Footnotes

• Contributors ST, AS and YM were involved in the examinations and wrote the manuscript. HS constructed the figures and editing of the manuscript. MO provided clinical supervision and edited the manuscript.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Provenance and peer review Not commissioned; externally peer reviewed.