Parkinson’s Disease Early diagnosis and treatment

Parkinson's Disease Diagnosis and Treatment

Parkinson’s is a very much associated with a progressive loss of dopamine neuron.  These are striatonigral neurons and those neurons release dopamine through allow us to move normally.  It turns out that person who lose about 50% to 60% of these neuron and dopamine and the striatum would be reduced to about 50% to 60% before the onset of motor signs of Parkinson’s disease occur.  We still don’t have to-date a biological marker of Parkinson’s disease.  There are imaging technologies that are available in research sites and some of these may be available on a more widespread basis soon, but one can use either beta-CIT or other ligand and SPECT imaging where these ligand binds to dopamine transporters and the dopamine nerve terminals and it gives you an index of remaining dopamine neurons, so this is a sort of representation from the early Parkinson’s disease.  So Parkinson’s Disease then still remains a clinical diagnosis based on history and examination with expectations to have a relatively slowly progressive disorder and we say for research purposes we need to see 2/3 coronal features these being bradykinesia or slowness of movement, rigidity, or increased tone and rest tremor or tremor with a limp at rest.  Parkinson’s disease almost always starts on one side and that side usually stays worse throughout the disease, another key feature of Parkinson’s disease is asymmetry and to that we also add that once patient’s have enough bradykinesia and rigidity that you can see it relatively easily.  we do expect a rather substantial unsustained response to dopaminergic medications.  I should say that normally patients with Parkinson’s disease have tremor, it turns out about 70% do which means that 30% don’t.  When rest tremor is present, the diagnosis is a lot easier and when rest tremor is not present, we need to think a lot more closely about the diagnosis and what other conditions might be present with a lack of tremor does not exclude Parkinson’s disease.  There has been recognition that the important non-motor features that are part of Parkinson’s disease.  

I have some of them listed here:

1.  Loss of smell

2.  Depression

3.  Anxiety.

4.  Sleep disorders

5.  Sleepiness

6.  Fatigue

7.  Constipation

8.  Dementia.

Just to pick at few of these out, depression rather is very very important and is very common and occurs in about 40% to 50% patient’s with Parkinson’s disease, sometimes in the course of the disorder and it probably has the greatest effect on individual’s quality of life.  So it is important when you see patients to canvas for depression and get that treated.  The other important one I am going to point out here is that long-term patients run in to two big problems, one is balance and the other is dementia or cognitive decline.  These represent very important long term causes of disability.  We borrow the medications from Alzheimer’s disease to try and treat dementia as best we can.  We really don’t have good treatments for balance and so one of things just tells me that we really need to work hard to develop treatments that will slow progression of the disease.