Rigid spine syndrome: a radiologic and manometric study of the pharynx and esophagus

The rigid spine syndrome (RSS) is not a recognized cause of dysphagia. The "vacuolar variant" of RSS causes mild, generalized, and slowly progressive weakness. Respiratory evaluation detected severe restrictive chest wall defect and significant respiratory muscle weakness. We identified nine patients at our Neuromuscular Clinic over a period of years. The aim of this evaluation was to ascertain whether pharyngoesophageal dysfunction caused cough (2/9), intermittent oropharyngeal dysphagia (4/9), and aspiration pneumonia (3/9). Pharyngeal and esophageal functions were evaluated separately by conventional cineradiography and intraluminal esophageal manometry over a one-year study period. An age- and gender-matched volunteer group without swallowing complaints partook in the manometric component of the study. There were seven male and two female patients. The mean age of patients was 19.1 years (17.8 years for controls), and the age range was 11-36 years (13-32 years for controls). The mean disease duration was 17.2 years (range=8-31 years). Patients were commonly underweight (7/9). Cineradiology detected abnormal swallow physiology of pharyngeal striated muscle (1/9) and of esophageal smooth muscle (2/9). Mean manometric pressures in patients were not significantly different from control data. Manometry detected "nonspecific" contractility abnormalities (3/9) that were not reflected in the mean data. The relative lack of instrumental findings suggested minor upper alimentary tract dysmotility in patients with the RSS. The myopathy that underlies this syndrome likely caused dysfunction of the striated muscle of the pharyngeal constrictors and upper esophageal sphincter. The documented abnormalities of esophageal smooth muscle motility were nonspecific and tenuously associated with the muscle disorder. The incongruity between complaints of intermittent dysphagia and study results was perhaps due to transient pharyngoesophageal dysmotility, altered swallowing mechanics of limited cervical spine mobility, altered swallowing perception after previous intubation/tracheostomy, or a "functional" upper intestinal complaint.