A concussion is a mild traumatic brain injury (mTBI) caused by a bump, blow, or jolt to the head that causes the brain to move rapidly within the skull. This sudden movement temporarily disrupts normal brain function, leading to a variety of symptoms. Tinnitus is the perception of sound, often described as ringing, buzzing, hissing, or clicking, when no external sound source is present. Tinnitus is a frequent consequence of head trauma, confirming that a concussion can cause this auditory symptom.
Confirming the Link: Post-Traumatic Tinnitus
The auditory disturbance that follows a head injury is known as post-traumatic tinnitus. This symptom is common among individuals who experience a mild traumatic brain injury, affecting 53% to 66% of patients according to some studies. This type of tinnitus is subjective, meaning the sound is audible only to the person experiencing it. It is frequently described as a high-pitched ringing or persistent buzzing, and can manifest in one ear (unilateral) or both ears (bilateral). Tinnitus is also recognized as a component of Post-Concussion Syndrome (PCS), where symptoms persist beyond the expected recovery period.
Understanding the Neurological Cause
A concussion initiates neurochemical and mechanical changes that disrupt the auditory system. The physical force can directly damage fine structures of the inner ear, such as the hair cells within the cochlea, which convert sound waves into electrical signals. This damage can also affect the vestibulocochlear nerve (Cranial Nerve VIII), which transmits these signals to the brain.
Beyond structural damage, the trauma affects the central auditory pathways. The sudden movement can stretch or shear connections in the brainstem and the auditory cortex, the area responsible for processing sound. This leads to compensatory hyperexcitability in the auditory cortex neurons. This abnormal neural firing is believed to be the brain’s attempt to fill the gap of missing external input, which is perceived as the phantom sound of tinnitus.
A disruption in neurovascular coupling may also contribute. This process normally directs blood flow to the parts of the brain that need it most, but a concussion can impair this function. If auditory regions receive insufficient oxygen and nutrients due to altered blood flow, malfunction can manifest as auditory disturbances. Damage to the upper cervical spine or the temporomandibular joint (TMJ) from the same event can also irritate nerves connected to the auditory system, creating a somatic form of tinnitus linked to muscle tension.
Acute vs. Persistent Symptoms
The timeline for post-concussion tinnitus varies, falling into two categories: acute and persistent. Acute tinnitus often begins immediately following the injury and is temporary, resolving within days or a few weeks. The symptoms fade as the brain recovers from the initial metabolic and inflammatory shock. For most people, the tinnitus resolves completely within three months, along with other concussion symptoms.
If the sensation lasts for three to six months or longer, it is classified as chronic or persistent tinnitus. This prolonged duration is more likely if the person experiences other lasting symptoms associated with Post-Concussion Syndrome. Factors like the severity of the initial injury, accompanying hearing loss, or pre-existing conditions can influence persistence. A sudden onset of new or worsening tinnitus, especially if accompanied by sudden hearing loss or if it is noticeably worse in only one ear, warrants an immediate medical evaluation.
Management and Coping Strategies
While there is no single cure for post-concussion tinnitus, several strategies can help manage symptoms and reduce their perception.
Sound Therapy
Sound therapy is a common non-invasive approach that involves introducing external, low-level sounds (such as white noise, nature sounds, or specialized tones) to mask the ringing or distract the auditory system. This helps the brain habituate to the internal sound, making it less noticeable over time.
Cognitive Behavioral Therapy (CBT)
CBT is an effective coping strategy that does not eliminate the sound but changes a person’s emotional reaction to it. CBT focuses on reducing the stress and anxiety associated with tinnitus, which can lessen the perception of its loudness and intensity.
Lifestyle Adjustments
Simple lifestyle adjustments are also beneficial, including prioritizing good sleep hygiene and practicing stress reduction techniques like meditation or deep breathing, as fatigue and stress can amplify tinnitus. If the tinnitus is accompanied by measurable hearing loss, using a hearing aid can be helpful because amplifying external sounds often helps to drown out the internal phantom noise.