Cerebral Blood Flow Changes in Tinnitus Explained

A study of 87 participants has identified a specific pattern of reduced blood flow in the brains of people with a particular type of tinnitus linked to vascular issues. The research, published in *Brain Imaging and Behavior*, connects these cerebral blood flow (CBF) reductions directly to symptom severity, including longer tinnitus duration and poorer sleep quality.

How Venous Congestion Can Change Brain Blood Flow

The study from Capital Medical University in Beijing focused on a condition called cerebral venous congestion (CVC). This includes internal jugular vein stenosis (IJVS) and cerebral venous sinus stenosis (CVSS), where veins that drain blood from the brain become narrowed. When venous outflow is impaired, it can lead to a secondary reduction in the flow of fresh, oxygenated blood into brain tissues.

Lead researcher Lu Liu and the team hypothesized that this vascular problem could be a key mechanism behind non-auditory tinnitus (NAT). Unlike typical tinnitus often linked to cochlear damage, NAT is thought to originate from issues within the brain’s central neural circuits. The researchers used a non-invasive MRI technique called multi-delay pseudo-continuous arterial spin labeling (ASL) to measure blood flow. This method allowed them to create a detailed map of perfusion across the entire brain, adjusted for the speed of blood arrival.

Mapping the Brain’s Blood Flow in Three Groups

The researchers compared three groups: 34 patients with CVC and NAT (NAT+), 17 patients with CVC but without NAT (NAT-), and 36 healthy controls. By analyzing whole-brain and regional CBF based on a detailed anatomical atlas, they looked for patterns specific to the tinnitus experience.

The findings were clear. “Patients in the NAT+ group exhibited significant CBF reductions in the left hemisphere, cerebrum, and specific regions, including the insula, paracentral lobule, and precentral gyrus, compared to those in the NAT- and HC groups,” the authors report. This means the reduction was not a general feature of having venous congestion, but was specifically pronounced in those who experienced tinnitus.

Further network analysis showed the affected brain regions were part of major functional networks. These included networks for attention and sensorimotor processing, the default mode network (active during rest and self-referential thought), and cerebellar networks. This suggests the vascular issue disrupts not just one area, but coordinated systems involved in perception, focus, and emotional regulation.

Blood Flow Reductions Correlate with Real-World Symptoms

A critical part of the study linked the biological data to patient-reported symptoms. The team analyzed correlations between CBF measurements and clinical variables like tinnitus duration, sleep quality (using the Pittsburgh Sleep Quality Index), and scores for anxiety and depression (using the Hospital Anxiety and Depression Scale).

The results showed a direct relationship: greater reductions in cerebral blood flow were associated with a longer history of tinnitus, poorer sleep quality, and worse depression scores. This moves the finding from an abstract brain scan result to one with tangible implications for patient well-being. It supports the idea that the vascular-driven change in brain environment contributes to the persistence and burden of the condition. The connection to emotional dysregulation also intersects with research on amygdala plasticity in hearing disorders.

Practical Implications and Future Directions

This study offers a more concrete path for understanding and potentially treating a subset of tinnitus cases. It provides imaging evidence that supports evaluating vascular health in patients with persistent, non-auditory tinnitus, especially when accompanied by sleep or mood complaints. Diagnosing conditions like IJVS or CVSS could become a more standard part of the clinical workup for complex cases.

The findings also suggest that treatments aimed at improving cerebral venous drainage or increasing cerebral perfusion merit investigation for this patient group. It reframes some tinnitus not solely as a hearing or auditory processing disorder, but as a possible symptom of broader cerebrovascular health.

Future research with larger, longitudinal studies is needed to confirm if treating the venous congestion can normalize blood flow patterns and alleviate tinnitus and its associated symptoms. This work also highlights the value of advanced perfusion imaging, like ASL, in uncovering the vascular contributors to neurological symptoms. For patients and clinicians, it underscores that tinnitus is a heterogeneous condition, and identifying specific subtypes like this is the first step toward targeted management.

Source: Liu L, Jia M, Li H, et al. Cerebral blood flow alterations in non-auditory tinnitus: implications for cerebral venous congestion pathophysiology. Brain Imaging Behav. 2026;20(2):72. doi:10.1007/s11682-026-01144-8. PMID: 41957332.