“…Other tests that are considered complementary for studying dysphagia are oro-pharyngo-oesophageal scintigraphy [17,18,19], ultrasound [20,21,22,23], pH manometry [24,25,26,27] and, most recently, high-resolution manometry [27,28,29,30]. All the instrumental tests used for assessing dysphagia have advantages, disadvantages and side effects.…”