Parkinson's disease is a neurological movement disorder with a wide range of symptoms including slowness of movement, rigidity of muscles, memory impairment and others. Both Parkinson’s disease and dystonia can arise in the same person because they seem to originate in the same part of the brain: the basal ganglia. Sometimes symptoms similar to Parkinson’s disease (parkinsonism) arise together with dystonia due to a genetic defect as in the rare condition, x-linked dystonia parkinsonism.
However, the most common cause of dystonia in Parkinson’s patients is a secondary dystonia arising from the effect of treating Parkinson’s disease using the medication, Levodopa.
Levodopa is a chemical that converts into dopamine, a chemical messenger in the brain. It is a shortage of dopamine that causes Parkinson’s and dopamine is also thought to play a role in dystonia although what exactly this role is has yet to be fully clarified. Curiously, dystonia is caused both when the effect of Levodopa is too strong and too weak. Off-period dystonia occurs when the effect is the Levodopa is wearing off and the symptoms include postural changes in the hands and feet and also in the neck. On-period dystonia happens when levodopa is at its most effective.
It is thought around a third of those on medication for Parkinson’s disease experience dystonia. As levodopa is so frequently used in treatment this will amount to many thousands of people. However, these conditions are so frequent that most doctors think of them as part of Parkinson's disease and they are not included in the Dystonia Society’s estimate of 70,000 people with dystonia.
Last reviewed March 2012
The Dystonia Society provides the information on this page as general information only. It is not intended to provide instruction and you should not rely on this information to determine diagnosis, prognosis or a course of treatment. It should not be used in place of a professional consultation with a doctor.
The Dystonia Society is not responsible for the consequences of your decisions resulting from the use of this information, including, but not limited to, your choosing to seek or not to seek professional medical care, or from choosing or not choosing specific treatment based on the information. You should not disregard the advice of your physician or other qualified health care provider because of any information you receive from us. If you have any health care questions, please consult the relevant medical practitioner.