Posts

Early Involvement of Caudate Brain Region Linked to Worse Prognosis in Parkinson’s Patients, Study Finds

caudate involvement

Almost half of people in the early stages of Parkinson’s disease already have signs of neurodegeneration in a brain region called the caudate, which was previously thought to affect mostly those at advanced disease stages, a study reports.

Early caudate involvement on both sides of the brain, as seen by DaTscan imaging of the brain, appeared to predict the risk for worse outcomes, including cognitive impairment, depression, and gait problems, over a four-year follow-up period.

These findings suggest that caudate involvement detected through DaTscan neuroimaging may serve as an early biomarker to identify patients at a greater risk of faster disease progression in the near future.

The study, “Clinical implications of early caudate dysfunction in Parkinson’s disease,” was published in the Journal of Neurology, Neurosurgery & Psychiatry.

Parkinson’s disease is believed to be caused by the impairment or death of dopamine-producing nerve cells (neurons) in a region of the brain called the substantia nigra, which controls the body’s balance and movement.

When the disease is established, or advanced, the degeneration of dopaminergic neurons and nerve fibers frequently extends to a brain region called the caudate nucleus. This region plays important roles in motor control as well as in various other non-motor tasks, such as learning and sleep.

In fact, the loss of dopaminergic function in this region is known to contribute to the hallmark symptoms of Parkinson’s including cognitive impairment, depression, sleep disorders, and gait problems.

Although less common, caudate dopaminergic dysfunction may also emerge in the early stages of the disease, in which case it could also contribute to the onset of non-motor symptoms. However, the frequency of this specific brain impairment in early Parkinson’s is unknown as are its clinical implications for patients.

To address this lack of knowledge, a team, led by researchers at the University of Milan in Italy and Newcastle University in England, investigated the prevalence of caudate dopaminergic dysfunction in people who were still in the very early stages of Parkinson’s.

By comparing the participants’ state at the beginning of the study and four years later, they also looked for associations between caudate involvement and an increased risk of disease progression.

They analyzed clinical data from 397 patients who had had a Parkinson’s diagnosis for two years or less, and were participating in the Parkinson’s Progression Markers Initiative (PPMI), an ongoing study attempting to identify biomarkers of disease progression. The team compared the collected clinical data from Parkinson’s patients with that of 177 healthy volunteers.

Caudate dysfunction was detected using 123I-FP-CIT single-photon emission computed tomography, commonly known as DaTscan. This is an imaging technique that depicts the levels of dopamine transporters in the brain that is often used to confirm a Parkinson’s diagnosis.

Based on DaTscan imaging data, the participants were divided into three groups: those who had no reduction of dopamine transporters, those who showed reduction in just one side of the brain, and those who had involvement of both sides of the brain.

Initial data showed that 51.6% of the patients had signs of normal caudate dopamine function, while 26% had caudate dopaminergic dysfunction on one side of the brain (unilateral), and 22.4% on both sides (bilateral).

Four years later, the patients who initially had bilateral caudate involvement were found to experience more frequent and worse cognitive impairment and depression, and more severe gait disability.

In general, after four years of follow-up, more patients showed a loss of dopaminergic nerve fibers in the caudate, compared with the study start, affecting 83.9% of patients (unilateral 22.5%, bilateral 61.4%).

“In this study, we have demonstrated a high frequency of early caudate dopaminergic dysfunction in patients with recently diagnosed [Parkinson’s disease],” the researchers wrote.

“Our study suggests that early bilateral caudate dopaminergic dysfunction is associated with an increased frequency of clinically significant depression and to worse depressive symptoms, regardless of age,” they added.

DaTscan parameters used to define the presence of early caudate dysfunction may be a “valid indicator of more rapid onset of such symptoms,” they said, which may help in “identifying patients at risk of clinical progression to cognitive impairment, depression, and gait problems in the near future.”

Assessment of caudate dopaminergic denervation may also assist clinicians in better predicting disease course at an early stage and identifying patients who may benefit the most from early, targeted disease-modifying therapies.

The post Early Involvement of Caudate Brain Region Linked to Worse Prognosis in Parkinson’s Patients, Study Finds appeared first on Parkinson’s News Today.

My DaTscan Results Made My PD Diagnosis ‘Real’

DaTscan

When I was first diagnosed with Parkinson’s disease (PD) in 2015, I asked the neurologist if there was a definitive test to confirm a PD diagnosis. I mentioned a DaTscan, but he said the test is not entirely conclusive. He also indicated that DaTscan results likely would not change his prescribed course of treatment for me.

His view was that the best way to confirm a PD diagnosis is to give a patient the medication levodopa to see if PD symptoms disappeared. Other neurologists I consulted for second opinions concurred with his assessment.

What is a DaTscan?

DaTscan is a medication that is injected into the bloodstream to assess dopamine-containing neurons that are involved in controlling movement. The contrast agent ioflupane (123I) is distributed around the body in the bloodstream and accumulates in the area of the brain called the striatum, where it attaches to the structures that transport dopamine. The patient then has a single-photon emission computed tomography (SPECT) scan.

The DaTscan test was designed to differentiate parkinsonian syndromes from essential tremor. PD is the most common form of parkinsonian syndromes, but there are other forms, including multiple system atrophy and progressive supranuclear palsy.

My DaTscan

A comparison between a normal and an abnormal DaTscan can be viewed here. A normal DaTscan will show two distinct comma-like or crescent shapes. An abnormal DaTscan will have two period-like or oval shapes, or a combination of period and comma shapes, indicating a reduced uptake of DaTscan in certain areas of the brain. Parts of the image that are “lit up,” indicate more surviving brain cells. Dark areas could mean either PD or parkinsonism.

My DaTscan image showed that the right side of my brain is less “lit up” than the left side. The right hemisphere of the brain coordinates the left side of the body. The left side of my body is the one most affected by PD, so it makes sense that my right side brain is less “lit up.”

Am I convinced that I have PD?

Three years after my diagnosis, I am still struggling to find relief from my symptoms and slow the progression of this disease. I exercise, eating a mostly vegan and gluten-free diet, take Sinemet (carbidopa-levodopa), and use the Neupro transdermal patch. I am working with my current neurologist to fine-tune my medication “cocktail.”

I had wondered whether I did have PD since I’ve never had an “aha” moment in which I feel somewhat normal after taking medications. People tell me I look fine and they don’t observe any external signs of the disease. However, my tremors are internal and I feel horrible and constantly fatigued.

Why now?

I am subjecting my body to what I believe are toxic medications to treat a disease that I feel has been subjectively diagnosed. My symptoms have not been completely alleviated with my current exercise, diet, and prescription medication regimen. I wanted more concrete evidence that I have PD, so my neurologist prescribed a DaTscan. Much to my dismay, the results were abnormal and compatible with Parkinson’s syndrome.

Seeing my brain image with areas not “lit up” where they should be, when contrasted with a normal DaTScan, made my diagnosis very real for me. I have a form of parkinsonian syndrome — most likely PD.

Would I still have gotten a DaTscan?

It was important for me to have confirmation other than my symptoms of abnormalities in my brain. I think this scan can be used as a baseline to follow my disease progression.

So, yes, I would have still gotten this test, although the $2,000 out-of-pocket cost upfront may have given me pause.

***

Note: Parkinson’s News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website. The opinions expressed in this column are not those of Parkinson’s News Today or its parent company, BioNews Services, and are intended to spark discussion about issues pertaining to Parkinson’s disease.

The post My DaTscan Results Made My PD Diagnosis ‘Real’ appeared first on Parkinson’s News Today.