What Is Parkinson's?
Parkinson's disease (PD) is a neurodegenerative disorder that affects predominately dopamine-producing (“dopaminergic”) neurons.
Every hour, 2 people in the UK are told they have Parkinson’s.
The number of people diagnosed with Parkinson’s in 2018 in the UK is around 145,000. That’s around 1 adult (ie people aged 18 or over) in every 350. Most people who get Parkinson’s are aged 50 or over but younger people can get it too.
Parkinson’s disease is caused by the gradual loss of dopamine-producing cells in the brain. Dopamine is a brain chemical that, among other things, helps regulate movement and emotional responses.
What Are The Symptoms of Parkinson's?
Symptoms generally develop slowly over years. The progression of symptoms is often a bit different from one person to another due to the diversity of the disease. People with PD may experience:
- Tremor, mainly at rest and described as a pill-rolling tremor in hands. Other forms of tremor are possible
- Bradykinesia (slowness of movement)
- Limb rigidity
- Gait and balance problems
Current Treatments for Parkinson's
Current treatments for Parkinson’s include the drug Levodopa, which was discovered in the 1960s. It is converted into dopamine in the body, so it acts as a stand-in for the lost dopamine-producing neurons.
Some other drugs act like dopamine to stimulate the nerve cells. Patients are also treated with occupational therapy, physiotherapy, a healthy diet and exercise. Surgery, such as deep brain stimulation with implanted electrodes, is used to treat more advanced cases, especially in those where the drugs are working less well.
These treatments relieve the symptoms of Parkinson’s disease but do not slow down or reverse the damage to nerve cells in the brain.
Over time, the clinical features get worse despite treatment. By the time patients are diagnosed with Parkinson’s they have often had the disease for years and have lost over half of the dopamine cells within the nigra.
Tests that detect Parkinson’s earlier may help, but scientists are searching for a way to replace the damaged cells.
Breakthrough in Stem Cell Treatment for Parkinson's
Replacing Lost Cells
In a major breakthrough for the treatment of Parkinson’s disease, researchers working with laboratory rats show it is possible to make dopamine cells from embryonic stem cells and transplant them into the brain, replacing the cells lost to the disease.
There are no cures for Parkinson’s disease; there are drugs that ease symptoms, but none that slow it down. Deep brain stimulation can alleviate symptoms of Parkinson’s in certain patients.
Human embryonic stem cells – precursor cells that have the potential to become any cell of the body – are a promising source of new dopamine cells, but they have proved difficult to harness for this purpose.
Now, a breakthrough study from Lund University in Sweden shows it is possible to get human embryonic stem cells to produce a new generation of dopamine cells that behave like native dopamine cells when transplanted into the brains of rats.
“The study shows that the cells that we generate from stem cells, they function equally as well as the cells that we find in the brain,” says Prof. Parmar.
The team says the new cells show all the properties and functions of the dopamine neurons that are lost in Parkinson’s disease, and the potentially unlimited supply sourced from stem cell lines opens the door to clinical application.
The authors note that the transplanted cells:
- Survived in the long term and restored production of dopamine in the brain
- Functioned in a similar way to dopamine cells of the “human fetal midbrain”
- Are capable of producing long-distance links to the correct parts of the brain
- The axons that they grow “meet the requirements for use in humans.”
The next step is to prepare for human clinical trials
Embryonic Stem Cells vs Umbilical Stem Cells
Stem cell research has sparked ethical, religious and political debates in recent years.
Embryonic stem cell storage and treatments involve the destruction of an embryo; umbilical cord stem cells come from the blood left over in the umbilical cord after birth, and the baby is not harmed in any way.