May 12, 2019
Superior Canal Dehiscence
This is an important common cause of “dizziness”.
It has 3 key features: –
i)A long-standing complaint** of non-spinning “dizziness” on most days.
ii)Associated with anxiety and low mood.
iii)Normal clinical examination.
The dizziness is described as with the following features: –
a) Unsteadiness when upright i.e. “Unsteady on walking”, “Unsteady on feet”, “cannot feel the ground properly” “a feeling of toppling over” but not actually falling
b) A feeling of altered conscious level e.g. “Lightheaded” but not fainting
c) A feeling of altered mental state e.g. an “Empty feeling in head’”
d) Difficult to describe dizziness
The sensation of spinning dizziness (“vertigo”) is very rare.
Symptoms are present most days, often increasing throughout the day, and may fluctuate.
The patient complains of diminishes function, such as: –
Poor concentration, work difficulties, loss of confidence, poor motivation, panic attacks, low mood, poor sleep & anxiety.
The dizziness may be triggered visual stimulation such as bridges, driving a car, empty rooms, long corridors, large crowds of people in a store or restaurant cinema, television & computers.
The dizziness may improve or resolves during sport activities (bicycling, tennis) or taking some alcohol.
There may be a history of a significant attack of vertigo in the past.
When the patient is examined there is nothing abnormal.
The cause is not certain, emerging research suggests that it may arise from processing problems in the brain which control posture, multi-sensory information processing, or co integration of spatial orientation and threat assessment.
Treatment is based on a clear positive diagnosis and explanation that the patient can work with. An understanding of how the nervous system has become sensitized can help desensitize it.
Vestibular therapy works by desensitization. As the symptoms of have built up, most people avoid moving their eyes, neck and body as much as they used to. Physiotherapy and specific vestibular physiotherapy can be useful to help desensitize the nervous system and start to overcome ingrained patterns of movement.
Medication – especially so-called antidepressants SSRIs has a role in patients with PPPD who have anxiety or low mood, but more studies are needed to be confident of this.
*This condition has had many previous names such as somatoform dizziness, postural phobic vertigo, psychogenic dizziness & functional dizziness.
**for at least 3 months.