On 19 August 2016 a computerized rotation chair was used for the first time in South Africa. The System 2000™ Reclining Chair from Micromedical Technologies is a standard vertical axis rotational vestibular chair that can recline to perform videonystagmography (VNG) testing.
Rotation chair testing is usually performed with VNG and is the gold standard for diagnosing bilateral vestibular loss.
The Department of Communication Pathology of the University of Pretoria (UP) recently obtained one of these chairs as part of their comprehensive vestibular testing laboratory. Dr Barbara Heinze (PhD) is responsible for the vestibular testing of patients and training of students at UP. Two patients with complicated vestibular and balance problems were the first ones tested with a computerized rotation chair in South Africa.
With rotation chair testing the patient is rotated in the seated position whilst the eye movements are recorded. Rotation chair testing determines how well the eyes and the inner ear work together. The horizontal canal vestibulo ocular reflex (VOR) is the reflexive response that the eyes make on head rotation in the horizontal plain. Without an intact VOR, everything would blur with fast head movements. Rotation chair testing is performed to determine if dizziness is due to a disorder of inner ear or brain, and specifically to determine if both inner ears are impaired at the same time.
Rotation chair testing is of benefit in the following cases:
- weakness of both inner ear balance organs (lateral canals)
- managing of ototoxicity (medication that damages the inner ear)
- testing children (whilst seated on the parent’s lap)
- clarifying inconclusive VNG findings
- vestibular compensation
As with the majority of vestibular tests, rotation chair testing needs to be conducted as part of a vestibular test battery. Unfortunately it has limited value on its own.
