The adjusted HR for id‐CBI was 2.02 (95% CI, 1.70–2.41) for older and 1.22 (95% CI, 1.15–1.30) for younger patients for either modality. Dementia risk was strongly correlated with id‐WMD severity; adjusted HRs compared with patients who were negative for id‐WMD by MRI ranged from 1.41 (95% CI, 1.25–1.60) for those with mild disease on MRI to 4.11 (95% CI, 3.58–4.72) for those with severe disease on CT. Conclusions Incidentally discovered CCD is common and associated with a high risk of dementia, representing an opportunity for prevention. The association is strengthened when discovered at younger age, by increasing id‐WMD severity, and when id‐WMD is detected by CT scan rather than MRI.

Is Incidentally Discovered Covert Cerebrovascular Disease Ignorable?

“…WMD was also associated with an approximately 2-fold higher risk of incident dementia in community-dwelling adult research cohorts . In parallel, in clinically acquired imaging identified through natural language processing, the annualized dementia incidence rates were 2% to 3% for patients with any form of CCD compared with just 0.5% for those without CCD . Fittingly, the adjusted HRs of dementia progression were approximately 2-fold higher for those with vs without CCD.…”

“…1 In parallel, in clinically acquired imaging identified through natural language processing, the annualized dementia incidence rates were 2% to 3% for patients with any form of CCD compared with just 0.5% for those without CCD. 4 Fittingly, the adjusted HRs of dementia progression were approximately 2-fold higher for those with vs without CCD. WMD detection by CT was associated with several-fold higher dementia progression rates compared with WMD detected by MRI, presumably since detection on the less sensitive modality indicates more advanced disease.…”

“…WMD detection by CT was associated with several-fold higher dementia progression rates compared with WMD detected by MRI, presumably since detection on the less sensitive modality indicates more advanced disease. 4 How Experts Believe CCD Should Be Addressed vs How They Are Addressed…”

“…Fittingly, the adjusted HRs of dementia progression were approximately 2-fold higher for those with vs without CCD. WMD detection by CT was associated with several-fold higher dementia progression rates compared with WMD detected by MRI, presumably since detection on the less sensitive modality indicates more advanced disease …”

Mortality Outcomes in a Large Population with and without Covert Cerebrovascular Disease

“…Covert cerebrovascular disease (CCD) is commonly discovered incidentally on routine clinical neuroimaging and is associated with a substantial increase in the risk of future stroke and dementia [1,2]. Covert cerebrovascular disease (CCD) refers to incidentally-detected small or large vessel cerebrovascular disease that is not associated with a history of stroke or cognitive impairment, e.g.…”