Morten Harket, the lead singer of Norwegian band A-ha, whose Take On Me track remains one of the most popular songs from the 1980s, said on Wednesday that he had been diagnosed with Parkinson's disease.

In a statement on the band's website, and confirmed by record label Sony Music, Harket, 65, said he had undergone several rounds of brain surgery and that he was managing the symptoms of the disease.

Parkinson's causes deterioration in the brain's nervous system, leading to tremors and other symptoms that can become progressively worse over time. The disease can be treated with surgery and medication, but there is no cure.

Harket said he last year underwent neurological procedures to have electrodes implanted inside his brain and that this had reduced the symptoms.

Known for the wide range of his voice, Harket said he did not know if he would be able to perform again.

"I've got no problem accepting the diagnosis," he said, adding that it was difficult to balance medication and managing side effects of the treatment.

"I'm trying the best I can to prevent my entire system from going into decline," Harket said.

[embed]https://www.youtube.com/watch?v=djV11Xbc914[/embed]

Formed in 1982 by Harket and his friends Paul Waaktaar-Savoy and Magne Furuholmen, a-ha saw a global breakthrough in 1985 with their debut album Hunting High and Low which yielded several hits such as Take On Me and The Sun Always Shines on TV.

Take On Me was recently featured in the second season of HBO's hit series The Last of Us when the main character Ellie, played by Bella Ramsey, performed an acoustic version of the song.