United Kingdom, May 25 -- Billy Joel's daughter, Alexa Ray Joel, says her father "continues to regain his strength" amid his battle with a brain disorder.

The 76-year-old musician revealed this week that he was diagnosed with Normal Pressure Hydrocephalus, which has caused problems with his hearing, vision and balance.

A statement posted on his Instagram read: "Billy Joel has announced that he will be cancelling all scheduled concerts following a recent diagnosis of Normal Pressure Hydrocephalus (NPH). This condition has been exacerbated by recent concert performances, leading to problems with hearing, vision and balance."

Billy is currently undergoing treatment and doctors have advised that performing would have an adverse affect on h...