Dysphagia in amyotrophic lateral sclerosis: Quantification of bulbar motor dysfunction.

BACKGROUND: Dysphagia as a sequel and possible early sign of amyotrophic lateral sclerosis (ALS) is caused by progressive impaired bulbar motor function. OBJECTIVE: To evaluate bulbar motor dysfunction in patients suffering from ALS compared to a healthy reference group. METHODS: A clinical study and prospective group comparison was designed. Patients and healthy volunteers were examined in the outpatient clinic of our university medical center. Ten patients with ALS and 20 healthy volunteers were included. All participants underwent a flexible endoscopic evaluation of swallowing (FEES) and a manometric measurement of the maximal sub-palatal atmospheric pressure generated by suction as well as of the prevalent pressure during swallowing. Additionally, the Sydney Swallow Questionnaire (SSQ) was completed by all participants to score the self-rated extent of dysphagia. RESULTS: Comparing maximal suction pressures, the group of patients showed significantly lower values (p < .001). There was a significant correlation between reduced pressures and the degree of dysphagia (SSQ score) (r = -0.73). CONCLUSIONS: As the oral cavity is an easily accessible compartment of the upper digestive tract, manometric measurements might serve as a simple instrument in order to detect or to monitor bulbar motor dysfunction. Oral manometry may facilitate early detection and monitoring of dysphagia in ALS. Larger studies are required to confirm our findings.

Real-time MRI of swallowing: intraoral pressure reduction supports larynx elevation.

The reduction in intraoral pressure during swallowing has previously been linked to bolus transport, although no such relation has yet been proven. The purpose of this work was to evaluate the time course of intraoral pressure during swallowing using simultaneous real-time magnetic resonance imaging (MRI) and dynamic pressure recordings. Real-time MRI based on highly undersampled radial fast low-angle shot (FLASH) and regularized nonlinear inverse reconstruction was performed at 3 T using a standard head coil and a mid-sagittal section covering the entire oral cavity. Voluntary swallowing (10 mL of pineapple juice or saliva) was monitored for about 30 s in 11 normal subjects at spatial and temporal resolution of 1.3 × 1.3 × 8 mm3 and 40 ms, respectively. Simultaneously, the intraoral atmospheric pressure was recorded at a resolution of 10 ms during the entire course of deglutition. Quantitative measures of bolus transport, larynx elevation and submental muscle changes were obtained from the image series. As a key result, negative intraoral pressure accompanied laryngeal elevation during swallowing in all subjects. A reduction in submental muscle length during swallowing was also observed. No correlations of maximum negative pressure with larynx elevation and submental muscle change were found. In conclusion, intraoral pressure reduction during swallowing is not connected to oral bolus transport, but supports laryngeal elevation by palatal fixation of the tongue.

Failure of cathodal direct current stimulation to improve fine motor control in musician's dystonia.

Musician's dystonia (MD) is a task-specific movement disorder with a loss of voluntary motor control in highly trained movements. Defective inhibition on different levels of the central nervous system is involved in its pathophysiology. Cathodal transcranial direct current stimulation (ctDCS) diminishes excitability of the motor cortex and improves performance in overlearned tasks in healthy subjects. The aim of this study was to investigate whether ctDCS improves fine motor control in MD. Professional guitarists (n = 10) with MD played exercises before, directly after ctDCS, and 60 min after ctDCS. ctDCS (2 mA, 20 min) was applied on the primary motor cortex contralateral to the affected hand. Guitar exercises were video-documented and symptoms were evaluated by three independent experts. No beneficial effect of ctDCS on fine motor control was found for the entire group. However, motor control of one guitarist improved after stimulation. This patient suffered from arm dystonia, whereas the other guitarists suffered from hand dystonia.