Shadows Bright as Glass
University of Tennessee at Martin
One normal function of the human body is the ability to maintain equilibrium, or balance. When our sense of equilibrium is disrupted it can result in dizziness, which is one of the most common complaints causing patients to see their physician (1). One type of dizziness is vertigo, causing illusions of movement such as spinning, unsteady sensations when walking, or illusions of environmental rotation. although many people experience the sensation of dizziness, most complaints cannot be diagnosed as true vertigo.
Equilibrium in our bodies is primarily coordinated in the brain stem. Environmental stimuli is necessary in determining the position of our body in relation to movement and steadiness. Environmental stimuli is received from the eyes for visual input, the ears receive auditory and vestibular input, and proprioceptive input for applying movement, or articulation. Collectively, the eyes help recognize the position of the body in relation to the ground. The ears register sounds and allow accelerated or decelerated movement. Movement is also processed in the frontal lobes of the brain which coordinate and plan the movement. Control and smoothness of the movement is aided by the basal ganglia, the ears, and processing information to and from the body is controlled by the cerebellum.
Vertigo can stem from the brain or the ear and can be classified as either central or peripheral. Central vertigo is due to disorders of the brain stem or cerebellum. Central causes of vertigo include: stroke, brain stem tumor, migraines, head trauma, anxiety, sedative drugs, or multiple sclerosis. Peripheral vertigo is due to disorders of the inner ear (vestibulocochlear) and can include ear trauma, Meinere's disease, and labrynthitis. Peripheral causes are less severe in that they do not...