Dr Pienaar is a locally trained physician, graduating from the University of Western Australia. He is an experienced and independent geriatrician, working in both public and private hospitals with consulting rooms at St John of God Murdoch Clinic. 

Dr Pienaar specialises in neurological conditions of the elderly, including memory concerns, dementia, Parkinson’s, tremors, falls and strokes. He can provide capacity assessments for legal documents such as wills, Enduring Power of Attorney, and Enduring Power of Guardianship.

He is a registered provider for donanemab, a treatment that may help slow disease progression in early Alzheimer’s disease.