Comparing Pregabalin and Placebo in Patients With Persistent Globus Sensation

Globus, defined as a feeling of a lump in the throat, unexplained by structural lesions, GERD, or histopathology-based esophageal motility disorders, is a frequently occurring symptom of unknown etiology. Today there is no appropriate treatment for patients with a globus sensation. Pathophysiological mechanisms that have been implicated in the pathogenesis of globus include gastroesophageal reflux disease, oesophageal motor disorders, overactive cricopharyngeal muscle, psychological factors, gastric islet patches in the proximal esophagus and deformations of the cervical spine. However, none of these convincingly explains the clinical picture in globus patients.

Investigators recently observed that a large majority (80%) of patients with persistent globus sensation have a pathological EMG examination of the larynx, indicative of neuropathy in the laryngeal area. The investigators believe that this neuropathy may explain some of the symptoms that are experienced by patients with globus, and may actually contribute to some observations of unclear pathophysiological relevance such as a hyperreactive ciricopharyngeal muscle. Neuropathies may respond to specific therapies, such as the pregabalin.

The aim of the study is to evaluate if treatment with pregabalin (Lyrica®) is effective in these patients. The effect of gabapentin, another anti-epileptic drug with therapeutic efficacy in neuropathy, was evaluated in patients with chronic cough as sign of laryngeal sensory neuropathy. In this study 68% of the patients experienced improvement, with an even higher efficacy in the group of patients with a pathological EMG (80%).

In order to better understand the underlying pathophysiology, and how this responds to therapy, the investigators will also evaluate upper esophageal sphincter high resolution manometric properties during the study. An elevated resting pressure in the upper sphincter was already reported in previous studie, but not confirmed in a more recent study, which did report a hyperreactive UES, mainly characterized by a hyperdynamic respiratory pressure change.

Esophageal inlet patches have also been implicated in the pathogenesis of globus, although the exact mechanism remains unclear. In the present study, all patients will undergo a strict evaluation of the upper part of the esophagus during endoscopy, to document presence or absence of inlet patches.