The mainstay of treating Parkinson's disease is to replace dopamine in the brain.
E's can contain toxic other chemicals like MPTP, a drug known to cause irreversible Parkinson's disease.
The Guardian, Thursday 29 June Parkinson's disease is often misdiagnosed, according to new research.
Levodopa, the metabolic precursor of dopamine, relieves the symptoms of Parkinson's disease presumably by being converted to dopamine in the brain.
She had suffered various illnesses in recent years, including Parkinson's disease and died at her Connecticut home at 6pm British time yesterday.