Tinnitus and Cerebral Blood Flow Changes

A 2026 study of 87 participants has identified specific patterns of reduced blood flow in the brains of people with tinnitus linked to vascular issues. This research connects impaired venous drainage in the brain to the presence of non-auditory tinnitus and related symptoms like poor sleep and depression.

Connecting Vascular Health to Tinnitus Symptoms

The study, published in Brain Imaging and Behavior, investigated cerebral venous congestion (CVC). CVC is a condition where drainage from the brain is impaired, often due to narrowing in veins like the internal jugular or cerebral venous sinuses. Researchers led by Lu Liu and Chen Zhou at Capital Medical University in Beijing proposed that this backup of blood could reduce fresh, oxygenated blood flow to brain tissue, potentially causing neurological symptoms like tinnitus.

Their focus was on non-auditory tinnitus (NAT). Unlike tinnitus caused by direct damage to the ear’s hearing apparatus, NAT is thought to originate from issues within the brain’s neural or vascular systems. The team wanted to see if they could measure a direct link between CVC, altered brain blood flow, and the presence of this specific tinnitus type.

How Researchers Measured Brain Blood Flow

Liu and colleagues recruited 87 individuals for a cross-sectional analysis. The cohort included 34 patients with CVC and non-auditory tinnitus (NAT+), 17 patients with CVC but no tinnitus (NAT-), and 36 healthy control participants.

To measure cerebral blood flow (CBF), they used an advanced MRI technique called multi-delay pseudo-continuous arterial spin labeling (ASL). This method is non-invasive, using magnetic labels on arterial blood water as a tracer to quantify how much blood is delivered to different brain regions per minute. A key advantage is that it adjusts for arterial transit time, providing a more accurate picture of perfusion, especially in cases where vascular flow might be slowed.

They scanned each participant and mapped CBF across 170 brain regions defined by the Anatomical Automatic Labeling atlas. The team then compared blood flow patterns between the three groups. They also analyzed correlations between CBF measurements and clinical data, including tinnitus duration, sleep quality scores, and assessments for anxiety, depression, and cognitive function.

Regional Blood Flow Reductions Linked to Tinnitus

The imaging data revealed a clear pattern. Patients in the NAT+ group had significantly lower cerebral blood flow compared to both the healthy controls and the CVC patients without tinnitus.

The reductions were not uniform. The left hemisphere and the cerebrum as a whole showed lower perfusion. When looking at specific regions, the most notable decreases were found in the left insula, left paracentral lobule, and left precentral gyrus. The precentral gyrus is a primary motor control area, the insula is involved in interoception and emotional awareness, and the paracentral lobule manages sensation and motor function for the lower limbs.

Further network analysis showed these areas are part of major functional brain networks. The affected regions participate in the attention network, the sensorimotor network, the default mode network (active during rest and self-referential thought), and the cerebellar network. This suggests the vascular issue disrupts not just isolated spots but integrated systems involved in perception, focus, and self-awareness. For more on how tinnitus alters brain function, see our article on Tinnitus Linked to Cerebral Blood Flow Changes.

The Symptom Connection: Duration, Sleep, and Mood

The statistical analysis went beyond simple group differences. Researchers found that within the NAT+ group, the degree of blood flow reduction was directly related to the severity of their clinical experience.

Lower CBF measurements correlated with a longer history of tinnitus. They also correlated with poorer scores on sleep quality assessments and higher scores on depression scales. This creates a tangible link between the physiological measure (reduced blood flow) and the patient’s lived symptoms, moving from correlation closer to potential causation. The relationship with emotional dysregulation is an area of growing interest, as discussed in our review of Hyperacusis Alters Brain Structure and Function.

Implications for Understanding and Treatment

This study offers concrete evidence for a vascular model of some tinnitus cases. It supports the idea that impaired venous drainage can lead to a measurable decrease in cerebral perfusion, which in turn may generate or exacerbate tinnitus and associated neuropsychiatric symptoms.

For patients and clinicians, these findings point to a potential diagnostic pathway. When tinnitus presents without clear auditory damage, especially alongside complaints of poor sleep or low mood, an investigation into cerebral vascular health could be warranted. Advanced ASL MRI provides a tool to assess this.

Therapeutically, it opens a discussion about treatments aimed at improving cerebral venous outflow or perfusion. While the study does not test treatments, it provides a physiological rationale for exploring such approaches in future clinical trials. Understanding these brain-wide network effects also reinforces the need for multidisciplinary management addressing both the perceptual symptom and its cognitive and emotional consequences. This aligns with broader trends in hearing research, detailed in our piece on fMRI Advances in Hearing and ENT Disorders.

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.