Skin biopsy test for phosphorylated alpha‑synuclein to find which essential tremor patients are at risk for Parkinson's disease

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This observational protocol enrolls people aged 50–85 with essential tremor or ET‑Plus and collects small cutaneous biopsies to test for phosphorylated alpha‑synuclein using the Syn‑One assay. Participants receive baseline clinical characterization and longitudinal follow‑up to see which biomarker‑positive individuals later develop Parkinsonian features. The aim is to identify a subgroup of ET patients with underlying synucleinopathy and to develop predictors of phenoconversion without relying on costly or invasive imaging. The work is conducted at the CND Clinical Research Center in Scottsdale, Arizona and does not involve investigational drug treatments.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* Age 50-85 years old
* Diagnosis of ET as defined by the 2018 MDS Task force paper "1) isolated tremor syndrome of bilateral upper limb action tremor 2) at least 3 years' duration 3) with or without tremor in other locations (e.g., head, voice, or lower limbs) 4) absence of other neurological signs, such as dystonia, ataxia, or parkinsonism." OR
* Diagnosis of ET-Plus as stated by the 2018 MDS Task force paper, "Tremor with the characteristics of ET and additional neurological signs of uncertain significance such as impaired tandem gait, questionable dystonic posturing, memory impairment, or other mild neurologic signs of unknown significance that do not suffice to make an additional syndrome classification or diagnosis. ET with tremor at rest should be classified here."
* Willing to participate in all study procedures
* Able and willing to provide written informed consent

Exclusion Criteria:

* Under age 50, Over age 85
* Clinical evidence of severe peripheral vascular disease
* Clinically active coronary artery or cerebrovascular disease
* Participant is currently on anticoagulant or dual anti-platelet therapy
* Alcoholism
* Allergic reaction to local anesthesia
* History of or increased risk for impaired wound healing, scarring, or keloid formation
* Diagnosis of ET or ET-Plus that is clinically determined to likely be secondary to brain injury or vascular compromise
* History of other neurodegenerative disorder or evidence of neurological co-pathology
* Abnormal DaTscan
* Participant is currently receiving treatment with carbidopa-levodopa for PD
* Isolated focal tremors (head, voice)
* Task-specific tremor (e.g., primary writing tremor)
* Position-specific tremors that does not otherwise meet clinical diagnostic criteria for ET
* Sudden onset and step-wise deterioration
* Prior to enrollment, receipt of an intracranial procedure intended to treat tremor or parkinsonism, including thalamic deep brain stimulation (DBS) implantation or focused ultrasound (FUS) thalamotomy. Other prior intracranial surgery is exclusionary only when, in the investigator's or Sponsor's Chief Medical Officer's judgment, it could materially affect motor assessments, diagnostic classification, participant safety, or interpretation of study outcomes.

Where it's running

• CND Clinical Research Center
  Scottsdale, Arizona, United States Recruiting
• Movement Disorders Center of Arizona
  Scottsdale, Arizona, United States Recruiting
• Neurology One
  Orlando, Florida, United States Recruiting
• University of Kansas Medical Center
  Kansas City, Kansas, United States Recruiting
• Norton Healthcare
  Louisville, Kentucky, United States Recruiting
• Quest Research Institute
  Farmington Hills, Michigan, United States Recruiting

Study contacts

• Study coordinator: Jeannie Director of Clinical Research
• Email: ClinicalResearch@cndlifesciences.com
• Phone: 480-434-6446

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.