The Glasgow-born comedian was diagnosed with the disease three and a half years ago and is increasingly dependent on his wife, Pamela Stephenson, to move around.
Life with Parkinson’s has meant Connolly, 74, can no longer play the banjo - the instrument that led to him first performing on stage as part of the folk duo The Humblebums in the late 1960s.
He bought his first banjo from Glasgow’s famous Barrowland market and soon began playing gigs in music pubs across the city, such as The Scotia.
“(Parkinson’s) is the first thing I think about in the morning because getting out of bed is quite hard,” he said in an interview with the Daily Mail.
“It’s a weird thing because it stopped me playing the banjo and it stopped me smoking cigars. It seems to creep up on everything I like and take it away from me.
“It’s like I’m being tested... ‘Cope with that, cope with life without your banjo. Now I’m going to make your hand shake so you can’t tie your fishing flies any more.”
Connolly rose to international fame in the mid-1970s after moving away from music to focus on stand-up comedy performances, but singing and playing the banjo remained a key part of his routines.
He recorded several comedic songs that enjoyed commercial success, including a parody of Tammy Wynette’s song D.I.V.O.R.C.E., which he performed on Top of the Pops in December 1975.
He met Stephenson, an actor and comedian, in 1979 and the couple married 10 years later.
“It’s kind of drawn us together,” he said. “I’m really dependent on her, you know, physically, whereas I used to be the strong guy.”
An ITV special to mark Connolly’s 50-year career in showbusiness will be broadcast later this week.