Olfactory swab sampling optimization for α-synuclein aggregate detection in patients with Parkinson's disease.

BACKGROUND: In patients with Parkinson's disease (PD), real-time quaking-induced conversion (RT-QuIC) detection of pathological α-synuclein (α-syn) in olfactory mucosa (OM) is not as accurate as in other α-synucleinopathies. It is unknown whether these variable results might be related to a different distribution of pathological α-syn in OM. Thus, we investigated whether nasal swab (NS) performed in areas with a different coverage by olfactory neuroepithelium, such as agger nasi (AN) and middle turbinate (MT), might affect the detection of pathological α-syn. METHODS: NS was performed in 66 patients with PD and 29 non-PD between September 2018 and April 2021. In 43 patients, cerebrospinal fluid (CSF) was also obtained and all samples were analyzed by RT-QuIC for α-syn. RESULTS: In the first round, 72 OM samples were collected by NS, from AN (NSAN) or from MT (NSMT), and 35 resulted positive for α-syn RT-QuIC, including 27/32 (84%) from AN, 5/11 (45%) from MT, and 3/29 (10%) belonging to the non-PD patients. Furthermore, 23 additional PD patients underwent NS at both AN and MT, and RT-QuIC revealed α-syn positive in 18/23 (78%) NSAN samples and in 10/23 (44%) NSMT samples. Immunocytochemistry of NS preparations showed a higher representation of olfactory neural cells in NSAN compared to NSMT. We also observed α-syn and phospho-α-syn deposits in NS from PD patients but not in controls. Finally, RT-QuIC was positive in 22/24 CSF samples from PD patients (92%) and in 1/19 non-PD. CONCLUSION: In PD patients, RT-QuIC sensitivity is significantly increased (from 45% to 84%) when NS is performed at AN, indicating that α-syn aggregates are preferentially detected in olfactory areas with higher concentration of olfactory neurons. Although RT-QuIC analysis of CSF showed a higher diagnostic accuracy compared to NS, due to the non-invasiveness, NS might be considered as an ancillary procedure for PD diagnosis.

Salivary bypass tube placement in esophageal stricture: A technical note and report of three cases.

Hypopharyngeal and cervical esophageal strictures can be caused by advanced malignancies, ingestion of caustic materials, or can follow surgery or radiation therapy. They cause marked dysphagia and consequently patients need nasogastric or gastrostomy tube feeding, with a remarkable impact on quality of life. To restore oral feeding, the stenosis can be progressively dilated by using rubber bougies of increasing diameter, and a Montgomery® Salivary Bypass Tube can then be inserted to maintain the obtained calibre. However, while its flexibility makes it easy to tolerate, it has the drawback of making insertion difficult because the tube tends to bend. The aim of this paper is to present a possible solution to this problem. A Montgomery® Salivary Bypass Tube was distally sutured to a Cook Airway Exchange Catheter® to simplify its initial insertion through a laryngoscope and following replacements. The catheter was then easily removed leaving the bypass tube in the correct position. In our experience, this innovative approach proved effective in facilitating Montgomery® Salivary Bypass Tube insertion in three patients, without risks for the patient, additional operative time or increase in costs.