Dynamic Spatiotemporal Shifts of Cerebral Microbleeds and Intracerebral Hemorrhage Over 11 Years in a Patient With Mixed Cerebral Small Vessel Disease Phenotype: A Case Report and Literature Review

This report describes a patient with a mixed cerebral small vessel disease (CSVD) phenotype in whom approximately 11 years of longitudinal neuroimaging and clinical follow-up enabled an integrated assessment of (1) the temporal and spatial relationships between cerebral microbleeds (CMBs) and intracerebral hemorrhage (ICH), (2) the dynamic evolution of the mixed CMB distribution, and (3) the association between CMB progression and epileptic seizures. From an early stage, CMBs were present in both lobar and deep regions. Over time, their distribution expanded from lobar to deep and subsequently to infratentorial regions, and the locations of symptomatic ICH shifted in parallel. In both lobar and deep regions, ICH occurred within areas showing new CMB formation, clustering, or morphological changes. Notably, in the left parieto-occipital region, an ICH developed in very close spatial proximity to dynamically changing CMBs, strongly suggesting continuity between microvascular injury reflected by evolving CMBs and subsequent macrohemorrhage. Epileptic seizures were not fully explained by single ICH events or cross-sectional CMB burden alone. Instead, seizures tended to occur during a phase of rapid emergence and increase of lobar CMBs, and no seizure recurrence was observed after the CMB count reached a plateau. These findings raise the possibility that dynamic CMB activity may reflect an active phase of cortical small vessel injury and may be associated with seizure susceptibility. After stabilization of blood pressure and daily routines following institutionalization, new CMB formation decreased, recurrence of epileptic seizures and ICH events was suppressed, and basic activities of daily living were largely preserved. Although this is a single-case observation and cannot be generalized, long-term longitudinal imaging suggests that mixed CSVD phenotype may be better understood as a dynamic spectrum disorder. In addition to quantitative CMB burden, qualitative and temporal CMB dynamics may represent imaging markers of disease activity and may be temporally associated with ICH and epileptic seizures in selected patients.