Objective:

Despite diagnostic and therapeutic advances, national mortality patterns remain
underexplored. This study examines temporal, demographic, and geographic trends in IC/ISAG-
related mortality in the United States from 1999 to 2023.

Background:

Intracranial and intraspinal abscesses and granulomas (IC/ISAG) are rare but severe
infections of the central nervous system.

Design/Methods:

Mortality data were retrieved from the CDC WONDER Multiple Cause of Death database
for individuals with ICD-10 codes G06.0–G06.2. Age-adjusted mortality rates (AAMRs) and crude
rates (CR) per 100,000 population were calculated using the 2000 U.S. standard population. Trends
were analyzed through Joinpoint regression to estimate Annual Percent Change (APC) and Average
Annual Percent Change (AAPC) with 95% confidence intervals (CIs).

Results:

Between 1999 and 2023, 17978 deaths were attributed to IC/ISAG, corresponding to an
overall AAMR of 0.202 per 100,000 population. A significant inflection occurred in 2016 (95% CI:
2013–2018). Mortality rose gradually between 1999–2016 (APC = 0.70, p = 0.03) and rapidly from
2016–2023 (APC = 6.59, p <0.01), resulting in an overall AAPC of 2.38 (p < 0.001).Males had higher
death rate (AAMR=0.28) as compare to female (AAMR=0.14). In ten year age groups, crude rates
increases as per age with highest 85+ year age group(CR=1.11). Black or African American race
(AAMR=0.25) had higher AAMR than whites (AAMR=0.20). Regional variation in AAMRs was
evident (West:0.24,South:0.20,Midwest:0.20,Northeast:0.17).Residents of rural areas showed
slightly greater AAMR(0.19) than those of urban areas(0.18). District of Columbia had the highest
AAMR (0.346) among all the states.

Conclusions:

IC/ISAG mortality in the U.S. has increased notably since 2016, particularly among
elderly and rural populations. Strengthening infection surveillance, improving access to
neuroimaging, and ensuring equitable care are essential to mitigate rising mortality trends.