Submandibular gland needle biopsy for the diagnosis of Parkinson disease

Objective: This study investigates salivary gland biopsies in living patients with Parkinson disease (PD). Methods: Patients with PD for $5 years underwent outpatient transcutaneous needle core biopsies (18-gauge or 16-gauge) of 1 submandibular gland. Minor salivary glands were removed via a small incision in the lower lip. Tissue was fixed in formalin and serial 6-mm paraffin sections were immunohistochemically stained for phosphorylated a-synuclein and reviewed for evidence of Lewy type a-synucleinopathy (LTS). Results: Fifteen patients with PD were biopsied: 9 female/6 male, mean age 68.7 years, mean PD duration 11.8 years. Twelve of the needle core biopsies had microscopically evident submandibular gland tissue to assess and 9/12 (75%) had LTS. Only 1/15 (6.7%) minor salivary gland biopsies were positive for LTS. Five patients had an adverse event; all were minor and transient. Conclusions: This study demonstrates the feasibility of performing needle core biopsies of the submandibular gland in living patients with PD to assess LTS. Although this was a small study, this tissue biopsy method may be important for tissue confirmation of PD in patients being considered for invasive procedures and in research studies of other PD biomarkers.