Otolith Function in Patients With Primary Ciliary Dyskinesia

• The results of the utricular centrifugation test, VEMPs & ocular counter-rolling test [ Time Frame: One session only ] [ Designated as safety issue: No ]
  These are the balance tests that specifically assess the otolith organ. They will then be compared to normative data.
  
  

Other: Utricular centrifugation test, vestibular evoked myogenic potentials & ocular counter-rolling test
Standard tests of balance function

Primary ciliary dyskinesia (PCD) is a genetically inherited condition. It is due to structural abnormalities of cilia, which are microscopic hairs found in organs and cells throughout the body. Patients with this condition typically develop upper respiratory tract symptoms such as sinusitis and glue ear, lower respiratory tract problems such as recurrent chest infections, and fertility problems. There is currently no evidence that patients with PCD have a higher incidence of balance problems. However, recent animal studies have shown that cilia may also be important in the development of part of the inner ear balance (vestibular) system, specifically the part that detects linear movement known as the otolith system.

The investigators hope to determine whether patients with PCD have absent or reduced otolith function compared to the normal population. Balance problems are not currently screened for in PCD patients, and could be unrecognized and therefore untreated. It is also possible that PCD patients have compensated for absent otolith function and so are unaffected under normal circumstances; any additional insult to their balance system would cause more pronounced difficulties than expected and treatment might need to reflect this.