There are several additional Non-Vestibular forms of dizziness. Some are described below:
Persistent postural perceptual dizziness (PPPD)
PPPD might occur when a patient fails to recover from an episode of dizziness. Inappropriate compensation strategies (for example holding your head still) mean that the brain is unable to adapt to the change in sensory inputs. The result is a sensitivity to motion and to visual inputs (visual vertigo). Often the brain then becomes ‘hyper-attentive’ and amplifies ALL the sensory inputs, resulting in exaggerated symptoms. This is known as a ‘functional dizziness’ as the symptoms are no longer related to damage or disease. It is important to realise that this is NOT imaginary or psychological – it is very real! Further information can be found here.
Many patients who complain of pain and stiffness in the neck also notice dizziness or unsteadiness. This is due to difficulty processing the signals comming from the small muscles of the neck. Muscles in spasm give false balance information. Treatment to the neck usually resolves the pain, stiffness and dizziness.
Conflicting sensory input
There are times that the sensory input that we receive from one of the sources conflicts with the input from the other sources. For example, when standing next to a bus that is pulling away from the curb, your visual input from the large rolling bus may indicate that you are moving. You may lean forward a little to compensate for that sensation, or feel dizzy. But your muscles and joints send input that you are not moving, and other visual input finally indicates that other objects are stationary, and a correction is made. This is the reason for experiencing symptoms of motion sickness.
‘Mal de debarquement’
This is an unusual variant of motion sickness, which typically occurs after a boat trip. Usually we experience this as rubbery legs or a feeling of still being at sea, and it settles within a few hours. For some, it worsens and often takes months to fade away. Vestibular coordination training is very helpful in settling symptoms as rapidly as possible.
Visual disturbances can result in lightheadedness or dizziness. Some people feel dizzy while adjusting to bifocals or a new eyeglass prescription, or from reduced vision due to cataracts. You may notice that you are dizzy in situations with confusing visual stimuli, eg. supermarkets, crowds, bright lights, cinema etc. This is due to an increased sensitivity to visual sensory inputs. This often occurs during compensation from a vestibular deficit, for example BPPV or neuritis. Vestibular coordination exercises which help your brain to integrate visual inputs together with inputs from your head and neck, usually have a very good effect.
Stress & Fatigue
Even stress, tension, or fatigue may cause dizziness. Under these conditions, the balance system functions less efficiently, resulting in less automatic reflex control of balance. This means that you have to concentrate more on balancing, with more conscious energy being used to help maintain balance. Lightheadedness and unsteadiness can result.
Decreased blood flow to the brain or brain stem can cause dizziness, because insufficient oxygen is reaching the cells. Conditions that can reduce blood flow to the brain include low blood pressure upon suddenly rising up, dehydration, and arterio-sclerosis (hardening or narrowing of blood vessels).
Nervous System Disorders
Nervous-system disorders such as peripheral neuropathies (diminished nerve function in the legs or feet) can cause unsteadiness. A tumor may affect the brain stem, the cerebellum (the coordination center of the brain), or the part of the cerebral cortex that controls voluntary muscle movements. Serious causes of dizziness are usually easily identified.