Tinnitus Treatment: Neurodegenerative Disease Insights

Tinnitus, the perception of sound without an external source, affects approximately 14% of adults. Researchers J L Liu and Peng Liu propose that its persistence is not merely a hearing issue but a brain disorder with roots in processes that also drive Alzheimer’s and Parkinson’s disease. Their 2026 review argues that treatments designed for neurodegeneration could be effectively repurposed for tinnitus.

**Shared Mechanisms: Neuroinflammation and Excitotoxicity**

The central thesis is that tinnitus and neurodegeneration are linked by maladaptive neuroplasticity. After hearing loss or trauma, the brain’s auditory pathways reorganize incorrectly, creating the phantom sound. This reorganization involves specific damaging processes.

Neuroinflammation is one key process. Microglia, the brain’s immune cells, become chronically activated in both tinnitus and neurodegenerative conditions. They release inflammatory signals that can damage neurons and synapses, potentially locking in the tinnitus signal. Another is glutamate-mediated excitotoxicity. Glutamate is the brain’s primary excitatory neurotransmitter. In excess, it overstimulates neurons, leading to dysfunction and death—a well-known problem in Alzheimer’s disease that also appears in auditory pathways after noise trauma.

**Repurposing Neurodegeneration Drugs: A Systematic Review**

Liu and Liu systematically examined three main therapeutic approaches from neurodegeneration research for their potential in tinnitus.

First, targeting neuroinflammatory cascades. Drugs that suppress overactive microglia or block specific inflammatory cytokines, like those being tested for multiple sclerosis, could calm the inflammatory environment that sustains tinnitus. Second, modulating neurotrophic factors. These are proteins that support neuron survival and health. In neurodegeneration, boosting factors like BDNF (Brain-Derived Neurotrophic Factor) is a strategy; in tinnitus, it could help repair damaged auditory circuits. Third, mitigating excitotoxicity. NMDA receptor antagonists, which block excessive glutamate action, are used in some neurological conditions. They have shown tinnitus-suppressing effects in animal models, and the drug lidocaine, which modulates neural excitability, provides a clinical parallel.

The review notes that preclinical evidence for these approaches in animal tinnitus models is promising. However, clinical translation for tinnitus remains sparse. Most existing tinnitus treatments manage symptoms or use behavioral strategies. Repurposing offers a direct path to mechanism-based drugs.

**Methodology and Findings: Building a Cohesive Framework**

The authors conducted a narrative review, synthesizing evidence from molecular studies, animal models, and available human trials. They did not report a new experiment but built a theoretical framework by connecting disparate fields.

A clear finding is that the biological overlap is substantial. The pathological signatures in brain regions involved in tinnitus—such as the auditory cortex and limbic system—mirror those in early neurodegeneration. This suggests tinnitus could be viewed as a localized, condition-specific form of neural degradation. Another finding is that several repurposed drugs already have established safety profiles from neurological use, which could accelerate their path to tinnitus trials.

**Practical Implications for Treatment Development**

This framework shifts the goal from merely masking the tinnitus sound to modifying the underlying brain pathology. For patients, it introduces the possibility of pharmaceutical interventions that directly target the condition’s biology, similar to how a disease-modifying drug works for Alzheimer’s.

It also suggests combination therapies. A drug reducing neuroinflammation might be paired with a bimodal neuromodulation device that retrains brain networks, addressing both the chemical and electrical dysfunctions. Furthermore, the focus on excitotoxicity and neuroplasticity links tinnitus to other sensory processing disorders like misophonia and hyperacusis, suggesting broader applications for these repurposed drugs.

**Future Directions and Research Needs**

Liu and Liu identify clear gaps. Robust clinical trials testing neurodegeneration drugs in tinnitus patients are urgently needed. Biomarkers to measure neuroinflammation or synaptic dysfunction in the auditory system must be developed to track drug efficacy. Finally, personalized approaches are critical—the specific mechanistic driver (inflammation vs. excitotoxicity) may vary between individuals, requiring tailored treatment.

By reframing tinnitus as a disorder sharing neurodegenerative pathways, this review opens a new chapter for therapeutic development. It moves beyond general sound therapy toward precise medical interventions.

*This article is based on the research review “Repurposing Neurodegeneration Therapeutics for Tinnitus Intervention” by J L Liu and Peng Liu (DOI: 10.3389/fnagi.2026.1835649).*