Clinical Utility of Skin Biopsy Compared to DaTscan in Diagnosing Synucleinopathies
Nikita Urval1, Leon Meytin1, Benjamin Dorfman1, Jeffrey Lahrmann1, Elena Bortan1, Michelle Dagostine1, James Duffy1, Maria Moro-de-Casillas1, Duarte Machado1, Sulada Kanchana1, Joy DeMarcaida1
1Hartford Healthcare Chase Family Movement Disorders Center
To compare the utility of skin biopsy versus DaTscan in supporting a diagnosis of a synucleinopathy.  
Though the diagnosis of synucleinopathies (Lewy Body Dementia, Parkinson’s disease, Multiple System Atrophy, Pure Autonomic Failure) is clinical, there are supportive tests that can aid in the diagnosis. SPECT imaging with DaTscan (Ioflupane 123-I SPECT) identifies pre-synaptic dopaminergic deficits, which helps distinguish neurodegenerative parkinsonian syndromes from non-dopamine deficiency disorders. Skin biopsy in identifies the presence of phosphorylated synuclein (p-syn) within cutaneous nerves, and can help distinguish synucleinopathies from other atypical parkinsonian syndromes and non-parkinsonian disorders. 

24 patients were identified that were seen in the movement disorders clinic for possible parkinsonism. All patients underwent a DaTscan and a skin biopsy (3 small punch biopsies in the cervical area, thigh and leg). DaTscan and skin biopsy results were compared to clinician’s suspected diagnosis (prior to testing, synucleinopathy vs other disorder) to assess diagnostic efficacy.

DaTscan results were congruent with clinician’s suspected diagnosis in 15/24 cases (62.5%). Skin biopsy results were congruent with clinician’s suspected diagnosis in 20/24 cases (83.3%). In two cases, the skin biopsy was positive for p-syn deposition where a synucleinopathy was not suspected. In 8 patients where the DaTscan was negative but clinician suspicion for a synucleinopathy was high, skin biopsies were positive. 

Skin biopsy had greater diagnostic accuracy than the DaTscan when compared to the clinician’s suspected pre-testing diagnosis. This suggests that performing skin biopsies (minimally invasive, lower cost, can be done in the office) may be of higher diagnostic utility than a DaTscan.