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-µm paraffin sections were immunohistochemically stained for phosphorylated α-synuclein and reviewed for evidence of Lewy type α-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.