THE VESTIBULAR TRAUMA SYNDROME

The vestibular system is responsible for maintaining a stable perceptual frame of reference whenever we are in motion or when things are in motion around us. We are kept in balance and oriented in space by a complex feedback system that integrates the rate and angle of our motion into our positional adjustments and our visual perceptions so that we and our world remain stable (Ciuffreda and Tannen, 1995). This system performs this complex task through 5 end-organs within the temporal bone-the three semicircular canals, sensing angular rotation, and the saccule and utricle, sensing gravity and linear acceleration. The central projections to the brain are complex and include afferent and efferent connections from and to a variety of areas of the body, including eye muscles (oculomotor pathways), allowing for smooth tracking of eye movements (Kapoor and Ciuffreda, 2006), and neck and spinal muscles, keeping the head and body correctly oriented.

The vestibular trauma syndrome (VTS) is virtually identical to the post-concussion syndrome (PCS), and it provides a better explanation for the commonly seen set of symptoms in mild head injury. Problems with balance, dizziness and nausea are the direct product of even subtlely aberrant signals from the semicircular canals. The dynamic visual focusing difficulties following concussion make sense in terms of aberrant vestibulo-ocular reflex signals that result in visual distortions, photosensitivity, and an inability to sustain a visual focus while scanning a text while reading or performing other visual tasks. VTS patients experience secondary symptoms of anxiety associated with persistent imbalance and slowed information processing as well as headaches and fatigue from their attempts to maintain their visual focus.

It has been suggested that the vestibular system may be more sensitive to rapid acceleration/deceleration trauma than the brain and that central vestibular system symptoms often recover slowly and incompletely (Hain et.al., 2007). Despite the high prevalence of vestibular system dysfunction in head trauma cases, vestibular symptoms are usually incorporated into a post-concussion syndrome diagnosis with little additional consideration, evaluation or treatment. Further, vestibular system symptoms are seldom questioned when they arise within the context of a PCS diagnosis.