Traumatic Brain Injury (TBI) is a spectrum of head injuries, ranging from a mild concussion to a severe, penetrating injury, caused by an external force impacting the head. Vertigo is a specific type of dizziness characterized by the sensation of spinning or whirling, where the individual feels they are moving or the world around them is in motion. Vertigo is a frequently reported and often debilitating symptom following head trauma. The physical forces involved in a TBI can directly damage the delicate structures responsible for maintaining spatial orientation, establishing a clear link between injury and the onset of vertigo.
Understanding How TBI Affects the Balance System
The body’s complex balance system relies on continuous, accurate signals from three main sources: the eyes, the muscles and joints (proprioception), and the inner ear’s vestibular system. TBI disrupts this system by causing damage at either the peripheral level (inner ear) or the central level (brain structures that process signals). The vestibular system, housed within the temporal bone, contains fluid-filled canals and chambers that detect head movement and position relative to gravity.
A severe jolt or blow to the head can create a shockwave that travels through the skull, causing physical damage to the inner ear structures. This mechanical disruption is considered a peripheral cause of vertigo. The inner ear transmits signals via the vestibular nerve to the brainstem and cerebellum, which are the central processing centers for balance and coordination. Injury to these central pathways, even from a mild concussion, can lead to a mismatch between signals, resulting in unsteadiness and dizziness.
The brain’s ability to regulate its blood flow and metabolism, known as neurovascular coupling, can be temporarily or permanently disrupted after a TBI. If brain areas integrating balance information do not receive necessary resources, they struggle to function correctly. This metabolic dysfunction can manifest as chronic dizziness or vertigo, even when inner ear structures remain intact. Shearing forces from a sudden impact can also injure the vestibular nerve as it enters the brainstem, complicating the central processing of balance signals.
Specific Types of Post-Traumatic Vertigo
The most common specific diagnosis following a head injury is Post-Traumatic Benign Paroxysmal Positional Vertigo (BPPV). BPPV occurs when tiny calcium carbonate crystals, called otoconia, become dislodged from the utricle and migrate into one of the inner ear’s semicircular canals. This loose debris causes the fluid in the canal to move inappropriately when the head changes position. This triggers brief but intense episodes of spinning vertigo that typically last less than one minute.
A second major cause is Post-Concussion Dizziness, often a component of Post-Concussion Syndrome (PCS). This presents as a persistent, non-spinning unsteadiness rather than true rotational vertigo. This dizziness is often exacerbated by complex visual environments, such as shopping aisles or crowds, due to motion sensitivity and visual overload. This central vestibular dysfunction stems from injury to the brain’s processing centers, leading to poor signal integration and chronic imbalance.
A third distinct cause is Cervicogenic Dizziness, frequently seen when a TBI is accompanied by whiplash or a neck injury. The neck joints contain proprioceptors that send information to the brain about the position of the head and neck relative to the body. Trauma to the cervical spine can inflame the muscles and joints, delivering faulty signals that conflict with the inner ear and visual inputs. This confusion manifests as dizziness or unsteadiness, particularly when turning the head while the body remains stationary.
Assessment and Therapeutic Interventions
Accurately diagnosing the specific cause of post-traumatic vertigo is important because treatment differs significantly based on whether the issue is peripheral, central, or cervicogenic. Assessment begins with a detailed patient history, focusing on the triggers, duration, and quality of the dizziness to differentiate between spinning vertigo and general unsteadiness. Clinicians use specific physical maneuvers, such as the Dix-Hallpike test, to observe for involuntary eye movements (nystagmus). This confirms the presence of BPPV and identifies the affected semicircular canal.
Specialized tests, including videonystagmography (VNG) or electronystagmography (ENG), help assess the function of the inner ear and the central brain pathways. Advanced balance testing quantifies the degree of instability and helps determine the relative contributions of the visual, vestibular, and proprioceptive systems to the overall balance deficit. This comprehensive evaluation guides the development of a targeted recovery plan tailored to the patient’s specific injury profile.
Treatment for BPPV involves Canalith Repositioning Maneuvers, such as the Epley or Semont maneuvers. These maneuvers use a specific sequence of head and body movements to physically guide the dislodged crystals back into the utricle. For central causes, Vestibular Rehabilitation Therapy (VRT) is the primary intervention. VRT uses customized exercises to encourage the brain to adapt to or compensate for damaged balance signals, including habituation and gaze stabilization exercises. When Cervicogenic Dizziness is diagnosed, targeted physical therapy focusing on neck range of motion and joint mobility is incorporated.