Detection of Ruptured and Unruptured Brain Arteriovenous Malformations Has Decreased: A Population-Based Study

Area of Science:

• Neuroscience
• Epidemiology
• Vascular Neurology

Background:

• Increasing use of noninvasive imaging leads to more incidental intracranial findings, including unruptured brain arteriovenous malformations (AVMs).
• Conflicting literature exists on trends in ruptured AVM incidence, prompting investigation into detection rate changes over time.

Purpose of the Study:

• To investigate the hypothesis that the detection rate of unruptured AVMs increased and ruptured AVMs changed over an 18-year period.
• To explore potential links to shifts in vascular risk profiles and preventive health behaviors.

Main Methods:

• Retrospective, population-based study in Southern Finland (1998-2015).
• Identification of individuals with AVMs using national death registers and the Helsinki AVM Register.
• Calculation of age-standardized detection rates for ruptured and unruptured AVMs at 3-year intervals, analyzed via Poisson regression.

Main Results:

• Overall detection rates for both ruptured and unruptured AVMs decreased from 0.91 to 0.40 per 100,000 person-years.
• Significant annual decreases observed: 5.7% in men, 4.8% in 30-59 year olds, 5.9% in patients <30 years, and 2.2% in women.
• Annual detection rate declines were 4.6% for ruptured AVMs and 3.1% for unruptured AVMs.

Conclusions:

• Contrary to the hypothesis, a decline in the overall detection rate of unruptured AVMs was observed.
• A substantial reduction in ruptured AVMs was noted across men, women, and patients younger than 60 years.
• The reasons for these observed rapid changes in AVM detection rates remain unclear and require further investigation.