Do patient ratings of symptoms match functional improvements in Parkinson’s Disease?

 

It may seem strange, but asking patients with Parkinson’s disease to rate how much their symptoms have improved doesn’t seem to match up to clinical improvements, at least as assessed by using the conventional symptoms scores used by clinical researchers.

 

Doctors and researchers use different symptom scores to help measure the symptoms of people with Parkinson’s disease. Examples are the Unified Parkinson’s Disease Rating Scale (UPDRS), the Mini-Mental State Examination (MMSE), and the 39-item Parkinson’s Disease Questionnaire (PDQ-39).

 

These tools are useful as they enable neurologists to assess how much a person is affected by the symptoms of Parkinson’s. These scores may also be useful to weigh up if a treatment works, by measuring the patient’s symptom scores before and after treatment. The scores can be important for working out if a person has Parkinson’s disease, or a different type of movement disorder.

 

People with Parkinson’s will usually improve after taking dopamine agonists. In addition to symptom scores, neurologists will often ask patients how they feel after taking treatment – without any real objective appraisal.

 

In recent research published in JNNP – a study of 133 patients with Parkinson’s disease measured the improvement in people’s symptoms immediately after starting treatment with dopamine agonists, then again after an average of six and then 12 months of treatment.

 

Researchers used symptom scores and tests, as well as asking patients to rate how much their symptoms had improved. They then compared the test results with people’s own ratings, to see how they matched up.

 

Of interest, most patients showed improvements in their measured scores although there was little relationship between these scores and how patients rated their own symptoms. The best match was between patient scores and the results of the UPRDS. When the researchers compared people’s own scores with this scale, they found around 33 in 100 people who showed no improvement in their UPDRS score at the first follow-up rated their improvement as moderate or better. Around 29 in 100 of those whose UPDRS score showed a good response said they had either no improvement or only a slight improvement.

 

What do these findings mean for the clinician?

Clearly, neurologists and their patients eed to come up with better ways to establish treatment responses.

Any suggestions?

 

 

Further reading: Davidson MA, McGhee DJM, Counsell CE. Comparison of patient rated treatment response with measured improvement in Parkinson’s disease. J Neurol Neurosurg Psychiatry 2012;83:1001–1005. http://jnnp.bmj.com/content/83/10/1001.full