Objective: The aim of our study was to compare somatic and autonomic small fiber density, through skin biopsy, in Parkinson’s disease (PD) and atypical parkinsonisms (AP), in particular progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS).

Background: Increasing evidence suggests a high prevalence of small fiber neuropathy (SFN) in neurodegenerative disorders [1]. At present, while various studies focussed on SFN in synucleinopathies, mainly PD [2,3], data concerning tauopathies associated with parkinsonism are still lacking.

Method: We recruited 27 patients with a clinical diagnosis of PD and phosphorylated α-synuclein (p-syn) deposits on skin biopsy (19F, mean age 72±7,5y, mean disease duration 5±5y, mean UPDRS score 28±11) and 19 patients with a clinical diagnosis of progressive supranuclear palsy (PSP)/corticobasal syndrome (CBS), without p-syn on skin biopsy (15F, mean age 71,5±7y, mean disease duration 2,3±1y, mean UPDRS score 35±9). Any possible causes of peripheral neuropathy, such as diabetes, were excluded. All patients underwent skin biopsies from proximal (i.e. cervical) and distal (i.e. thigh and leg) skin sites, with quantification of somatic and autonomic innervation. 25 matched healthy subjects served as controls.

Results: Epidermal nerve fiber density resulted normal in all controls. All (100%) PD patients showed reduced somatic innervation, with 93% presenting also with autonomic involvement. Regarding the tauopathies, skin biopsy revealed abnormal somatic innervation in 74% of cases; notably, autonomic denervation was detected only in 42% of patients, while no abnormalities were disclosed in26.3%. Patients affected by SFN presented with higher age, disease duration and UPDRS score.

Conclusion: Our study showed a lower prevalence of SFN in tauopathies, compared with synucleinopathies, with a remarkable preservation of autonomic small fibers. These data confirm skin biopsy as a useful technique in the differential diagnosis of parkinsonisms, through evaluation of both p-syn deposits and innervation, providing interesting implications concerning the pathology of these disorders.

References: [1] Cazzato D, Lauria G. Small fibre neuropathy. Curr Opin Neurol. 2017 Oct;30(5):490-499. [2] Podgorny PJ, Suchowersky O, et al. Evidence for small fiber neuropathy in early Parkinson’s disease. Parkinsonism Relat Disord. 2016 Jul;28:94-9. [3] Nolano M, Provitera V, et al. Loss of cutaneous large and small fibers in naive and l-dopa-treated PD patients. Neurology. 2017 Aug 22;89(8):776-784.

« Back to 2019 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/skin-in-the-game-small-fiber-neuropathy-in-parkinsons-disease-and-atypical-parkinsonisms/