The Veronicas' Lisa Origliasso shares rare video of her caring for her mother Colleen during her devastating battle with Lewy body dementia

Lisa Origliasso has shared a rare video showing her caring for her mother, Colleen, who was diagnosed with Lewy body dementia three years ago. 

On Sunday, The Veronicas singer, 36, posted a tender clip to Instagram Stories, in which she tenderly brushes away her mother's hair from her face. 

Colleen, 71, who is holding a drink Lisa gave her, gazes lovingly at her daughter during the gentle moment. 

On the same day, Lisa shared a Facebook post she wrote in 2012, when her mother was battling what was then a mystery illness. 

Captioning it, she wrote: 'You've always been my cure for everything. My heart is heavy mummy. My best friend, I'd give anything to go back in time and live there forever. 

'The pain of not being able to change this reality kills me every single day. I'm praying I can be stronger. You are the strongest woman in the world. 

'I miss you too much, I miss living with you, cooking together, laughing, gossiping, feeling free, carefree. Everything. I miss the peace of knowing you aren't in pain. 

'You deserve so much more. I pray for miracles. You have the biggest piece of my heart forever my mama bear. Goodnight mummy.' 

She added:  'Thank god for my mummy Colleen Origlasso. She's the only one who can cure my heavy heart.' 

Last year, Lisa and her sister and bandmate, Jessica, spoke about their mother's health battle.

Speaking out for National Carers Week, the twins shared just how 'difficult' their mum's battle with the illness has been.   

In an emotional interview with Brisbane's B105 FM, Jess and Lisa said caring for the 71-year-old was the least they could do for their 'absolute hero' and 'best friend'.

'We are in awe every day of this woman. Just our absolute hero, and to be able to care for her, give back to her even a tiny bit of the love she has thrown us throughout our lives is an absolute honour... but it is incredibly difficult work,' they confessed.

'It's heartbreaking. You're grieving. Your best friend, your mummy... and you know the statistics. There are 2.6 million unpaid carers in Australia and a lot of them don't even realise they are carers.

'We're just here to say that if you are someone who is caring for a loved one - a friend or family member - that we see you and thank you for everything you're doing.'

Lewy body dementia is a debilitating disease which causes a sufferer's thinking, memory and movement to slowly deteriorate.