Of the conditions known to impact public health in the USA, the burden of Parkinson’s disease is one of the fastest growing.
In 2020, Yang, Hamilton, and colleagues reported their findings on overall public cost of Parkinson’s in Nature. A staggering $25.4 billion of direct medical costs and $26.5 additional indirect and non-medical cost, such as caregiver costs, disability payments, and others, are projected to only increase in the future.
While Alzheimer’s disease, the most common neurodegenerative disorder in the world, was in the center of attention since the early 90ties, Parkinson’s was less known to the public. Since Dr. James Parkinson first described the condition in mid-19th century and up until late 20th century, Parkinson’s disease remained a rare disorder.
This started to change sometime during 2000s. According to Dorsey, Ray, et al, “from 1990 to 2015, the number of people with Parkinson disease doubled to over 6 million”, and this number is projected to double again to over 12 millions by 2040.
Parkinson’s disease affects the lives of the patients profoundly, limiting their ability to perform work, enjoy favorite activities and life, and in later stages, their cognitive function.
In this series of posts, we will review that changes that occur in patient’s bodies and how those changes affect quality of life. We will also outline some of the complementary measures to take that might help the practitioners and patients achieve optimal results.
First, let’s see what is going on at the level of the nervous system cells called neurons.
When the brains of people who died with Parkinson’s disease are carefully studied, two findings stand out:
When it comes to clinical diagnosis, the following is what practitioners see:
For the doctor to clinically diagnose Parkinson’s disease, a patient must have bradykinesia PLUS one of the three: resting tremor, postural instability, or rigidity.
We will discuss each of these in more detail in future entries.
Currently, doctors consider diagnosis of Parkinson to be mostly clinical. That is because the changes that happen in the brain are initially on such a small scale, that imaging might not pick it up, but careful physical examination and review of history of patient's symptoms could reveal a recognizable pattern early on.
By the time when brain imaging findings are notable enough for common imaging techniques, most patients already experience signs and symptoms of Parkinson's that significantly affects their lives.
In 2011, FDA approved a DaTscan, a type of single photon emission computed tomography (SPECT) scan with the contrast ioflupane iodine-123 injection.
It helps to discriminate between essential tremor and tremor related to depletion in Dopamine transporters in the brain.
While not specific for Parkinson, the scan picks up dopamine depletion in striatum and helps physicians pick up on pathologies leading to such depletion, of which Parkinson is the most common. Two other major pathologies are Multiple System Atrophy (MSA) and Progressive Supranuclear Palsy (PSP).
The scan is relatively expensive, and will help to diagnose estimated 5% - 15% of patients seen by doctors for movement disorders. Therefore, many doctors do not order DaTscan when they feel that clinical picture is clear enough for diagnosis.